Update googletest to 1.14.0

contrib/googletest/.clang-format

@@ -0,0 +1,4 @@
+# Run manually to reformat a file:
+# clang-format -i --style=file <file>
+Language:        Cpp
+BasedOnStyle:  Google

contrib/googletest/.github/ISSUE_TEMPLATE/00-bug_report.yml

@@ -0,0 +1,53 @@
+name: Bug Report
+description: Let us know that something does not work as expected.
+title: "[Bug]: Please title this bug report"
+body:
+  - type: textarea
+    id: what-happened
+    attributes:
+      label: Describe the issue
+      description: What happened, and what did you expect to happen?
+    validations:
+      required: true
+  - type: textarea
+    id: steps
+    attributes:
+      label: Steps to reproduce the problem
+      description: It is important that we are able to reproduce the problem that you are experiencing. Please provide all code and relevant steps to reproduce the problem, including your `BUILD`/`CMakeLists.txt` file and build commands. Links to a GitHub branch or [godbolt.org](https://godbolt.org/) that demonstrate the problem are also helpful.
+    validations:
+      required: true
+  - type: textarea
+    id: version
+    attributes:
+      label: What version of GoogleTest are you using?
+      description: Please include the output of `git rev-parse HEAD` or the GoogleTest release version number that you are using.
+    validations:
+      required: true
+  - type: textarea
+    id: os
+    attributes:
+      label: What operating system and version are you using?
+      description: If you are using a Linux distribution please include the name and version of the distribution as well.
+    validations:
+      required: true
+  - type: textarea
+    id: compiler
+    attributes:
+      label: What compiler and version are you using?
+      description: Please include the output of `gcc -v` or `clang -v`, or the equivalent for your compiler.
+    validations:
+      required: true
+  - type: textarea
+    id: buildsystem
+    attributes:
+      label: What build system are you using?
+      description: Please include the output of `bazel --version` or `cmake --version`, or the equivalent for your build system.
+    validations:
+      required: true
+  - type: textarea
+    id: additional
+    attributes:
+      label: Additional context
+      description: Add any other context about the problem here.
+    validations:
+      required: false

contrib/googletest/.github/ISSUE_TEMPLATE/10-feature_request.yml

@@ -0,0 +1,33 @@
+name: Feature request
+description: Propose a new feature.
+title: "[FR]: Please title this feature request"
+labels: "enhancement"
+body:
+  - type: textarea
+    id: version
+    attributes:
+      label: Does the feature exist in the most recent commit?
+      description: We recommend using the latest commit from GitHub in your projects.
+    validations:
+      required: true
+  - type: textarea
+    id: why
+    attributes:
+      label: Why do we need this feature?
+      description: Ideally, explain why a combination of existing features cannot be used instead.
+    validations:
+      required: true
+  - type: textarea
+    id: proposal
+    attributes:
+      label: Describe the proposal.
+      description: Include a detailed description of the feature, with usage examples.
+    validations:
+      required: true
+  - type: textarea
+    id: platform
+    attributes:
+      label: Is the feature specific to an operating system, compiler, or build system version?
+      description: If it is, please specify which versions.
+    validations:
+      required: true

contrib/googletest/.github/ISSUE_TEMPLATE/config.yml

@@ -0,0 +1,5 @@
+blank_issues_enabled: false
+contact_links:
+    - name: Get Help
+      url: https://github.com/google/googletest/discussions
+      about: Please ask and answer questions here.

contrib/googletest/.github/workflows/gtest-ci.yml

@@ -0,0 +1,43 @@
+name: ci
+
+on:
+  push:
+  pull_request:
+
+env:
+  BAZEL_CXXOPTS: -std=c++14
+
+jobs:
+  Linux:
+    runs-on: ubuntu-latest
+    steps:
+
+    - uses: actions/checkout@v3
+      with:
+        fetch-depth: 0
+
+    - name: Tests
+      run: bazel test --cxxopt=-std=c++14 --features=external_include_paths --test_output=errors ...
+
+  macOS:
+    runs-on: macos-latest
+    steps:
+
+    - uses: actions/checkout@v3
+      with:
+        fetch-depth: 0
+
+    - name: Tests
+      run:  bazel test --cxxopt=-std=c++14 --features=external_include_paths --test_output=errors ...
+
+
+  Windows:
+    runs-on: windows-latest
+    steps:
+
+    - uses: actions/checkout@v3
+      with:
+        fetch-depth: 0
+
+    - name: Tests
+      run: bazel test --cxxopt=/std:c++14 --features=external_include_paths --test_output=errors ...

contrib/googletest/.gitignore

@@ -0,0 +1,88 @@
+# Ignore CI build directory
+build/
+xcuserdata
+cmake-build-debug/
+.idea/
+bazel-bin
+bazel-genfiles
+bazel-googletest
+bazel-out
+bazel-testlogs
+# python
+*.pyc
+
+# Visual Studio files
+.vs
+*.sdf
+*.opensdf
+*.VC.opendb
+*.suo
+*.user
+_ReSharper.Caches/
+Win32-Debug/
+Win32-Release/
+x64-Debug/
+x64-Release/
+
+# VSCode files
+.cache/
+cmake-variants.yaml
+
+# Ignore autoconf / automake files
+Makefile.in
+aclocal.m4
+configure
+build-aux/
+autom4te.cache/
+googletest/m4/libtool.m4
+googletest/m4/ltoptions.m4
+googletest/m4/ltsugar.m4
+googletest/m4/ltversion.m4
+googletest/m4/lt~obsolete.m4
+googlemock/m4
+
+# Ignore generated directories.
+googlemock/fused-src/
+googletest/fused-src/
+
+# macOS files
+.DS_Store
+googletest/.DS_Store
+googletest/xcode/.DS_Store
+
+# Ignore cmake generated directories and files.
+CMakeFiles
+CTestTestfile.cmake
+Makefile
+cmake_install.cmake
+googlemock/CMakeFiles
+googlemock/CTestTestfile.cmake
+googlemock/Makefile
+googlemock/cmake_install.cmake
+googlemock/gtest
+/bin
+/googlemock/gmock.dir
+/googlemock/gmock_main.dir
+/googlemock/RUN_TESTS.vcxproj.filters
+/googlemock/RUN_TESTS.vcxproj
+/googlemock/INSTALL.vcxproj.filters
+/googlemock/INSTALL.vcxproj
+/googlemock/gmock_main.vcxproj.filters
+/googlemock/gmock_main.vcxproj
+/googlemock/gmock.vcxproj.filters
+/googlemock/gmock.vcxproj
+/googlemock/gmock.sln
+/googlemock/ALL_BUILD.vcxproj.filters
+/googlemock/ALL_BUILD.vcxproj
+/lib
+/Win32
+/ZERO_CHECK.vcxproj.filters
+/ZERO_CHECK.vcxproj
+/RUN_TESTS.vcxproj.filters
+/RUN_TESTS.vcxproj
+/INSTALL.vcxproj.filters
+/INSTALL.vcxproj
+/googletest-distribution.sln
+/CMakeCache.txt
+/ALL_BUILD.vcxproj.filters
+/ALL_BUILD.vcxproj

contrib/googletest/BUILD.bazel

@@ -0,0 +1,219 @@
+# Copyright 2017 Google Inc.
+# All Rights Reserved.
+#
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are
+# met:
+#
+#     * Redistributions of source code must retain the above copyright
+# notice, this list of conditions and the following disclaimer.
+#     * Redistributions in binary form must reproduce the above
+# copyright notice, this list of conditions and the following disclaimer
+# in the documentation and/or other materials provided with the
+# distribution.
+#     * Neither the name of Google Inc. nor the names of its
+# contributors may be used to endorse or promote products derived from
+# this software without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+#
+#   Bazel Build for Google C++ Testing Framework(Google Test)
+
+package(default_visibility = ["//visibility:public"])
+
+licenses(["notice"])
+
+exports_files(["LICENSE"])
+
+config_setting(
+    name = "qnx",
+    constraint_values = ["@platforms//os:qnx"],
+)
+
+config_setting(
+    name = "windows",
+    constraint_values = ["@platforms//os:windows"],
+)
+
+config_setting(
+    name = "freebsd",
+    constraint_values = ["@platforms//os:freebsd"],
+)
+
+config_setting(
+    name = "openbsd",
+    constraint_values = ["@platforms//os:openbsd"],
+)
+
+config_setting(
+    name = "msvc_compiler",
+    flag_values = {
+        "@bazel_tools//tools/cpp:compiler": "msvc-cl",
+    },
+    visibility = [":__subpackages__"],
+)
+
+config_setting(
+    name = "has_absl",
+    values = {"define": "absl=1"},
+)
+
+# Library that defines the FRIEND_TEST macro.
+cc_library(
+    name = "gtest_prod",
+    hdrs = ["googletest/include/gtest/gtest_prod.h"],
+    includes = ["googletest/include"],
+)
+
+# Google Test including Google Mock
+cc_library(
+    name = "gtest",
+    srcs = glob(
+        include = [
+            "googletest/src/*.cc",
+            "googletest/src/*.h",
+            "googletest/include/gtest/**/*.h",
+            "googlemock/src/*.cc",
+            "googlemock/include/gmock/**/*.h",
+        ],
+        exclude = [
+            "googletest/src/gtest-all.cc",
+            "googletest/src/gtest_main.cc",
+            "googlemock/src/gmock-all.cc",
+            "googlemock/src/gmock_main.cc",
+        ],
+    ),
+    hdrs = glob([
+        "googletest/include/gtest/*.h",
+        "googlemock/include/gmock/*.h",
+    ]),
+    copts = select({
+        ":qnx": [],
+        ":windows": [],
+        "//conditions:default": ["-pthread"],
+    }),
+    defines = select({
+        ":has_absl": ["GTEST_HAS_ABSL=1"],
+        "//conditions:default": [],
+    }),
+    features = select({
+        ":windows": ["windows_export_all_symbols"],
+        "//conditions:default": [],
+    }),
+    includes = [
+        "googlemock",
+        "googlemock/include",
+        "googletest",
+        "googletest/include",
+    ],
+    linkopts = select({
+        ":qnx": ["-lregex"],
+        ":windows": [],
+        ":freebsd": [
+            "-lm",
+            "-pthread",
+        ],
+        ":openbsd": [
+            "-lm",
+            "-pthread",
+        ],
+        "//conditions:default": ["-pthread"],
+    }),
+    deps = select({
+        ":has_absl": [
+            "@com_google_absl//absl/container:flat_hash_set",
+            "@com_google_absl//absl/debugging:failure_signal_handler",
+            "@com_google_absl//absl/debugging:stacktrace",
+            "@com_google_absl//absl/debugging:symbolize",
+            "@com_google_absl//absl/flags:flag",
+            "@com_google_absl//absl/flags:parse",
+            "@com_google_absl//absl/flags:reflection",
+            "@com_google_absl//absl/flags:usage",
+            "@com_google_absl//absl/strings",
+            "@com_google_absl//absl/types:any",
+            "@com_google_absl//absl/types:optional",
+            "@com_google_absl//absl/types:variant",
+            "@com_googlesource_code_re2//:re2",
+        ],
+        "//conditions:default": [],
+    }),
+)
+
+cc_library(
+    name = "gtest_main",
+    srcs = ["googlemock/src/gmock_main.cc"],
+    features = select({
+        ":windows": ["windows_export_all_symbols"],
+        "//conditions:default": [],
+    }),
+    deps = [":gtest"],
+)
+
+# The following rules build samples of how to use gTest.
+cc_library(
+    name = "gtest_sample_lib",
+    srcs = [
+        "googletest/samples/sample1.cc",
+        "googletest/samples/sample2.cc",
+        "googletest/samples/sample4.cc",
+    ],
+    hdrs = [
+        "googletest/samples/prime_tables.h",
+        "googletest/samples/sample1.h",
+        "googletest/samples/sample2.h",
+        "googletest/samples/sample3-inl.h",
+        "googletest/samples/sample4.h",
+    ],
+    features = select({
+        ":windows": ["windows_export_all_symbols"],
+        "//conditions:default": [],
+    }),
+)
+
+cc_test(
+    name = "gtest_samples",
+    size = "small",
+    # All Samples except:
+    #   sample9 (main)
+    #   sample10 (main and takes a command line option and needs to be separate)
+    srcs = [
+        "googletest/samples/sample1_unittest.cc",
+        "googletest/samples/sample2_unittest.cc",
+        "googletest/samples/sample3_unittest.cc",
+        "googletest/samples/sample4_unittest.cc",
+        "googletest/samples/sample5_unittest.cc",
+        "googletest/samples/sample6_unittest.cc",
+        "googletest/samples/sample7_unittest.cc",
+        "googletest/samples/sample8_unittest.cc",
+    ],
+    linkstatic = 0,
+    deps = [
+        "gtest_sample_lib",
+        ":gtest_main",
+    ],
+)
+
+cc_test(
+    name = "sample9_unittest",
+    size = "small",
+    srcs = ["googletest/samples/sample9_unittest.cc"],
+    deps = [":gtest"],
+)
+
+cc_test(
+    name = "sample10_unittest",
+    size = "small",
+    srcs = ["googletest/samples/sample10_unittest.cc"],
+    deps = [":gtest"],
+)

contrib/googletest/CMakeLists.txt

@@ -0,0 +1,27 @@
+# Note: CMake support is community-based. The maintainers do not use CMake
+# internally.
+
+cmake_minimum_required(VERSION 3.13)
+
+project(googletest-distribution)
+set(GOOGLETEST_VERSION 1.14.0)
+
+if(NOT CYGWIN AND NOT MSYS AND NOT ${CMAKE_SYSTEM_NAME} STREQUAL QNX)
+  set(CMAKE_CXX_EXTENSIONS OFF)
+endif()
+
+enable_testing()
+
+include(CMakeDependentOption)
+include(GNUInstallDirs)
+
+#Note that googlemock target already builds googletest
+option(BUILD_GMOCK "Builds the googlemock subproject" ON)
+option(INSTALL_GTEST "Enable installation of googletest. (Projects embedding googletest may want to turn this OFF.)" ON)
+option(GTEST_HAS_ABSL "Use Abseil and RE2. Requires Abseil and RE2 to be separately added to the build." OFF)
+
+if(BUILD_GMOCK)
+  add_subdirectory( googlemock )
+else()
+  add_subdirectory( googletest )
+endif()

contrib/googletest/CONTRIBUTING.md

@@ -0,0 +1,141 @@
+# How to become a contributor and submit your own code
+
+## Contributor License Agreements
+
+We'd love to accept your patches! Before we can take them, we have to jump a
+couple of legal hurdles.
+
+Please fill out either the individual or corporate Contributor License Agreement
+(CLA).
+
+*   If you are an individual writing original source code and you're sure you
+    own the intellectual property, then you'll need to sign an
+    [individual CLA](https://developers.google.com/open-source/cla/individual).
+*   If you work for a company that wants to allow you to contribute your work,
+    then you'll need to sign a
+    [corporate CLA](https://developers.google.com/open-source/cla/corporate).
+
+Follow either of the two links above to access the appropriate CLA and
+instructions for how to sign and return it. Once we receive it, we'll be able to
+accept your pull requests.
+
+## Are you a Googler?
+
+If you are a Googler, please make an attempt to submit an internal contribution
+rather than a GitHub Pull Request. If you are not able to submit internally, a
+PR is acceptable as an alternative.
+
+## Contributing A Patch
+
+1.  Submit an issue describing your proposed change to the
+    [issue tracker](https://github.com/google/googletest/issues).
+2.  Please don't mix more than one logical change per submittal, because it
+    makes the history hard to follow. If you want to make a change that doesn't
+    have a corresponding issue in the issue tracker, please create one.
+3.  Also, coordinate with team members that are listed on the issue in question.
+    This ensures that work isn't being duplicated and communicating your plan
+    early also generally leads to better patches.
+4.  If your proposed change is accepted, and you haven't already done so, sign a
+    Contributor License Agreement
+    ([see details above](#contributor-license-agreements)).
+5.  Fork the desired repo, develop and test your code changes.
+6.  Ensure that your code adheres to the existing style in the sample to which
+    you are contributing.
+7.  Ensure that your code has an appropriate set of unit tests which all pass.
+8.  Submit a pull request.
+
+## The Google Test and Google Mock Communities
+
+The Google Test community exists primarily through the
+[discussion group](http://groups.google.com/group/googletestframework) and the
+GitHub repository. Likewise, the Google Mock community exists primarily through
+their own [discussion group](http://groups.google.com/group/googlemock). You are
+definitely encouraged to contribute to the discussion and you can also help us
+to keep the effectiveness of the group high by following and promoting the
+guidelines listed here.
+
+### Please Be Friendly
+
+Showing courtesy and respect to others is a vital part of the Google culture,
+and we strongly encourage everyone participating in Google Test development to
+join us in accepting nothing less. Of course, being courteous is not the same as
+failing to constructively disagree with each other, but it does mean that we
+should be respectful of each other when enumerating the 42 technical reasons
+that a particular proposal may not be the best choice. There's never a reason to
+be antagonistic or dismissive toward anyone who is sincerely trying to
+contribute to a discussion.
+
+Sure, C++ testing is serious business and all that, but it's also a lot of fun.
+Let's keep it that way. Let's strive to be one of the friendliest communities in
+all of open source.
+
+As always, discuss Google Test in the official GoogleTest discussion group. You
+don't have to actually submit code in order to sign up. Your participation
+itself is a valuable contribution.
+
+## Style
+
+To keep the source consistent, readable, diffable and easy to merge, we use a
+fairly rigid coding style, as defined by the
+[google-styleguide](https://github.com/google/styleguide) project. All patches
+will be expected to conform to the style outlined
+[here](https://google.github.io/styleguide/cppguide.html). Use
+[.clang-format](https://github.com/google/googletest/blob/main/.clang-format) to
+check your formatting.
+
+## Requirements for Contributors
+
+If you plan to contribute a patch, you need to build Google Test, Google Mock,
+and their own tests from a git checkout, which has further requirements:
+
+*   [Python](https://www.python.org/) v3.6 or newer (for running some of the
+    tests and re-generating certain source files from templates)
+*   [CMake](https://cmake.org/) v2.8.12 or newer
+
+## Developing Google Test and Google Mock
+
+This section discusses how to make your own changes to the Google Test project.
+
+### Testing Google Test and Google Mock Themselves
+
+To make sure your changes work as intended and don't break existing
+functionality, you'll want to compile and run Google Test and GoogleMock's own
+tests. For that you can use CMake:
+
+```
+mkdir mybuild
+cd mybuild
+cmake -Dgtest_build_tests=ON -Dgmock_build_tests=ON ${GTEST_REPO_DIR}
+```
+
+To choose between building only Google Test or Google Mock, you may modify your
+cmake command to be one of each
+
+```
+cmake -Dgtest_build_tests=ON ${GTEST_DIR} # sets up Google Test tests
+cmake -Dgmock_build_tests=ON ${GMOCK_DIR} # sets up Google Mock tests
+```
+
+Make sure you have Python installed, as some of Google Test's tests are written
+in Python. If the cmake command complains about not being able to find Python
+(`Could NOT find PythonInterp (missing: PYTHON_EXECUTABLE)`), try telling it
+explicitly where your Python executable can be found:
+
+```
+cmake -DPYTHON_EXECUTABLE=path/to/python ...
+```
+
+Next, you can build Google Test and / or Google Mock and all desired tests. On
+\*nix, this is usually done by
+
+```
+make
+```
+
+To run the tests, do
+
+```
+make test
+```
+
+All tests should pass.

contrib/gtest/CONTRIBUTORS → contrib/googletest/CONTRIBUTORS

@@ -5,33 +5,61 @@
 
 Ajay Joshi <[email protected]>
 Balázs Dán <[email protected]>
+Benoit Sigoure <[email protected]>
 Bharat Mediratta <[email protected]>
+Bogdan Piloca <[email protected]>
 Chandler Carruth <[email protected]>
 Chris Prince <[email protected]>
 Chris Taylor <[email protected]>
 Dan Egnor <[email protected]>
+Dave MacLachlan <[email protected]>
+David Anderson <[email protected]>
+Dean Sturtevant
 Eric Roman <[email protected]>
+Gene Volovich <[email protected]>
 Hady Zalek <[email protected]>
+Hal Burch <[email protected]>
 Jeffrey Yasskin <[email protected]>
+Jim Keller <[email protected]>
+Joe Walnes <[email protected]>
+Jon Wray <[email protected]>
 Jói Sigurðsson <[email protected]>
 Keir Mierle <[email protected]>
 Keith Ray <[email protected]>
 Kenton Varda <[email protected]>
+Kostya Serebryany <[email protected]>
+Krystian Kuzniarek <[email protected]>
+Lev Makhlis
 Manuel Klimek <[email protected]>
+Mario Tanev <[email protected]>
+Mark Paskin
 Markus Heule <[email protected]>
+Martijn Vels <[email protected]>
+Matthew Simmons <[email protected]>
 Mika Raento <[email protected]>
+Mike Bland <[email protected]>
 Miklós Fazekas <[email protected]>
+Neal Norwitz <[email protected]>
+Nermin Ozkiranartli <[email protected]>
+Owen Carlsen <[email protected]>
+Paneendra Ba <[email protected]>
 Pasi Valminen <[email protected]>
 Patrick Hanna <[email protected]>
 Patrick Riley <[email protected]>
+Paul Menage <[email protected]>
 Peter Kaminski <[email protected]>
+Piotr Kaminski <[email protected]>
 Preston Jackson <[email protected]>
 Rainer Klaffenboeck <[email protected]>
 Russ Cox <[email protected]>
 Russ Rufer <[email protected]>
 Sean Mcafee <[email protected]>
 Sigurður Ásgeirsson <[email protected]>
+Sverre Sundsdal <[email protected]>
+Szymon Sobik <[email protected]>
+Takeshi Yoshino <[email protected]>
 Tracy Bialik <[email protected]>
 Vadim Berman <[email protected]>
 Vlad Losev <[email protected]>
+Wolfgang Klier <[email protected]>
 Zhanyong Wan <[email protected]>

contrib/googletest/README.md

@@ -0,0 +1,146 @@
+# GoogleTest
+
+### Announcements
+
+#### Live at Head
+
+GoogleTest now follows the
+[Abseil Live at Head philosophy](https://abseil.io/about/philosophy#upgrade-support).
+We recommend
+[updating to the latest commit in the `main` branch as often as possible](https://github.com/abseil/abseil-cpp/blob/master/FAQ.md#what-is-live-at-head-and-how-do-i-do-it).
+We do publish occasional semantic versions, tagged with
+`v${major}.${minor}.${patch}` (e.g. `v1.13.0`).
+
+#### Documentation Updates
+
+Our documentation is now live on GitHub Pages at
+https://google.github.io/googletest/. We recommend browsing the documentation on
+GitHub Pages rather than directly in the repository.
+
+#### Release 1.13.0
+
+[Release 1.13.0](https://github.com/google/googletest/releases/tag/v1.13.0) is
+now available.
+
+The 1.13.x branch requires at least C++14.
+
+#### Continuous Integration
+
+We use Google's internal systems for continuous integration. \
+GitHub Actions were added for the convenience of open-source contributors. They
+are exclusively maintained by the open-source community and not used by the
+GoogleTest team.
+
+#### Coming Soon
+
+*   We are planning to take a dependency on
+    [Abseil](https://github.com/abseil/abseil-cpp).
+*   More documentation improvements are planned.
+
+## Welcome to **GoogleTest**, Google's C++ test framework!
+
+This repository is a merger of the formerly separate GoogleTest and GoogleMock
+projects. These were so closely related that it makes sense to maintain and
+release them together.
+
+### Getting Started
+
+See the [GoogleTest User's Guide](https://google.github.io/googletest/) for
+documentation. We recommend starting with the
+[GoogleTest Primer](https://google.github.io/googletest/primer.html).
+
+More information about building GoogleTest can be found at
+[googletest/README.md](googletest/README.md).
+
+## Features
+
+*   xUnit test framework: \
+    Googletest is based on the [xUnit](https://en.wikipedia.org/wiki/XUnit)
+    testing framework, a popular architecture for unit testing
+*   Test discovery: \
+    Googletest automatically discovers and runs your tests, eliminating the need
+    to manually register your tests
+*   Rich set of assertions: \
+    Googletest provides a variety of assertions, such as equality, inequality,
+    exceptions, and more, making it easy to test your code
+*   User-defined assertions: \
+    You can define your own assertions with Googletest, making it simple to
+    write tests that are specific to your code
+*   Death tests: \
+    Googletest supports death tests, which verify that your code exits in a
+    certain way, making it useful for testing error-handling code
+*   Fatal and non-fatal failures: \
+    You can specify whether a test failure should be treated as fatal or
+    non-fatal with Googletest, allowing tests to continue running even if a
+    failure occurs
+*   Value-parameterized tests: \
+    Googletest supports value-parameterized tests, which run multiple times with
+    different input values, making it useful for testing functions that take
+    different inputs
+*   Type-parameterized tests: \
+    Googletest also supports type-parameterized tests, which run with different
+    data types, making it useful for testing functions that work with different
+    data types
+*   Various options for running tests: \
+    Googletest provides many options for running tests including running
+    individual tests, running tests in a specific order and running tests in
+    parallel
+
+## Supported Platforms
+
+GoogleTest follows Google's
+[Foundational C++ Support Policy](https://opensource.google/documentation/policies/cplusplus-support).
+See
+[this table](https://github.com/google/oss-policies-info/blob/main/foundational-cxx-support-matrix.md)
+for a list of currently supported versions of compilers, platforms, and build
+tools.
+
+## Who Is Using GoogleTest?
+
+In addition to many internal projects at Google, GoogleTest is also used by the
+following notable projects:
+
+*   The [Chromium projects](http://www.chromium.org/) (behind the Chrome browser
+    and Chrome OS).
+*   The [LLVM](http://llvm.org/) compiler.
+*   [Protocol Buffers](https://github.com/google/protobuf), Google's data
+    interchange format.
+*   The [OpenCV](http://opencv.org/) computer vision library.
+
+## Related Open Source Projects
+
+[GTest Runner](https://github.com/nholthaus/gtest-runner) is a Qt5 based
+automated test-runner and Graphical User Interface with powerful features for
+Windows and Linux platforms.
+
+[GoogleTest UI](https://github.com/ospector/gtest-gbar) is a test runner that
+runs your test binary, allows you to track its progress via a progress bar, and
+displays a list of test failures. Clicking on one shows failure text. GoogleTest
+UI is written in C#.
+
+[GTest TAP Listener](https://github.com/kinow/gtest-tap-listener) is an event
+listener for GoogleTest that implements the
+[TAP protocol](https://en.wikipedia.org/wiki/Test_Anything_Protocol) for test
+result output. If your test runner understands TAP, you may find it useful.
+
+[gtest-parallel](https://github.com/google/gtest-parallel) is a test runner that
+runs tests from your binary in parallel to provide significant speed-up.
+
+[GoogleTest Adapter](https://marketplace.visualstudio.com/items?itemName=DavidSchuldenfrei.gtest-adapter)
+is a VS Code extension allowing to view GoogleTest in a tree view and run/debug
+your tests.
+
+[C++ TestMate](https://github.com/matepek/vscode-catch2-test-adapter) is a VS
+Code extension allowing to view GoogleTest in a tree view and run/debug your
+tests.
+
+[Cornichon](https://pypi.org/project/cornichon/) is a small Gherkin DSL parser
+that generates stub code for GoogleTest.
+
+## Contributing Changes
+
+Please read
+[`CONTRIBUTING.md`](https://github.com/google/googletest/blob/main/CONTRIBUTING.md)
+for details on how to contribute to this project.
+
+Happy testing!

contrib/googletest/WORKSPACE

@@ -0,0 +1,27 @@
+workspace(name = "com_google_googletest")
+
+load("//:googletest_deps.bzl", "googletest_deps")
+googletest_deps()
+
+load("@bazel_tools//tools/build_defs/repo:http.bzl", "http_archive")
+
+http_archive(
+  name = "rules_python",  # 2023-07-31T20:39:27Z
+  sha256 = "1250b59a33c591a1c4ba68c62e95fc88a84c334ec35a2e23f46cbc1b9a5a8b55",
+  strip_prefix = "rules_python-e355becc30275939d87116a4ec83dad4bb50d9e1",
+  urls = ["https://github.com/bazelbuild/rules_python/archive/e355becc30275939d87116a4ec83dad4bb50d9e1.zip"],
+)
+
+http_archive(
+  name = "bazel_skylib",  # 2023-05-31T19:24:07Z
+  sha256 = "08c0386f45821ce246bbbf77503c973246ed6ee5c3463e41efc197fa9bc3a7f4",
+  strip_prefix = "bazel-skylib-288731ef9f7f688932bd50e704a91a45ec185f9b",
+  urls = ["https://github.com/bazelbuild/bazel-skylib/archive/288731ef9f7f688932bd50e704a91a45ec185f9b.zip"],
+)
+
+http_archive(
+  name = "platforms",  # 2023-07-28T19:44:27Z
+  sha256 = "40eb313613ff00a5c03eed20aba58890046f4d38dec7344f00bb9a8867853526",
+  strip_prefix = "platforms-4ad40ef271da8176d4fc0194d2089b8a76e19d7b",
+  urls = ["https://github.com/bazelbuild/platforms/archive/4ad40ef271da8176d4fc0194d2089b8a76e19d7b.zip"],
+)

contrib/googletest/ci/linux-presubmit.sh

@@ -0,0 +1,137 @@
+#!/bin/bash
+#
+# Copyright 2020, Google Inc.
+# All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are
+# met:
+#
+#     * Redistributions of source code must retain the above copyright
+# notice, this list of conditions and the following disclaimer.
+#     * Redistributions in binary form must reproduce the above
+# copyright notice, this list of conditions and the following disclaimer
+# in the documentation and/or other materials provided with the
+# distribution.
+#     * Neither the name of Google Inc. nor the names of its
+# contributors may be used to endorse or promote products derived from
+# this software without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+set -euox pipefail
+
+readonly LINUX_LATEST_CONTAINER="gcr.io/google.com/absl-177019/linux_hybrid-latest:20230217"
+readonly LINUX_GCC_FLOOR_CONTAINER="gcr.io/google.com/absl-177019/linux_gcc-floor:20230120"
+
+if [[ -z ${GTEST_ROOT:-} ]]; then
+  GTEST_ROOT="$(realpath $(dirname ${0})/..)"
+fi
+
+if [[ -z ${STD:-} ]]; then
+  STD="c++14 c++17 c++20"
+fi
+
+# Test the CMake build
+for cc in /usr/local/bin/gcc /opt/llvm/clang/bin/clang; do
+  for cmake_off_on in OFF ON; do
+    time docker run \
+      --volume="${GTEST_ROOT}:/src:ro" \
+      --tmpfs="/build:exec" \
+      --workdir="/build" \
+      --rm \
+      --env="CC=${cc}" \
+      --env=CXXFLAGS="-Werror -Wdeprecated" \
+      ${LINUX_LATEST_CONTAINER} \
+      /bin/bash -c "
+        cmake /src \
+          -DCMAKE_CXX_STANDARD=14 \
+          -Dgtest_build_samples=ON \
+          -Dgtest_build_tests=ON \
+          -Dgmock_build_tests=ON \
+          -Dcxx_no_exception=${cmake_off_on} \
+          -Dcxx_no_rtti=${cmake_off_on} && \
+        make -j$(nproc) && \
+        ctest -j$(nproc) --output-on-failure"
+  done
+done
+
+# Do one test with an older version of GCC
+time docker run \
+  --volume="${GTEST_ROOT}:/src:ro" \
+  --workdir="/src" \
+  --rm \
+  --env="CC=/usr/local/bin/gcc" \
+  --env="BAZEL_CXXOPTS=-std=c++14" \
+  ${LINUX_GCC_FLOOR_CONTAINER} \
+    /usr/local/bin/bazel test ... \
+      --copt="-Wall" \
+      --copt="-Werror" \
+      --copt="-Wuninitialized" \
+      --copt="-Wundef" \
+      --copt="-Wno-error=pragmas" \
+      --distdir="/bazel-distdir" \
+      --features=external_include_paths \
+      --keep_going \
+      --show_timestamps \
+      --test_output=errors
+
+# Test GCC
+for std in ${STD}; do
+  for absl in 0 1; do
+    time docker run \
+      --volume="${GTEST_ROOT}:/src:ro" \
+      --workdir="/src" \
+      --rm \
+      --env="CC=/usr/local/bin/gcc" \
+      --env="BAZEL_CXXOPTS=-std=${std}" \
+      ${LINUX_LATEST_CONTAINER} \
+      /usr/local/bin/bazel test ... \
+        --copt="-Wall" \
+        --copt="-Werror" \
+        --copt="-Wuninitialized" \
+        --copt="-Wundef" \
+        --define="absl=${absl}" \
+        --distdir="/bazel-distdir" \
+        --features=external_include_paths \
+        --keep_going \
+        --show_timestamps \
+        --test_output=errors
+  done
+done
+
+# Test Clang
+for std in ${STD}; do
+  for absl in 0 1; do
+    time docker run \
+      --volume="${GTEST_ROOT}:/src:ro" \
+      --workdir="/src" \
+      --rm \
+      --env="CC=/opt/llvm/clang/bin/clang" \
+      --env="BAZEL_CXXOPTS=-std=${std}" \
+      ${LINUX_LATEST_CONTAINER} \
+      /usr/local/bin/bazel test ... \
+        --copt="--gcc-toolchain=/usr/local" \
+        --copt="-Wall" \
+        --copt="-Werror" \
+        --copt="-Wuninitialized" \
+        --copt="-Wundef" \
+        --define="absl=${absl}" \
+        --distdir="/bazel-distdir" \
+        --features=external_include_paths \
+        --keep_going \
+        --linkopt="--gcc-toolchain=/usr/local" \
+        --show_timestamps \
+        --test_output=errors
+  done
+done

contrib/googletest/ci/macos-presubmit.sh

@@ -0,0 +1,76 @@
+#!/bin/bash
+#
+# Copyright 2020, Google Inc.
+# All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are
+# met:
+#
+#     * Redistributions of source code must retain the above copyright
+# notice, this list of conditions and the following disclaimer.
+#     * Redistributions in binary form must reproduce the above
+# copyright notice, this list of conditions and the following disclaimer
+# in the documentation and/or other materials provided with the
+# distribution.
+#     * Neither the name of Google Inc. nor the names of its
+# contributors may be used to endorse or promote products derived from
+# this software without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+set -euox pipefail
+
+if [[ -z ${GTEST_ROOT:-} ]]; then
+  GTEST_ROOT="$(realpath $(dirname ${0})/..)"
+fi
+
+# Test the CMake build
+for cmake_off_on in OFF ON; do
+  BUILD_DIR=$(mktemp -d build_dir.XXXXXXXX)
+  cd ${BUILD_DIR}
+  time cmake ${GTEST_ROOT} \
+    -DCMAKE_CXX_STANDARD=14 \
+    -Dgtest_build_samples=ON \
+    -Dgtest_build_tests=ON \
+    -Dgmock_build_tests=ON \
+    -Dcxx_no_exception=${cmake_off_on} \
+    -Dcxx_no_rtti=${cmake_off_on}
+  time make
+  time ctest -j$(nproc) --output-on-failure
+done
+
+# Test the Bazel build
+
+# If we are running on Kokoro, check for a versioned Bazel binary.
+KOKORO_GFILE_BAZEL_BIN="bazel-5.1.1-darwin-x86_64"
+if [[ ${KOKORO_GFILE_DIR:-} ]] && [[ -f ${KOKORO_GFILE_DIR}/${KOKORO_GFILE_BAZEL_BIN} ]]; then
+  BAZEL_BIN="${KOKORO_GFILE_DIR}/${KOKORO_GFILE_BAZEL_BIN}"
+  chmod +x ${BAZEL_BIN}
+else
+  BAZEL_BIN="bazel"
+fi
+
+cd ${GTEST_ROOT}
+for absl in 0 1; do
+  ${BAZEL_BIN} test ... \
+    --copt="-Wall" \
+    --copt="-Werror" \
+    --copt="-Wundef" \
+    --cxxopt="-std=c++14" \
+    --define="absl=${absl}" \
+    --features=external_include_paths \
+    --keep_going \
+    --show_timestamps \
+    --test_output=errors
+done

contrib/googletest/ci/windows-presubmit.bat

@@ -0,0 +1,58 @@
+SETLOCAL ENABLEDELAYEDEXPANSION
+
+SET BAZEL_EXE=%KOKORO_GFILE_DIR%\bazel-5.1.1-windows-x86_64.exe
+
+SET PATH=C:\Python34;%PATH%
+SET BAZEL_PYTHON=C:\python34\python.exe
+SET BAZEL_SH=C:\tools\msys64\usr\bin\bash.exe
+SET CMAKE_BIN="cmake.exe"
+SET CTEST_BIN="ctest.exe"
+SET CTEST_OUTPUT_ON_FAILURE=1
+SET CMAKE_BUILD_PARALLEL_LEVEL=16
+SET CTEST_PARALLEL_LEVEL=16
+
+IF EXIST git\googletest (
+  CD git\googletest
+) ELSE IF EXIST github\googletest (
+  CD github\googletest
+)
+
+IF %errorlevel% neq 0 EXIT /B 1
+
+:: ----------------------------------------------------------------------------
+:: CMake
+MKDIR cmake_msvc2022
+CD cmake_msvc2022
+
+%CMAKE_BIN% .. ^
+  -G "Visual Studio 17 2022" ^
+  -DPYTHON_EXECUTABLE:FILEPATH=c:\python37\python.exe ^
+  -DPYTHON_INCLUDE_DIR:PATH=c:\python37\include ^
+  -DPYTHON_LIBRARY:FILEPATH=c:\python37\lib\site-packages\pip ^
+  -Dgtest_build_samples=ON ^
+  -Dgtest_build_tests=ON ^
+  -Dgmock_build_tests=ON
+IF %errorlevel% neq 0 EXIT /B 1
+
+%CMAKE_BIN% --build . --target ALL_BUILD --config Debug -- -maxcpucount
+IF %errorlevel% neq 0 EXIT /B 1
+
+%CTEST_BIN% -C Debug --timeout 600
+IF %errorlevel% neq 0 EXIT /B 1
+
+CD ..
+RMDIR /S /Q cmake_msvc2022
+
+:: ----------------------------------------------------------------------------
+:: Bazel
+
+SET BAZEL_VS=C:\Program Files\Microsoft Visual Studio\2022\Community
+%BAZEL_EXE% test ... ^
+  --compilation_mode=dbg ^
+  --copt=/std:c++14 ^
+  --copt=/WX ^
+  --features=external_include_paths ^
+  --keep_going ^
+  --test_output=errors ^
+  --test_tag_filters=-no_test_msvc2017
+IF %errorlevel% neq 0 EXIT /B 1

contrib/googletest/docs/_config.yml

@@ -0,0 +1 @@
+title: GoogleTest

contrib/googletest/docs/_data/navigation.yml

@@ -0,0 +1,43 @@
+nav:
+- section: "Get Started"
+  items:
+  - title: "Supported Platforms"
+    url: "/platforms.html"
+  - title: "Quickstart: Bazel"
+    url: "/quickstart-bazel.html"
+  - title: "Quickstart: CMake"
+    url: "/quickstart-cmake.html"
+- section: "Guides"
+  items:
+  - title: "GoogleTest Primer"
+    url: "/primer.html"
+  - title: "Advanced Topics"
+    url: "/advanced.html"
+  - title: "Mocking for Dummies"
+    url: "/gmock_for_dummies.html"
+  - title: "Mocking Cookbook"
+    url: "/gmock_cook_book.html"
+  - title: "Mocking Cheat Sheet"
+    url: "/gmock_cheat_sheet.html"
+- section: "References"
+  items:
+  - title: "Testing Reference"
+    url: "/reference/testing.html"
+  - title: "Mocking Reference"
+    url: "/reference/mocking.html"
+  - title: "Assertions"
+    url: "/reference/assertions.html"
+  - title: "Matchers"
+    url: "/reference/matchers.html"
+  - title: "Actions"
+    url: "/reference/actions.html"
+  - title: "Testing FAQ"
+    url: "/faq.html"
+  - title: "Mocking FAQ"
+    url: "/gmock_faq.html"
+  - title: "Code Samples"
+    url: "/samples.html"
+  - title: "Using pkg-config"
+    url: "/pkgconfig.html"
+  - title: "Community Documentation"
+    url: "/community_created_documentation.html"

contrib/googletest/docs/_layouts/default.html

@@ -0,0 +1,58 @@
+<!DOCTYPE html>
+<html lang="{{ site.lang | default: "en-US" }}">
+  <head>
+    <meta charset="UTF-8">
+    <meta http-equiv="X-UA-Compatible" content="IE=edge">
+    <meta name="viewport" content="width=device-width, initial-scale=1">
+
+{% seo %}
+    <link rel="stylesheet" href="{{ "/assets/css/style.css?v=" | append: site.github.build_revision | relative_url }}">
+    <script>
+      window.ga=window.ga||function(){(ga.q=ga.q||[]).push(arguments)};ga.l=+new Date;
+      ga('create', 'UA-197576187-1', { 'storage': 'none' });
+      ga('set', 'referrer', document.referrer.split('?')[0]);
+      ga('set', 'location', window.location.href.split('?')[0]);
+      ga('set', 'anonymizeIp', true);
+      ga('send', 'pageview');
+    </script>
+    <script async src='https://www.google-analytics.com/analytics.js'></script>
+  </head>
+  <body>
+    <div class="sidebar">
+      <div class="header">
+        <h1><a href="{{ "/" | relative_url }}">{{ site.title | default: "Documentation" }}</a></h1>
+      </div>
+      <input type="checkbox" id="nav-toggle" class="nav-toggle">
+      <label for="nav-toggle" class="expander">
+        <span class="arrow"></span>
+      </label>
+      <nav>
+        {% for item in site.data.navigation.nav %}
+        <h2>{{ item.section }}</h2>
+        <ul>
+          {% for subitem in item.items %}
+          <a href="{{subitem.url | relative_url }}">
+            <li class="{% if subitem.url == page.url %}active{% endif %}">
+              {{ subitem.title }}
+            </li>
+          </a>
+          {% endfor %}
+        </ul>
+        {% endfor %}
+      </nav>
+    </div>
+    <div class="main markdown-body">
+      <div class="main-inner">
+        {{ content }}
+      </div>
+      <div class="footer">
+        GoogleTest &middot;
+        <a href="https://github.com/google/googletest">GitHub Repository</a> &middot;
+        <a href="https://github.com/google/googletest/blob/main/LICENSE">License</a> &middot;
+        <a href="https://policies.google.com/privacy">Privacy Policy</a>
+      </div>
+    </div>
+    <script src="https://cdnjs.cloudflare.com/ajax/libs/anchor-js/4.1.0/anchor.min.js" integrity="sha256-lZaRhKri35AyJSypXXs4o6OPFTbTmUoltBbDCbdzegg=" crossorigin="anonymous"></script>
+    <script>anchors.add('.main h2, .main h3, .main h4, .main h5, .main h6');</script>
+  </body>
+</html>

contrib/googletest/docs/_sass/main.scss

@@ -0,0 +1,200 @@
+// Styles for GoogleTest docs website on GitHub Pages.
+// Color variables are defined in
+// https://github.com/pages-themes/primer/tree/master/_sass/primer-support/lib/variables
+
+$sidebar-width: 260px;
+
+body {
+  display: flex;
+  margin: 0;
+}
+
+.sidebar {
+  background: $black;
+  color: $text-white;
+  flex-shrink: 0;
+  height: 100vh;
+  overflow: auto;
+  position: sticky;
+  top: 0;
+  width: $sidebar-width;
+}
+
+.sidebar h1 {
+  font-size: 1.5em;
+}
+
+.sidebar h2 {
+  color: $gray-light;
+  font-size: 0.8em;
+  font-weight: normal;
+  margin-bottom: 0.8em;
+  padding-left: 2.5em;
+  text-transform: uppercase;
+}
+
+.sidebar .header {
+  background: $black;
+  padding: 2em;
+  position: sticky;
+  top: 0;
+  width: 100%;
+}
+
+.sidebar .header a {
+  color: $text-white;
+  text-decoration: none;
+}
+
+.sidebar .nav-toggle {
+  display: none;
+}
+
+.sidebar .expander {
+  cursor: pointer;
+  display: none;
+  height: 3em;
+  position: absolute;
+  right: 1em;
+  top: 1.5em;
+  width: 3em;
+}
+
+.sidebar .expander .arrow {
+  border: solid $white;
+  border-width: 0 3px 3px 0;
+  display: block;
+  height: 0.7em;
+  margin: 1em auto;
+  transform: rotate(45deg);
+  transition: transform 0.5s;
+  width: 0.7em;
+}
+
+.sidebar nav {
+  width: 100%;
+}
+
+.sidebar nav ul {
+  list-style-type: none;
+  margin-bottom: 1em;
+  padding: 0;
+
+  &:last-child {
+    margin-bottom: 2em;
+  }
+
+  a {
+   text-decoration: none;
+  }
+
+  li {
+    color: $text-white;
+    padding-left: 2em;
+    text-decoration: none;
+  }
+
+  li.active {
+    background: $border-gray-darker;
+    font-weight: bold;
+  }
+
+  li:hover {
+    background: $border-gray-darker;
+  }
+}
+
+.main {
+  background-color: $bg-gray;
+  width: calc(100% - #{$sidebar-width});
+}
+
+.main .main-inner {
+  background-color: $white;
+  padding: 2em;
+}
+
+.main .footer {
+  margin: 0;
+  padding: 2em;
+}
+
+.main table th {
+  text-align: left;
+}
+
+.main .callout {
+  border-left: 0.25em solid $white;
+  padding: 1em;
+
+  a {
+    text-decoration: underline;
+  }
+
+  &.important {
+    background-color: $bg-yellow-light;
+    border-color: $bg-yellow;
+    color: $black;
+  }
+
+  &.note {
+    background-color: $bg-blue-light;
+    border-color: $text-blue;
+    color: $text-blue;
+  }
+
+  &.tip {
+    background-color: $green-000;
+    border-color: $green-700;
+    color: $green-700;
+  }
+
+  &.warning {
+    background-color: $red-000;
+    border-color: $text-red;
+    color: $text-red;
+  }
+}
+
+.main .good pre {
+  background-color: $bg-green-light;
+}
+
+.main .bad pre {
+  background-color: $red-000;
+}
+
+@media all and (max-width: 768px) {
+  body {
+    flex-direction: column;
+  }
+
+  .sidebar {
+    height: auto;
+    position: relative;
+    width: 100%;
+  }
+
+  .sidebar .expander {
+    display: block;
+  }
+
+  .sidebar nav {
+    height: 0;
+    overflow: hidden;
+  }
+
+  .sidebar .nav-toggle:checked {
+    & ~ nav {
+      height: auto;
+    }
+
+    & + .expander .arrow {
+      transform: rotate(-135deg);
+    }
+  }
+
+  .main {
+    width: 100%;
+  }
+}

contrib/googletest/docs/advanced.md

@@ -0,0 +1,2436 @@
+# Advanced GoogleTest Topics
+
+## Introduction
+
+Now that you have read the [GoogleTest Primer](primer.md) and learned how to
+write tests using GoogleTest, it's time to learn some new tricks. This document
+will show you more assertions as well as how to construct complex failure
+messages, propagate fatal failures, reuse and speed up your test fixtures, and
+use various flags with your tests.
+
+## More Assertions
+
+This section covers some less frequently used, but still significant,
+assertions.
+
+### Explicit Success and Failure
+
+See [Explicit Success and Failure](reference/assertions.md#success-failure) in
+the Assertions Reference.
+
+### Exception Assertions
+
+See [Exception Assertions](reference/assertions.md#exceptions) in the Assertions
+Reference.
+
+### Predicate Assertions for Better Error Messages
+
+Even though GoogleTest has a rich set of assertions, they can never be complete,
+as it's impossible (nor a good idea) to anticipate all scenarios a user might
+run into. Therefore, sometimes a user has to use `EXPECT_TRUE()` to check a
+complex expression, for lack of a better macro. This has the problem of not
+showing you the values of the parts of the expression, making it hard to
+understand what went wrong. As a workaround, some users choose to construct the
+failure message by themselves, streaming it into `EXPECT_TRUE()`. However, this
+is awkward especially when the expression has side-effects or is expensive to
+evaluate.
+
+GoogleTest gives you three different options to solve this problem:
+
+#### Using an Existing Boolean Function
+
+If you already have a function or functor that returns `bool` (or a type that
+can be implicitly converted to `bool`), you can use it in a *predicate
+assertion* to get the function arguments printed for free. See
+[`EXPECT_PRED*`](reference/assertions.md#EXPECT_PRED) in the Assertions
+Reference for details.
+
+#### Using a Function That Returns an AssertionResult
+
+While `EXPECT_PRED*()` and friends are handy for a quick job, the syntax is not
+satisfactory: you have to use different macros for different arities, and it
+feels more like Lisp than C++. The `::testing::AssertionResult` class solves
+this problem.
+
+An `AssertionResult` object represents the result of an assertion (whether it's
+a success or a failure, and an associated message). You can create an
+`AssertionResult` using one of these factory functions:
+
+```c++
+namespace testing {
+
+// Returns an AssertionResult object to indicate that an assertion has
+// succeeded.
+AssertionResult AssertionSuccess();
+
+// Returns an AssertionResult object to indicate that an assertion has
+// failed.
+AssertionResult AssertionFailure();
+
+}
+```
+
+You can then use the `<<` operator to stream messages to the `AssertionResult`
+object.
+
+To provide more readable messages in Boolean assertions (e.g. `EXPECT_TRUE()`),
+write a predicate function that returns `AssertionResult` instead of `bool`. For
+example, if you define `IsEven()` as:
+
+```c++
+testing::AssertionResult IsEven(int n) {
+  if ((n % 2) == 0)
+    return testing::AssertionSuccess();
+  else
+    return testing::AssertionFailure() << n << " is odd";
+}
+```
+
+instead of:
+
+```c++
+bool IsEven(int n) {
+  return (n % 2) == 0;
+}
+```
+
+the failed assertion `EXPECT_TRUE(IsEven(Fib(4)))` will print:
+
+```none
+Value of: IsEven(Fib(4))
+  Actual: false (3 is odd)
+Expected: true
+```
+
+instead of a more opaque
+
+```none
+Value of: IsEven(Fib(4))
+  Actual: false
+Expected: true
+```
+
+If you want informative messages in `EXPECT_FALSE` and `ASSERT_FALSE` as well
+(one third of Boolean assertions in the Google code base are negative ones), and
+are fine with making the predicate slower in the success case, you can supply a
+success message:
+
+```c++
+testing::AssertionResult IsEven(int n) {
+  if ((n % 2) == 0)
+    return testing::AssertionSuccess() << n << " is even";
+  else
+    return testing::AssertionFailure() << n << " is odd";
+}
+```
+
+Then the statement `EXPECT_FALSE(IsEven(Fib(6)))` will print
+
+```none
+  Value of: IsEven(Fib(6))
+     Actual: true (8 is even)
+  Expected: false
+```
+
+#### Using a Predicate-Formatter
+
+If you find the default message generated by
+[`EXPECT_PRED*`](reference/assertions.md#EXPECT_PRED) and
+[`EXPECT_TRUE`](reference/assertions.md#EXPECT_TRUE) unsatisfactory, or some
+arguments to your predicate do not support streaming to `ostream`, you can
+instead use *predicate-formatter assertions* to *fully* customize how the
+message is formatted. See
+[`EXPECT_PRED_FORMAT*`](reference/assertions.md#EXPECT_PRED_FORMAT) in the
+Assertions Reference for details.
+
+### Floating-Point Comparison
+
+See [Floating-Point Comparison](reference/assertions.md#floating-point) in the
+Assertions Reference.
+
+#### Floating-Point Predicate-Format Functions
+
+Some floating-point operations are useful, but not that often used. In order to
+avoid an explosion of new macros, we provide them as predicate-format functions
+that can be used in the predicate assertion macro
+[`EXPECT_PRED_FORMAT2`](reference/assertions.md#EXPECT_PRED_FORMAT), for
+example:
+
+```c++
+using ::testing::FloatLE;
+using ::testing::DoubleLE;
+...
+EXPECT_PRED_FORMAT2(FloatLE, val1, val2);
+EXPECT_PRED_FORMAT2(DoubleLE, val1, val2);
+```
+
+The above code verifies that `val1` is less than, or approximately equal to,
+`val2`.
+
+### Asserting Using gMock Matchers
+
+See [`EXPECT_THAT`](reference/assertions.md#EXPECT_THAT) in the Assertions
+Reference.
+
+### More String Assertions
+
+(Please read the [previous](#asserting-using-gmock-matchers) section first if
+you haven't.)
+
+You can use the gMock [string matchers](reference/matchers.md#string-matchers)
+with [`EXPECT_THAT`](reference/assertions.md#EXPECT_THAT) to do more string
+comparison tricks (sub-string, prefix, suffix, regular expression, and etc). For
+example,
+
+```c++
+using ::testing::HasSubstr;
+using ::testing::MatchesRegex;
+...
+  ASSERT_THAT(foo_string, HasSubstr("needle"));
+  EXPECT_THAT(bar_string, MatchesRegex("\\w*\\d+"));
+```
+
+### Windows HRESULT assertions
+
+See [Windows HRESULT Assertions](reference/assertions.md#HRESULT) in the
+Assertions Reference.
+
+### Type Assertions
+
+You can call the function
+
+```c++
+::testing::StaticAssertTypeEq<T1, T2>();
+```
+
+to assert that types `T1` and `T2` are the same. The function does nothing if
+the assertion is satisfied. If the types are different, the function call will
+fail to compile, the compiler error message will say that `T1 and T2 are not the
+same type` and most likely (depending on the compiler) show you the actual
+values of `T1` and `T2`. This is mainly useful inside template code.
+
+**Caveat**: When used inside a member function of a class template or a function
+template, `StaticAssertTypeEq<T1, T2>()` is effective only if the function is
+instantiated. For example, given:
+
+```c++
+template <typename T> class Foo {
+ public:
+  void Bar() { testing::StaticAssertTypeEq<int, T>(); }
+};
+```
+
+the code:
+
+```c++
+void Test1() { Foo<bool> foo; }
+```
+
+will not generate a compiler error, as `Foo<bool>::Bar()` is never actually
+instantiated. Instead, you need:
+
+```c++
+void Test2() { Foo<bool> foo; foo.Bar(); }
+```
+
+to cause a compiler error.
+
+### Assertion Placement
+
+You can use assertions in any C++ function. In particular, it doesn't have to be
+a method of the test fixture class. The one constraint is that assertions that
+generate a fatal failure (`FAIL*` and `ASSERT_*`) can only be used in
+void-returning functions. This is a consequence of Google's not using
+exceptions. By placing it in a non-void function you'll get a confusing compile
+error like `"error: void value not ignored as it ought to be"` or `"cannot
+initialize return object of type 'bool' with an rvalue of type 'void'"` or
+`"error: no viable conversion from 'void' to 'string'"`.
+
+If you need to use fatal assertions in a function that returns non-void, one
+option is to make the function return the value in an out parameter instead. For
+example, you can rewrite `T2 Foo(T1 x)` to `void Foo(T1 x, T2* result)`. You
+need to make sure that `*result` contains some sensible value even when the
+function returns prematurely. As the function now returns `void`, you can use
+any assertion inside of it.
+
+If changing the function's type is not an option, you should just use assertions
+that generate non-fatal failures, such as `ADD_FAILURE*` and `EXPECT_*`.
+
+{: .callout .note}
+NOTE: Constructors and destructors are not considered void-returning functions,
+according to the C++ language specification, and so you may not use fatal
+assertions in them; you'll get a compilation error if you try. Instead, either
+call `abort` and crash the entire test executable, or put the fatal assertion in
+a `SetUp`/`TearDown` function; see
+[constructor/destructor vs. `SetUp`/`TearDown`](faq.md#CtorVsSetUp)
+
+{: .callout .warning}
+WARNING: A fatal assertion in a helper function (private void-returning method)
+called from a constructor or destructor does not terminate the current test, as
+your intuition might suggest: it merely returns from the constructor or
+destructor early, possibly leaving your object in a partially-constructed or
+partially-destructed state! You almost certainly want to `abort` or use
+`SetUp`/`TearDown` instead.
+
+## Skipping test execution
+
+Related to the assertions `SUCCEED()` and `FAIL()`, you can prevent further test
+execution at runtime with the `GTEST_SKIP()` macro. This is useful when you need
+to check for preconditions of the system under test during runtime and skip
+tests in a meaningful way.
+
+`GTEST_SKIP()` can be used in individual test cases or in the `SetUp()` methods
+of classes derived from either `::testing::Environment` or `::testing::Test`.
+For example:
+
+```c++
+TEST(SkipTest, DoesSkip) {
+  GTEST_SKIP() << "Skipping single test";
+  EXPECT_EQ(0, 1);  // Won't fail; it won't be executed
+}
+
+class SkipFixture : public ::testing::Test {
+ protected:
+  void SetUp() override {
+    GTEST_SKIP() << "Skipping all tests for this fixture";
+  }
+};
+
+// Tests for SkipFixture won't be executed.
+TEST_F(SkipFixture, SkipsOneTest) {
+  EXPECT_EQ(5, 7);  // Won't fail
+}
+```
+
+As with assertion macros, you can stream a custom message into `GTEST_SKIP()`.
+
+## Teaching GoogleTest How to Print Your Values
+
+When a test assertion such as `EXPECT_EQ` fails, GoogleTest prints the argument
+values to help you debug. It does this using a user-extensible value printer.
+
+This printer knows how to print built-in C++ types, native arrays, STL
+containers, and any type that supports the `<<` operator. For other types, it
+prints the raw bytes in the value and hopes that you the user can figure it out.
+
+As mentioned earlier, the printer is *extensible*. That means you can teach it
+to do a better job at printing your particular type than to dump the bytes. To
+do that, define an `AbslStringify()` overload as a `friend` function template
+for your type:
+
+```cpp
+namespace foo {
+
+class Point {  // We want GoogleTest to be able to print instances of this.
+  ...
+  // Provide a friend overload.
+  template <typename Sink>
+  friend void AbslStringify(Sink& sink, const Point& point) {
+    absl::Format(&sink, "(%d, %d)", point.x, point.y);
+  }
+
+  int x;
+  int y;
+};
+
+// If you can't declare the function in the class it's important that the
+// AbslStringify overload is defined in the SAME namespace that defines Point.
+// C++'s look-up rules rely on that.
+enum class EnumWithStringify { kMany = 0, kChoices = 1 };
+
+template <typename Sink>
+void AbslStringify(Sink& sink, EnumWithStringify e) {
+  absl::Format(&sink, "%s", e == EnumWithStringify::kMany ? "Many" : "Choices");
+}
+
+}  // namespace foo
+```
+
+{: .callout .note}
+Note: `AbslStringify()` utilizes a generic "sink" buffer to construct its
+string. For more information about supported operations on `AbslStringify()`'s
+sink, see go/abslstringify.
+
+`AbslStringify()` can also use `absl::StrFormat`'s catch-all `%v` type specifier
+within its own format strings to perform type deduction. `Point` above could be
+formatted as `"(%v, %v)"` for example, and deduce the `int` values as `%d`.
+
+Sometimes, `AbslStringify()` might not be an option: your team may wish to print
+types with extra debugging information for testing purposes only. If so, you can
+instead define a `PrintTo()` function like this:
+
+```c++
+#include <ostream>
+
+namespace foo {
+
+class Point {
+  ...
+  friend void PrintTo(const Point& point, std::ostream* os) {
+    *os << "(" << point.x << "," << point.y << ")";
+  }
+
+  int x;
+  int y;
+};
+
+// If you can't declare the function in the class it's important that PrintTo()
+// is defined in the SAME namespace that defines Point.  C++'s look-up rules
+// rely on that.
+void PrintTo(const Point& point, std::ostream* os) {
+    *os << "(" << point.x << "," << point.y << ")";
+}
+
+}  // namespace foo
+```
+
+If you have defined both `AbslStringify()` and `PrintTo()`, the latter will be
+used by GoogleTest. This allows you to customize how the value appears in
+GoogleTest's output without affecting code that relies on the behavior of
+`AbslStringify()`.
+
+If you have an existing `<<` operator and would like to define an
+`AbslStringify()`, the latter will be used for GoogleTest printing.
+
+If you want to print a value `x` using GoogleTest's value printer yourself, just
+call `::testing::PrintToString(x)`, which returns an `std::string`:
+
+```c++
+vector<pair<Point, int> > point_ints = GetPointIntVector();
+
+EXPECT_TRUE(IsCorrectPointIntVector(point_ints))
+    << "point_ints = " << testing::PrintToString(point_ints);
+```
+
+For more details regarding `AbslStringify()` and its integration with other
+libraries, see go/abslstringify.
+
+## Death Tests
+
+In many applications, there are assertions that can cause application failure if
+a condition is not met. These consistency checks, which ensure that the program
+is in a known good state, are there to fail at the earliest possible time after
+some program state is corrupted. If the assertion checks the wrong condition,
+then the program may proceed in an erroneous state, which could lead to memory
+corruption, security holes, or worse. Hence it is vitally important to test that
+such assertion statements work as expected.
+
+Since these precondition checks cause the processes to die, we call such tests
+_death tests_. More generally, any test that checks that a program terminates
+(except by throwing an exception) in an expected fashion is also a death test.
+
+Note that if a piece of code throws an exception, we don't consider it "death"
+for the purpose of death tests, as the caller of the code could catch the
+exception and avoid the crash. If you want to verify exceptions thrown by your
+code, see [Exception Assertions](#ExceptionAssertions).
+
+If you want to test `EXPECT_*()/ASSERT_*()` failures in your test code, see
+["Catching" Failures](#catching-failures).
+
+### How to Write a Death Test
+
+GoogleTest provides assertion macros to support death tests. See
+[Death Assertions](reference/assertions.md#death) in the Assertions Reference
+for details.
+
+To write a death test, simply use one of the macros inside your test function.
+For example,
+
+```c++
+TEST(MyDeathTest, Foo) {
+  // This death test uses a compound statement.
+  ASSERT_DEATH({
+    int n = 5;
+    Foo(&n);
+  }, "Error on line .* of Foo()");
+}
+
+TEST(MyDeathTest, NormalExit) {
+  EXPECT_EXIT(NormalExit(), testing::ExitedWithCode(0), "Success");
+}
+
+TEST(MyDeathTest, KillProcess) {
+  EXPECT_EXIT(KillProcess(), testing::KilledBySignal(SIGKILL),
+              "Sending myself unblockable signal");
+}
+```
+
+verifies that:
+
+*   calling `Foo(5)` causes the process to die with the given error message,
+*   calling `NormalExit()` causes the process to print `"Success"` to stderr and
+    exit with exit code 0, and
+*   calling `KillProcess()` kills the process with signal `SIGKILL`.
+
+The test function body may contain other assertions and statements as well, if
+necessary.
+
+Note that a death test only cares about three things:
+
+1.  does `statement` abort or exit the process?
+2.  (in the case of `ASSERT_EXIT` and `EXPECT_EXIT`) does the exit status
+    satisfy `predicate`? Or (in the case of `ASSERT_DEATH` and `EXPECT_DEATH`)
+    is the exit status non-zero? And
+3.  does the stderr output match `matcher`?
+
+In particular, if `statement` generates an `ASSERT_*` or `EXPECT_*` failure, it
+will **not** cause the death test to fail, as GoogleTest assertions don't abort
+the process.
+
+### Death Test Naming
+
+{: .callout .important}
+IMPORTANT: We strongly recommend you to follow the convention of naming your
+**test suite** (not test) `*DeathTest` when it contains a death test, as
+demonstrated in the above example. The
+[Death Tests And Threads](#death-tests-and-threads) section below explains why.
+
+If a test fixture class is shared by normal tests and death tests, you can use
+`using` or `typedef` to introduce an alias for the fixture class and avoid
+duplicating its code:
+
+```c++
+class FooTest : public testing::Test { ... };
+
+using FooDeathTest = FooTest;
+
+TEST_F(FooTest, DoesThis) {
+  // normal test
+}
+
+TEST_F(FooDeathTest, DoesThat) {
+  // death test
+}
+```
+
+### Regular Expression Syntax
+
+When built with Bazel and using Abseil, GoogleTest uses the
+[RE2](https://github.com/google/re2/wiki/Syntax) syntax. Otherwise, for POSIX
+systems (Linux, Cygwin, Mac), GoogleTest uses the
+[POSIX extended regular expression](http://www.opengroup.org/onlinepubs/009695399/basedefs/xbd_chap09.html#tag_09_04)
+syntax. To learn about POSIX syntax, you may want to read this
+[Wikipedia entry](http://en.wikipedia.org/wiki/Regular_expression#POSIX_extended).
+
+On Windows, GoogleTest uses its own simple regular expression implementation. It
+lacks many features. For example, we don't support union (`"x|y"`), grouping
+(`"(xy)"`), brackets (`"[xy]"`), and repetition count (`"x{5,7}"`), among
+others. Below is what we do support (`A` denotes a literal character, period
+(`.`), or a single `\\ ` escape sequence; `x` and `y` denote regular
+expressions.):
+
+Expression | Meaning
+---------- | --------------------------------------------------------------
+`c`        | matches any literal character `c`
+`\\d`      | matches any decimal digit
+`\\D`      | matches any character that's not a decimal digit
+`\\f`      | matches `\f`
+`\\n`      | matches `\n`
+`\\r`      | matches `\r`
+`\\s`      | matches any ASCII whitespace, including `\n`
+`\\S`      | matches any character that's not a whitespace
+`\\t`      | matches `\t`
+`\\v`      | matches `\v`
+`\\w`      | matches any letter, `_`, or decimal digit
+`\\W`      | matches any character that `\\w` doesn't match
+`\\c`      | matches any literal character `c`, which must be a punctuation
+`.`        | matches any single character except `\n`
+`A?`       | matches 0 or 1 occurrences of `A`
+`A*`       | matches 0 or many occurrences of `A`
+`A+`       | matches 1 or many occurrences of `A`
+`^`        | matches the beginning of a string (not that of each line)
+`$`        | matches the end of a string (not that of each line)
+`xy`       | matches `x` followed by `y`
+
+To help you determine which capability is available on your system, GoogleTest
+defines macros to govern which regular expression it is using. The macros are:
+`GTEST_USES_SIMPLE_RE=1` or `GTEST_USES_POSIX_RE=1`. If you want your death
+tests to work in all cases, you can either `#if` on these macros or use the more
+limited syntax only.
+
+### How It Works
+
+See [Death Assertions](reference/assertions.md#death) in the Assertions
+Reference.
+
+### Death Tests And Threads
+
+The reason for the two death test styles has to do with thread safety. Due to
+well-known problems with forking in the presence of threads, death tests should
+be run in a single-threaded context. Sometimes, however, it isn't feasible to
+arrange that kind of environment. For example, statically-initialized modules
+may start threads before main is ever reached. Once threads have been created,
+it may be difficult or impossible to clean them up.
+
+GoogleTest has three features intended to raise awareness of threading issues.
+
+1.  A warning is emitted if multiple threads are running when a death test is
+    encountered.
+2.  Test suites with a name ending in "DeathTest" are run before all other
+    tests.
+3.  It uses `clone()` instead of `fork()` to spawn the child process on Linux
+    (`clone()` is not available on Cygwin and Mac), as `fork()` is more likely
+    to cause the child to hang when the parent process has multiple threads.
+
+It's perfectly fine to create threads inside a death test statement; they are
+executed in a separate process and cannot affect the parent.
+
+### Death Test Styles
+
+The "threadsafe" death test style was introduced in order to help mitigate the
+risks of testing in a possibly multithreaded environment. It trades increased
+test execution time (potentially dramatically so) for improved thread safety.
+
+The automated testing framework does not set the style flag. You can choose a
+particular style of death tests by setting the flag programmatically:
+
+```c++
+GTEST_FLAG_SET(death_test_style, "threadsafe");
+```
+
+You can do this in `main()` to set the style for all death tests in the binary,
+or in individual tests. Recall that flags are saved before running each test and
+restored afterwards, so you need not do that yourself. For example:
+
+```c++
+int main(int argc, char** argv) {
+  testing::InitGoogleTest(&argc, argv);
+  GTEST_FLAG_SET(death_test_style, "fast");
+  return RUN_ALL_TESTS();
+}
+
+TEST(MyDeathTest, TestOne) {
+  GTEST_FLAG_SET(death_test_style, "threadsafe");
+  // This test is run in the "threadsafe" style:
+  ASSERT_DEATH(ThisShouldDie(), "");
+}
+
+TEST(MyDeathTest, TestTwo) {
+  // This test is run in the "fast" style:
+  ASSERT_DEATH(ThisShouldDie(), "");
+}
+```
+
+### Caveats
+
+The `statement` argument of `ASSERT_EXIT()` can be any valid C++ statement. If
+it leaves the current function via a `return` statement or by throwing an
+exception, the death test is considered to have failed. Some GoogleTest macros
+may return from the current function (e.g. `ASSERT_TRUE()`), so be sure to avoid
+them in `statement`.
+
+Since `statement` runs in the child process, any in-memory side effect (e.g.
+modifying a variable, releasing memory, etc) it causes will *not* be observable
+in the parent process. In particular, if you release memory in a death test,
+your program will fail the heap check as the parent process will never see the
+memory reclaimed. To solve this problem, you can
+
+1.  try not to free memory in a death test;
+2.  free the memory again in the parent process; or
+3.  do not use the heap checker in your program.
+
+Due to an implementation detail, you cannot place multiple death test assertions
+on the same line; otherwise, compilation will fail with an unobvious error
+message.
+
+Despite the improved thread safety afforded by the "threadsafe" style of death
+test, thread problems such as deadlock are still possible in the presence of
+handlers registered with `pthread_atfork(3)`.
+
+## Using Assertions in Sub-routines
+
+{: .callout .note}
+Note: If you want to put a series of test assertions in a subroutine to check
+for a complex condition, consider using
+[a custom GMock matcher](gmock_cook_book.md#NewMatchers) instead. This lets you
+provide a more readable error message in case of failure and avoid all of the
+issues described below.
+
+### Adding Traces to Assertions
+
+If a test sub-routine is called from several places, when an assertion inside it
+fails, it can be hard to tell which invocation of the sub-routine the failure is
+from. You can alleviate this problem using extra logging or custom failure
+messages, but that usually clutters up your tests. A better solution is to use
+the `SCOPED_TRACE` macro or the `ScopedTrace` utility:
+
+```c++
+SCOPED_TRACE(message);
+```
+
+```c++
+ScopedTrace trace("file_path", line_number, message);
+```
+
+where `message` can be anything streamable to `std::ostream`. `SCOPED_TRACE`
+macro will cause the current file name, line number, and the given message to be
+added in every failure message. `ScopedTrace` accepts explicit file name and
+line number in arguments, which is useful for writing test helpers. The effect
+will be undone when the control leaves the current lexical scope.
+
+For example,
+
+```c++
+10: void Sub1(int n) {
+11:   EXPECT_EQ(Bar(n), 1);
+12:   EXPECT_EQ(Bar(n + 1), 2);
+13: }
+14:
+15: TEST(FooTest, Bar) {
+16:   {
+17:     SCOPED_TRACE("A");  // This trace point will be included in
+18:                         // every failure in this scope.
+19:     Sub1(1);
+20:   }
+21:   // Now it won't.
+22:   Sub1(9);
+23: }
+```
+
+could result in messages like these:
+
+```none
+path/to/foo_test.cc:11: Failure
+Value of: Bar(n)
+Expected: 1
+  Actual: 2
+Google Test trace:
+path/to/foo_test.cc:17: A
+
+path/to/foo_test.cc:12: Failure
+Value of: Bar(n + 1)
+Expected: 2
+  Actual: 3
+```
+
+Without the trace, it would've been difficult to know which invocation of
+`Sub1()` the two failures come from respectively. (You could add an extra
+message to each assertion in `Sub1()` to indicate the value of `n`, but that's
+tedious.)
+
+Some tips on using `SCOPED_TRACE`:
+
+1.  With a suitable message, it's often enough to use `SCOPED_TRACE` at the
+    beginning of a sub-routine, instead of at each call site.
+2.  When calling sub-routines inside a loop, make the loop iterator part of the
+    message in `SCOPED_TRACE` such that you can know which iteration the failure
+    is from.
+3.  Sometimes the line number of the trace point is enough for identifying the
+    particular invocation of a sub-routine. In this case, you don't have to
+    choose a unique message for `SCOPED_TRACE`. You can simply use `""`.
+4.  You can use `SCOPED_TRACE` in an inner scope when there is one in the outer
+    scope. In this case, all active trace points will be included in the failure
+    messages, in reverse order they are encountered.
+5.  The trace dump is clickable in Emacs - hit `return` on a line number and
+    you'll be taken to that line in the source file!
+
+### Propagating Fatal Failures
+
+A common pitfall when using `ASSERT_*` and `FAIL*` is not understanding that
+when they fail they only abort the _current function_, not the entire test. For
+example, the following test will segfault:
+
+```c++
+void Subroutine() {
+  // Generates a fatal failure and aborts the current function.
+  ASSERT_EQ(1, 2);
+
+  // The following won't be executed.
+  ...
+}
+
+TEST(FooTest, Bar) {
+  Subroutine();  // The intended behavior is for the fatal failure
+                 // in Subroutine() to abort the entire test.
+
+  // The actual behavior: the function goes on after Subroutine() returns.
+  int* p = nullptr;
+  *p = 3;  // Segfault!
+}
+```
+
+To alleviate this, GoogleTest provides three different solutions. You could use
+either exceptions, the `(ASSERT|EXPECT)_NO_FATAL_FAILURE` assertions or the
+`HasFatalFailure()` function. They are described in the following two
+subsections.
+
+#### Asserting on Subroutines with an exception
+
+The following code can turn ASSERT-failure into an exception:
+
+```c++
+class ThrowListener : public testing::EmptyTestEventListener {
+  void OnTestPartResult(const testing::TestPartResult& result) override {
+    if (result.type() == testing::TestPartResult::kFatalFailure) {
+      throw testing::AssertionException(result);
+    }
+  }
+};
+int main(int argc, char** argv) {
+  ...
+  testing::UnitTest::GetInstance()->listeners().Append(new ThrowListener);
+  return RUN_ALL_TESTS();
+}
+```
+
+This listener should be added after other listeners if you have any, otherwise
+they won't see failed `OnTestPartResult`.
+
+#### Asserting on Subroutines
+
+As shown above, if your test calls a subroutine that has an `ASSERT_*` failure
+in it, the test will continue after the subroutine returns. This may not be what
+you want.
+
+Often people want fatal failures to propagate like exceptions. For that
+GoogleTest offers the following macros:
+
+Fatal assertion                       | Nonfatal assertion                    | Verifies
+------------------------------------- | ------------------------------------- | --------
+`ASSERT_NO_FATAL_FAILURE(statement);` | `EXPECT_NO_FATAL_FAILURE(statement);` | `statement` doesn't generate any new fatal failures in the current thread.
+
+Only failures in the thread that executes the assertion are checked to determine
+the result of this type of assertions. If `statement` creates new threads,
+failures in these threads are ignored.
+
+Examples:
+
+```c++
+ASSERT_NO_FATAL_FAILURE(Foo());
+
+int i;
+EXPECT_NO_FATAL_FAILURE({
+  i = Bar();
+});
+```
+
+Assertions from multiple threads are currently not supported on Windows.
+
+#### Checking for Failures in the Current Test
+
+`HasFatalFailure()` in the `::testing::Test` class returns `true` if an
+assertion in the current test has suffered a fatal failure. This allows
+functions to catch fatal failures in a sub-routine and return early.
+
+```c++
+class Test {
+ public:
+  ...
+  static bool HasFatalFailure();
+};
+```
+
+The typical usage, which basically simulates the behavior of a thrown exception,
+is:
+
+```c++
+TEST(FooTest, Bar) {
+  Subroutine();
+  // Aborts if Subroutine() had a fatal failure.
+  if (HasFatalFailure()) return;
+
+  // The following won't be executed.
+  ...
+}
+```
+
+If `HasFatalFailure()` is used outside of `TEST()` , `TEST_F()` , or a test
+fixture, you must add the `::testing::Test::` prefix, as in:
+
+```c++
+if (testing::Test::HasFatalFailure()) return;
+```
+
+Similarly, `HasNonfatalFailure()` returns `true` if the current test has at
+least one non-fatal failure, and `HasFailure()` returns `true` if the current
+test has at least one failure of either kind.
+
+## Logging Additional Information
+
+In your test code, you can call `RecordProperty("key", value)` to log additional
+information, where `value` can be either a string or an `int`. The *last* value
+recorded for a key will be emitted to the
+[XML output](#generating-an-xml-report) if you specify one. For example, the
+test
+
+```c++
+TEST_F(WidgetUsageTest, MinAndMaxWidgets) {
+  RecordProperty("MaximumWidgets", ComputeMaxUsage());
+  RecordProperty("MinimumWidgets", ComputeMinUsage());
+}
+```
+
+will output XML like this:
+
+```xml
+  ...
+    <testcase name="MinAndMaxWidgets" file="test.cpp" line="1" status="run" time="0.006" classname="WidgetUsageTest" MaximumWidgets="12" MinimumWidgets="9" />
+  ...
+```
+
+{: .callout .note}
+> NOTE:
+>
+> *   `RecordProperty()` is a static member of the `Test` class. Therefore it
+>     needs to be prefixed with `::testing::Test::` if used outside of the
+>     `TEST` body and the test fixture class.
+> *   *`key`* must be a valid XML attribute name, and cannot conflict with the
+>     ones already used by GoogleTest (`name`, `status`, `time`, `classname`,
+>     `type_param`, and `value_param`).
+> *   Calling `RecordProperty()` outside of the lifespan of a test is allowed.
+>     If it's called outside of a test but between a test suite's
+>     `SetUpTestSuite()` and `TearDownTestSuite()` methods, it will be
+>     attributed to the XML element for the test suite. If it's called outside
+>     of all test suites (e.g. in a test environment), it will be attributed to
+>     the top-level XML element.
+
+## Sharing Resources Between Tests in the Same Test Suite
+
+GoogleTest creates a new test fixture object for each test in order to make
+tests independent and easier to debug. However, sometimes tests use resources
+that are expensive to set up, making the one-copy-per-test model prohibitively
+expensive.
+
+If the tests don't change the resource, there's no harm in their sharing a
+single resource copy. So, in addition to per-test set-up/tear-down, GoogleTest
+also supports per-test-suite set-up/tear-down. To use it:
+
+1.  In your test fixture class (say `FooTest` ), declare as `static` some member
+    variables to hold the shared resources.
+2.  Outside your test fixture class (typically just below it), define those
+    member variables, optionally giving them initial values.
+3.  In the same test fixture class, define a `static void SetUpTestSuite()`
+    function (remember not to spell it as **`SetupTestSuite`** with a small
+    `u`!) to set up the shared resources and a `static void TearDownTestSuite()`
+    function to tear them down.
+
+That's it! GoogleTest automatically calls `SetUpTestSuite()` before running the
+*first test* in the `FooTest` test suite (i.e. before creating the first
+`FooTest` object), and calls `TearDownTestSuite()` after running the *last test*
+in it (i.e. after deleting the last `FooTest` object). In between, the tests can
+use the shared resources.
+
+Remember that the test order is undefined, so your code can't depend on a test
+preceding or following another. Also, the tests must either not modify the state
+of any shared resource, or, if they do modify the state, they must restore the
+state to its original value before passing control to the next test.
+
+Note that `SetUpTestSuite()` may be called multiple times for a test fixture
+class that has derived classes, so you should not expect code in the function
+body to be run only once. Also, derived classes still have access to shared
+resources defined as static members, so careful consideration is needed when
+managing shared resources to avoid memory leaks if shared resources are not
+properly cleaned up in `TearDownTestSuite()`.
+
+Here's an example of per-test-suite set-up and tear-down:
+
+```c++
+class FooTest : public testing::Test {
+ protected:
+  // Per-test-suite set-up.
+  // Called before the first test in this test suite.
+  // Can be omitted if not needed.
+  static void SetUpTestSuite() {
+    shared_resource_ = new ...;
+
+    // If `shared_resource_` is **not deleted** in `TearDownTestSuite()`,
+    // reallocation should be prevented because `SetUpTestSuite()` may be called
+    // in subclasses of FooTest and lead to memory leak.
+    //
+    // if (shared_resource_ == nullptr) {
+    //   shared_resource_ = new ...;
+    // }
+  }
+
+  // Per-test-suite tear-down.
+  // Called after the last test in this test suite.
+  // Can be omitted if not needed.
+  static void TearDownTestSuite() {
+    delete shared_resource_;
+    shared_resource_ = nullptr;
+  }
+
+  // You can define per-test set-up logic as usual.
+  void SetUp() override { ... }
+
+  // You can define per-test tear-down logic as usual.
+  void TearDown() override { ... }
+
+  // Some expensive resource shared by all tests.
+  static T* shared_resource_;
+};
+
+T* FooTest::shared_resource_ = nullptr;
+
+TEST_F(FooTest, Test1) {
+  ... you can refer to shared_resource_ here ...
+}
+
+TEST_F(FooTest, Test2) {
+  ... you can refer to shared_resource_ here ...
+}
+```
+
+{: .callout .note}
+NOTE: Though the above code declares `SetUpTestSuite()` protected, it may
+sometimes be necessary to declare it public, such as when using it with
+`TEST_P`.
+
+## Global Set-Up and Tear-Down
+
+Just as you can do set-up and tear-down at the test level and the test suite
+level, you can also do it at the test program level. Here's how.
+
+First, you subclass the `::testing::Environment` class to define a test
+environment, which knows how to set-up and tear-down:
+
+```c++
+class Environment : public ::testing::Environment {
+ public:
+  ~Environment() override {}
+
+  // Override this to define how to set up the environment.
+  void SetUp() override {}
+
+  // Override this to define how to tear down the environment.
+  void TearDown() override {}
+};
+```
+
+Then, you register an instance of your environment class with GoogleTest by
+calling the `::testing::AddGlobalTestEnvironment()` function:
+
+```c++
+Environment* AddGlobalTestEnvironment(Environment* env);
+```
+
+Now, when `RUN_ALL_TESTS()` is called, it first calls the `SetUp()` method of
+each environment object, then runs the tests if none of the environments
+reported fatal failures and `GTEST_SKIP()` was not called. `RUN_ALL_TESTS()`
+always calls `TearDown()` with each environment object, regardless of whether or
+not the tests were run.
+
+It's OK to register multiple environment objects. In this suite, their `SetUp()`
+will be called in the order they are registered, and their `TearDown()` will be
+called in the reverse order.
+
+Note that GoogleTest takes ownership of the registered environment objects.
+Therefore **do not delete them** by yourself.
+
+You should call `AddGlobalTestEnvironment()` before `RUN_ALL_TESTS()` is called,
+probably in `main()`. If you use `gtest_main`, you need to call this before
+`main()` starts for it to take effect. One way to do this is to define a global
+variable like this:
+
+```c++
+testing::Environment* const foo_env =
+    testing::AddGlobalTestEnvironment(new FooEnvironment);
+```
+
+However, we strongly recommend you to write your own `main()` and call
+`AddGlobalTestEnvironment()` there, as relying on initialization of global
+variables makes the code harder to read and may cause problems when you register
+multiple environments from different translation units and the environments have
+dependencies among them (remember that the compiler doesn't guarantee the order
+in which global variables from different translation units are initialized).
+
+## Value-Parameterized Tests
+
+*Value-parameterized tests* allow you to test your code with different
+parameters without writing multiple copies of the same test. This is useful in a
+number of situations, for example:
+
+*   You have a piece of code whose behavior is affected by one or more
+    command-line flags. You want to make sure your code performs correctly for
+    various values of those flags.
+*   You want to test different implementations of an OO interface.
+*   You want to test your code over various inputs (a.k.a. data-driven testing).
+    This feature is easy to abuse, so please exercise your good sense when doing
+    it!
+
+### How to Write Value-Parameterized Tests
+
+To write value-parameterized tests, first you should define a fixture class. It
+must be derived from both `testing::Test` and `testing::WithParamInterface<T>`
+(the latter is a pure interface), where `T` is the type of your parameter
+values. For convenience, you can just derive the fixture class from
+`testing::TestWithParam<T>`, which itself is derived from both `testing::Test`
+and `testing::WithParamInterface<T>`. `T` can be any copyable type. If it's a
+raw pointer, you are responsible for managing the lifespan of the pointed
+values.
+
+{: .callout .note}
+NOTE: If your test fixture defines `SetUpTestSuite()` or `TearDownTestSuite()`
+they must be declared **public** rather than **protected** in order to use
+`TEST_P`.
+
+```c++
+class FooTest :
+    public testing::TestWithParam<absl::string_view> {
+  // You can implement all the usual fixture class members here.
+  // To access the test parameter, call GetParam() from class
+  // TestWithParam<T>.
+};
+
+// Or, when you want to add parameters to a pre-existing fixture class:
+class BaseTest : public testing::Test {
+  ...
+};
+class BarTest : public BaseTest,
+                public testing::WithParamInterface<absl::string_view> {
+  ...
+};
+```
+
+Then, use the `TEST_P` macro to define as many test patterns using this fixture
+as you want. The `_P` suffix is for "parameterized" or "pattern", whichever you
+prefer to think.
+
+```c++
+TEST_P(FooTest, DoesBlah) {
+  // Inside a test, access the test parameter with the GetParam() method
+  // of the TestWithParam<T> class:
+  EXPECT_TRUE(foo.Blah(GetParam()));
+  ...
+}
+
+TEST_P(FooTest, HasBlahBlah) {
+  ...
+}
+```
+
+Finally, you can use the `INSTANTIATE_TEST_SUITE_P` macro to instantiate the
+test suite with any set of parameters you want. GoogleTest defines a number of
+functions for generating test parameters—see details at
+[`INSTANTIATE_TEST_SUITE_P`](reference/testing.md#INSTANTIATE_TEST_SUITE_P) in
+the Testing Reference.
+
+For example, the following statement will instantiate tests from the `FooTest`
+test suite each with parameter values `"meeny"`, `"miny"`, and `"moe"` using the
+[`Values`](reference/testing.md#param-generators) parameter generator:
+
+```c++
+INSTANTIATE_TEST_SUITE_P(MeenyMinyMoe,
+                         FooTest,
+                         testing::Values("meeny", "miny", "moe"));
+```
+
+{: .callout .note}
+NOTE: The code above must be placed at global or namespace scope, not at
+function scope.
+
+The first argument to `INSTANTIATE_TEST_SUITE_P` is a unique name for the
+instantiation of the test suite. The next argument is the name of the test
+pattern, and the last is the
+[parameter generator](reference/testing.md#param-generators).
+
+The parameter generator expression is not evaluated until GoogleTest is
+initialized (via `InitGoogleTest()`). Any prior initialization done in the
+`main` function will be accessible from the parameter generator, for example,
+the results of flag parsing.
+
+You can instantiate a test pattern more than once, so to distinguish different
+instances of the pattern, the instantiation name is added as a prefix to the
+actual test suite name. Remember to pick unique prefixes for different
+instantiations. The tests from the instantiation above will have these names:
+
+*   `MeenyMinyMoe/FooTest.DoesBlah/0` for `"meeny"`
+*   `MeenyMinyMoe/FooTest.DoesBlah/1` for `"miny"`
+*   `MeenyMinyMoe/FooTest.DoesBlah/2` for `"moe"`
+*   `MeenyMinyMoe/FooTest.HasBlahBlah/0` for `"meeny"`
+*   `MeenyMinyMoe/FooTest.HasBlahBlah/1` for `"miny"`
+*   `MeenyMinyMoe/FooTest.HasBlahBlah/2` for `"moe"`
+
+You can use these names in [`--gtest_filter`](#running-a-subset-of-the-tests).
+
+The following statement will instantiate all tests from `FooTest` again, each
+with parameter values `"cat"` and `"dog"` using the
+[`ValuesIn`](reference/testing.md#param-generators) parameter generator:
+
+```c++
+constexpr absl::string_view kPets[] = {"cat", "dog"};
+INSTANTIATE_TEST_SUITE_P(Pets, FooTest, testing::ValuesIn(kPets));
+```
+
+The tests from the instantiation above will have these names:
+
+*   `Pets/FooTest.DoesBlah/0` for `"cat"`
+*   `Pets/FooTest.DoesBlah/1` for `"dog"`
+*   `Pets/FooTest.HasBlahBlah/0` for `"cat"`
+*   `Pets/FooTest.HasBlahBlah/1` for `"dog"`
+
+Please note that `INSTANTIATE_TEST_SUITE_P` will instantiate *all* tests in the
+given test suite, whether their definitions come before or *after* the
+`INSTANTIATE_TEST_SUITE_P` statement.
+
+Additionally, by default, every `TEST_P` without a corresponding
+`INSTANTIATE_TEST_SUITE_P` causes a failing test in test suite
+`GoogleTestVerification`. If you have a test suite where that omission is not an
+error, for example it is in a library that may be linked in for other reasons or
+where the list of test cases is dynamic and may be empty, then this check can be
+suppressed by tagging the test suite:
+
+```c++
+GTEST_ALLOW_UNINSTANTIATED_PARAMETERIZED_TEST(FooTest);
+```
+
+You can see [sample7_unittest.cc] and [sample8_unittest.cc] for more examples.
+
+[sample7_unittest.cc]: https://github.com/google/googletest/blob/main/googletest/samples/sample7_unittest.cc "Parameterized Test example"
+[sample8_unittest.cc]: https://github.com/google/googletest/blob/main/googletest/samples/sample8_unittest.cc "Parameterized Test example with multiple parameters"
+
+### Creating Value-Parameterized Abstract Tests
+
+In the above, we define and instantiate `FooTest` in the *same* source file.
+Sometimes you may want to define value-parameterized tests in a library and let
+other people instantiate them later. This pattern is known as *abstract tests*.
+As an example of its application, when you are designing an interface you can
+write a standard suite of abstract tests (perhaps using a factory function as
+the test parameter) that all implementations of the interface are expected to
+pass. When someone implements the interface, they can instantiate your suite to
+get all the interface-conformance tests for free.
+
+To define abstract tests, you should organize your code like this:
+
+1.  Put the definition of the parameterized test fixture class (e.g. `FooTest`)
+    in a header file, say `foo_param_test.h`. Think of this as *declaring* your
+    abstract tests.
+2.  Put the `TEST_P` definitions in `foo_param_test.cc`, which includes
+    `foo_param_test.h`. Think of this as *implementing* your abstract tests.
+
+Once they are defined, you can instantiate them by including `foo_param_test.h`,
+invoking `INSTANTIATE_TEST_SUITE_P()`, and depending on the library target that
+contains `foo_param_test.cc`. You can instantiate the same abstract test suite
+multiple times, possibly in different source files.
+
+### Specifying Names for Value-Parameterized Test Parameters
+
+The optional last argument to `INSTANTIATE_TEST_SUITE_P()` allows the user to
+specify a function or functor that generates custom test name suffixes based on
+the test parameters. The function should accept one argument of type
+`testing::TestParamInfo<class ParamType>`, and return `std::string`.
+
+`testing::PrintToStringParamName` is a builtin test suffix generator that
+returns the value of `testing::PrintToString(GetParam())`. It does not work for
+`std::string` or C strings.
+
+{: .callout .note}
+NOTE: test names must be non-empty, unique, and may only contain ASCII
+alphanumeric characters. In particular, they
+[should not contain underscores](faq.md#why-should-test-suite-names-and-test-names-not-contain-underscore)
+
+```c++
+class MyTestSuite : public testing::TestWithParam<int> {};
+
+TEST_P(MyTestSuite, MyTest)
+{
+  std::cout << "Example Test Param: " << GetParam() << std::endl;
+}
+
+INSTANTIATE_TEST_SUITE_P(MyGroup, MyTestSuite, testing::Range(0, 10),
+                         testing::PrintToStringParamName());
+```
+
+Providing a custom functor allows for more control over test parameter name
+generation, especially for types where the automatic conversion does not
+generate helpful parameter names (e.g. strings as demonstrated above). The
+following example illustrates this for multiple parameters, an enumeration type
+and a string, and also demonstrates how to combine generators. It uses a lambda
+for conciseness:
+
+```c++
+enum class MyType { MY_FOO = 0, MY_BAR = 1 };
+
+class MyTestSuite : public testing::TestWithParam<std::tuple<MyType, std::string>> {
+};
+
+INSTANTIATE_TEST_SUITE_P(
+    MyGroup, MyTestSuite,
+    testing::Combine(
+        testing::Values(MyType::MY_FOO, MyType::MY_BAR),
+        testing::Values("A", "B")),
+    [](const testing::TestParamInfo<MyTestSuite::ParamType>& info) {
+      std::string name = absl::StrCat(
+          std::get<0>(info.param) == MyType::MY_FOO ? "Foo" : "Bar",
+          std::get<1>(info.param));
+      absl::c_replace_if(name, [](char c) { return !std::isalnum(c); }, '_');
+      return name;
+    });
+```
+
+## Typed Tests
+
+Suppose you have multiple implementations of the same interface and want to make
+sure that all of them satisfy some common requirements. Or, you may have defined
+several types that are supposed to conform to the same "concept" and you want to
+verify it. In both cases, you want the same test logic repeated for different
+types.
+
+While you can write one `TEST` or `TEST_F` for each type you want to test (and
+you may even factor the test logic into a function template that you invoke from
+the `TEST`), it's tedious and doesn't scale: if you want `m` tests over `n`
+types, you'll end up writing `m*n` `TEST`s.
+
+*Typed tests* allow you to repeat the same test logic over a list of types. You
+only need to write the test logic once, although you must know the type list
+when writing typed tests. Here's how you do it:
+
+First, define a fixture class template. It should be parameterized by a type.
+Remember to derive it from `::testing::Test`:
+
+```c++
+template <typename T>
+class FooTest : public testing::Test {
+ public:
+  ...
+  using List = std::list<T>;
+  static T shared_;
+  T value_;
+};
+```
+
+Next, associate a list of types with the test suite, which will be repeated for
+each type in the list:
+
+```c++
+using MyTypes = ::testing::Types<char, int, unsigned int>;
+TYPED_TEST_SUITE(FooTest, MyTypes);
+```
+
+The type alias (`using` or `typedef`) is necessary for the `TYPED_TEST_SUITE`
+macro to parse correctly. Otherwise the compiler will think that each comma in
+the type list introduces a new macro argument.
+
+Then, use `TYPED_TEST()` instead of `TEST_F()` to define a typed test for this
+test suite. You can repeat this as many times as you want:
+
+```c++
+TYPED_TEST(FooTest, DoesBlah) {
+  // Inside a test, refer to the special name TypeParam to get the type
+  // parameter.  Since we are inside a derived class template, C++ requires
+  // us to visit the members of FooTest via 'this'.
+  TypeParam n = this->value_;
+
+  // To visit static members of the fixture, add the 'TestFixture::'
+  // prefix.
+  n += TestFixture::shared_;
+
+  // To refer to typedefs in the fixture, add the 'typename TestFixture::'
+  // prefix.  The 'typename' is required to satisfy the compiler.
+  typename TestFixture::List values;
+
+  values.push_back(n);
+  ...
+}
+
+TYPED_TEST(FooTest, HasPropertyA) { ... }
+```
+
+You can see [sample6_unittest.cc] for a complete example.
+
+[sample6_unittest.cc]: https://github.com/google/googletest/blob/main/googletest/samples/sample6_unittest.cc "Typed Test example"
+
+## Type-Parameterized Tests
+
+*Type-parameterized tests* are like typed tests, except that they don't require
+you to know the list of types ahead of time. Instead, you can define the test
+logic first and instantiate it with different type lists later. You can even
+instantiate it more than once in the same program.
+
+If you are designing an interface or concept, you can define a suite of
+type-parameterized tests to verify properties that any valid implementation of
+the interface/concept should have. Then, the author of each implementation can
+just instantiate the test suite with their type to verify that it conforms to
+the requirements, without having to write similar tests repeatedly. Here's an
+example:
+
+First, define a fixture class template, as we did with typed tests:
+
+```c++
+template <typename T>
+class FooTest : public testing::Test {
+  void DoSomethingInteresting();
+  ...
+};
+```
+
+Next, declare that you will define a type-parameterized test suite:
+
+```c++
+TYPED_TEST_SUITE_P(FooTest);
+```
+
+Then, use `TYPED_TEST_P()` to define a type-parameterized test. You can repeat
+this as many times as you want:
+
+```c++
+TYPED_TEST_P(FooTest, DoesBlah) {
+  // Inside a test, refer to TypeParam to get the type parameter.
+  TypeParam n = 0;
+
+  // You will need to use `this` explicitly to refer to fixture members.
+  this->DoSomethingInteresting()
+  ...
+}
+
+TYPED_TEST_P(FooTest, HasPropertyA) { ... }
+```
+
+Now the tricky part: you need to register all test patterns using the
+`REGISTER_TYPED_TEST_SUITE_P` macro before you can instantiate them. The first
+argument of the macro is the test suite name; the rest are the names of the
+tests in this test suite:
+
+```c++
+REGISTER_TYPED_TEST_SUITE_P(FooTest,
+                            DoesBlah, HasPropertyA);
+```
+
+Finally, you are free to instantiate the pattern with the types you want. If you
+put the above code in a header file, you can `#include` it in multiple C++
+source files and instantiate it multiple times.
+
+```c++
+using MyTypes = ::testing::Types<char, int, unsigned int>;
+INSTANTIATE_TYPED_TEST_SUITE_P(My, FooTest, MyTypes);
+```
+
+To distinguish different instances of the pattern, the first argument to the
+`INSTANTIATE_TYPED_TEST_SUITE_P` macro is a prefix that will be added to the
+actual test suite name. Remember to pick unique prefixes for different
+instances.
+
+In the special case where the type list contains only one type, you can write
+that type directly without `::testing::Types<...>`, like this:
+
+```c++
+INSTANTIATE_TYPED_TEST_SUITE_P(My, FooTest, int);
+```
+
+You can see [sample6_unittest.cc] for a complete example.
+
+## Testing Private Code
+
+If you change your software's internal implementation, your tests should not
+break as long as the change is not observable by users. Therefore, **per the
+black-box testing principle, most of the time you should test your code through
+its public interfaces.**
+
+**If you still find yourself needing to test internal implementation code,
+consider if there's a better design.** The desire to test internal
+implementation is often a sign that the class is doing too much. Consider
+extracting an implementation class, and testing it. Then use that implementation
+class in the original class.
+
+If you absolutely have to test non-public interface code though, you can. There
+are two cases to consider:
+
+*   Static functions ( *not* the same as static member functions!) or unnamed
+    namespaces, and
+*   Private or protected class members
+
+To test them, we use the following special techniques:
+
+*   Both static functions and definitions/declarations in an unnamed namespace
+    are only visible within the same translation unit. To test them, you can
+    `#include` the entire `.cc` file being tested in your `*_test.cc` file.
+    (#including `.cc` files is not a good way to reuse code - you should not do
+    this in production code!)
+
+    However, a better approach is to move the private code into the
+    `foo::internal` namespace, where `foo` is the namespace your project
+    normally uses, and put the private declarations in a `*-internal.h` file.
+    Your production `.cc` files and your tests are allowed to include this
+    internal header, but your clients are not. This way, you can fully test your
+    internal implementation without leaking it to your clients.
+
+*   Private class members are only accessible from within the class or by
+    friends. To access a class' private members, you can declare your test
+    fixture as a friend to the class and define accessors in your fixture. Tests
+    using the fixture can then access the private members of your production
+    class via the accessors in the fixture. Note that even though your fixture
+    is a friend to your production class, your tests are not automatically
+    friends to it, as they are technically defined in sub-classes of the
+    fixture.
+
+    Another way to test private members is to refactor them into an
+    implementation class, which is then declared in a `*-internal.h` file. Your
+    clients aren't allowed to include this header but your tests can. Such is
+    called the
+    [Pimpl](https://www.gamedev.net/articles/programming/general-and-gameplay-programming/the-c-pimpl-r1794/)
+    (Private Implementation) idiom.
+
+    Or, you can declare an individual test as a friend of your class by adding
+    this line in the class body:
+
+    ```c++
+        FRIEND_TEST(TestSuiteName, TestName);
+    ```
+
+    For example,
+
+    ```c++
+    // foo.h
+    class Foo {
+      ...
+     private:
+      FRIEND_TEST(FooTest, BarReturnsZeroOnNull);
+
+      int Bar(void* x);
+    };
+
+    // foo_test.cc
+    ...
+    TEST(FooTest, BarReturnsZeroOnNull) {
+      Foo foo;
+      EXPECT_EQ(foo.Bar(NULL), 0);  // Uses Foo's private member Bar().
+    }
+    ```
+
+    Pay special attention when your class is defined in a namespace. If you want
+    your test fixtures and tests to be friends of your class, then they must be
+    defined in the exact same namespace (no anonymous or inline namespaces).
+
+    For example, if the code to be tested looks like:
+
+    ```c++
+    namespace my_namespace {
+
+    class Foo {
+      friend class FooTest;
+      FRIEND_TEST(FooTest, Bar);
+      FRIEND_TEST(FooTest, Baz);
+      ... definition of the class Foo ...
+    };
+
+    }  // namespace my_namespace
+    ```
+
+    Your test code should be something like:
+
+    ```c++
+    namespace my_namespace {
+
+    class FooTest : public testing::Test {
+     protected:
+      ...
+    };
+
+    TEST_F(FooTest, Bar) { ... }
+    TEST_F(FooTest, Baz) { ... }
+
+    }  // namespace my_namespace
+    ```
+
+## "Catching" Failures
+
+If you are building a testing utility on top of GoogleTest, you'll want to test
+your utility. What framework would you use to test it? GoogleTest, of course.
+
+The challenge is to verify that your testing utility reports failures correctly.
+In frameworks that report a failure by throwing an exception, you could catch
+the exception and assert on it. But GoogleTest doesn't use exceptions, so how do
+we test that a piece of code generates an expected failure?
+
+`"gtest/gtest-spi.h"` contains some constructs to do this.
+After #including this header, you can use
+
+```c++
+  EXPECT_FATAL_FAILURE(statement, substring);
+```
+
+to assert that `statement` generates a fatal (e.g. `ASSERT_*`) failure in the
+current thread whose message contains the given `substring`, or use
+
+```c++
+  EXPECT_NONFATAL_FAILURE(statement, substring);
+```
+
+if you are expecting a non-fatal (e.g. `EXPECT_*`) failure.
+
+Only failures in the current thread are checked to determine the result of this
+type of expectations. If `statement` creates new threads, failures in these
+threads are also ignored. If you want to catch failures in other threads as
+well, use one of the following macros instead:
+
+```c++
+  EXPECT_FATAL_FAILURE_ON_ALL_THREADS(statement, substring);
+  EXPECT_NONFATAL_FAILURE_ON_ALL_THREADS(statement, substring);
+```
+
+{: .callout .note}
+NOTE: Assertions from multiple threads are currently not supported on Windows.
+
+For technical reasons, there are some caveats:
+
+1.  You cannot stream a failure message to either macro.
+
+2.  `statement` in `EXPECT_FATAL_FAILURE{_ON_ALL_THREADS}()` cannot reference
+    local non-static variables or non-static members of `this` object.
+
+3.  `statement` in `EXPECT_FATAL_FAILURE{_ON_ALL_THREADS}()` cannot return a
+    value.
+
+## Registering tests programmatically
+
+The `TEST` macros handle the vast majority of all use cases, but there are few
+where runtime registration logic is required. For those cases, the framework
+provides the `::testing::RegisterTest` that allows callers to register arbitrary
+tests dynamically.
+
+This is an advanced API only to be used when the `TEST` macros are insufficient.
+The macros should be preferred when possible, as they avoid most of the
+complexity of calling this function.
+
+It provides the following signature:
+
+```c++
+template <typename Factory>
+TestInfo* RegisterTest(const char* test_suite_name, const char* test_name,
+                       const char* type_param, const char* value_param,
+                       const char* file, int line, Factory factory);
+```
+
+The `factory` argument is a factory callable (move-constructible) object or
+function pointer that creates a new instance of the Test object. It handles
+ownership to the caller. The signature of the callable is `Fixture*()`, where
+`Fixture` is the test fixture class for the test. All tests registered with the
+same `test_suite_name` must return the same fixture type. This is checked at
+runtime.
+
+The framework will infer the fixture class from the factory and will call the
+`SetUpTestSuite` and `TearDownTestSuite` for it.
+
+Must be called before `RUN_ALL_TESTS()` is invoked, otherwise behavior is
+undefined.
+
+Use case example:
+
+```c++
+class MyFixture : public testing::Test {
+ public:
+  // All of these optional, just like in regular macro usage.
+  static void SetUpTestSuite() { ... }
+  static void TearDownTestSuite() { ... }
+  void SetUp() override { ... }
+  void TearDown() override { ... }
+};
+
+class MyTest : public MyFixture {
+ public:
+  explicit MyTest(int data) : data_(data) {}
+  void TestBody() override { ... }
+
+ private:
+  int data_;
+};
+
+void RegisterMyTests(const std::vector<int>& values) {
+  for (int v : values) {
+    testing::RegisterTest(
+        "MyFixture", ("Test" + std::to_string(v)).c_str(), nullptr,
+        std::to_string(v).c_str(),
+        __FILE__, __LINE__,
+        // Important to use the fixture type as the return type here.
+        [=]() -> MyFixture* { return new MyTest(v); });
+  }
+}
+...
+int main(int argc, char** argv) {
+  testing::InitGoogleTest(&argc, argv);
+  std::vector<int> values_to_test = LoadValuesFromConfig();
+  RegisterMyTests(values_to_test);
+  ...
+  return RUN_ALL_TESTS();
+}
+```
+
+## Getting the Current Test's Name
+
+Sometimes a function may need to know the name of the currently running test.
+For example, you may be using the `SetUp()` method of your test fixture to set
+the golden file name based on which test is running. The
+[`TestInfo`](reference/testing.md#TestInfo) class has this information.
+
+To obtain a `TestInfo` object for the currently running test, call
+`current_test_info()` on the [`UnitTest`](reference/testing.md#UnitTest)
+singleton object:
+
+```c++
+  // Gets information about the currently running test.
+  // Do NOT delete the returned object - it's managed by the UnitTest class.
+  const testing::TestInfo* const test_info =
+      testing::UnitTest::GetInstance()->current_test_info();
+
+  printf("We are in test %s of test suite %s.\n",
+         test_info->name(),
+         test_info->test_suite_name());
+```
+
+`current_test_info()` returns a null pointer if no test is running. In
+particular, you cannot find the test suite name in `SetUpTestSuite()`,
+`TearDownTestSuite()` (where you know the test suite name implicitly), or
+functions called from them.
+
+## Extending GoogleTest by Handling Test Events
+
+GoogleTest provides an **event listener API** to let you receive notifications
+about the progress of a test program and test failures. The events you can
+listen to include the start and end of the test program, a test suite, or a test
+method, among others. You may use this API to augment or replace the standard
+console output, replace the XML output, or provide a completely different form
+of output, such as a GUI or a database. You can also use test events as
+checkpoints to implement a resource leak checker, for example.
+
+### Defining Event Listeners
+
+To define a event listener, you subclass either
+[`testing::TestEventListener`](reference/testing.md#TestEventListener) or
+[`testing::EmptyTestEventListener`](reference/testing.md#EmptyTestEventListener)
+The former is an (abstract) interface, where *each pure virtual method can be
+overridden to handle a test event* (For example, when a test starts, the
+`OnTestStart()` method will be called.). The latter provides an empty
+implementation of all methods in the interface, such that a subclass only needs
+to override the methods it cares about.
+
+When an event is fired, its context is passed to the handler function as an
+argument. The following argument types are used:
+
+*   UnitTest reflects the state of the entire test program,
+*   TestSuite has information about a test suite, which can contain one or more
+    tests,
+*   TestInfo contains the state of a test, and
+*   TestPartResult represents the result of a test assertion.
+
+An event handler function can examine the argument it receives to find out
+interesting information about the event and the test program's state.
+
+Here's an example:
+
+```c++
+  class MinimalistPrinter : public testing::EmptyTestEventListener {
+    // Called before a test starts.
+    void OnTestStart(const testing::TestInfo& test_info) override {
+      printf("*** Test %s.%s starting.\n",
+             test_info.test_suite_name(), test_info.name());
+    }
+
+    // Called after a failed assertion or a SUCCESS().
+    void OnTestPartResult(const testing::TestPartResult& test_part_result) override {
+      printf("%s in %s:%d\n%s\n",
+             test_part_result.failed() ? "*** Failure" : "Success",
+             test_part_result.file_name(),
+             test_part_result.line_number(),
+             test_part_result.summary());
+    }
+
+    // Called after a test ends.
+    void OnTestEnd(const testing::TestInfo& test_info) override {
+      printf("*** Test %s.%s ending.\n",
+             test_info.test_suite_name(), test_info.name());
+    }
+  };
+```
+
+### Using Event Listeners
+
+To use the event listener you have defined, add an instance of it to the
+GoogleTest event listener list (represented by class
+[`TestEventListeners`](reference/testing.md#TestEventListeners) - note the "s"
+at the end of the name) in your `main()` function, before calling
+`RUN_ALL_TESTS()`:
+
+```c++
+int main(int argc, char** argv) {
+  testing::InitGoogleTest(&argc, argv);
+  // Gets hold of the event listener list.
+  testing::TestEventListeners& listeners =
+      testing::UnitTest::GetInstance()->listeners();
+  // Adds a listener to the end.  GoogleTest takes the ownership.
+  listeners.Append(new MinimalistPrinter);
+  return RUN_ALL_TESTS();
+}
+```
+
+There's only one problem: the default test result printer is still in effect, so
+its output will mingle with the output from your minimalist printer. To suppress
+the default printer, just release it from the event listener list and delete it.
+You can do so by adding one line:
+
+```c++
+  ...
+  delete listeners.Release(listeners.default_result_printer());
+  listeners.Append(new MinimalistPrinter);
+  return RUN_ALL_TESTS();
+```
+
+Now, sit back and enjoy a completely different output from your tests. For more
+details, see [sample9_unittest.cc].
+
+[sample9_unittest.cc]: https://github.com/google/googletest/blob/main/googletest/samples/sample9_unittest.cc "Event listener example"
+
+You may append more than one listener to the list. When an `On*Start()` or
+`OnTestPartResult()` event is fired, the listeners will receive it in the order
+they appear in the list (since new listeners are added to the end of the list,
+the default text printer and the default XML generator will receive the event
+first). An `On*End()` event will be received by the listeners in the *reverse*
+order. This allows output by listeners added later to be framed by output from
+listeners added earlier.
+
+### Generating Failures in Listeners
+
+You may use failure-raising macros (`EXPECT_*()`, `ASSERT_*()`, `FAIL()`, etc)
+when processing an event. There are some restrictions:
+
+1.  You cannot generate any failure in `OnTestPartResult()` (otherwise it will
+    cause `OnTestPartResult()` to be called recursively).
+2.  A listener that handles `OnTestPartResult()` is not allowed to generate any
+    failure.
+
+When you add listeners to the listener list, you should put listeners that
+handle `OnTestPartResult()` *before* listeners that can generate failures. This
+ensures that failures generated by the latter are attributed to the right test
+by the former.
+
+See [sample10_unittest.cc] for an example of a failure-raising listener.
+
+[sample10_unittest.cc]: https://github.com/google/googletest/blob/main/googletest/samples/sample10_unittest.cc "Failure-raising listener example"
+
+## Running Test Programs: Advanced Options
+
+GoogleTest test programs are ordinary executables. Once built, you can run them
+directly and affect their behavior via the following environment variables
+and/or command line flags. For the flags to work, your programs must call
+`::testing::InitGoogleTest()` before calling `RUN_ALL_TESTS()`.
+
+To see a list of supported flags and their usage, please run your test program
+with the `--help` flag. You can also use `-h`, `-?`, or `/?` for short.
+
+If an option is specified both by an environment variable and by a flag, the
+latter takes precedence.
+
+### Selecting Tests
+
+#### Listing Test Names
+
+Sometimes it is necessary to list the available tests in a program before
+running them so that a filter may be applied if needed. Including the flag
+`--gtest_list_tests` overrides all other flags and lists tests in the following
+format:
+
+```none
+TestSuite1.
+  TestName1
+  TestName2
+TestSuite2.
+  TestName
+```
+
+None of the tests listed are actually run if the flag is provided. There is no
+corresponding environment variable for this flag.
+
+#### Running a Subset of the Tests
+
+By default, a GoogleTest program runs all tests the user has defined. Sometimes,
+you want to run only a subset of the tests (e.g. for debugging or quickly
+verifying a change). If you set the `GTEST_FILTER` environment variable or the
+`--gtest_filter` flag to a filter string, GoogleTest will only run the tests
+whose full names (in the form of `TestSuiteName.TestName`) match the filter.
+
+The format of a filter is a '`:`'-separated list of wildcard patterns (called
+the *positive patterns*) optionally followed by a '`-`' and another
+'`:`'-separated pattern list (called the *negative patterns*). A test matches
+the filter if and only if it matches any of the positive patterns but does not
+match any of the negative patterns.
+
+A pattern may contain `'*'` (matches any string) or `'?'` (matches any single
+character). For convenience, the filter `'*-NegativePatterns'` can be also
+written as `'-NegativePatterns'`.
+
+For example:
+
+*   `./foo_test` Has no flag, and thus runs all its tests.
+*   `./foo_test --gtest_filter=*` Also runs everything, due to the single
+    match-everything `*` value.
+*   `./foo_test --gtest_filter=FooTest.*` Runs everything in test suite
+    `FooTest` .
+*   `./foo_test --gtest_filter=*Null*:*Constructor*` Runs any test whose full
+    name contains either `"Null"` or `"Constructor"` .
+*   `./foo_test --gtest_filter=-*DeathTest.*` Runs all non-death tests.
+*   `./foo_test --gtest_filter=FooTest.*-FooTest.Bar` Runs everything in test
+    suite `FooTest` except `FooTest.Bar`.
+*   `./foo_test --gtest_filter=FooTest.*:BarTest.*-FooTest.Bar:BarTest.Foo` Runs
+    everything in test suite `FooTest` except `FooTest.Bar` and everything in
+    test suite `BarTest` except `BarTest.Foo`.
+
+#### Stop test execution upon first failure
+
+By default, a GoogleTest program runs all tests the user has defined. In some
+cases (e.g. iterative test development & execution) it may be desirable stop
+test execution upon first failure (trading improved latency for completeness).
+If `GTEST_FAIL_FAST` environment variable or `--gtest_fail_fast` flag is set,
+the test runner will stop execution as soon as the first test failure is found.
+
+#### Temporarily Disabling Tests
+
+If you have a broken test that you cannot fix right away, you can add the
+`DISABLED_` prefix to its name. This will exclude it from execution. This is
+better than commenting out the code or using `#if 0`, as disabled tests are
+still compiled (and thus won't rot).
+
+If you need to disable all tests in a test suite, you can either add `DISABLED_`
+to the front of the name of each test, or alternatively add it to the front of
+the test suite name.
+
+For example, the following tests won't be run by GoogleTest, even though they
+will still be compiled:
+
+```c++
+// Tests that Foo does Abc.
+TEST(FooTest, DISABLED_DoesAbc) { ... }
+
+class DISABLED_BarTest : public testing::Test { ... };
+
+// Tests that Bar does Xyz.
+TEST_F(DISABLED_BarTest, DoesXyz) { ... }
+```
+
+{: .callout .note}
+NOTE: This feature should only be used for temporary pain-relief. You still have
+to fix the disabled tests at a later date. As a reminder, GoogleTest will print
+a banner warning you if a test program contains any disabled tests.
+
+{: .callout .tip}
+TIP: You can easily count the number of disabled tests you have using
+`grep`. This number can be used as a metric for
+improving your test quality.
+
+#### Temporarily Enabling Disabled Tests
+
+To include disabled tests in test execution, just invoke the test program with
+the `--gtest_also_run_disabled_tests` flag or set the
+`GTEST_ALSO_RUN_DISABLED_TESTS` environment variable to a value other than `0`.
+You can combine this with the `--gtest_filter` flag to further select which
+disabled tests to run.
+
+### Repeating the Tests
+
+Once in a while you'll run into a test whose result is hit-or-miss. Perhaps it
+will fail only 1% of the time, making it rather hard to reproduce the bug under
+a debugger. This can be a major source of frustration.
+
+The `--gtest_repeat` flag allows you to repeat all (or selected) test methods in
+a program many times. Hopefully, a flaky test will eventually fail and give you
+a chance to debug. Here's how to use it:
+
+```none
+$ foo_test --gtest_repeat=1000
+Repeat foo_test 1000 times and don't stop at failures.
+
+$ foo_test --gtest_repeat=-1
+A negative count means repeating forever.
+
+$ foo_test --gtest_repeat=1000 --gtest_break_on_failure
+Repeat foo_test 1000 times, stopping at the first failure.  This
+is especially useful when running under a debugger: when the test
+fails, it will drop into the debugger and you can then inspect
+variables and stacks.
+
+$ foo_test --gtest_repeat=1000 --gtest_filter=FooBar.*
+Repeat the tests whose name matches the filter 1000 times.
+```
+
+If your test program contains
+[global set-up/tear-down](#global-set-up-and-tear-down) code, it will be
+repeated in each iteration as well, as the flakiness may be in it. To avoid
+repeating global set-up/tear-down, specify
+`--gtest_recreate_environments_when_repeating=false`{.nowrap}.
+
+You can also specify the repeat count by setting the `GTEST_REPEAT` environment
+variable.
+
+### Shuffling the Tests
+
+You can specify the `--gtest_shuffle` flag (or set the `GTEST_SHUFFLE`
+environment variable to `1`) to run the tests in a program in a random order.
+This helps to reveal bad dependencies between tests.
+
+By default, GoogleTest uses a random seed calculated from the current time.
+Therefore you'll get a different order every time. The console output includes
+the random seed value, such that you can reproduce an order-related test failure
+later. To specify the random seed explicitly, use the `--gtest_random_seed=SEED`
+flag (or set the `GTEST_RANDOM_SEED` environment variable), where `SEED` is an
+integer in the range [0, 99999]. The seed value 0 is special: it tells
+GoogleTest to do the default behavior of calculating the seed from the current
+time.
+
+If you combine this with `--gtest_repeat=N`, GoogleTest will pick a different
+random seed and re-shuffle the tests in each iteration.
+
+### Distributing Test Functions to Multiple Machines
+
+If you have more than one machine you can use to run a test program, you might
+want to run the test functions in parallel and get the result faster. We call
+this technique *sharding*, where each machine is called a *shard*.
+
+GoogleTest is compatible with test sharding. To take advantage of this feature,
+your test runner (not part of GoogleTest) needs to do the following:
+
+1.  Allocate a number of machines (shards) to run the tests.
+1.  On each shard, set the `GTEST_TOTAL_SHARDS` environment variable to the total
+    number of shards. It must be the same for all shards.
+1.  On each shard, set the `GTEST_SHARD_INDEX` environment variable to the index
+    of the shard. Different shards must be assigned different indices, which
+    must be in the range `[0, GTEST_TOTAL_SHARDS - 1]`.
+1.  Run the same test program on all shards. When GoogleTest sees the above two
+    environment variables, it will select a subset of the test functions to run.
+    Across all shards, each test function in the program will be run exactly
+    once.
+1.  Wait for all shards to finish, then collect and report the results.
+
+Your project may have tests that were written without GoogleTest and thus don't
+understand this protocol. In order for your test runner to figure out which test
+supports sharding, it can set the environment variable `GTEST_SHARD_STATUS_FILE`
+to a non-existent file path. If a test program supports sharding, it will create
+this file to acknowledge that fact; otherwise it will not create it. The actual
+contents of the file are not important at this time, although we may put some
+useful information in it in the future.
+
+Here's an example to make it clear. Suppose you have a test program `foo_test`
+that contains the following 5 test functions:
+
+```
+TEST(A, V)
+TEST(A, W)
+TEST(B, X)
+TEST(B, Y)
+TEST(B, Z)
+```
+
+Suppose you have 3 machines at your disposal. To run the test functions in
+parallel, you would set `GTEST_TOTAL_SHARDS` to 3 on all machines, and set
+`GTEST_SHARD_INDEX` to 0, 1, and 2 on the machines respectively. Then you would
+run the same `foo_test` on each machine.
+
+GoogleTest reserves the right to change how the work is distributed across the
+shards, but here's one possible scenario:
+
+*   Machine #0 runs `A.V` and `B.X`.
+*   Machine #1 runs `A.W` and `B.Y`.
+*   Machine #2 runs `B.Z`.
+
+### Controlling Test Output
+
+#### Colored Terminal Output
+
+GoogleTest can use colors in its terminal output to make it easier to spot the
+important information:
+
+<pre>...
+<font color="green">[----------]</font> 1 test from FooTest
+<font color="green">[ RUN      ]</font> FooTest.DoesAbc
+<font color="green">[       OK ]</font> FooTest.DoesAbc
+<font color="green">[----------]</font> 2 tests from BarTest
+<font color="green">[ RUN      ]</font> BarTest.HasXyzProperty
+<font color="green">[       OK ]</font> BarTest.HasXyzProperty
+<font color="green">[ RUN      ]</font> BarTest.ReturnsTrueOnSuccess
+... some error messages ...
+<font color="red">[   FAILED ]</font> BarTest.ReturnsTrueOnSuccess
+...
+<font color="green">[==========]</font> 30 tests from 14 test suites ran.
+<font color="green">[   PASSED ]</font> 28 tests.
+<font color="red">[   FAILED ]</font> 2 tests, listed below:
+<font color="red">[   FAILED ]</font> BarTest.ReturnsTrueOnSuccess
+<font color="red">[   FAILED ]</font> AnotherTest.DoesXyz
+
+ 2 FAILED TESTS
+</pre>
+
+You can set the `GTEST_COLOR` environment variable or the `--gtest_color`
+command line flag to `yes`, `no`, or `auto` (the default) to enable colors,
+disable colors, or let GoogleTest decide. When the value is `auto`, GoogleTest
+will use colors if and only if the output goes to a terminal and (on non-Windows
+platforms) the `TERM` environment variable is set to `xterm` or `xterm-color`.
+
+#### Suppressing test passes
+
+By default, GoogleTest prints 1 line of output for each test, indicating if it
+passed or failed. To show only test failures, run the test program with
+`--gtest_brief=1`, or set the GTEST_BRIEF environment variable to `1`.
+
+#### Suppressing the Elapsed Time
+
+By default, GoogleTest prints the time it takes to run each test. To disable
+that, run the test program with the `--gtest_print_time=0` command line flag, or
+set the GTEST_PRINT_TIME environment variable to `0`.
+
+#### Suppressing UTF-8 Text Output
+
+In case of assertion failures, GoogleTest prints expected and actual values of
+type `string` both as hex-encoded strings as well as in readable UTF-8 text if
+they contain valid non-ASCII UTF-8 characters. If you want to suppress the UTF-8
+text because, for example, you don't have an UTF-8 compatible output medium, run
+the test program with `--gtest_print_utf8=0` or set the `GTEST_PRINT_UTF8`
+environment variable to `0`.
+
+#### Generating an XML Report
+
+GoogleTest can emit a detailed XML report to a file in addition to its normal
+textual output. The report contains the duration of each test, and thus can help
+you identify slow tests.
+
+To generate the XML report, set the `GTEST_OUTPUT` environment variable or the
+`--gtest_output` flag to the string `"xml:path_to_output_file"`, which will
+create the file at the given location. You can also just use the string `"xml"`,
+in which case the output can be found in the `test_detail.xml` file in the
+current directory.
+
+If you specify a directory (for example, `"xml:output/directory/"` on Linux or
+`"xml:output\directory\"` on Windows), GoogleTest will create the XML file in
+that directory, named after the test executable (e.g. `foo_test.xml` for test
+program `foo_test` or `foo_test.exe`). If the file already exists (perhaps left
+over from a previous run), GoogleTest will pick a different name (e.g.
+`foo_test_1.xml`) to avoid overwriting it.
+
+The report is based on the `junitreport` Ant task. Since that format was
+originally intended for Java, a little interpretation is required to make it
+apply to GoogleTest tests, as shown here:
+
+```xml
+<testsuites name="AllTests" ...>
+  <testsuite name="test_case_name" ...>
+    <testcase    name="test_name" ...>
+      <failure message="..."/>
+      <failure message="..."/>
+      <failure message="..."/>
+    </testcase>
+  </testsuite>
+</testsuites>
+```
+
+*   The root `<testsuites>` element corresponds to the entire test program.
+*   `<testsuite>` elements correspond to GoogleTest test suites.
+*   `<testcase>` elements correspond to GoogleTest test functions.
+
+For instance, the following program
+
+```c++
+TEST(MathTest, Addition) { ... }
+TEST(MathTest, Subtraction) { ... }
+TEST(LogicTest, NonContradiction) { ... }
+```
+
+could generate this report:
+
+```xml
+<?xml version="1.0" encoding="UTF-8"?>
+<testsuites tests="3" failures="1" errors="0" time="0.035" timestamp="2011-10-31T18:52:42" name="AllTests">
+  <testsuite name="MathTest" tests="2" failures="1" errors="0" time="0.015">
+    <testcase name="Addition" file="test.cpp" line="1" status="run" time="0.007" classname="">
+      <failure message="Value of: add(1, 1)&#x0A;  Actual: 3&#x0A;Expected: 2" type="">...</failure>
+      <failure message="Value of: add(1, -1)&#x0A;  Actual: 1&#x0A;Expected: 0" type="">...</failure>
+    </testcase>
+    <testcase name="Subtraction" file="test.cpp" line="2" status="run" time="0.005" classname="">
+    </testcase>
+  </testsuite>
+  <testsuite name="LogicTest" tests="1" failures="0" errors="0" time="0.005">
+    <testcase name="NonContradiction" file="test.cpp" line="3" status="run" time="0.005" classname="">
+    </testcase>
+  </testsuite>
+</testsuites>
+```
+
+Things to note:
+
+*   The `tests` attribute of a `<testsuites>` or `<testsuite>` element tells how
+    many test functions the GoogleTest program or test suite contains, while the
+    `failures` attribute tells how many of them failed.
+
+*   The `time` attribute expresses the duration of the test, test suite, or
+    entire test program in seconds.
+
+*   The `timestamp` attribute records the local date and time of the test
+    execution.
+
+*   The `file` and `line` attributes record the source file location, where the
+    test was defined.
+
+*   Each `<failure>` element corresponds to a single failed GoogleTest
+    assertion.
+
+#### Generating a JSON Report
+
+GoogleTest can also emit a JSON report as an alternative format to XML. To
+generate the JSON report, set the `GTEST_OUTPUT` environment variable or the
+`--gtest_output` flag to the string `"json:path_to_output_file"`, which will
+create the file at the given location. You can also just use the string
+`"json"`, in which case the output can be found in the `test_detail.json` file
+in the current directory.
+
+The report format conforms to the following JSON Schema:
+
+```json
+{
+  "$schema": "http://json-schema.org/schema#",
+  "type": "object",
+  "definitions": {
+    "TestCase": {
+      "type": "object",
+      "properties": {
+        "name": { "type": "string" },
+        "tests": { "type": "integer" },
+        "failures": { "type": "integer" },
+        "disabled": { "type": "integer" },
+        "time": { "type": "string" },
+        "testsuite": {
+          "type": "array",
+          "items": {
+            "$ref": "#/definitions/TestInfo"
+          }
+        }
+      }
+    },
+    "TestInfo": {
+      "type": "object",
+      "properties": {
+        "name": { "type": "string" },
+        "file": { "type": "string" },
+        "line": { "type": "integer" },
+        "status": {
+          "type": "string",
+          "enum": ["RUN", "NOTRUN"]
+        },
+        "time": { "type": "string" },
+        "classname": { "type": "string" },
+        "failures": {
+          "type": "array",
+          "items": {
+            "$ref": "#/definitions/Failure"
+          }
+        }
+      }
+    },
+    "Failure": {
+      "type": "object",
+      "properties": {
+        "failures": { "type": "string" },
+        "type": { "type": "string" }
+      }
+    }
+  },
+  "properties": {
+    "tests": { "type": "integer" },
+    "failures": { "type": "integer" },
+    "disabled": { "type": "integer" },
+    "errors": { "type": "integer" },
+    "timestamp": {
+      "type": "string",
+      "format": "date-time"
+    },
+    "time": { "type": "string" },
+    "name": { "type": "string" },
+    "testsuites": {
+      "type": "array",
+      "items": {
+        "$ref": "#/definitions/TestCase"
+      }
+    }
+  }
+}
+```
+
+The report uses the format that conforms to the following Proto3 using the
+[JSON encoding](https://developers.google.com/protocol-buffers/docs/proto3#json):
+
+```proto
+syntax = "proto3";
+
+package googletest;
+
+import "google/protobuf/timestamp.proto";
+import "google/protobuf/duration.proto";
+
+message UnitTest {
+  int32 tests = 1;
+  int32 failures = 2;
+  int32 disabled = 3;
+  int32 errors = 4;
+  google.protobuf.Timestamp timestamp = 5;
+  google.protobuf.Duration time = 6;
+  string name = 7;
+  repeated TestCase testsuites = 8;
+}
+
+message TestCase {
+  string name = 1;
+  int32 tests = 2;
+  int32 failures = 3;
+  int32 disabled = 4;
+  int32 errors = 5;
+  google.protobuf.Duration time = 6;
+  repeated TestInfo testsuite = 7;
+}
+
+message TestInfo {
+  string name = 1;
+  string file = 6;
+  int32 line = 7;
+  enum Status {
+    RUN = 0;
+    NOTRUN = 1;
+  }
+  Status status = 2;
+  google.protobuf.Duration time = 3;
+  string classname = 4;
+  message Failure {
+    string failures = 1;
+    string type = 2;
+  }
+  repeated Failure failures = 5;
+}
+```
+
+For instance, the following program
+
+```c++
+TEST(MathTest, Addition) { ... }
+TEST(MathTest, Subtraction) { ... }
+TEST(LogicTest, NonContradiction) { ... }
+```
+
+could generate this report:
+
+```json
+{
+  "tests": 3,
+  "failures": 1,
+  "errors": 0,
+  "time": "0.035s",
+  "timestamp": "2011-10-31T18:52:42Z",
+  "name": "AllTests",
+  "testsuites": [
+    {
+      "name": "MathTest",
+      "tests": 2,
+      "failures": 1,
+      "errors": 0,
+      "time": "0.015s",
+      "testsuite": [
+        {
+          "name": "Addition",
+          "file": "test.cpp",
+          "line": 1,
+          "status": "RUN",
+          "time": "0.007s",
+          "classname": "",
+          "failures": [
+            {
+              "message": "Value of: add(1, 1)\n  Actual: 3\nExpected: 2",
+              "type": ""
+            },
+            {
+              "message": "Value of: add(1, -1)\n  Actual: 1\nExpected: 0",
+              "type": ""
+            }
+          ]
+        },
+        {
+          "name": "Subtraction",
+          "file": "test.cpp",
+          "line": 2,
+          "status": "RUN",
+          "time": "0.005s",
+          "classname": ""
+        }
+      ]
+    },
+    {
+      "name": "LogicTest",
+      "tests": 1,
+      "failures": 0,
+      "errors": 0,
+      "time": "0.005s",
+      "testsuite": [
+        {
+          "name": "NonContradiction",
+          "file": "test.cpp",
+          "line": 3,
+          "status": "RUN",
+          "time": "0.005s",
+          "classname": ""
+        }
+      ]
+    }
+  ]
+}
+```
+
+{: .callout .important}
+IMPORTANT: The exact format of the JSON document is subject to change.
+
+### Controlling How Failures Are Reported
+
+#### Detecting Test Premature Exit
+
+Google Test implements the _premature-exit-file_ protocol for test runners to
+catch any kind of unexpected exits of test programs. Upon start, Google Test
+creates the file which will be automatically deleted after all work has been
+finished. Then, the test runner can check if this file exists. In case the file
+remains undeleted, the inspected test has exited prematurely.
+
+This feature is enabled only if the `TEST_PREMATURE_EXIT_FILE` environment
+variable has been set.
+
+#### Turning Assertion Failures into Break-Points
+
+When running test programs under a debugger, it's very convenient if the
+debugger can catch an assertion failure and automatically drop into interactive
+mode. GoogleTest's *break-on-failure* mode supports this behavior.
+
+To enable it, set the `GTEST_BREAK_ON_FAILURE` environment variable to a value
+other than `0`. Alternatively, you can use the `--gtest_break_on_failure`
+command line flag.
+
+#### Disabling Catching Test-Thrown Exceptions
+
+GoogleTest can be used either with or without exceptions enabled. If a test
+throws a C++ exception or (on Windows) a structured exception (SEH), by default
+GoogleTest catches it, reports it as a test failure, and continues with the next
+test method. This maximizes the coverage of a test run. Also, on Windows an
+uncaught exception will cause a pop-up window, so catching the exceptions allows
+you to run the tests automatically.
+
+When debugging the test failures, however, you may instead want the exceptions
+to be handled by the debugger, such that you can examine the call stack when an
+exception is thrown. To achieve that, set the `GTEST_CATCH_EXCEPTIONS`
+environment variable to `0`, or use the `--gtest_catch_exceptions=0` flag when
+running the tests.
+
+### Sanitizer Integration
+
+The
+[Undefined Behavior Sanitizer](https://clang.llvm.org/docs/UndefinedBehaviorSanitizer.html),
+[Address Sanitizer](https://github.com/google/sanitizers/wiki/AddressSanitizer),
+and
+[Thread Sanitizer](https://github.com/google/sanitizers/wiki/ThreadSanitizerCppManual)
+all provide weak functions that you can override to trigger explicit failures
+when they detect sanitizer errors, such as creating a reference from `nullptr`.
+To override these functions, place definitions for them in a source file that
+you compile as part of your main binary:
+
+```
+extern "C" {
+void __ubsan_on_report() {
+  FAIL() << "Encountered an undefined behavior sanitizer error";
+}
+void __asan_on_error() {
+  FAIL() << "Encountered an address sanitizer error";
+}
+void __tsan_on_report() {
+  FAIL() << "Encountered a thread sanitizer error";
+}
+}  // extern "C"
+```
+
+After compiling your project with one of the sanitizers enabled, if a particular
+test triggers a sanitizer error, GoogleTest will report that it failed.

contrib/googletest/docs/assets/css/style.scss

@@ -0,0 +1,5 @@
+---
+---
+
+@import "jekyll-theme-primer";
+@import "main";

contrib/googletest/docs/community_created_documentation.md

@@ -0,0 +1,7 @@
+# Community-Created Documentation
+
+The following is a list, in no particular order, of links to documentation
+created by the Googletest community.
+
+*   [Googlemock Insights](https://github.com/ElectricRCAircraftGuy/eRCaGuy_dotfiles/blob/master/googletest/insights.md),
+    by [ElectricRCAircraftGuy](https://github.com/ElectricRCAircraftGuy)

contrib/googletest/docs/faq.md

@@ -0,0 +1,692 @@
+# GoogleTest FAQ
+
+## Why should test suite names and test names not contain underscore?
+
+{: .callout .note}
+Note: GoogleTest reserves underscore (`_`) for special purpose keywords, such as
+[the `DISABLED_` prefix](advanced.md#temporarily-disabling-tests), in addition
+to the following rationale.
+
+Underscore (`_`) is special, as C++ reserves the following to be used by the
+compiler and the standard library:
+
+1.  any identifier that starts with an `_` followed by an upper-case letter, and
+2.  any identifier that contains two consecutive underscores (i.e. `__`)
+    *anywhere* in its name.
+
+User code is *prohibited* from using such identifiers.
+
+Now let's look at what this means for `TEST` and `TEST_F`.
+
+Currently `TEST(TestSuiteName, TestName)` generates a class named
+`TestSuiteName_TestName_Test`. What happens if `TestSuiteName` or `TestName`
+contains `_`?
+
+1.  If `TestSuiteName` starts with an `_` followed by an upper-case letter (say,
+    `_Foo`), we end up with `_Foo_TestName_Test`, which is reserved and thus
+    invalid.
+2.  If `TestSuiteName` ends with an `_` (say, `Foo_`), we get
+    `Foo__TestName_Test`, which is invalid.
+3.  If `TestName` starts with an `_` (say, `_Bar`), we get
+    `TestSuiteName__Bar_Test`, which is invalid.
+4.  If `TestName` ends with an `_` (say, `Bar_`), we get
+    `TestSuiteName_Bar__Test`, which is invalid.
+
+So clearly `TestSuiteName` and `TestName` cannot start or end with `_`
+(Actually, `TestSuiteName` can start with `_` -- as long as the `_` isn't
+followed by an upper-case letter. But that's getting complicated. So for
+simplicity we just say that it cannot start with `_`.).
+
+It may seem fine for `TestSuiteName` and `TestName` to contain `_` in the
+middle. However, consider this:
+
+```c++
+TEST(Time, Flies_Like_An_Arrow) { ... }
+TEST(Time_Flies, Like_An_Arrow) { ... }
+```
+
+Now, the two `TEST`s will both generate the same class
+(`Time_Flies_Like_An_Arrow_Test`). That's not good.
+
+So for simplicity, we just ask the users to avoid `_` in `TestSuiteName` and
+`TestName`. The rule is more constraining than necessary, but it's simple and
+easy to remember. It also gives GoogleTest some wiggle room in case its
+implementation needs to change in the future.
+
+If you violate the rule, there may not be immediate consequences, but your test
+may (just may) break with a new compiler (or a new version of the compiler you
+are using) or with a new version of GoogleTest. Therefore it's best to follow
+the rule.
+
+## Why does GoogleTest support `EXPECT_EQ(NULL, ptr)` and `ASSERT_EQ(NULL, ptr)` but not `EXPECT_NE(NULL, ptr)` and `ASSERT_NE(NULL, ptr)`?
+
+First of all, you can use `nullptr` with each of these macros, e.g.
+`EXPECT_EQ(ptr, nullptr)`, `EXPECT_NE(ptr, nullptr)`, `ASSERT_EQ(ptr, nullptr)`,
+`ASSERT_NE(ptr, nullptr)`. This is the preferred syntax in the style guide
+because `nullptr` does not have the type problems that `NULL` does.
+
+Due to some peculiarity of C++, it requires some non-trivial template meta
+programming tricks to support using `NULL` as an argument of the `EXPECT_XX()`
+and `ASSERT_XX()` macros. Therefore we only do it where it's most needed
+(otherwise we make the implementation of GoogleTest harder to maintain and more
+error-prone than necessary).
+
+Historically, the `EXPECT_EQ()` macro took the *expected* value as its first
+argument and the *actual* value as the second, though this argument order is now
+discouraged. It was reasonable that someone wanted
+to write `EXPECT_EQ(NULL, some_expression)`, and this indeed was requested
+several times. Therefore we implemented it.
+
+The need for `EXPECT_NE(NULL, ptr)` wasn't nearly as strong. When the assertion
+fails, you already know that `ptr` must be `NULL`, so it doesn't add any
+information to print `ptr` in this case. That means `EXPECT_TRUE(ptr != NULL)`
+works just as well.
+
+If we were to support `EXPECT_NE(NULL, ptr)`, for consistency we'd have to
+support `EXPECT_NE(ptr, NULL)` as well. This means using the template meta
+programming tricks twice in the implementation, making it even harder to
+understand and maintain. We believe the benefit doesn't justify the cost.
+
+Finally, with the growth of the gMock matcher library, we are encouraging people
+to use the unified `EXPECT_THAT(value, matcher)` syntax more often in tests. One
+significant advantage of the matcher approach is that matchers can be easily
+combined to form new matchers, while the `EXPECT_NE`, etc, macros cannot be
+easily combined. Therefore we want to invest more in the matchers than in the
+`EXPECT_XX()` macros.
+
+## I need to test that different implementations of an interface satisfy some common requirements. Should I use typed tests or value-parameterized tests?
+
+For testing various implementations of the same interface, either typed tests or
+value-parameterized tests can get it done. It's really up to you the user to
+decide which is more convenient for you, depending on your particular case. Some
+rough guidelines:
+
+*   Typed tests can be easier to write if instances of the different
+    implementations can be created the same way, modulo the type. For example,
+    if all these implementations have a public default constructor (such that
+    you can write `new TypeParam`), or if their factory functions have the same
+    form (e.g. `CreateInstance<TypeParam>()`).
+*   Value-parameterized tests can be easier to write if you need different code
+    patterns to create different implementations' instances, e.g. `new Foo` vs
+    `new Bar(5)`. To accommodate for the differences, you can write factory
+    function wrappers and pass these function pointers to the tests as their
+    parameters.
+*   When a typed test fails, the default output includes the name of the type,
+    which can help you quickly identify which implementation is wrong.
+    Value-parameterized tests only show the number of the failed iteration by
+    default. You will need to define a function that returns the iteration name
+    and pass it as the third parameter to INSTANTIATE_TEST_SUITE_P to have more
+    useful output.
+*   When using typed tests, you need to make sure you are testing against the
+    interface type, not the concrete types (in other words, you want to make
+    sure `implicit_cast<MyInterface*>(my_concrete_impl)` works, not just that
+    `my_concrete_impl` works). It's less likely to make mistakes in this area
+    when using value-parameterized tests.
+
+I hope I didn't confuse you more. :-) If you don't mind, I'd suggest you to give
+both approaches a try. Practice is a much better way to grasp the subtle
+differences between the two tools. Once you have some concrete experience, you
+can much more easily decide which one to use the next time.
+
+## I got some run-time errors about invalid proto descriptors when using `ProtocolMessageEquals`. Help!
+
+{: .callout .note}
+**Note:** `ProtocolMessageEquals` and `ProtocolMessageEquiv` are *deprecated*
+now. Please use `EqualsProto`, etc instead.
+
+`ProtocolMessageEquals` and `ProtocolMessageEquiv` were redefined recently and
+are now less tolerant of invalid protocol buffer definitions. In particular, if
+you have a `foo.proto` that doesn't fully qualify the type of a protocol message
+it references (e.g. `message<Bar>` where it should be `message<blah.Bar>`), you
+will now get run-time errors like:
+
+```
+... descriptor.cc:...] Invalid proto descriptor for file "path/to/foo.proto":
+... descriptor.cc:...]  blah.MyMessage.my_field: ".Bar" is not defined.
+```
+
+If you see this, your `.proto` file is broken and needs to be fixed by making
+the types fully qualified. The new definition of `ProtocolMessageEquals` and
+`ProtocolMessageEquiv` just happen to reveal your bug.
+
+## My death test modifies some state, but the change seems lost after the death test finishes. Why?
+
+Death tests (`EXPECT_DEATH`, etc) are executed in a sub-process s.t. the
+expected crash won't kill the test program (i.e. the parent process). As a
+result, any in-memory side effects they incur are observable in their respective
+sub-processes, but not in the parent process. You can think of them as running
+in a parallel universe, more or less.
+
+In particular, if you use mocking and the death test statement invokes some mock
+methods, the parent process will think the calls have never occurred. Therefore,
+you may want to move your `EXPECT_CALL` statements inside the `EXPECT_DEATH`
+macro.
+
+## EXPECT_EQ(htonl(blah), blah_blah) generates weird compiler errors in opt mode. Is this a GoogleTest bug?
+
+Actually, the bug is in `htonl()`.
+
+According to `'man htonl'`, `htonl()` is a *function*, which means it's valid to
+use `htonl` as a function pointer. However, in opt mode `htonl()` is defined as
+a *macro*, which breaks this usage.
+
+Worse, the macro definition of `htonl()` uses a `gcc` extension and is *not*
+standard C++. That hacky implementation has some ad hoc limitations. In
+particular, it prevents you from writing `Foo<sizeof(htonl(x))>()`, where `Foo`
+is a template that has an integral argument.
+
+The implementation of `EXPECT_EQ(a, b)` uses `sizeof(... a ...)` inside a
+template argument, and thus doesn't compile in opt mode when `a` contains a call
+to `htonl()`. It is difficult to make `EXPECT_EQ` bypass the `htonl()` bug, as
+the solution must work with different compilers on various platforms.
+
+## The compiler complains about "undefined references" to some static const member variables, but I did define them in the class body. What's wrong?
+
+If your class has a static data member:
+
+```c++
+// foo.h
+class Foo {
+  ...
+  static const int kBar = 100;
+};
+```
+
+You also need to define it *outside* of the class body in `foo.cc`:
+
+```c++
+const int Foo::kBar;  // No initializer here.
+```
+
+Otherwise your code is **invalid C++**, and may break in unexpected ways. In
+particular, using it in GoogleTest comparison assertions (`EXPECT_EQ`, etc) will
+generate an "undefined reference" linker error. The fact that "it used to work"
+doesn't mean it's valid. It just means that you were lucky. :-)
+
+If the declaration of the static data member is `constexpr` then it is
+implicitly an `inline` definition, and a separate definition in `foo.cc` is not
+needed:
+
+```c++
+// foo.h
+class Foo {
+  ...
+  static constexpr int kBar = 100;  // Defines kBar, no need to do it in foo.cc.
+};
+```
+
+## Can I derive a test fixture from another?
+
+Yes.
+
+Each test fixture has a corresponding and same named test suite. This means only
+one test suite can use a particular fixture. Sometimes, however, multiple test
+cases may want to use the same or slightly different fixtures. For example, you
+may want to make sure that all of a GUI library's test suites don't leak
+important system resources like fonts and brushes.
+
+In GoogleTest, you share a fixture among test suites by putting the shared logic
+in a base test fixture, then deriving from that base a separate fixture for each
+test suite that wants to use this common logic. You then use `TEST_F()` to write
+tests using each derived fixture.
+
+Typically, your code looks like this:
+
+```c++
+// Defines a base test fixture.
+class BaseTest : public ::testing::Test {
+ protected:
+  ...
+};
+
+// Derives a fixture FooTest from BaseTest.
+class FooTest : public BaseTest {
+ protected:
+  void SetUp() override {
+    BaseTest::SetUp();  // Sets up the base fixture first.
+    ... additional set-up work ...
+  }
+
+  void TearDown() override {
+    ... clean-up work for FooTest ...
+    BaseTest::TearDown();  // Remember to tear down the base fixture
+                           // after cleaning up FooTest!
+  }
+
+  ... functions and variables for FooTest ...
+};
+
+// Tests that use the fixture FooTest.
+TEST_F(FooTest, Bar) { ... }
+TEST_F(FooTest, Baz) { ... }
+
+... additional fixtures derived from BaseTest ...
+```
+
+If necessary, you can continue to derive test fixtures from a derived fixture.
+GoogleTest has no limit on how deep the hierarchy can be.
+
+For a complete example using derived test fixtures, see
+[sample5_unittest.cc](https://github.com/google/googletest/blob/main/googletest/samples/sample5_unittest.cc).
+
+## My compiler complains "void value not ignored as it ought to be." What does this mean?
+
+You're probably using an `ASSERT_*()` in a function that doesn't return `void`.
+`ASSERT_*()` can only be used in `void` functions, due to exceptions being
+disabled by our build system. Please see more details
+[here](advanced.md#assertion-placement).
+
+## My death test hangs (or seg-faults). How do I fix it?
+
+In GoogleTest, death tests are run in a child process and the way they work is
+delicate. To write death tests you really need to understand how they work—see
+the details at [Death Assertions](reference/assertions.md#death) in the
+Assertions Reference.
+
+In particular, death tests don't like having multiple threads in the parent
+process. So the first thing you can try is to eliminate creating threads outside
+of `EXPECT_DEATH()`. For example, you may want to use mocks or fake objects
+instead of real ones in your tests.
+
+Sometimes this is impossible as some library you must use may be creating
+threads before `main()` is even reached. In this case, you can try to minimize
+the chance of conflicts by either moving as many activities as possible inside
+`EXPECT_DEATH()` (in the extreme case, you want to move everything inside), or
+leaving as few things as possible in it. Also, you can try to set the death test
+style to `"threadsafe"`, which is safer but slower, and see if it helps.
+
+If you go with thread-safe death tests, remember that they rerun the test
+program from the beginning in the child process. Therefore make sure your
+program can run side-by-side with itself and is deterministic.
+
+In the end, this boils down to good concurrent programming. You have to make
+sure that there are no race conditions or deadlocks in your program. No silver
+bullet - sorry!
+
+## Should I use the constructor/destructor of the test fixture or SetUp()/TearDown()? {#CtorVsSetUp}
+
+The first thing to remember is that GoogleTest does **not** reuse the same test
+fixture object across multiple tests. For each `TEST_F`, GoogleTest will create
+a **fresh** test fixture object, immediately call `SetUp()`, run the test body,
+call `TearDown()`, and then delete the test fixture object.
+
+When you need to write per-test set-up and tear-down logic, you have the choice
+between using the test fixture constructor/destructor or `SetUp()/TearDown()`.
+The former is usually preferred, as it has the following benefits:
+
+*   By initializing a member variable in the constructor, we have the option to
+    make it `const`, which helps prevent accidental changes to its value and
+    makes the tests more obviously correct.
+*   In case we need to subclass the test fixture class, the subclass'
+    constructor is guaranteed to call the base class' constructor *first*, and
+    the subclass' destructor is guaranteed to call the base class' destructor
+    *afterward*. With `SetUp()/TearDown()`, a subclass may make the mistake of
+    forgetting to call the base class' `SetUp()/TearDown()` or call them at the
+    wrong time.
+
+You may still want to use `SetUp()/TearDown()` in the following cases:
+
+*   C++ does not allow virtual function calls in constructors and destructors.
+    You can call a method declared as virtual, but it will not use dynamic
+    dispatch. It will use the definition from the class the constructor of which
+    is currently executing. This is because calling a virtual method before the
+    derived class constructor has a chance to run is very dangerous - the
+    virtual method might operate on uninitialized data. Therefore, if you need
+    to call a method that will be overridden in a derived class, you have to use
+    `SetUp()/TearDown()`.
+*   In the body of a constructor (or destructor), it's not possible to use the
+    `ASSERT_xx` macros. Therefore, if the set-up operation could cause a fatal
+    test failure that should prevent the test from running, it's necessary to
+    use `abort` and abort the whole test
+    executable, or to use `SetUp()` instead of a constructor.
+*   If the tear-down operation could throw an exception, you must use
+    `TearDown()` as opposed to the destructor, as throwing in a destructor leads
+    to undefined behavior and usually will kill your program right away. Note
+    that many standard libraries (like STL) may throw when exceptions are
+    enabled in the compiler. Therefore you should prefer `TearDown()` if you
+    want to write portable tests that work with or without exceptions.
+*   The GoogleTest team is considering making the assertion macros throw on
+    platforms where exceptions are enabled (e.g. Windows, Mac OS, and Linux
+    client-side), which will eliminate the need for the user to propagate
+    failures from a subroutine to its caller. Therefore, you shouldn't use
+    GoogleTest assertions in a destructor if your code could run on such a
+    platform.
+
+## The compiler complains "no matching function to call" when I use ASSERT_PRED*. How do I fix it?
+
+See details for [`EXPECT_PRED*`](reference/assertions.md#EXPECT_PRED) in the
+Assertions Reference.
+
+## My compiler complains about "ignoring return value" when I call RUN_ALL_TESTS(). Why?
+
+Some people had been ignoring the return value of `RUN_ALL_TESTS()`. That is,
+instead of
+
+```c++
+  return RUN_ALL_TESTS();
+```
+
+they write
+
+```c++
+  RUN_ALL_TESTS();
+```
+
+This is **wrong and dangerous**. The testing services needs to see the return
+value of `RUN_ALL_TESTS()` in order to determine if a test has passed. If your
+`main()` function ignores it, your test will be considered successful even if it
+has a GoogleTest assertion failure. Very bad.
+
+We have decided to fix this (thanks to Michael Chastain for the idea). Now, your
+code will no longer be able to ignore `RUN_ALL_TESTS()` when compiled with
+`gcc`. If you do so, you'll get a compiler error.
+
+If you see the compiler complaining about you ignoring the return value of
+`RUN_ALL_TESTS()`, the fix is simple: just make sure its value is used as the
+return value of `main()`.
+
+But how could we introduce a change that breaks existing tests? Well, in this
+case, the code was already broken in the first place, so we didn't break it. :-)
+
+## My compiler complains that a constructor (or destructor) cannot return a value. What's going on?
+
+Due to a peculiarity of C++, in order to support the syntax for streaming
+messages to an `ASSERT_*`, e.g.
+
+```c++
+  ASSERT_EQ(1, Foo()) << "blah blah" << foo;
+```
+
+we had to give up using `ASSERT*` and `FAIL*` (but not `EXPECT*` and
+`ADD_FAILURE*`) in constructors and destructors. The workaround is to move the
+content of your constructor/destructor to a private void member function, or
+switch to `EXPECT_*()` if that works. This
+[section](advanced.md#assertion-placement) in the user's guide explains it.
+
+## My SetUp() function is not called. Why?
+
+C++ is case-sensitive. Did you spell it as `Setup()`?
+
+Similarly, sometimes people spell `SetUpTestSuite()` as `SetupTestSuite()` and
+wonder why it's never called.
+
+## I have several test suites which share the same test fixture logic, do I have to define a new test fixture class for each of them? This seems pretty tedious.
+
+You don't have to. Instead of
+
+```c++
+class FooTest : public BaseTest {};
+
+TEST_F(FooTest, Abc) { ... }
+TEST_F(FooTest, Def) { ... }
+
+class BarTest : public BaseTest {};
+
+TEST_F(BarTest, Abc) { ... }
+TEST_F(BarTest, Def) { ... }
+```
+
+you can simply `typedef` the test fixtures:
+
+```c++
+typedef BaseTest FooTest;
+
+TEST_F(FooTest, Abc) { ... }
+TEST_F(FooTest, Def) { ... }
+
+typedef BaseTest BarTest;
+
+TEST_F(BarTest, Abc) { ... }
+TEST_F(BarTest, Def) { ... }
+```
+
+## GoogleTest output is buried in a whole bunch of LOG messages. What do I do?
+
+The GoogleTest output is meant to be a concise and human-friendly report. If
+your test generates textual output itself, it will mix with the GoogleTest
+output, making it hard to read. However, there is an easy solution to this
+problem.
+
+Since `LOG` messages go to stderr, we decided to let GoogleTest output go to
+stdout. This way, you can easily separate the two using redirection. For
+example:
+
+```shell
+$ ./my_test > gtest_output.txt
+```
+
+## Why should I prefer test fixtures over global variables?
+
+There are several good reasons:
+
+1.  It's likely your test needs to change the states of its global variables.
+    This makes it difficult to keep side effects from escaping one test and
+    contaminating others, making debugging difficult. By using fixtures, each
+    test has a fresh set of variables that's different (but with the same
+    names). Thus, tests are kept independent of each other.
+2.  Global variables pollute the global namespace.
+3.  Test fixtures can be reused via subclassing, which cannot be done easily
+    with global variables. This is useful if many test suites have something in
+    common.
+
+## What can the statement argument in ASSERT_DEATH() be?
+
+`ASSERT_DEATH(statement, matcher)` (or any death assertion macro) can be used
+wherever *`statement`* is valid. So basically *`statement`* can be any C++
+statement that makes sense in the current context. In particular, it can
+reference global and/or local variables, and can be:
+
+*   a simple function call (often the case),
+*   a complex expression, or
+*   a compound statement.
+
+Some examples are shown here:
+
+```c++
+// A death test can be a simple function call.
+TEST(MyDeathTest, FunctionCall) {
+  ASSERT_DEATH(Xyz(5), "Xyz failed");
+}
+
+// Or a complex expression that references variables and functions.
+TEST(MyDeathTest, ComplexExpression) {
+  const bool c = Condition();
+  ASSERT_DEATH((c ? Func1(0) : object2.Method("test")),
+               "(Func1|Method) failed");
+}
+
+// Death assertions can be used anywhere in a function.  In
+// particular, they can be inside a loop.
+TEST(MyDeathTest, InsideLoop) {
+  // Verifies that Foo(0), Foo(1), ..., and Foo(4) all die.
+  for (int i = 0; i < 5; i++) {
+    EXPECT_DEATH_M(Foo(i), "Foo has \\d+ errors",
+                   ::testing::Message() << "where i is " << i);
+  }
+}
+
+// A death assertion can contain a compound statement.
+TEST(MyDeathTest, CompoundStatement) {
+  // Verifies that at lease one of Bar(0), Bar(1), ..., and
+  // Bar(4) dies.
+  ASSERT_DEATH({
+    for (int i = 0; i < 5; i++) {
+      Bar(i);
+    }
+  },
+  "Bar has \\d+ errors");
+}
+```
+
+## I have a fixture class `FooTest`, but `TEST_F(FooTest, Bar)` gives me error ``"no matching function for call to `FooTest::FooTest()'"``. Why?
+
+GoogleTest needs to be able to create objects of your test fixture class, so it
+must have a default constructor. Normally the compiler will define one for you.
+However, there are cases where you have to define your own:
+
+*   If you explicitly declare a non-default constructor for class `FooTest`
+    (`DISALLOW_EVIL_CONSTRUCTORS()` does this), then you need to define a
+    default constructor, even if it would be empty.
+*   If `FooTest` has a const non-static data member, then you have to define the
+    default constructor *and* initialize the const member in the initializer
+    list of the constructor. (Early versions of `gcc` doesn't force you to
+    initialize the const member. It's a bug that has been fixed in `gcc 4`.)
+
+## Why does ASSERT_DEATH complain about previous threads that were already joined?
+
+With the Linux pthread library, there is no turning back once you cross the line
+from a single thread to multiple threads. The first time you create a thread, a
+manager thread is created in addition, so you get 3, not 2, threads. Later when
+the thread you create joins the main thread, the thread count decrements by 1,
+but the manager thread will never be killed, so you still have 2 threads, which
+means you cannot safely run a death test.
+
+The new NPTL thread library doesn't suffer from this problem, as it doesn't
+create a manager thread. However, if you don't control which machine your test
+runs on, you shouldn't depend on this.
+
+## Why does GoogleTest require the entire test suite, instead of individual tests, to be named *DeathTest when it uses ASSERT_DEATH?
+
+GoogleTest does not interleave tests from different test suites. That is, it
+runs all tests in one test suite first, and then runs all tests in the next test
+suite, and so on. GoogleTest does this because it needs to set up a test suite
+before the first test in it is run, and tear it down afterwards. Splitting up
+the test case would require multiple set-up and tear-down processes, which is
+inefficient and makes the semantics unclean.
+
+If we were to determine the order of tests based on test name instead of test
+case name, then we would have a problem with the following situation:
+
+```c++
+TEST_F(FooTest, AbcDeathTest) { ... }
+TEST_F(FooTest, Uvw) { ... }
+
+TEST_F(BarTest, DefDeathTest) { ... }
+TEST_F(BarTest, Xyz) { ... }
+```
+
+Since `FooTest.AbcDeathTest` needs to run before `BarTest.Xyz`, and we don't
+interleave tests from different test suites, we need to run all tests in the
+`FooTest` case before running any test in the `BarTest` case. This contradicts
+with the requirement to run `BarTest.DefDeathTest` before `FooTest.Uvw`.
+
+## But I don't like calling my entire test suite \*DeathTest when it contains both death tests and non-death tests. What do I do?
+
+You don't have to, but if you like, you may split up the test suite into
+`FooTest` and `FooDeathTest`, where the names make it clear that they are
+related:
+
+```c++
+class FooTest : public ::testing::Test { ... };
+
+TEST_F(FooTest, Abc) { ... }
+TEST_F(FooTest, Def) { ... }
+
+using FooDeathTest = FooTest;
+
+TEST_F(FooDeathTest, Uvw) { ... EXPECT_DEATH(...) ... }
+TEST_F(FooDeathTest, Xyz) { ... ASSERT_DEATH(...) ... }
+```
+
+## GoogleTest prints the LOG messages in a death test's child process only when the test fails. How can I see the LOG messages when the death test succeeds?
+
+Printing the LOG messages generated by the statement inside `EXPECT_DEATH()`
+makes it harder to search for real problems in the parent's log. Therefore,
+GoogleTest only prints them when the death test has failed.
+
+If you really need to see such LOG messages, a workaround is to temporarily
+break the death test (e.g. by changing the regex pattern it is expected to
+match). Admittedly, this is a hack. We'll consider a more permanent solution
+after the fork-and-exec-style death tests are implemented.
+
+## The compiler complains about `no match for 'operator<<'` when I use an assertion. What gives?
+
+If you use a user-defined type `FooType` in an assertion, you must make sure
+there is an `std::ostream& operator<<(std::ostream&, const FooType&)` function
+defined such that we can print a value of `FooType`.
+
+In addition, if `FooType` is declared in a name space, the `<<` operator also
+needs to be defined in the *same* name space. See
+[Tip of the Week #49](http://abseil.io/tips/49) for details.
+
+## How do I suppress the memory leak messages on Windows?
+
+Since the statically initialized GoogleTest singleton requires allocations on
+the heap, the Visual C++ memory leak detector will report memory leaks at the
+end of the program run. The easiest way to avoid this is to use the
+`_CrtMemCheckpoint` and `_CrtMemDumpAllObjectsSince` calls to not report any
+statically initialized heap objects. See MSDN for more details and additional
+heap check/debug routines.
+
+## How can my code detect if it is running in a test?
+
+If you write code that sniffs whether it's running in a test and does different
+things accordingly, you are leaking test-only logic into production code and
+there is no easy way to ensure that the test-only code paths aren't run by
+mistake in production. Such cleverness also leads to
+[Heisenbugs](https://en.wikipedia.org/wiki/Heisenbug). Therefore we strongly
+advise against the practice, and GoogleTest doesn't provide a way to do it.
+
+In general, the recommended way to cause the code to behave differently under
+test is [Dependency Injection](http://en.wikipedia.org/wiki/Dependency_injection). You can inject
+different functionality from the test and from the production code. Since your
+production code doesn't link in the for-test logic at all (the
+[`testonly`](http://docs.bazel.build/versions/master/be/common-definitions.html#common.testonly) attribute for BUILD targets helps to ensure
+that), there is no danger in accidentally running it.
+
+However, if you *really*, *really*, *really* have no choice, and if you follow
+the rule of ending your test program names with `_test`, you can use the
+*horrible* hack of sniffing your executable name (`argv[0]` in `main()`) to know
+whether the code is under test.
+
+## How do I temporarily disable a test?
+
+If you have a broken test that you cannot fix right away, you can add the
+`DISABLED_` prefix to its name. This will exclude it from execution. This is
+better than commenting out the code or using `#if 0`, as disabled tests are
+still compiled (and thus won't rot).
+
+To include disabled tests in test execution, just invoke the test program with
+the `--gtest_also_run_disabled_tests` flag.
+
+## Is it OK if I have two separate `TEST(Foo, Bar)` test methods defined in different namespaces?
+
+Yes.
+
+The rule is **all test methods in the same test suite must use the same fixture
+class.** This means that the following is **allowed** because both tests use the
+same fixture class (`::testing::Test`).
+
+```c++
+namespace foo {
+TEST(CoolTest, DoSomething) {
+  SUCCEED();
+}
+}  // namespace foo
+
+namespace bar {
+TEST(CoolTest, DoSomething) {
+  SUCCEED();
+}
+}  // namespace bar
+```
+
+However, the following code is **not allowed** and will produce a runtime error
+from GoogleTest because the test methods are using different test fixture
+classes with the same test suite name.
+
+```c++
+namespace foo {
+class CoolTest : public ::testing::Test {};  // Fixture foo::CoolTest
+TEST_F(CoolTest, DoSomething) {
+  SUCCEED();
+}
+}  // namespace foo
+
+namespace bar {
+class CoolTest : public ::testing::Test {};  // Fixture: bar::CoolTest
+TEST_F(CoolTest, DoSomething) {
+  SUCCEED();
+}
+}  // namespace bar
+```

contrib/googletest/docs/gmock_cheat_sheet.md

@@ -0,0 +1,241 @@
+# gMock Cheat Sheet
+
+## Defining a Mock Class
+
+### Mocking a Normal Class {#MockClass}
+
+Given
+
+```cpp
+class Foo {
+ public:
+  virtual ~Foo();
+  virtual int GetSize() const = 0;
+  virtual string Describe(const char* name) = 0;
+  virtual string Describe(int type) = 0;
+  virtual bool Process(Bar elem, int count) = 0;
+};
+```
+
+(note that `~Foo()` **must** be virtual) we can define its mock as
+
+```cpp
+#include <gmock/gmock.h>
+
+class MockFoo : public Foo {
+ public:
+  MOCK_METHOD(int, GetSize, (), (const, override));
+  MOCK_METHOD(string, Describe, (const char* name), (override));
+  MOCK_METHOD(string, Describe, (int type), (override));
+  MOCK_METHOD(bool, Process, (Bar elem, int count), (override));
+};
+```
+
+To create a "nice" mock, which ignores all uninteresting calls, a "naggy" mock,
+which warns on all uninteresting calls, or a "strict" mock, which treats them as
+failures:
+
+```cpp
+using ::testing::NiceMock;
+using ::testing::NaggyMock;
+using ::testing::StrictMock;
+
+NiceMock<MockFoo> nice_foo;      // The type is a subclass of MockFoo.
+NaggyMock<MockFoo> naggy_foo;    // The type is a subclass of MockFoo.
+StrictMock<MockFoo> strict_foo;  // The type is a subclass of MockFoo.
+```
+
+{: .callout .note}
+**Note:** A mock object is currently naggy by default. We may make it nice by
+default in the future.
+
+### Mocking a Class Template {#MockTemplate}
+
+Class templates can be mocked just like any class.
+
+To mock
+
+```cpp
+template <typename Elem>
+class StackInterface {
+ public:
+  virtual ~StackInterface();
+  virtual int GetSize() const = 0;
+  virtual void Push(const Elem& x) = 0;
+};
+```
+
+(note that all member functions that are mocked, including `~StackInterface()`
+**must** be virtual).
+
+```cpp
+template <typename Elem>
+class MockStack : public StackInterface<Elem> {
+ public:
+  MOCK_METHOD(int, GetSize, (), (const, override));
+  MOCK_METHOD(void, Push, (const Elem& x), (override));
+};
+```
+
+### Specifying Calling Conventions for Mock Functions
+
+If your mock function doesn't use the default calling convention, you can
+specify it by adding `Calltype(convention)` to `MOCK_METHOD`'s 4th parameter.
+For example,
+
+```cpp
+  MOCK_METHOD(bool, Foo, (int n), (Calltype(STDMETHODCALLTYPE)));
+  MOCK_METHOD(int, Bar, (double x, double y),
+              (const, Calltype(STDMETHODCALLTYPE)));
+```
+
+where `STDMETHODCALLTYPE` is defined by `<objbase.h>` on Windows.
+
+## Using Mocks in Tests {#UsingMocks}
+
+The typical work flow is:
+
+1.  Import the gMock names you need to use. All gMock symbols are in the
+    `testing` namespace unless they are macros or otherwise noted.
+2.  Create the mock objects.
+3.  Optionally, set the default actions of the mock objects.
+4.  Set your expectations on the mock objects (How will they be called? What
+    will they do?).
+5.  Exercise code that uses the mock objects; if necessary, check the result
+    using googletest assertions.
+6.  When a mock object is destructed, gMock automatically verifies that all
+    expectations on it have been satisfied.
+
+Here's an example:
+
+```cpp
+using ::testing::Return;                          // #1
+
+TEST(BarTest, DoesThis) {
+  MockFoo foo;                                    // #2
+
+  ON_CALL(foo, GetSize())                         // #3
+      .WillByDefault(Return(1));
+  // ... other default actions ...
+
+  EXPECT_CALL(foo, Describe(5))                   // #4
+      .Times(3)
+      .WillRepeatedly(Return("Category 5"));
+  // ... other expectations ...
+
+  EXPECT_EQ(MyProductionFunction(&foo), "good");  // #5
+}                                                 // #6
+```
+
+## Setting Default Actions {#OnCall}
+
+gMock has a **built-in default action** for any function that returns `void`,
+`bool`, a numeric value, or a pointer. In C++11, it will additionally returns
+the default-constructed value, if one exists for the given type.
+
+To customize the default action for functions with return type `T`, use
+[`DefaultValue<T>`](reference/mocking.md#DefaultValue). For example:
+
+```cpp
+  // Sets the default action for return type std::unique_ptr<Buzz> to
+  // creating a new Buzz every time.
+  DefaultValue<std::unique_ptr<Buzz>>::SetFactory(
+      [] { return std::make_unique<Buzz>(AccessLevel::kInternal); });
+
+  // When this fires, the default action of MakeBuzz() will run, which
+  // will return a new Buzz object.
+  EXPECT_CALL(mock_buzzer_, MakeBuzz("hello")).Times(AnyNumber());
+
+  auto buzz1 = mock_buzzer_.MakeBuzz("hello");
+  auto buzz2 = mock_buzzer_.MakeBuzz("hello");
+  EXPECT_NE(buzz1, nullptr);
+  EXPECT_NE(buzz2, nullptr);
+  EXPECT_NE(buzz1, buzz2);
+
+  // Resets the default action for return type std::unique_ptr<Buzz>,
+  // to avoid interfere with other tests.
+  DefaultValue<std::unique_ptr<Buzz>>::Clear();
+```
+
+To customize the default action for a particular method of a specific mock
+object, use [`ON_CALL`](reference/mocking.md#ON_CALL). `ON_CALL` has a similar
+syntax to `EXPECT_CALL`, but it is used for setting default behaviors when you
+do not require that the mock method is called. See
+[Knowing When to Expect](gmock_cook_book.md#UseOnCall) for a more detailed
+discussion.
+
+## Setting Expectations {#ExpectCall}
+
+See [`EXPECT_CALL`](reference/mocking.md#EXPECT_CALL) in the Mocking Reference.
+
+## Matchers {#MatcherList}
+
+See the [Matchers Reference](reference/matchers.md).
+
+## Actions {#ActionList}
+
+See the [Actions Reference](reference/actions.md).
+
+## Cardinalities {#CardinalityList}
+
+See the [`Times` clause](reference/mocking.md#EXPECT_CALL.Times) of
+`EXPECT_CALL` in the Mocking Reference.
+
+## Expectation Order
+
+By default, expectations can be matched in *any* order. If some or all
+expectations must be matched in a given order, you can use the
+[`After` clause](reference/mocking.md#EXPECT_CALL.After) or
+[`InSequence` clause](reference/mocking.md#EXPECT_CALL.InSequence) of
+`EXPECT_CALL`, or use an [`InSequence` object](reference/mocking.md#InSequence).
+
+## Verifying and Resetting a Mock
+
+gMock will verify the expectations on a mock object when it is destructed, or
+you can do it earlier:
+
+```cpp
+using ::testing::Mock;
+...
+// Verifies and removes the expectations on mock_obj;
+// returns true if and only if successful.
+Mock::VerifyAndClearExpectations(&mock_obj);
+...
+// Verifies and removes the expectations on mock_obj;
+// also removes the default actions set by ON_CALL();
+// returns true if and only if successful.
+Mock::VerifyAndClear(&mock_obj);
+```
+
+Do not set new expectations after verifying and clearing a mock after its use.
+Setting expectations after code that exercises the mock has undefined behavior.
+See [Using Mocks in Tests](gmock_for_dummies.md#using-mocks-in-tests) for more
+information.
+
+You can also tell gMock that a mock object can be leaked and doesn't need to be
+verified:
+
+```cpp
+Mock::AllowLeak(&mock_obj);
+```
+
+## Mock Classes
+
+gMock defines a convenient mock class template
+
+```cpp
+class MockFunction<R(A1, ..., An)> {
+ public:
+  MOCK_METHOD(R, Call, (A1, ..., An));
+};
+```
+
+See this [recipe](gmock_cook_book.md#UsingCheckPoints) for one application of
+it.
+
+## Flags
+
+| Flag                           | Description                               |
+| :----------------------------- | :---------------------------------------- |
+| `--gmock_catch_leaked_mocks=0` | Don't report leaked mock objects as failures. |
+| `--gmock_verbose=LEVEL` | Sets the default verbosity level (`info`, `warning`, or `error`) of Google Mock messages. |

contrib/googletest/docs/gmock_cook_book.md

@@ -0,0 +1,4344 @@
+# gMock Cookbook
+
+You can find recipes for using gMock here. If you haven't yet, please read
+[the dummy guide](gmock_for_dummies.md) first to make sure you understand the
+basics.
+
+{: .callout .note}
+**Note:** gMock lives in the `testing` name space. For readability, it is
+recommended to write `using ::testing::Foo;` once in your file before using the
+name `Foo` defined by gMock. We omit such `using` statements in this section for
+brevity, but you should do it in your own code.
+
+## Creating Mock Classes
+
+Mock classes are defined as normal classes, using the `MOCK_METHOD` macro to
+generate mocked methods. The macro gets 3 or 4 parameters:
+
+```cpp
+class MyMock {
+ public:
+  MOCK_METHOD(ReturnType, MethodName, (Args...));
+  MOCK_METHOD(ReturnType, MethodName, (Args...), (Specs...));
+};
+```
+
+The first 3 parameters are simply the method declaration, split into 3 parts.
+The 4th parameter accepts a closed list of qualifiers, which affect the
+generated method:
+
+*   **`const`** - Makes the mocked method a `const` method. Required if
+    overriding a `const` method.
+*   **`override`** - Marks the method with `override`. Recommended if overriding
+    a `virtual` method.
+*   **`noexcept`** - Marks the method with `noexcept`. Required if overriding a
+    `noexcept` method.
+*   **`Calltype(...)`** - Sets the call type for the method (e.g. to
+    `STDMETHODCALLTYPE`), useful in Windows.
+*   **`ref(...)`** - Marks the method with the reference qualification
+    specified. Required if overriding a method that has reference
+    qualifications. Eg `ref(&)` or `ref(&&)`.
+
+### Dealing with unprotected commas
+
+Unprotected commas, i.e. commas which are not surrounded by parentheses, prevent
+`MOCK_METHOD` from parsing its arguments correctly:
+
+{: .bad}
+```cpp
+class MockFoo {
+ public:
+  MOCK_METHOD(std::pair<bool, int>, GetPair, ());  // Won't compile!
+  MOCK_METHOD(bool, CheckMap, (std::map<int, double>, bool));  // Won't compile!
+};
+```
+
+Solution 1 - wrap with parentheses:
+
+{: .good}
+```cpp
+class MockFoo {
+ public:
+  MOCK_METHOD((std::pair<bool, int>), GetPair, ());
+  MOCK_METHOD(bool, CheckMap, ((std::map<int, double>), bool));
+};
+```
+
+Note that wrapping a return or argument type with parentheses is, in general,
+invalid C++. `MOCK_METHOD` removes the parentheses.
+
+Solution 2 - define an alias:
+
+{: .good}
+```cpp
+class MockFoo {
+ public:
+  using BoolAndInt = std::pair<bool, int>;
+  MOCK_METHOD(BoolAndInt, GetPair, ());
+  using MapIntDouble = std::map<int, double>;
+  MOCK_METHOD(bool, CheckMap, (MapIntDouble, bool));
+};
+```
+
+### Mocking Private or Protected Methods
+
+You must always put a mock method definition (`MOCK_METHOD`) in a `public:`
+section of the mock class, regardless of the method being mocked being `public`,
+`protected`, or `private` in the base class. This allows `ON_CALL` and
+`EXPECT_CALL` to reference the mock function from outside of the mock class.
+(Yes, C++ allows a subclass to change the access level of a virtual function in
+the base class.) Example:
+
+```cpp
+class Foo {
+ public:
+  ...
+  virtual bool Transform(Gadget* g) = 0;
+
+ protected:
+  virtual void Resume();
+
+ private:
+  virtual int GetTimeOut();
+};
+
+class MockFoo : public Foo {
+ public:
+  ...
+  MOCK_METHOD(bool, Transform, (Gadget* g), (override));
+
+  // The following must be in the public section, even though the
+  // methods are protected or private in the base class.
+  MOCK_METHOD(void, Resume, (), (override));
+  MOCK_METHOD(int, GetTimeOut, (), (override));
+};
+```
+
+### Mocking Overloaded Methods
+
+You can mock overloaded functions as usual. No special attention is required:
+
+```cpp
+class Foo {
+  ...
+
+  // Must be virtual as we'll inherit from Foo.
+  virtual ~Foo();
+
+  // Overloaded on the types and/or numbers of arguments.
+  virtual int Add(Element x);
+  virtual int Add(int times, Element x);
+
+  // Overloaded on the const-ness of this object.
+  virtual Bar& GetBar();
+  virtual const Bar& GetBar() const;
+};
+
+class MockFoo : public Foo {
+  ...
+  MOCK_METHOD(int, Add, (Element x), (override));
+  MOCK_METHOD(int, Add, (int times, Element x), (override));
+
+  MOCK_METHOD(Bar&, GetBar, (), (override));
+  MOCK_METHOD(const Bar&, GetBar, (), (const, override));
+};
+```
+
+{: .callout .note}
+**Note:** if you don't mock all versions of the overloaded method, the compiler
+will give you a warning about some methods in the base class being hidden. To
+fix that, use `using` to bring them in scope:
+
+```cpp
+class MockFoo : public Foo {
+  ...
+  using Foo::Add;
+  MOCK_METHOD(int, Add, (Element x), (override));
+  // We don't want to mock int Add(int times, Element x);
+  ...
+};
+```
+
+### Mocking Class Templates
+
+You can mock class templates just like any class.
+
+```cpp
+template <typename Elem>
+class StackInterface {
+  ...
+  // Must be virtual as we'll inherit from StackInterface.
+  virtual ~StackInterface();
+
+  virtual int GetSize() const = 0;
+  virtual void Push(const Elem& x) = 0;
+};
+
+template <typename Elem>
+class MockStack : public StackInterface<Elem> {
+  ...
+  MOCK_METHOD(int, GetSize, (), (override));
+  MOCK_METHOD(void, Push, (const Elem& x), (override));
+};
+```
+
+### Mocking Non-virtual Methods {#MockingNonVirtualMethods}
+
+gMock can mock non-virtual functions to be used in Hi-perf dependency injection.
+
+In this case, instead of sharing a common base class with the real class, your
+mock class will be *unrelated* to the real class, but contain methods with the
+same signatures. The syntax for mocking non-virtual methods is the *same* as
+mocking virtual methods (just don't add `override`):
+
+```cpp
+// A simple packet stream class.  None of its members is virtual.
+class ConcretePacketStream {
+ public:
+  void AppendPacket(Packet* new_packet);
+  const Packet* GetPacket(size_t packet_number) const;
+  size_t NumberOfPackets() const;
+  ...
+};
+
+// A mock packet stream class.  It inherits from no other, but defines
+// GetPacket() and NumberOfPackets().
+class MockPacketStream {
+ public:
+  MOCK_METHOD(const Packet*, GetPacket, (size_t packet_number), (const));
+  MOCK_METHOD(size_t, NumberOfPackets, (), (const));
+  ...
+};
+```
+
+Note that the mock class doesn't define `AppendPacket()`, unlike the real class.
+That's fine as long as the test doesn't need to call it.
+
+Next, you need a way to say that you want to use `ConcretePacketStream` in
+production code, and use `MockPacketStream` in tests. Since the functions are
+not virtual and the two classes are unrelated, you must specify your choice at
+*compile time* (as opposed to run time).
+
+One way to do it is to templatize your code that needs to use a packet stream.
+More specifically, you will give your code a template type argument for the type
+of the packet stream. In production, you will instantiate your template with
+`ConcretePacketStream` as the type argument. In tests, you will instantiate the
+same template with `MockPacketStream`. For example, you may write:
+
+```cpp
+template <class PacketStream>
+void CreateConnection(PacketStream* stream) { ... }
+
+template <class PacketStream>
+class PacketReader {
+ public:
+  void ReadPackets(PacketStream* stream, size_t packet_num);
+};
+```
+
+Then you can use `CreateConnection<ConcretePacketStream>()` and
+`PacketReader<ConcretePacketStream>` in production code, and use
+`CreateConnection<MockPacketStream>()` and `PacketReader<MockPacketStream>` in
+tests.
+
+```cpp
+  MockPacketStream mock_stream;
+  EXPECT_CALL(mock_stream, ...)...;
+  .. set more expectations on mock_stream ...
+  PacketReader<MockPacketStream> reader(&mock_stream);
+  ... exercise reader ...
+```
+
+### Mocking Free Functions
+
+It is not possible to directly mock a free function (i.e. a C-style function or
+a static method). If you need to, you can rewrite your code to use an interface
+(abstract class).
+
+Instead of calling a free function (say, `OpenFile`) directly, introduce an
+interface for it and have a concrete subclass that calls the free function:
+
+```cpp
+class FileInterface {
+ public:
+  ...
+  virtual bool Open(const char* path, const char* mode) = 0;
+};
+
+class File : public FileInterface {
+ public:
+  ...
+  bool Open(const char* path, const char* mode) override {
+     return OpenFile(path, mode);
+  }
+};
+```
+
+Your code should talk to `FileInterface` to open a file. Now it's easy to mock
+out the function.
+
+This may seem like a lot of hassle, but in practice you often have multiple
+related functions that you can put in the same interface, so the per-function
+syntactic overhead will be much lower.
+
+If you are concerned about the performance overhead incurred by virtual
+functions, and profiling confirms your concern, you can combine this with the
+recipe for [mocking non-virtual methods](#MockingNonVirtualMethods).
+
+Alternatively, instead of introducing a new interface, you can rewrite your code
+to accept a std::function instead of the free function, and then use
+[MockFunction](#MockFunction) to mock the std::function.
+
+### Old-Style `MOCK_METHODn` Macros
+
+Before the generic `MOCK_METHOD` macro
+[was introduced in 2018](https://github.com/google/googletest/commit/c5f08bf91944ce1b19bcf414fa1760e69d20afc2),
+mocks where created using a family of macros collectively called `MOCK_METHODn`.
+These macros are still supported, though migration to the new `MOCK_METHOD` is
+recommended.
+
+The macros in the `MOCK_METHODn` family differ from `MOCK_METHOD`:
+
+*   The general structure is `MOCK_METHODn(MethodName, ReturnType(Args))`,
+    instead of `MOCK_METHOD(ReturnType, MethodName, (Args))`.
+*   The number `n` must equal the number of arguments.
+*   When mocking a const method, one must use `MOCK_CONST_METHODn`.
+*   When mocking a class template, the macro name must be suffixed with `_T`.
+*   In order to specify the call type, the macro name must be suffixed with
+    `_WITH_CALLTYPE`, and the call type is the first macro argument.
+
+Old macros and their new equivalents:
+
+<table>
+  <tr><th colspan=2>Simple</th></tr>
+  <tr>
+    <td>Old</td>
+    <td><code>MOCK_METHOD1(Foo, bool(int))</code></td>
+  </tr>
+  <tr>
+    <td>New</td>
+    <td><code>MOCK_METHOD(bool, Foo, (int))</code></td>
+  </tr>
+
+  <tr><th colspan=2>Const Method</th></tr>
+  <tr>
+    <td>Old</td>
+    <td><code>MOCK_CONST_METHOD1(Foo, bool(int))</code></td>
+  </tr>
+  <tr>
+    <td>New</td>
+    <td><code>MOCK_METHOD(bool, Foo, (int), (const))</code></td>
+  </tr>
+
+  <tr><th colspan=2>Method in a Class Template</th></tr>
+  <tr>
+    <td>Old</td>
+    <td><code>MOCK_METHOD1_T(Foo, bool(int))</code></td>
+  </tr>
+  <tr>
+    <td>New</td>
+    <td><code>MOCK_METHOD(bool, Foo, (int))</code></td>
+  </tr>
+
+  <tr><th colspan=2>Const Method in a Class Template</th></tr>
+  <tr>
+    <td>Old</td>
+    <td><code>MOCK_CONST_METHOD1_T(Foo, bool(int))</code></td>
+  </tr>
+  <tr>
+    <td>New</td>
+    <td><code>MOCK_METHOD(bool, Foo, (int), (const))</code></td>
+  </tr>
+
+  <tr><th colspan=2>Method with Call Type</th></tr>
+  <tr>
+    <td>Old</td>
+    <td><code>MOCK_METHOD1_WITH_CALLTYPE(STDMETHODCALLTYPE, Foo, bool(int))</code></td>
+  </tr>
+  <tr>
+    <td>New</td>
+    <td><code>MOCK_METHOD(bool, Foo, (int), (Calltype(STDMETHODCALLTYPE)))</code></td>
+  </tr>
+
+  <tr><th colspan=2>Const Method with Call Type</th></tr>
+  <tr>
+    <td>Old</td>
+    <td><code>MOCK_CONST_METHOD1_WITH_CALLTYPE(STDMETHODCALLTYPE, Foo, bool(int))</code></td>
+  </tr>
+  <tr>
+    <td>New</td>
+    <td><code>MOCK_METHOD(bool, Foo, (int), (const, Calltype(STDMETHODCALLTYPE)))</code></td>
+  </tr>
+
+  <tr><th colspan=2>Method with Call Type in a Class Template</th></tr>
+  <tr>
+    <td>Old</td>
+    <td><code>MOCK_METHOD1_T_WITH_CALLTYPE(STDMETHODCALLTYPE, Foo, bool(int))</code></td>
+  </tr>
+  <tr>
+    <td>New</td>
+    <td><code>MOCK_METHOD(bool, Foo, (int), (Calltype(STDMETHODCALLTYPE)))</code></td>
+  </tr>
+
+  <tr><th colspan=2>Const Method with Call Type in a Class Template</th></tr>
+  <tr>
+    <td>Old</td>
+    <td><code>MOCK_CONST_METHOD1_T_WITH_CALLTYPE(STDMETHODCALLTYPE, Foo, bool(int))</code></td>
+  </tr>
+  <tr>
+    <td>New</td>
+    <td><code>MOCK_METHOD(bool, Foo, (int), (const, Calltype(STDMETHODCALLTYPE)))</code></td>
+  </tr>
+</table>
+
+### The Nice, the Strict, and the Naggy {#NiceStrictNaggy}
+
+If a mock method has no `EXPECT_CALL` spec but is called, we say that it's an
+"uninteresting call", and the default action (which can be specified using
+`ON_CALL()`) of the method will be taken. Currently, an uninteresting call will
+also by default cause gMock to print a warning.
+
+However, sometimes you may want to ignore these uninteresting calls, and
+sometimes you may want to treat them as errors. gMock lets you make the decision
+on a per-mock-object basis.
+
+Suppose your test uses a mock class `MockFoo`:
+
+```cpp
+TEST(...) {
+  MockFoo mock_foo;
+  EXPECT_CALL(mock_foo, DoThis());
+  ... code that uses mock_foo ...
+}
+```
+
+If a method of `mock_foo` other than `DoThis()` is called, you will get a
+warning. However, if you rewrite your test to use `NiceMock<MockFoo>` instead,
+you can suppress the warning:
+
+```cpp
+using ::testing::NiceMock;
+
+TEST(...) {
+  NiceMock<MockFoo> mock_foo;
+  EXPECT_CALL(mock_foo, DoThis());
+  ... code that uses mock_foo ...
+}
+```
+
+`NiceMock<MockFoo>` is a subclass of `MockFoo`, so it can be used wherever
+`MockFoo` is accepted.
+
+It also works if `MockFoo`'s constructor takes some arguments, as
+`NiceMock<MockFoo>` "inherits" `MockFoo`'s constructors:
+
+```cpp
+using ::testing::NiceMock;
+
+TEST(...) {
+  NiceMock<MockFoo> mock_foo(5, "hi");  // Calls MockFoo(5, "hi").
+  EXPECT_CALL(mock_foo, DoThis());
+  ... code that uses mock_foo ...
+}
+```
+
+The usage of `StrictMock` is similar, except that it makes all uninteresting
+calls failures:
+
+```cpp
+using ::testing::StrictMock;
+
+TEST(...) {
+  StrictMock<MockFoo> mock_foo;
+  EXPECT_CALL(mock_foo, DoThis());
+  ... code that uses mock_foo ...
+
+  // The test will fail if a method of mock_foo other than DoThis()
+  // is called.
+}
+```
+
+{: .callout .note}
+NOTE: `NiceMock` and `StrictMock` only affects *uninteresting* calls (calls of
+*methods* with no expectations); they do not affect *unexpected* calls (calls of
+methods with expectations, but they don't match). See
+[Understanding Uninteresting vs Unexpected Calls](#uninteresting-vs-unexpected).
+
+There are some caveats though (sadly they are side effects of C++'s
+limitations):
+
+1.  `NiceMock<MockFoo>` and `StrictMock<MockFoo>` only work for mock methods
+    defined using the `MOCK_METHOD` macro **directly** in the `MockFoo` class.
+    If a mock method is defined in a **base class** of `MockFoo`, the "nice" or
+    "strict" modifier may not affect it, depending on the compiler. In
+    particular, nesting `NiceMock` and `StrictMock` (e.g.
+    `NiceMock<StrictMock<MockFoo> >`) is **not** supported.
+2.  `NiceMock<MockFoo>` and `StrictMock<MockFoo>` may not work correctly if the
+    destructor of `MockFoo` is not virtual. We would like to fix this, but it
+    requires cleaning up existing tests.
+
+Finally, you should be **very cautious** about when to use naggy or strict
+mocks, as they tend to make tests more brittle and harder to maintain. When you
+refactor your code without changing its externally visible behavior, ideally you
+shouldn't need to update any tests. If your code interacts with a naggy mock,
+however, you may start to get spammed with warnings as the result of your
+change. Worse, if your code interacts with a strict mock, your tests may start
+to fail and you'll be forced to fix them. Our general recommendation is to use
+nice mocks (not yet the default) most of the time, use naggy mocks (the current
+default) when developing or debugging tests, and use strict mocks only as the
+last resort.
+
+### Simplifying the Interface without Breaking Existing Code {#SimplerInterfaces}
+
+Sometimes a method has a long list of arguments that is mostly uninteresting.
+For example:
+
+```cpp
+class LogSink {
+ public:
+  ...
+  virtual void send(LogSeverity severity, const char* full_filename,
+                    const char* base_filename, int line,
+                    const struct tm* tm_time,
+                    const char* message, size_t message_len) = 0;
+};
+```
+
+This method's argument list is lengthy and hard to work with (the `message`
+argument is not even 0-terminated). If we mock it as is, using the mock will be
+awkward. If, however, we try to simplify this interface, we'll need to fix all
+clients depending on it, which is often infeasible.
+
+The trick is to redispatch the method in the mock class:
+
+```cpp
+class ScopedMockLog : public LogSink {
+ public:
+  ...
+  void send(LogSeverity severity, const char* full_filename,
+                    const char* base_filename, int line, const tm* tm_time,
+                    const char* message, size_t message_len) override {
+    // We are only interested in the log severity, full file name, and
+    // log message.
+    Log(severity, full_filename, std::string(message, message_len));
+  }
+
+  // Implements the mock method:
+  //
+  //   void Log(LogSeverity severity,
+  //            const string& file_path,
+  //            const string& message);
+  MOCK_METHOD(void, Log,
+              (LogSeverity severity, const string& file_path,
+               const string& message));
+};
+```
+
+By defining a new mock method with a trimmed argument list, we make the mock
+class more user-friendly.
+
+This technique may also be applied to make overloaded methods more amenable to
+mocking. For example, when overloads have been used to implement default
+arguments:
+
+```cpp
+class MockTurtleFactory : public TurtleFactory {
+ public:
+  Turtle* MakeTurtle(int length, int weight) override { ... }
+  Turtle* MakeTurtle(int length, int weight, int speed) override { ... }
+
+  // the above methods delegate to this one:
+  MOCK_METHOD(Turtle*, DoMakeTurtle, ());
+};
+```
+
+This allows tests that don't care which overload was invoked to avoid specifying
+argument matchers:
+
+```cpp
+ON_CALL(factory, DoMakeTurtle)
+    .WillByDefault(Return(MakeMockTurtle()));
+```
+
+### Alternative to Mocking Concrete Classes
+
+Often you may find yourself using classes that don't implement interfaces. In
+order to test your code that uses such a class (let's call it `Concrete`), you
+may be tempted to make the methods of `Concrete` virtual and then mock it.
+
+Try not to do that.
+
+Making a non-virtual function virtual is a big decision. It creates an extension
+point where subclasses can tweak your class' behavior. This weakens your control
+on the class because now it's harder to maintain the class invariants. You
+should make a function virtual only when there is a valid reason for a subclass
+to override it.
+
+Mocking concrete classes directly is problematic as it creates a tight coupling
+between the class and the tests - any small change in the class may invalidate
+your tests and make test maintenance a pain.
+
+To avoid such problems, many programmers have been practicing "coding to
+interfaces": instead of talking to the `Concrete` class, your code would define
+an interface and talk to it. Then you implement that interface as an adaptor on
+top of `Concrete`. In tests, you can easily mock that interface to observe how
+your code is doing.
+
+This technique incurs some overhead:
+
+*   You pay the cost of virtual function calls (usually not a problem).
+*   There is more abstraction for the programmers to learn.
+
+However, it can also bring significant benefits in addition to better
+testability:
+
+*   `Concrete`'s API may not fit your problem domain very well, as you may not
+    be the only client it tries to serve. By designing your own interface, you
+    have a chance to tailor it to your need - you may add higher-level
+    functionalities, rename stuff, etc instead of just trimming the class. This
+    allows you to write your code (user of the interface) in a more natural way,
+    which means it will be more readable, more maintainable, and you'll be more
+    productive.
+*   If `Concrete`'s implementation ever has to change, you don't have to rewrite
+    everywhere it is used. Instead, you can absorb the change in your
+    implementation of the interface, and your other code and tests will be
+    insulated from this change.
+
+Some people worry that if everyone is practicing this technique, they will end
+up writing lots of redundant code. This concern is totally understandable.
+However, there are two reasons why it may not be the case:
+
+*   Different projects may need to use `Concrete` in different ways, so the best
+    interfaces for them will be different. Therefore, each of them will have its
+    own domain-specific interface on top of `Concrete`, and they will not be the
+    same code.
+*   If enough projects want to use the same interface, they can always share it,
+    just like they have been sharing `Concrete`. You can check in the interface
+    and the adaptor somewhere near `Concrete` (perhaps in a `contrib`
+    sub-directory) and let many projects use it.
+
+You need to weigh the pros and cons carefully for your particular problem, but
+I'd like to assure you that the Java community has been practicing this for a
+long time and it's a proven effective technique applicable in a wide variety of
+situations. :-)
+
+### Delegating Calls to a Fake {#DelegatingToFake}
+
+Some times you have a non-trivial fake implementation of an interface. For
+example:
+
+```cpp
+class Foo {
+ public:
+  virtual ~Foo() {}
+  virtual char DoThis(int n) = 0;
+  virtual void DoThat(const char* s, int* p) = 0;
+};
+
+class FakeFoo : public Foo {
+ public:
+  char DoThis(int n) override {
+    return (n > 0) ? '+' :
+           (n < 0) ? '-' : '0';
+  }
+
+  void DoThat(const char* s, int* p) override {
+    *p = strlen(s);
+  }
+};
+```
+
+Now you want to mock this interface such that you can set expectations on it.
+However, you also want to use `FakeFoo` for the default behavior, as duplicating
+it in the mock object is, well, a lot of work.
+
+When you define the mock class using gMock, you can have it delegate its default
+action to a fake class you already have, using this pattern:
+
+```cpp
+class MockFoo : public Foo {
+ public:
+  // Normal mock method definitions using gMock.
+  MOCK_METHOD(char, DoThis, (int n), (override));
+  MOCK_METHOD(void, DoThat, (const char* s, int* p), (override));
+
+  // Delegates the default actions of the methods to a FakeFoo object.
+  // This must be called *before* the custom ON_CALL() statements.
+  void DelegateToFake() {
+    ON_CALL(*this, DoThis).WillByDefault([this](int n) {
+      return fake_.DoThis(n);
+    });
+    ON_CALL(*this, DoThat).WillByDefault([this](const char* s, int* p) {
+      fake_.DoThat(s, p);
+    });
+  }
+
+ private:
+  FakeFoo fake_;  // Keeps an instance of the fake in the mock.
+};
+```
+
+With that, you can use `MockFoo` in your tests as usual. Just remember that if
+you don't explicitly set an action in an `ON_CALL()` or `EXPECT_CALL()`, the
+fake will be called upon to do it.:
+
+```cpp
+using ::testing::_;
+
+TEST(AbcTest, Xyz) {
+  MockFoo foo;
+
+  foo.DelegateToFake();  // Enables the fake for delegation.
+
+  // Put your ON_CALL(foo, ...)s here, if any.
+
+  // No action specified, meaning to use the default action.
+  EXPECT_CALL(foo, DoThis(5));
+  EXPECT_CALL(foo, DoThat(_, _));
+
+  int n = 0;
+  EXPECT_EQ(foo.DoThis(5), '+');  // FakeFoo::DoThis() is invoked.
+  foo.DoThat("Hi", &n);  // FakeFoo::DoThat() is invoked.
+  EXPECT_EQ(n, 2);
+}
+```
+
+**Some tips:**
+
+*   If you want, you can still override the default action by providing your own
+    `ON_CALL()` or using `.WillOnce()` / `.WillRepeatedly()` in `EXPECT_CALL()`.
+*   In `DelegateToFake()`, you only need to delegate the methods whose fake
+    implementation you intend to use.
+
+*   The general technique discussed here works for overloaded methods, but
+    you'll need to tell the compiler which version you mean. To disambiguate a
+    mock function (the one you specify inside the parentheses of `ON_CALL()`),
+    use [this technique](#SelectOverload); to disambiguate a fake function (the
+    one you place inside `Invoke()`), use a `static_cast` to specify the
+    function's type. For instance, if class `Foo` has methods `char DoThis(int
+    n)` and `bool DoThis(double x) const`, and you want to invoke the latter,
+    you need to write `Invoke(&fake_, static_cast<bool (FakeFoo::*)(double)
+    const>(&FakeFoo::DoThis))` instead of `Invoke(&fake_, &FakeFoo::DoThis)`
+    (The strange-looking thing inside the angled brackets of `static_cast` is
+    the type of a function pointer to the second `DoThis()` method.).
+
+*   Having to mix a mock and a fake is often a sign of something gone wrong.
+    Perhaps you haven't got used to the interaction-based way of testing yet. Or
+    perhaps your interface is taking on too many roles and should be split up.
+    Therefore, **don't abuse this**. We would only recommend to do it as an
+    intermediate step when you are refactoring your code.
+
+Regarding the tip on mixing a mock and a fake, here's an example on why it may
+be a bad sign: Suppose you have a class `System` for low-level system
+operations. In particular, it does file and I/O operations. And suppose you want
+to test how your code uses `System` to do I/O, and you just want the file
+operations to work normally. If you mock out the entire `System` class, you'll
+have to provide a fake implementation for the file operation part, which
+suggests that `System` is taking on too many roles.
+
+Instead, you can define a `FileOps` interface and an `IOOps` interface and split
+`System`'s functionalities into the two. Then you can mock `IOOps` without
+mocking `FileOps`.
+
+### Delegating Calls to a Real Object
+
+When using testing doubles (mocks, fakes, stubs, and etc), sometimes their
+behaviors will differ from those of the real objects. This difference could be
+either intentional (as in simulating an error such that you can test the error
+handling code) or unintentional. If your mocks have different behaviors than the
+real objects by mistake, you could end up with code that passes the tests but
+fails in production.
+
+You can use the *delegating-to-real* technique to ensure that your mock has the
+same behavior as the real object while retaining the ability to validate calls.
+This technique is very similar to the [delegating-to-fake](#DelegatingToFake)
+technique, the difference being that we use a real object instead of a fake.
+Here's an example:
+
+```cpp
+using ::testing::AtLeast;
+
+class MockFoo : public Foo {
+ public:
+  MockFoo() {
+    // By default, all calls are delegated to the real object.
+    ON_CALL(*this, DoThis).WillByDefault([this](int n) {
+      return real_.DoThis(n);
+    });
+    ON_CALL(*this, DoThat).WillByDefault([this](const char* s, int* p) {
+      real_.DoThat(s, p);
+    });
+    ...
+  }
+  MOCK_METHOD(char, DoThis, ...);
+  MOCK_METHOD(void, DoThat, ...);
+  ...
+ private:
+  Foo real_;
+};
+
+...
+  MockFoo mock;
+  EXPECT_CALL(mock, DoThis())
+      .Times(3);
+  EXPECT_CALL(mock, DoThat("Hi"))
+      .Times(AtLeast(1));
+  ... use mock in test ...
+```
+
+With this, gMock will verify that your code made the right calls (with the right
+arguments, in the right order, called the right number of times, etc), and a
+real object will answer the calls (so the behavior will be the same as in
+production). This gives you the best of both worlds.
+
+### Delegating Calls to a Parent Class
+
+Ideally, you should code to interfaces, whose methods are all pure virtual. In
+reality, sometimes you do need to mock a virtual method that is not pure (i.e,
+it already has an implementation). For example:
+
+```cpp
+class Foo {
+ public:
+  virtual ~Foo();
+
+  virtual void Pure(int n) = 0;
+  virtual int Concrete(const char* str) { ... }
+};
+
+class MockFoo : public Foo {
+ public:
+  // Mocking a pure method.
+  MOCK_METHOD(void, Pure, (int n), (override));
+  // Mocking a concrete method.  Foo::Concrete() is shadowed.
+  MOCK_METHOD(int, Concrete, (const char* str), (override));
+};
+```
+
+Sometimes you may want to call `Foo::Concrete()` instead of
+`MockFoo::Concrete()`. Perhaps you want to do it as part of a stub action, or
+perhaps your test doesn't need to mock `Concrete()` at all (but it would be
+oh-so painful to have to define a new mock class whenever you don't need to mock
+one of its methods).
+
+You can call `Foo::Concrete()` inside an action by:
+
+```cpp
+...
+  EXPECT_CALL(foo, Concrete).WillOnce([&foo](const char* str) {
+    return foo.Foo::Concrete(str);
+  });
+```
+
+or tell the mock object that you don't want to mock `Concrete()`:
+
+```cpp
+...
+  ON_CALL(foo, Concrete).WillByDefault([&foo](const char* str) {
+    return foo.Foo::Concrete(str);
+  });
+```
+
+(Why don't we just write `{ return foo.Concrete(str); }`? If you do that,
+`MockFoo::Concrete()` will be called (and cause an infinite recursion) since
+`Foo::Concrete()` is virtual. That's just how C++ works.)
+
+## Using Matchers
+
+### Matching Argument Values Exactly
+
+You can specify exactly which arguments a mock method is expecting:
+
+```cpp
+using ::testing::Return;
+...
+  EXPECT_CALL(foo, DoThis(5))
+      .WillOnce(Return('a'));
+  EXPECT_CALL(foo, DoThat("Hello", bar));
+```
+
+### Using Simple Matchers
+
+You can use matchers to match arguments that have a certain property:
+
+```cpp
+using ::testing::NotNull;
+using ::testing::Return;
+...
+  EXPECT_CALL(foo, DoThis(Ge(5)))  // The argument must be >= 5.
+      .WillOnce(Return('a'));
+  EXPECT_CALL(foo, DoThat("Hello", NotNull()));
+      // The second argument must not be NULL.
+```
+
+A frequently used matcher is `_`, which matches anything:
+
+```cpp
+  EXPECT_CALL(foo, DoThat(_, NotNull()));
+```
+
+### Combining Matchers {#CombiningMatchers}
+
+You can build complex matchers from existing ones using `AllOf()`,
+`AllOfArray()`, `AnyOf()`, `AnyOfArray()` and `Not()`:
+
+```cpp
+using ::testing::AllOf;
+using ::testing::Gt;
+using ::testing::HasSubstr;
+using ::testing::Ne;
+using ::testing::Not;
+...
+  // The argument must be > 5 and != 10.
+  EXPECT_CALL(foo, DoThis(AllOf(Gt(5),
+                                Ne(10))));
+
+  // The first argument must not contain sub-string "blah".
+  EXPECT_CALL(foo, DoThat(Not(HasSubstr("blah")),
+                          NULL));
+```
+
+Matchers are function objects, and parametrized matchers can be composed just
+like any other function. However because their types can be long and rarely
+provide meaningful information, it can be easier to express them with C++14
+generic lambdas to avoid specifying types. For example,
+
+```cpp
+using ::testing::Contains;
+using ::testing::Property;
+
+inline constexpr auto HasFoo = [](const auto& f) {
+  return Property("foo", &MyClass::foo, Contains(f));
+};
+...
+  EXPECT_THAT(x, HasFoo("blah"));
+```
+
+### Casting Matchers {#SafeMatcherCast}
+
+gMock matchers are statically typed, meaning that the compiler can catch your
+mistake if you use a matcher of the wrong type (for example, if you use `Eq(5)`
+to match a `string` argument). Good for you!
+
+Sometimes, however, you know what you're doing and want the compiler to give you
+some slack. One example is that you have a matcher for `long` and the argument
+you want to match is `int`. While the two types aren't exactly the same, there
+is nothing really wrong with using a `Matcher<long>` to match an `int` - after
+all, we can first convert the `int` argument to a `long` losslessly before
+giving it to the matcher.
+
+To support this need, gMock gives you the `SafeMatcherCast<T>(m)` function. It
+casts a matcher `m` to type `Matcher<T>`. To ensure safety, gMock checks that
+(let `U` be the type `m` accepts :
+
+1.  Type `T` can be *implicitly* cast to type `U`;
+2.  When both `T` and `U` are built-in arithmetic types (`bool`, integers, and
+    floating-point numbers), the conversion from `T` to `U` is not lossy (in
+    other words, any value representable by `T` can also be represented by `U`);
+    and
+3.  When `U` is a reference, `T` must also be a reference (as the underlying
+    matcher may be interested in the address of the `U` value).
+
+The code won't compile if any of these conditions isn't met.
+
+Here's one example:
+
+```cpp
+using ::testing::SafeMatcherCast;
+
+// A base class and a child class.
+class Base { ... };
+class Derived : public Base { ... };
+
+class MockFoo : public Foo {
+ public:
+  MOCK_METHOD(void, DoThis, (Derived* derived), (override));
+};
+
+...
+  MockFoo foo;
+  // m is a Matcher<Base*> we got from somewhere.
+  EXPECT_CALL(foo, DoThis(SafeMatcherCast<Derived*>(m)));
+```
+
+If you find `SafeMatcherCast<T>(m)` too limiting, you can use a similar function
+`MatcherCast<T>(m)`. The difference is that `MatcherCast` works as long as you
+can `static_cast` type `T` to type `U`.
+
+`MatcherCast` essentially lets you bypass C++'s type system (`static_cast` isn't
+always safe as it could throw away information, for example), so be careful not
+to misuse/abuse it.
+
+### Selecting Between Overloaded Functions {#SelectOverload}
+
+If you expect an overloaded function to be called, the compiler may need some
+help on which overloaded version it is.
+
+To disambiguate functions overloaded on the const-ness of this object, use the
+`Const()` argument wrapper.
+
+```cpp
+using ::testing::ReturnRef;
+
+class MockFoo : public Foo {
+  ...
+  MOCK_METHOD(Bar&, GetBar, (), (override));
+  MOCK_METHOD(const Bar&, GetBar, (), (const, override));
+};
+
+...
+  MockFoo foo;
+  Bar bar1, bar2;
+  EXPECT_CALL(foo, GetBar())         // The non-const GetBar().
+      .WillOnce(ReturnRef(bar1));
+  EXPECT_CALL(Const(foo), GetBar())  // The const GetBar().
+      .WillOnce(ReturnRef(bar2));
+```
+
+(`Const()` is defined by gMock and returns a `const` reference to its argument.)
+
+To disambiguate overloaded functions with the same number of arguments but
+different argument types, you may need to specify the exact type of a matcher,
+either by wrapping your matcher in `Matcher<type>()`, or using a matcher whose
+type is fixed (`TypedEq<type>`, `An<type>()`, etc):
+
+```cpp
+using ::testing::An;
+using ::testing::Matcher;
+using ::testing::TypedEq;
+
+class MockPrinter : public Printer {
+ public:
+  MOCK_METHOD(void, Print, (int n), (override));
+  MOCK_METHOD(void, Print, (char c), (override));
+};
+
+TEST(PrinterTest, Print) {
+  MockPrinter printer;
+
+  EXPECT_CALL(printer, Print(An<int>()));            // void Print(int);
+  EXPECT_CALL(printer, Print(Matcher<int>(Lt(5))));  // void Print(int);
+  EXPECT_CALL(printer, Print(TypedEq<char>('a')));   // void Print(char);
+
+  printer.Print(3);
+  printer.Print(6);
+  printer.Print('a');
+}
+```
+
+### Performing Different Actions Based on the Arguments
+
+When a mock method is called, the *last* matching expectation that's still
+active will be selected (think "newer overrides older"). So, you can make a
+method do different things depending on its argument values like this:
+
+```cpp
+using ::testing::_;
+using ::testing::Lt;
+using ::testing::Return;
+...
+  // The default case.
+  EXPECT_CALL(foo, DoThis(_))
+      .WillRepeatedly(Return('b'));
+  // The more specific case.
+  EXPECT_CALL(foo, DoThis(Lt(5)))
+      .WillRepeatedly(Return('a'));
+```
+
+Now, if `foo.DoThis()` is called with a value less than 5, `'a'` will be
+returned; otherwise `'b'` will be returned.
+
+### Matching Multiple Arguments as a Whole
+
+Sometimes it's not enough to match the arguments individually. For example, we
+may want to say that the first argument must be less than the second argument.
+The `With()` clause allows us to match all arguments of a mock function as a
+whole. For example,
+
+```cpp
+using ::testing::_;
+using ::testing::Ne;
+using ::testing::Lt;
+...
+  EXPECT_CALL(foo, InRange(Ne(0), _))
+      .With(Lt());
+```
+
+says that the first argument of `InRange()` must not be 0, and must be less than
+the second argument.
+
+The expression inside `With()` must be a matcher of type `Matcher<std::tuple<A1,
+..., An>>`, where `A1`, ..., `An` are the types of the function arguments.
+
+You can also write `AllArgs(m)` instead of `m` inside `.With()`. The two forms
+are equivalent, but `.With(AllArgs(Lt()))` is more readable than `.With(Lt())`.
+
+You can use `Args<k1, ..., kn>(m)` to match the `n` selected arguments (as a
+tuple) against `m`. For example,
+
+```cpp
+using ::testing::_;
+using ::testing::AllOf;
+using ::testing::Args;
+using ::testing::Lt;
+...
+  EXPECT_CALL(foo, Blah)
+      .With(AllOf(Args<0, 1>(Lt()), Args<1, 2>(Lt())));
+```
+
+says that `Blah` will be called with arguments `x`, `y`, and `z` where `x < y <
+z`. Note that in this example, it wasn't necessary to specify the positional
+matchers.
+
+As a convenience and example, gMock provides some matchers for 2-tuples,
+including the `Lt()` matcher above. See
+[Multi-argument Matchers](reference/matchers.md#MultiArgMatchers) for the
+complete list.
+
+Note that if you want to pass the arguments to a predicate of your own (e.g.
+`.With(Args<0, 1>(Truly(&MyPredicate)))`), that predicate MUST be written to
+take a `std::tuple` as its argument; gMock will pass the `n` selected arguments
+as *one* single tuple to the predicate.
+
+### Using Matchers as Predicates
+
+Have you noticed that a matcher is just a fancy predicate that also knows how to
+describe itself? Many existing algorithms take predicates as arguments (e.g.
+those defined in STL's `<algorithm>` header), and it would be a shame if gMock
+matchers were not allowed to participate.
+
+Luckily, you can use a matcher where a unary predicate functor is expected by
+wrapping it inside the `Matches()` function. For example,
+
+```cpp
+#include <algorithm>
+#include <vector>
+
+using ::testing::Matches;
+using ::testing::Ge;
+
+vector<int> v;
+...
+// How many elements in v are >= 10?
+const int count = count_if(v.begin(), v.end(), Matches(Ge(10)));
+```
+
+Since you can build complex matchers from simpler ones easily using gMock, this
+gives you a way to conveniently construct composite predicates (doing the same
+using STL's `<functional>` header is just painful). For example, here's a
+predicate that's satisfied by any number that is >= 0, <= 100, and != 50:
+
+```cpp
+using ::testing::AllOf;
+using ::testing::Ge;
+using ::testing::Le;
+using ::testing::Matches;
+using ::testing::Ne;
+...
+Matches(AllOf(Ge(0), Le(100), Ne(50)))
+```
+
+### Using Matchers in googletest Assertions
+
+See [`EXPECT_THAT`](reference/assertions.md#EXPECT_THAT) in the Assertions
+Reference.
+
+### Using Predicates as Matchers
+
+gMock provides a set of built-in matchers for matching arguments with expected
+values—see the [Matchers Reference](reference/matchers.md) for more information.
+In case you find the built-in set lacking, you can use an arbitrary unary
+predicate function or functor as a matcher - as long as the predicate accepts a
+value of the type you want. You do this by wrapping the predicate inside the
+`Truly()` function, for example:
+
+```cpp
+using ::testing::Truly;
+
+int IsEven(int n) { return (n % 2) == 0 ? 1 : 0; }
+...
+  // Bar() must be called with an even number.
+  EXPECT_CALL(foo, Bar(Truly(IsEven)));
+```
+
+Note that the predicate function / functor doesn't have to return `bool`. It
+works as long as the return value can be used as the condition in the statement
+`if (condition) ...`.
+
+### Matching Arguments that Are Not Copyable
+
+When you do an `EXPECT_CALL(mock_obj, Foo(bar))`, gMock saves away a copy of
+`bar`. When `Foo()` is called later, gMock compares the argument to `Foo()` with
+the saved copy of `bar`. This way, you don't need to worry about `bar` being
+modified or destroyed after the `EXPECT_CALL()` is executed. The same is true
+when you use matchers like `Eq(bar)`, `Le(bar)`, and so on.
+
+But what if `bar` cannot be copied (i.e. has no copy constructor)? You could
+define your own matcher function or callback and use it with `Truly()`, as the
+previous couple of recipes have shown. Or, you may be able to get away from it
+if you can guarantee that `bar` won't be changed after the `EXPECT_CALL()` is
+executed. Just tell gMock that it should save a reference to `bar`, instead of a
+copy of it. Here's how:
+
+```cpp
+using ::testing::Eq;
+using ::testing::Lt;
+...
+  // Expects that Foo()'s argument == bar.
+  EXPECT_CALL(mock_obj, Foo(Eq(std::ref(bar))));
+
+  // Expects that Foo()'s argument < bar.
+  EXPECT_CALL(mock_obj, Foo(Lt(std::ref(bar))));
+```
+
+Remember: if you do this, don't change `bar` after the `EXPECT_CALL()`, or the
+result is undefined.
+
+### Validating a Member of an Object
+
+Often a mock function takes a reference to object as an argument. When matching
+the argument, you may not want to compare the entire object against a fixed
+object, as that may be over-specification. Instead, you may need to validate a
+certain member variable or the result of a certain getter method of the object.
+You can do this with `Field()` and `Property()`. More specifically,
+
+```cpp
+Field(&Foo::bar, m)
+```
+
+is a matcher that matches a `Foo` object whose `bar` member variable satisfies
+matcher `m`.
+
+```cpp
+Property(&Foo::baz, m)
+```
+
+is a matcher that matches a `Foo` object whose `baz()` method returns a value
+that satisfies matcher `m`.
+
+For example:
+
+| Expression                   | Description                              |
+| :--------------------------- | :--------------------------------------- |
+| `Field(&Foo::number, Ge(3))` | Matches `x` where `x.number >= 3`.       |
+| `Property(&Foo::name,  StartsWith("John "))` | Matches `x` where `x.name()` starts with  `"John "`. |
+
+Note that in `Property(&Foo::baz, ...)`, method `baz()` must take no argument
+and be declared as `const`. Don't use `Property()` against member functions that
+you do not own, because taking addresses of functions is fragile and generally
+not part of the contract of the function.
+
+`Field()` and `Property()` can also match plain pointers to objects. For
+instance,
+
+```cpp
+using ::testing::Field;
+using ::testing::Ge;
+...
+Field(&Foo::number, Ge(3))
+```
+
+matches a plain pointer `p` where `p->number >= 3`. If `p` is `NULL`, the match
+will always fail regardless of the inner matcher.
+
+What if you want to validate more than one members at the same time? Remember
+that there are [`AllOf()` and `AllOfArray()`](#CombiningMatchers).
+
+Finally `Field()` and `Property()` provide overloads that take the field or
+property names as the first argument to include it in the error message. This
+can be useful when creating combined matchers.
+
+```cpp
+using ::testing::AllOf;
+using ::testing::Field;
+using ::testing::Matcher;
+using ::testing::SafeMatcherCast;
+
+Matcher<Foo> IsFoo(const Foo& foo) {
+  return AllOf(Field("some_field", &Foo::some_field, foo.some_field),
+               Field("other_field", &Foo::other_field, foo.other_field),
+               Field("last_field", &Foo::last_field, foo.last_field));
+}
+```
+
+### Validating the Value Pointed to by a Pointer Argument
+
+C++ functions often take pointers as arguments. You can use matchers like
+`IsNull()`, `NotNull()`, and other comparison matchers to match a pointer, but
+what if you want to make sure the value *pointed to* by the pointer, instead of
+the pointer itself, has a certain property? Well, you can use the `Pointee(m)`
+matcher.
+
+`Pointee(m)` matches a pointer if and only if `m` matches the value the pointer
+points to. For example:
+
+```cpp
+using ::testing::Ge;
+using ::testing::Pointee;
+...
+  EXPECT_CALL(foo, Bar(Pointee(Ge(3))));
+```
+
+expects `foo.Bar()` to be called with a pointer that points to a value greater
+than or equal to 3.
+
+One nice thing about `Pointee()` is that it treats a `NULL` pointer as a match
+failure, so you can write `Pointee(m)` instead of
+
+```cpp
+using ::testing::AllOf;
+using ::testing::NotNull;
+using ::testing::Pointee;
+...
+  AllOf(NotNull(), Pointee(m))
+```
+
+without worrying that a `NULL` pointer will crash your test.
+
+Also, did we tell you that `Pointee()` works with both raw pointers **and**
+smart pointers (`std::unique_ptr`, `std::shared_ptr`, etc)?
+
+What if you have a pointer to pointer? You guessed it - you can use nested
+`Pointee()` to probe deeper inside the value. For example,
+`Pointee(Pointee(Lt(3)))` matches a pointer that points to a pointer that points
+to a number less than 3 (what a mouthful...).
+
+### Defining a Custom Matcher Class {#CustomMatcherClass}
+
+Most matchers can be simply defined using [the MATCHER* macros](#NewMatchers),
+which are terse and flexible, and produce good error messages. However, these
+macros are not very explicit about the interfaces they create and are not always
+suitable, especially for matchers that will be widely reused.
+
+For more advanced cases, you may need to define your own matcher class. A custom
+matcher allows you to test a specific invariant property of that object. Let's
+take a look at how to do so.
+
+Imagine you have a mock function that takes an object of type `Foo`, which has
+an `int bar()` method and an `int baz()` method. You want to constrain that the
+argument's `bar()` value plus its `baz()` value is a given number. (This is an
+invariant.) Here's how we can write and use a matcher class to do so:
+
+```cpp
+class BarPlusBazEqMatcher {
+ public:
+  using is_gtest_matcher = void;
+
+  explicit BarPlusBazEqMatcher(int expected_sum)
+      : expected_sum_(expected_sum) {}
+
+  bool MatchAndExplain(const Foo& foo,
+                       std::ostream* /* listener */) const {
+    return (foo.bar() + foo.baz()) == expected_sum_;
+  }
+
+  void DescribeTo(std::ostream* os) const {
+    *os << "bar() + baz() equals " << expected_sum_;
+  }
+
+  void DescribeNegationTo(std::ostream* os) const {
+    *os << "bar() + baz() does not equal " << expected_sum_;
+  }
+ private:
+  const int expected_sum_;
+};
+
+::testing::Matcher<const Foo&> BarPlusBazEq(int expected_sum) {
+  return BarPlusBazEqMatcher(expected_sum);
+}
+
+...
+  Foo foo;
+  EXPECT_THAT(foo, BarPlusBazEq(5))...;
+```
+
+### Matching Containers
+
+Sometimes an STL container (e.g. list, vector, map, ...) is passed to a mock
+function and you may want to validate it. Since most STL containers support the
+`==` operator, you can write `Eq(expected_container)` or simply
+`expected_container` to match a container exactly.
+
+Sometimes, though, you may want to be more flexible (for example, the first
+element must be an exact match, but the second element can be any positive
+number, and so on). Also, containers used in tests often have a small number of
+elements, and having to define the expected container out-of-line is a bit of a
+hassle.
+
+You can use the `ElementsAre()` or `UnorderedElementsAre()` matcher in such
+cases:
+
+```cpp
+using ::testing::_;
+using ::testing::ElementsAre;
+using ::testing::Gt;
+...
+  MOCK_METHOD(void, Foo, (const vector<int>& numbers), (override));
+...
+  EXPECT_CALL(mock, Foo(ElementsAre(1, Gt(0), _, 5)));
+```
+
+The above matcher says that the container must have 4 elements, which must be 1,
+greater than 0, anything, and 5 respectively.
+
+If you instead write:
+
+```cpp
+using ::testing::_;
+using ::testing::Gt;
+using ::testing::UnorderedElementsAre;
+...
+  MOCK_METHOD(void, Foo, (const vector<int>& numbers), (override));
+...
+  EXPECT_CALL(mock, Foo(UnorderedElementsAre(1, Gt(0), _, 5)));
+```
+
+It means that the container must have 4 elements, which (under some permutation)
+must be 1, greater than 0, anything, and 5 respectively.
+
+As an alternative you can place the arguments in a C-style array and use
+`ElementsAreArray()` or `UnorderedElementsAreArray()` instead:
+
+```cpp
+using ::testing::ElementsAreArray;
+...
+  // ElementsAreArray accepts an array of element values.
+  const int expected_vector1[] = {1, 5, 2, 4, ...};
+  EXPECT_CALL(mock, Foo(ElementsAreArray(expected_vector1)));
+
+  // Or, an array of element matchers.
+  Matcher<int> expected_vector2[] = {1, Gt(2), _, 3, ...};
+  EXPECT_CALL(mock, Foo(ElementsAreArray(expected_vector2)));
+```
+
+In case the array needs to be dynamically created (and therefore the array size
+cannot be inferred by the compiler), you can give `ElementsAreArray()` an
+additional argument to specify the array size:
+
+```cpp
+using ::testing::ElementsAreArray;
+...
+  int* const expected_vector3 = new int[count];
+  ... fill expected_vector3 with values ...
+  EXPECT_CALL(mock, Foo(ElementsAreArray(expected_vector3, count)));
+```
+
+Use `Pair` when comparing maps or other associative containers.
+
+{% raw %}
+
+```cpp
+using ::testing::UnorderedElementsAre;
+using ::testing::Pair;
+...
+  absl::flat_hash_map<string, int> m = {{"a", 1}, {"b", 2}, {"c", 3}};
+  EXPECT_THAT(m, UnorderedElementsAre(
+      Pair("a", 1), Pair("b", 2), Pair("c", 3)));
+```
+
+{% endraw %}
+
+**Tips:**
+
+*   `ElementsAre*()` can be used to match *any* container that implements the
+    STL iterator pattern (i.e. it has a `const_iterator` type and supports
+    `begin()/end()`), not just the ones defined in STL. It will even work with
+    container types yet to be written - as long as they follows the above
+    pattern.
+*   You can use nested `ElementsAre*()` to match nested (multi-dimensional)
+    containers.
+*   If the container is passed by pointer instead of by reference, just write
+    `Pointee(ElementsAre*(...))`.
+*   The order of elements *matters* for `ElementsAre*()`. If you are using it
+    with containers whose element order are undefined (such as a
+    `std::unordered_map`) you should use `UnorderedElementsAre`.
+
+### Sharing Matchers
+
+Under the hood, a gMock matcher object consists of a pointer to a ref-counted
+implementation object. Copying matchers is allowed and very efficient, as only
+the pointer is copied. When the last matcher that references the implementation
+object dies, the implementation object will be deleted.
+
+Therefore, if you have some complex matcher that you want to use again and
+again, there is no need to build it every time. Just assign it to a matcher
+variable and use that variable repeatedly! For example,
+
+```cpp
+using ::testing::AllOf;
+using ::testing::Gt;
+using ::testing::Le;
+using ::testing::Matcher;
+...
+  Matcher<int> in_range = AllOf(Gt(5), Le(10));
+  ... use in_range as a matcher in multiple EXPECT_CALLs ...
+```
+
+### Matchers must have no side-effects {#PureMatchers}
+
+{: .callout .warning}
+WARNING: gMock does not guarantee when or how many times a matcher will be
+invoked. Therefore, all matchers must be *purely functional*: they cannot have
+any side effects, and the match result must not depend on anything other than
+the matcher's parameters and the value being matched.
+
+This requirement must be satisfied no matter how a matcher is defined (e.g., if
+it is one of the standard matchers, or a custom matcher). In particular, a
+matcher can never call a mock function, as that will affect the state of the
+mock object and gMock.
+
+## Setting Expectations
+
+### Knowing When to Expect {#UseOnCall}
+
+**`ON_CALL`** is likely the *single most under-utilized construct* in gMock.
+
+There are basically two constructs for defining the behavior of a mock object:
+`ON_CALL` and `EXPECT_CALL`. The difference? `ON_CALL` defines what happens when
+a mock method is called, but <em>doesn't imply any expectation on the method
+being called</em>. `EXPECT_CALL` not only defines the behavior, but also sets an
+expectation that <em>the method will be called with the given arguments, for the
+given number of times</em> (and *in the given order* when you specify the order
+too).
+
+Since `EXPECT_CALL` does more, isn't it better than `ON_CALL`? Not really. Every
+`EXPECT_CALL` adds a constraint on the behavior of the code under test. Having
+more constraints than necessary is *baaad* - even worse than not having enough
+constraints.
+
+This may be counter-intuitive. How could tests that verify more be worse than
+tests that verify less? Isn't verification the whole point of tests?
+
+The answer lies in *what* a test should verify. **A good test verifies the
+contract of the code.** If a test over-specifies, it doesn't leave enough
+freedom to the implementation. As a result, changing the implementation without
+breaking the contract (e.g. refactoring and optimization), which should be
+perfectly fine to do, can break such tests. Then you have to spend time fixing
+them, only to see them broken again the next time the implementation is changed.
+
+Keep in mind that one doesn't have to verify more than one property in one test.
+In fact, **it's a good style to verify only one thing in one test.** If you do
+that, a bug will likely break only one or two tests instead of dozens (which
+case would you rather debug?). If you are also in the habit of giving tests
+descriptive names that tell what they verify, you can often easily guess what's
+wrong just from the test log itself.
+
+So use `ON_CALL` by default, and only use `EXPECT_CALL` when you actually intend
+to verify that the call is made. For example, you may have a bunch of `ON_CALL`s
+in your test fixture to set the common mock behavior shared by all tests in the
+same group, and write (scarcely) different `EXPECT_CALL`s in different `TEST_F`s
+to verify different aspects of the code's behavior. Compared with the style
+where each `TEST` has many `EXPECT_CALL`s, this leads to tests that are more
+resilient to implementational changes (and thus less likely to require
+maintenance) and makes the intent of the tests more obvious (so they are easier
+to maintain when you do need to maintain them).
+
+If you are bothered by the "Uninteresting mock function call" message printed
+when a mock method without an `EXPECT_CALL` is called, you may use a `NiceMock`
+instead to suppress all such messages for the mock object, or suppress the
+message for specific methods by adding `EXPECT_CALL(...).Times(AnyNumber())`. DO
+NOT suppress it by blindly adding an `EXPECT_CALL(...)`, or you'll have a test
+that's a pain to maintain.
+
+### Ignoring Uninteresting Calls
+
+If you are not interested in how a mock method is called, just don't say
+anything about it. In this case, if the method is ever called, gMock will
+perform its default action to allow the test program to continue. If you are not
+happy with the default action taken by gMock, you can override it using
+`DefaultValue<T>::Set()` (described [here](#DefaultValue)) or `ON_CALL()`.
+
+Please note that once you expressed interest in a particular mock method (via
+`EXPECT_CALL()`), all invocations to it must match some expectation. If this
+function is called but the arguments don't match any `EXPECT_CALL()` statement,
+it will be an error.
+
+### Disallowing Unexpected Calls
+
+If a mock method shouldn't be called at all, explicitly say so:
+
+```cpp
+using ::testing::_;
+...
+  EXPECT_CALL(foo, Bar(_))
+      .Times(0);
+```
+
+If some calls to the method are allowed, but the rest are not, just list all the
+expected calls:
+
+```cpp
+using ::testing::AnyNumber;
+using ::testing::Gt;
+...
+  EXPECT_CALL(foo, Bar(5));
+  EXPECT_CALL(foo, Bar(Gt(10)))
+      .Times(AnyNumber());
+```
+
+A call to `foo.Bar()` that doesn't match any of the `EXPECT_CALL()` statements
+will be an error.
+
+### Understanding Uninteresting vs Unexpected Calls {#uninteresting-vs-unexpected}
+
+*Uninteresting* calls and *unexpected* calls are different concepts in gMock.
+*Very* different.
+
+A call `x.Y(...)` is **uninteresting** if there's *not even a single*
+`EXPECT_CALL(x, Y(...))` set. In other words, the test isn't interested in the
+`x.Y()` method at all, as evident in that the test doesn't care to say anything
+about it.
+
+A call `x.Y(...)` is **unexpected** if there are *some* `EXPECT_CALL(x,
+Y(...))`s set, but none of them matches the call. Put another way, the test is
+interested in the `x.Y()` method (therefore it explicitly sets some
+`EXPECT_CALL` to verify how it's called); however, the verification fails as the
+test doesn't expect this particular call to happen.
+
+**An unexpected call is always an error,** as the code under test doesn't behave
+the way the test expects it to behave.
+
+**By default, an uninteresting call is not an error,** as it violates no
+constraint specified by the test. (gMock's philosophy is that saying nothing
+means there is no constraint.) However, it leads to a warning, as it *might*
+indicate a problem (e.g. the test author might have forgotten to specify a
+constraint).
+
+In gMock, `NiceMock` and `StrictMock` can be used to make a mock class "nice" or
+"strict". How does this affect uninteresting calls and unexpected calls?
+
+A **nice mock** suppresses uninteresting call *warnings*. It is less chatty than
+the default mock, but otherwise is the same. If a test fails with a default
+mock, it will also fail using a nice mock instead. And vice versa. Don't expect
+making a mock nice to change the test's result.
+
+A **strict mock** turns uninteresting call warnings into errors. So making a
+mock strict may change the test's result.
+
+Let's look at an example:
+
+```cpp
+TEST(...) {
+  NiceMock<MockDomainRegistry> mock_registry;
+  EXPECT_CALL(mock_registry, GetDomainOwner("google.com"))
+          .WillRepeatedly(Return("Larry Page"));
+
+  // Use mock_registry in code under test.
+  ... &mock_registry ...
+}
+```
+
+The sole `EXPECT_CALL` here says that all calls to `GetDomainOwner()` must have
+`"google.com"` as the argument. If `GetDomainOwner("yahoo.com")` is called, it
+will be an unexpected call, and thus an error. *Having a nice mock doesn't
+change the severity of an unexpected call.*
+
+So how do we tell gMock that `GetDomainOwner()` can be called with some other
+arguments as well? The standard technique is to add a "catch all" `EXPECT_CALL`:
+
+```cpp
+  EXPECT_CALL(mock_registry, GetDomainOwner(_))
+        .Times(AnyNumber());  // catches all other calls to this method.
+  EXPECT_CALL(mock_registry, GetDomainOwner("google.com"))
+        .WillRepeatedly(Return("Larry Page"));
+```
+
+Remember that `_` is the wildcard matcher that matches anything. With this, if
+`GetDomainOwner("google.com")` is called, it will do what the second
+`EXPECT_CALL` says; if it is called with a different argument, it will do what
+the first `EXPECT_CALL` says.
+
+Note that the order of the two `EXPECT_CALL`s is important, as a newer
+`EXPECT_CALL` takes precedence over an older one.
+
+For more on uninteresting calls, nice mocks, and strict mocks, read
+["The Nice, the Strict, and the Naggy"](#NiceStrictNaggy).
+
+### Ignoring Uninteresting Arguments {#ParameterlessExpectations}
+
+If your test doesn't care about the parameters (it only cares about the number
+or order of calls), you can often simply omit the parameter list:
+
+```cpp
+  // Expect foo.Bar( ... ) twice with any arguments.
+  EXPECT_CALL(foo, Bar).Times(2);
+
+  // Delegate to the given method whenever the factory is invoked.
+  ON_CALL(foo_factory, MakeFoo)
+      .WillByDefault(&BuildFooForTest);
+```
+
+This functionality is only available when a method is not overloaded; to prevent
+unexpected behavior it is a compilation error to try to set an expectation on a
+method where the specific overload is ambiguous. You can work around this by
+supplying a [simpler mock interface](#SimplerInterfaces) than the mocked class
+provides.
+
+This pattern is also useful when the arguments are interesting, but match logic
+is substantially complex. You can leave the argument list unspecified and use
+SaveArg actions to [save the values for later verification](#SaveArgVerify). If
+you do that, you can easily differentiate calling the method the wrong number of
+times from calling it with the wrong arguments.
+
+### Expecting Ordered Calls {#OrderedCalls}
+
+Although an `EXPECT_CALL()` statement defined later takes precedence when gMock
+tries to match a function call with an expectation, by default calls don't have
+to happen in the order `EXPECT_CALL()` statements are written. For example, if
+the arguments match the matchers in the second `EXPECT_CALL()`, but not those in
+the first and third, then the second expectation will be used.
+
+If you would rather have all calls occur in the order of the expectations, put
+the `EXPECT_CALL()` statements in a block where you define a variable of type
+`InSequence`:
+
+```cpp
+using ::testing::_;
+using ::testing::InSequence;
+
+  {
+    InSequence s;
+
+    EXPECT_CALL(foo, DoThis(5));
+    EXPECT_CALL(bar, DoThat(_))
+        .Times(2);
+    EXPECT_CALL(foo, DoThis(6));
+  }
+```
+
+In this example, we expect a call to `foo.DoThis(5)`, followed by two calls to
+`bar.DoThat()` where the argument can be anything, which are in turn followed by
+a call to `foo.DoThis(6)`. If a call occurred out-of-order, gMock will report an
+error.
+
+### Expecting Partially Ordered Calls {#PartialOrder}
+
+Sometimes requiring everything to occur in a predetermined order can lead to
+brittle tests. For example, we may care about `A` occurring before both `B` and
+`C`, but aren't interested in the relative order of `B` and `C`. In this case,
+the test should reflect our real intent, instead of being overly constraining.
+
+gMock allows you to impose an arbitrary DAG (directed acyclic graph) on the
+calls. One way to express the DAG is to use the
+[`After` clause](reference/mocking.md#EXPECT_CALL.After) of `EXPECT_CALL`.
+
+Another way is via the `InSequence()` clause (not the same as the `InSequence`
+class), which we borrowed from jMock 2. It's less flexible than `After()`, but
+more convenient when you have long chains of sequential calls, as it doesn't
+require you to come up with different names for the expectations in the chains.
+Here's how it works:
+
+If we view `EXPECT_CALL()` statements as nodes in a graph, and add an edge from
+node A to node B wherever A must occur before B, we can get a DAG. We use the
+term "sequence" to mean a directed path in this DAG. Now, if we decompose the
+DAG into sequences, we just need to know which sequences each `EXPECT_CALL()`
+belongs to in order to be able to reconstruct the original DAG.
+
+So, to specify the partial order on the expectations we need to do two things:
+first to define some `Sequence` objects, and then for each `EXPECT_CALL()` say
+which `Sequence` objects it is part of.
+
+Expectations in the same sequence must occur in the order they are written. For
+example,
+
+```cpp
+using ::testing::Sequence;
+...
+  Sequence s1, s2;
+
+  EXPECT_CALL(foo, A())
+      .InSequence(s1, s2);
+  EXPECT_CALL(bar, B())
+      .InSequence(s1);
+  EXPECT_CALL(bar, C())
+      .InSequence(s2);
+  EXPECT_CALL(foo, D())
+      .InSequence(s2);
+```
+
+specifies the following DAG (where `s1` is `A -> B`, and `s2` is `A -> C -> D`):
+
+```text
+       +---> B
+       |
+  A ---|
+       |
+       +---> C ---> D
+```
+
+This means that A must occur before B and C, and C must occur before D. There's
+no restriction about the order other than these.
+
+### Controlling When an Expectation Retires
+
+When a mock method is called, gMock only considers expectations that are still
+active. An expectation is active when created, and becomes inactive (aka
+*retires*) when a call that has to occur later has occurred. For example, in
+
+```cpp
+using ::testing::_;
+using ::testing::Sequence;
+...
+  Sequence s1, s2;
+
+  EXPECT_CALL(log, Log(WARNING, _, "File too large."))      // #1
+      .Times(AnyNumber())
+      .InSequence(s1, s2);
+  EXPECT_CALL(log, Log(WARNING, _, "Data set is empty."))   // #2
+      .InSequence(s1);
+  EXPECT_CALL(log, Log(WARNING, _, "User not found."))      // #3
+      .InSequence(s2);
+```
+
+as soon as either #2 or #3 is matched, #1 will retire. If a warning `"File too
+large."` is logged after this, it will be an error.
+
+Note that an expectation doesn't retire automatically when it's saturated. For
+example,
+
+```cpp
+using ::testing::_;
+...
+  EXPECT_CALL(log, Log(WARNING, _, _));                     // #1
+  EXPECT_CALL(log, Log(WARNING, _, "File too large."));     // #2
+```
+
+says that there will be exactly one warning with the message `"File too
+large."`. If the second warning contains this message too, #2 will match again
+and result in an upper-bound-violated error.
+
+If this is not what you want, you can ask an expectation to retire as soon as it
+becomes saturated:
+
+```cpp
+using ::testing::_;
+...
+  EXPECT_CALL(log, Log(WARNING, _, _));                     // #1
+  EXPECT_CALL(log, Log(WARNING, _, "File too large."))      // #2
+      .RetiresOnSaturation();
+```
+
+Here #2 can be used only once, so if you have two warnings with the message
+`"File too large."`, the first will match #2 and the second will match #1 -
+there will be no error.
+
+## Using Actions
+
+### Returning References from Mock Methods
+
+If a mock function's return type is a reference, you need to use `ReturnRef()`
+instead of `Return()` to return a result:
+
+```cpp
+using ::testing::ReturnRef;
+
+class MockFoo : public Foo {
+ public:
+  MOCK_METHOD(Bar&, GetBar, (), (override));
+};
+...
+  MockFoo foo;
+  Bar bar;
+  EXPECT_CALL(foo, GetBar())
+      .WillOnce(ReturnRef(bar));
+...
+```
+
+### Returning Live Values from Mock Methods
+
+The `Return(x)` action saves a copy of `x` when the action is created, and
+always returns the same value whenever it's executed. Sometimes you may want to
+instead return the *live* value of `x` (i.e. its value at the time when the
+action is *executed*.). Use either `ReturnRef()` or `ReturnPointee()` for this
+purpose.
+
+If the mock function's return type is a reference, you can do it using
+`ReturnRef(x)`, as shown in the previous recipe ("Returning References from Mock
+Methods"). However, gMock doesn't let you use `ReturnRef()` in a mock function
+whose return type is not a reference, as doing that usually indicates a user
+error. So, what shall you do?
+
+Though you may be tempted, DO NOT use `std::ref()`:
+
+```cpp
+using ::testing::Return;
+
+class MockFoo : public Foo {
+ public:
+  MOCK_METHOD(int, GetValue, (), (override));
+};
+...
+  int x = 0;
+  MockFoo foo;
+  EXPECT_CALL(foo, GetValue())
+      .WillRepeatedly(Return(std::ref(x)));  // Wrong!
+  x = 42;
+  EXPECT_EQ(foo.GetValue(), 42);
+```
+
+Unfortunately, it doesn't work here. The above code will fail with error:
+
+```text
+Value of: foo.GetValue()
+  Actual: 0
+Expected: 42
+```
+
+The reason is that `Return(*value*)` converts `value` to the actual return type
+of the mock function at the time when the action is *created*, not when it is
+*executed*. (This behavior was chosen for the action to be safe when `value` is
+a proxy object that references some temporary objects.) As a result,
+`std::ref(x)` is converted to an `int` value (instead of a `const int&`) when
+the expectation is set, and `Return(std::ref(x))` will always return 0.
+
+`ReturnPointee(pointer)` was provided to solve this problem specifically. It
+returns the value pointed to by `pointer` at the time the action is *executed*:
+
+```cpp
+using ::testing::ReturnPointee;
+...
+  int x = 0;
+  MockFoo foo;
+  EXPECT_CALL(foo, GetValue())
+      .WillRepeatedly(ReturnPointee(&x));  // Note the & here.
+  x = 42;
+  EXPECT_EQ(foo.GetValue(), 42);  // This will succeed now.
+```
+
+### Combining Actions
+
+Want to do more than one thing when a function is called? That's fine. `DoAll()`
+allows you to do a sequence of actions every time. Only the return value of the
+last action in the sequence will be used.
+
+```cpp
+using ::testing::_;
+using ::testing::DoAll;
+
+class MockFoo : public Foo {
+ public:
+  MOCK_METHOD(bool, Bar, (int n), (override));
+};
+...
+  EXPECT_CALL(foo, Bar(_))
+      .WillOnce(DoAll(action_1,
+                      action_2,
+                      ...
+                      action_n));
+```
+
+### Verifying Complex Arguments {#SaveArgVerify}
+
+If you want to verify that a method is called with a particular argument but the
+match criteria is complex, it can be difficult to distinguish between
+cardinality failures (calling the method the wrong number of times) and argument
+match failures. Similarly, if you are matching multiple parameters, it may not
+be easy to distinguishing which argument failed to match. For example:
+
+```cpp
+  // Not ideal: this could fail because of a problem with arg1 or arg2, or maybe
+  // just the method wasn't called.
+  EXPECT_CALL(foo, SendValues(_, ElementsAre(1, 4, 4, 7), EqualsProto( ... )));
+```
+
+You can instead save the arguments and test them individually:
+
+```cpp
+  EXPECT_CALL(foo, SendValues)
+      .WillOnce(DoAll(SaveArg<1>(&actual_array), SaveArg<2>(&actual_proto)));
+  ... run the test
+  EXPECT_THAT(actual_array, ElementsAre(1, 4, 4, 7));
+  EXPECT_THAT(actual_proto, EqualsProto( ... ));
+```
+
+### Mocking Side Effects {#MockingSideEffects}
+
+Sometimes a method exhibits its effect not via returning a value but via side
+effects. For example, it may change some global state or modify an output
+argument. To mock side effects, in general you can define your own action by
+implementing `::testing::ActionInterface`.
+
+If all you need to do is to change an output argument, the built-in
+`SetArgPointee()` action is convenient:
+
+```cpp
+using ::testing::_;
+using ::testing::SetArgPointee;
+
+class MockMutator : public Mutator {
+ public:
+  MOCK_METHOD(void, Mutate, (bool mutate, int* value), (override));
+  ...
+}
+...
+  MockMutator mutator;
+  EXPECT_CALL(mutator, Mutate(true, _))
+      .WillOnce(SetArgPointee<1>(5));
+```
+
+In this example, when `mutator.Mutate()` is called, we will assign 5 to the
+`int` variable pointed to by argument #1 (0-based).
+
+`SetArgPointee()` conveniently makes an internal copy of the value you pass to
+it, removing the need to keep the value in scope and alive. The implication
+however is that the value must have a copy constructor and assignment operator.
+
+If the mock method also needs to return a value as well, you can chain
+`SetArgPointee()` with `Return()` using `DoAll()`, remembering to put the
+`Return()` statement last:
+
+```cpp
+using ::testing::_;
+using ::testing::DoAll;
+using ::testing::Return;
+using ::testing::SetArgPointee;
+
+class MockMutator : public Mutator {
+ public:
+  ...
+  MOCK_METHOD(bool, MutateInt, (int* value), (override));
+}
+...
+  MockMutator mutator;
+  EXPECT_CALL(mutator, MutateInt(_))
+      .WillOnce(DoAll(SetArgPointee<0>(5),
+                      Return(true)));
+```
+
+Note, however, that if you use the `ReturnOKWith()` method, it will override the
+values provided by `SetArgPointee()` in the response parameters of your function
+call.
+
+If the output argument is an array, use the `SetArrayArgument<N>(first, last)`
+action instead. It copies the elements in source range `[first, last)` to the
+array pointed to by the `N`-th (0-based) argument:
+
+```cpp
+using ::testing::NotNull;
+using ::testing::SetArrayArgument;
+
+class MockArrayMutator : public ArrayMutator {
+ public:
+  MOCK_METHOD(void, Mutate, (int* values, int num_values), (override));
+  ...
+}
+...
+  MockArrayMutator mutator;
+  int values[5] = {1, 2, 3, 4, 5};
+  EXPECT_CALL(mutator, Mutate(NotNull(), 5))
+      .WillOnce(SetArrayArgument<0>(values, values + 5));
+```
+
+This also works when the argument is an output iterator:
+
+```cpp
+using ::testing::_;
+using ::testing::SetArrayArgument;
+
+class MockRolodex : public Rolodex {
+ public:
+  MOCK_METHOD(void, GetNames, (std::back_insert_iterator<vector<string>>),
+              (override));
+  ...
+}
+...
+  MockRolodex rolodex;
+  vector<string> names = {"George", "John", "Thomas"};
+  EXPECT_CALL(rolodex, GetNames(_))
+      .WillOnce(SetArrayArgument<0>(names.begin(), names.end()));
+```
+
+### Changing a Mock Object's Behavior Based on the State
+
+If you expect a call to change the behavior of a mock object, you can use
+`::testing::InSequence` to specify different behaviors before and after the
+call:
+
+```cpp
+using ::testing::InSequence;
+using ::testing::Return;
+
+...
+  {
+     InSequence seq;
+     EXPECT_CALL(my_mock, IsDirty())
+         .WillRepeatedly(Return(true));
+     EXPECT_CALL(my_mock, Flush());
+     EXPECT_CALL(my_mock, IsDirty())
+         .WillRepeatedly(Return(false));
+  }
+  my_mock.FlushIfDirty();
+```
+
+This makes `my_mock.IsDirty()` return `true` before `my_mock.Flush()` is called
+and return `false` afterwards.
+
+If the behavior change is more complex, you can store the effects in a variable
+and make a mock method get its return value from that variable:
+
+```cpp
+using ::testing::_;
+using ::testing::SaveArg;
+using ::testing::Return;
+
+ACTION_P(ReturnPointee, p) { return *p; }
+...
+  int previous_value = 0;
+  EXPECT_CALL(my_mock, GetPrevValue)
+      .WillRepeatedly(ReturnPointee(&previous_value));
+  EXPECT_CALL(my_mock, UpdateValue)
+      .WillRepeatedly(SaveArg<0>(&previous_value));
+  my_mock.DoSomethingToUpdateValue();
+```
+
+Here `my_mock.GetPrevValue()` will always return the argument of the last
+`UpdateValue()` call.
+
+### Setting the Default Value for a Return Type {#DefaultValue}
+
+If a mock method's return type is a built-in C++ type or pointer, by default it
+will return 0 when invoked. Also, in C++ 11 and above, a mock method whose
+return type has a default constructor will return a default-constructed value by
+default. You only need to specify an action if this default value doesn't work
+for you.
+
+Sometimes, you may want to change this default value, or you may want to specify
+a default value for types gMock doesn't know about. You can do this using the
+`::testing::DefaultValue` class template:
+
+```cpp
+using ::testing::DefaultValue;
+
+class MockFoo : public Foo {
+ public:
+  MOCK_METHOD(Bar, CalculateBar, (), (override));
+};
+
+
+...
+  Bar default_bar;
+  // Sets the default return value for type Bar.
+  DefaultValue<Bar>::Set(default_bar);
+
+  MockFoo foo;
+
+  // We don't need to specify an action here, as the default
+  // return value works for us.
+  EXPECT_CALL(foo, CalculateBar());
+
+  foo.CalculateBar();  // This should return default_bar.
+
+  // Unsets the default return value.
+  DefaultValue<Bar>::Clear();
+```
+
+Please note that changing the default value for a type can make your tests hard
+to understand. We recommend you to use this feature judiciously. For example,
+you may want to make sure the `Set()` and `Clear()` calls are right next to the
+code that uses your mock.
+
+### Setting the Default Actions for a Mock Method
+
+You've learned how to change the default value of a given type. However, this
+may be too coarse for your purpose: perhaps you have two mock methods with the
+same return type and you want them to have different behaviors. The `ON_CALL()`
+macro allows you to customize your mock's behavior at the method level:
+
+```cpp
+using ::testing::_;
+using ::testing::AnyNumber;
+using ::testing::Gt;
+using ::testing::Return;
+...
+  ON_CALL(foo, Sign(_))
+      .WillByDefault(Return(-1));
+  ON_CALL(foo, Sign(0))
+      .WillByDefault(Return(0));
+  ON_CALL(foo, Sign(Gt(0)))
+      .WillByDefault(Return(1));
+
+  EXPECT_CALL(foo, Sign(_))
+      .Times(AnyNumber());
+
+  foo.Sign(5);   // This should return 1.
+  foo.Sign(-9);  // This should return -1.
+  foo.Sign(0);   // This should return 0.
+```
+
+As you may have guessed, when there are more than one `ON_CALL()` statements,
+the newer ones in the order take precedence over the older ones. In other words,
+the **last** one that matches the function arguments will be used. This matching
+order allows you to set up the common behavior in a mock object's constructor or
+the test fixture's set-up phase and specialize the mock's behavior later.
+
+Note that both `ON_CALL` and `EXPECT_CALL` have the same "later statements take
+precedence" rule, but they don't interact. That is, `EXPECT_CALL`s have their
+own precedence order distinct from the `ON_CALL` precedence order.
+
+### Using Functions/Methods/Functors/Lambdas as Actions {#FunctionsAsActions}
+
+If the built-in actions don't suit you, you can use an existing callable
+(function, `std::function`, method, functor, lambda) as an action.
+
+```cpp
+using ::testing::_; using ::testing::Invoke;
+
+class MockFoo : public Foo {
+ public:
+  MOCK_METHOD(int, Sum, (int x, int y), (override));
+  MOCK_METHOD(bool, ComplexJob, (int x), (override));
+};
+
+int CalculateSum(int x, int y) { return x + y; }
+int Sum3(int x, int y, int z) { return x + y + z; }
+
+class Helper {
+ public:
+  bool ComplexJob(int x);
+};
+
+...
+  MockFoo foo;
+  Helper helper;
+  EXPECT_CALL(foo, Sum(_, _))
+      .WillOnce(&CalculateSum)
+      .WillRepeatedly(Invoke(NewPermanentCallback(Sum3, 1)));
+  EXPECT_CALL(foo, ComplexJob(_))
+      .WillOnce(Invoke(&helper, &Helper::ComplexJob))
+      .WillOnce([] { return true; })
+      .WillRepeatedly([](int x) { return x > 0; });
+
+  foo.Sum(5, 6);         // Invokes CalculateSum(5, 6).
+  foo.Sum(2, 3);         // Invokes Sum3(1, 2, 3).
+  foo.ComplexJob(10);    // Invokes helper.ComplexJob(10).
+  foo.ComplexJob(-1);    // Invokes the inline lambda.
+```
+
+The only requirement is that the type of the function, etc must be *compatible*
+with the signature of the mock function, meaning that the latter's arguments (if
+it takes any) can be implicitly converted to the corresponding arguments of the
+former, and the former's return type can be implicitly converted to that of the
+latter. So, you can invoke something whose type is *not* exactly the same as the
+mock function, as long as it's safe to do so - nice, huh?
+
+Note that:
+
+*   The action takes ownership of the callback and will delete it when the
+    action itself is destructed.
+*   If the type of a callback is derived from a base callback type `C`, you need
+    to implicitly cast it to `C` to resolve the overloading, e.g.
+
+    ```cpp
+    using ::testing::Invoke;
+    ...
+      ResultCallback<bool>* is_ok = ...;
+      ... Invoke(is_ok) ...;  // This works.
+
+      BlockingClosure* done = new BlockingClosure;
+      ... Invoke(implicit_cast<Closure*>(done)) ...;  // The cast is necessary.
+    ```
+
+### Using Functions with Extra Info as Actions
+
+The function or functor you call using `Invoke()` must have the same number of
+arguments as the mock function you use it for. Sometimes you may have a function
+that takes more arguments, and you are willing to pass in the extra arguments
+yourself to fill the gap. You can do this in gMock using callbacks with
+pre-bound arguments. Here's an example:
+
+```cpp
+using ::testing::Invoke;
+
+class MockFoo : public Foo {
+ public:
+  MOCK_METHOD(char, DoThis, (int n), (override));
+};
+
+char SignOfSum(int x, int y) {
+  const int sum = x + y;
+  return (sum > 0) ? '+' : (sum < 0) ? '-' : '0';
+}
+
+TEST_F(FooTest, Test) {
+  MockFoo foo;
+
+  EXPECT_CALL(foo, DoThis(2))
+      .WillOnce(Invoke(NewPermanentCallback(SignOfSum, 5)));
+  EXPECT_EQ(foo.DoThis(2), '+');  // Invokes SignOfSum(5, 2).
+}
+```
+
+### Invoking a Function/Method/Functor/Lambda/Callback Without Arguments
+
+`Invoke()` passes the mock function's arguments to the function, etc being
+invoked such that the callee has the full context of the call to work with. If
+the invoked function is not interested in some or all of the arguments, it can
+simply ignore them.
+
+Yet, a common pattern is that a test author wants to invoke a function without
+the arguments of the mock function. She could do that using a wrapper function
+that throws away the arguments before invoking an underlining nullary function.
+Needless to say, this can be tedious and obscures the intent of the test.
+
+There are two solutions to this problem. First, you can pass any callable of
+zero args as an action. Alternatively, use `InvokeWithoutArgs()`, which is like
+`Invoke()` except that it doesn't pass the mock function's arguments to the
+callee. Here's an example of each:
+
+```cpp
+using ::testing::_;
+using ::testing::InvokeWithoutArgs;
+
+class MockFoo : public Foo {
+ public:
+  MOCK_METHOD(bool, ComplexJob, (int n), (override));
+};
+
+bool Job1() { ... }
+bool Job2(int n, char c) { ... }
+
+...
+  MockFoo foo;
+  EXPECT_CALL(foo, ComplexJob(_))
+      .WillOnce([] { Job1(); });
+      .WillOnce(InvokeWithoutArgs(NewPermanentCallback(Job2, 5, 'a')));
+
+  foo.ComplexJob(10);  // Invokes Job1().
+  foo.ComplexJob(20);  // Invokes Job2(5, 'a').
+```
+
+Note that:
+
+*   The action takes ownership of the callback and will delete it when the
+    action itself is destructed.
+*   If the type of a callback is derived from a base callback type `C`, you need
+    to implicitly cast it to `C` to resolve the overloading, e.g.
+
+    ```cpp
+    using ::testing::InvokeWithoutArgs;
+    ...
+      ResultCallback<bool>* is_ok = ...;
+      ... InvokeWithoutArgs(is_ok) ...;  // This works.
+
+      BlockingClosure* done = ...;
+      ... InvokeWithoutArgs(implicit_cast<Closure*>(done)) ...;
+      // The cast is necessary.
+    ```
+
+### Invoking an Argument of the Mock Function
+
+Sometimes a mock function will receive a function pointer, a functor (in other
+words, a "callable") as an argument, e.g.
+
+```cpp
+class MockFoo : public Foo {
+ public:
+  MOCK_METHOD(bool, DoThis, (int n, (ResultCallback1<bool, int>* callback)),
+              (override));
+};
+```
+
+and you may want to invoke this callable argument:
+
+```cpp
+using ::testing::_;
+...
+  MockFoo foo;
+  EXPECT_CALL(foo, DoThis(_, _))
+      .WillOnce(...);
+      // Will execute callback->Run(5), where callback is the
+      // second argument DoThis() receives.
+```
+
+{: .callout .note}
+NOTE: The section below is legacy documentation from before C++ had lambdas:
+
+Arghh, you need to refer to a mock function argument but C++ has no lambda
+(yet), so you have to define your own action. :-( Or do you really?
+
+Well, gMock has an action to solve *exactly* this problem:
+
+```cpp
+InvokeArgument<N>(arg_1, arg_2, ..., arg_m)
+```
+
+will invoke the `N`-th (0-based) argument the mock function receives, with
+`arg_1`, `arg_2`, ..., and `arg_m`. No matter if the argument is a function
+pointer, a functor, or a callback. gMock handles them all.
+
+With that, you could write:
+
+```cpp
+using ::testing::_;
+using ::testing::InvokeArgument;
+...
+  EXPECT_CALL(foo, DoThis(_, _))
+      .WillOnce(InvokeArgument<1>(5));
+      // Will execute callback->Run(5), where callback is the
+      // second argument DoThis() receives.
+```
+
+What if the callable takes an argument by reference? No problem - just wrap it
+inside `std::ref()`:
+
+```cpp
+  ...
+  MOCK_METHOD(bool, Bar,
+              ((ResultCallback2<bool, int, const Helper&>* callback)),
+              (override));
+  ...
+  using ::testing::_;
+  using ::testing::InvokeArgument;
+  ...
+  MockFoo foo;
+  Helper helper;
+  ...
+  EXPECT_CALL(foo, Bar(_))
+      .WillOnce(InvokeArgument<0>(5, std::ref(helper)));
+      // std::ref(helper) guarantees that a reference to helper, not a copy of
+      // it, will be passed to the callback.
+```
+
+What if the callable takes an argument by reference and we do **not** wrap the
+argument in `std::ref()`? Then `InvokeArgument()` will *make a copy* of the
+argument, and pass a *reference to the copy*, instead of a reference to the
+original value, to the callable. This is especially handy when the argument is a
+temporary value:
+
+```cpp
+  ...
+  MOCK_METHOD(bool, DoThat, (bool (*f)(const double& x, const string& s)),
+              (override));
+  ...
+  using ::testing::_;
+  using ::testing::InvokeArgument;
+  ...
+  MockFoo foo;
+  ...
+  EXPECT_CALL(foo, DoThat(_))
+      .WillOnce(InvokeArgument<0>(5.0, string("Hi")));
+      // Will execute (*f)(5.0, string("Hi")), where f is the function pointer
+      // DoThat() receives.  Note that the values 5.0 and string("Hi") are
+      // temporary and dead once the EXPECT_CALL() statement finishes.  Yet
+      // it's fine to perform this action later, since a copy of the values
+      // are kept inside the InvokeArgument action.
+```
+
+### Ignoring an Action's Result
+
+Sometimes you have an action that returns *something*, but you need an action
+that returns `void` (perhaps you want to use it in a mock function that returns
+`void`, or perhaps it needs to be used in `DoAll()` and it's not the last in the
+list). `IgnoreResult()` lets you do that. For example:
+
+```cpp
+using ::testing::_;
+using ::testing::DoAll;
+using ::testing::IgnoreResult;
+using ::testing::Return;
+
+int Process(const MyData& data);
+string DoSomething();
+
+class MockFoo : public Foo {
+ public:
+  MOCK_METHOD(void, Abc, (const MyData& data), (override));
+  MOCK_METHOD(bool, Xyz, (), (override));
+};
+
+  ...
+  MockFoo foo;
+  EXPECT_CALL(foo, Abc(_))
+      // .WillOnce(Invoke(Process));
+      // The above line won't compile as Process() returns int but Abc() needs
+      // to return void.
+      .WillOnce(IgnoreResult(Process));
+  EXPECT_CALL(foo, Xyz())
+      .WillOnce(DoAll(IgnoreResult(DoSomething),
+                      // Ignores the string DoSomething() returns.
+                      Return(true)));
+```
+
+Note that you **cannot** use `IgnoreResult()` on an action that already returns
+`void`. Doing so will lead to ugly compiler errors.
+
+### Selecting an Action's Arguments {#SelectingArgs}
+
+Say you have a mock function `Foo()` that takes seven arguments, and you have a
+custom action that you want to invoke when `Foo()` is called. Trouble is, the
+custom action only wants three arguments:
+
+```cpp
+using ::testing::_;
+using ::testing::Invoke;
+...
+  MOCK_METHOD(bool, Foo,
+              (bool visible, const string& name, int x, int y,
+               (const map<pair<int, int>>), double& weight, double min_weight,
+               double max_wight));
+...
+bool IsVisibleInQuadrant1(bool visible, int x, int y) {
+  return visible && x >= 0 && y >= 0;
+}
+...
+  EXPECT_CALL(mock, Foo)
+      .WillOnce(Invoke(IsVisibleInQuadrant1));  // Uh, won't compile. :-(
+```
+
+To please the compiler God, you need to define an "adaptor" that has the same
+signature as `Foo()` and calls the custom action with the right arguments:
+
+```cpp
+using ::testing::_;
+using ::testing::Invoke;
+...
+bool MyIsVisibleInQuadrant1(bool visible, const string& name, int x, int y,
+                            const map<pair<int, int>, double>& weight,
+                            double min_weight, double max_wight) {
+  return IsVisibleInQuadrant1(visible, x, y);
+}
+...
+  EXPECT_CALL(mock, Foo)
+      .WillOnce(Invoke(MyIsVisibleInQuadrant1));  // Now it works.
+```
+
+But isn't this awkward?
+
+gMock provides a generic *action adaptor*, so you can spend your time minding
+more important business than writing your own adaptors. Here's the syntax:
+
+```cpp
+WithArgs<N1, N2, ..., Nk>(action)
+```
+
+creates an action that passes the arguments of the mock function at the given
+indices (0-based) to the inner `action` and performs it. Using `WithArgs`, our
+original example can be written as:
+
+```cpp
+using ::testing::_;
+using ::testing::Invoke;
+using ::testing::WithArgs;
+...
+  EXPECT_CALL(mock, Foo)
+      .WillOnce(WithArgs<0, 2, 3>(Invoke(IsVisibleInQuadrant1)));  // No need to define your own adaptor.
+```
+
+For better readability, gMock also gives you:
+
+*   `WithoutArgs(action)` when the inner `action` takes *no* argument, and
+*   `WithArg<N>(action)` (no `s` after `Arg`) when the inner `action` takes
+    *one* argument.
+
+As you may have realized, `InvokeWithoutArgs(...)` is just syntactic sugar for
+`WithoutArgs(Invoke(...))`.
+
+Here are more tips:
+
+*   The inner action used in `WithArgs` and friends does not have to be
+    `Invoke()` -- it can be anything.
+*   You can repeat an argument in the argument list if necessary, e.g.
+    `WithArgs<2, 3, 3, 5>(...)`.
+*   You can change the order of the arguments, e.g. `WithArgs<3, 2, 1>(...)`.
+*   The types of the selected arguments do *not* have to match the signature of
+    the inner action exactly. It works as long as they can be implicitly
+    converted to the corresponding arguments of the inner action. For example,
+    if the 4-th argument of the mock function is an `int` and `my_action` takes
+    a `double`, `WithArg<4>(my_action)` will work.
+
+### Ignoring Arguments in Action Functions
+
+The [selecting-an-action's-arguments](#SelectingArgs) recipe showed us one way
+to make a mock function and an action with incompatible argument lists fit
+together. The downside is that wrapping the action in `WithArgs<...>()` can get
+tedious for people writing the tests.
+
+If you are defining a function (or method, functor, lambda, callback) to be used
+with `Invoke*()`, and you are not interested in some of its arguments, an
+alternative to `WithArgs` is to declare the uninteresting arguments as `Unused`.
+This makes the definition less cluttered and less fragile in case the types of
+the uninteresting arguments change. It could also increase the chance the action
+function can be reused. For example, given
+
+```cpp
+ public:
+  MOCK_METHOD(double, Foo, double(const string& label, double x, double y),
+              (override));
+  MOCK_METHOD(double, Bar, (int index, double x, double y), (override));
+```
+
+instead of
+
+```cpp
+using ::testing::_;
+using ::testing::Invoke;
+
+double DistanceToOriginWithLabel(const string& label, double x, double y) {
+  return sqrt(x*x + y*y);
+}
+double DistanceToOriginWithIndex(int index, double x, double y) {
+  return sqrt(x*x + y*y);
+}
+...
+  EXPECT_CALL(mock, Foo("abc", _, _))
+      .WillOnce(Invoke(DistanceToOriginWithLabel));
+  EXPECT_CALL(mock, Bar(5, _, _))
+      .WillOnce(Invoke(DistanceToOriginWithIndex));
+```
+
+you could write
+
+```cpp
+using ::testing::_;
+using ::testing::Invoke;
+using ::testing::Unused;
+
+double DistanceToOrigin(Unused, double x, double y) {
+  return sqrt(x*x + y*y);
+}
+...
+  EXPECT_CALL(mock, Foo("abc", _, _))
+      .WillOnce(Invoke(DistanceToOrigin));
+  EXPECT_CALL(mock, Bar(5, _, _))
+      .WillOnce(Invoke(DistanceToOrigin));
+```
+
+### Sharing Actions
+
+Just like matchers, a gMock action object consists of a pointer to a ref-counted
+implementation object. Therefore copying actions is also allowed and very
+efficient. When the last action that references the implementation object dies,
+the implementation object will be deleted.
+
+If you have some complex action that you want to use again and again, you may
+not have to build it from scratch every time. If the action doesn't have an
+internal state (i.e. if it always does the same thing no matter how many times
+it has been called), you can assign it to an action variable and use that
+variable repeatedly. For example:
+
+```cpp
+using ::testing::Action;
+using ::testing::DoAll;
+using ::testing::Return;
+using ::testing::SetArgPointee;
+...
+  Action<bool(int*)> set_flag = DoAll(SetArgPointee<0>(5),
+                                      Return(true));
+  ... use set_flag in .WillOnce() and .WillRepeatedly() ...
+```
+
+However, if the action has its own state, you may be surprised if you share the
+action object. Suppose you have an action factory `IncrementCounter(init)` which
+creates an action that increments and returns a counter whose initial value is
+`init`, using two actions created from the same expression and using a shared
+action will exhibit different behaviors. Example:
+
+```cpp
+  EXPECT_CALL(foo, DoThis())
+      .WillRepeatedly(IncrementCounter(0));
+  EXPECT_CALL(foo, DoThat())
+      .WillRepeatedly(IncrementCounter(0));
+  foo.DoThis();  // Returns 1.
+  foo.DoThis();  // Returns 2.
+  foo.DoThat();  // Returns 1 - DoThat() uses a different
+                 // counter than DoThis()'s.
+```
+
+versus
+
+```cpp
+using ::testing::Action;
+...
+  Action<int()> increment = IncrementCounter(0);
+  EXPECT_CALL(foo, DoThis())
+      .WillRepeatedly(increment);
+  EXPECT_CALL(foo, DoThat())
+      .WillRepeatedly(increment);
+  foo.DoThis();  // Returns 1.
+  foo.DoThis();  // Returns 2.
+  foo.DoThat();  // Returns 3 - the counter is shared.
+```
+
+### Testing Asynchronous Behavior
+
+One oft-encountered problem with gMock is that it can be hard to test
+asynchronous behavior. Suppose you had a `EventQueue` class that you wanted to
+test, and you created a separate `EventDispatcher` interface so that you could
+easily mock it out. However, the implementation of the class fired all the
+events on a background thread, which made test timings difficult. You could just
+insert `sleep()` statements and hope for the best, but that makes your test
+behavior nondeterministic. A better way is to use gMock actions and
+`Notification` objects to force your asynchronous test to behave synchronously.
+
+```cpp
+class MockEventDispatcher : public EventDispatcher {
+  MOCK_METHOD(bool, DispatchEvent, (int32), (override));
+};
+
+TEST(EventQueueTest, EnqueueEventTest) {
+  MockEventDispatcher mock_event_dispatcher;
+  EventQueue event_queue(&mock_event_dispatcher);
+
+  const int32 kEventId = 321;
+  absl::Notification done;
+  EXPECT_CALL(mock_event_dispatcher, DispatchEvent(kEventId))
+      .WillOnce([&done] { done.Notify(); });
+
+  event_queue.EnqueueEvent(kEventId);
+  done.WaitForNotification();
+}
+```
+
+In the example above, we set our normal gMock expectations, but then add an
+additional action to notify the `Notification` object. Now we can just call
+`Notification::WaitForNotification()` in the main thread to wait for the
+asynchronous call to finish. After that, our test suite is complete and we can
+safely exit.
+
+{: .callout .note}
+Note: this example has a downside: namely, if the expectation is not satisfied,
+our test will run forever. It will eventually time-out and fail, but it will
+take longer and be slightly harder to debug. To alleviate this problem, you can
+use `WaitForNotificationWithTimeout(ms)` instead of `WaitForNotification()`.
+
+## Misc Recipes on Using gMock
+
+### Mocking Methods That Use Move-Only Types
+
+C++11 introduced *move-only types*. A move-only-typed value can be moved from
+one object to another, but cannot be copied. `std::unique_ptr<T>` is probably
+the most commonly used move-only type.
+
+Mocking a method that takes and/or returns move-only types presents some
+challenges, but nothing insurmountable. This recipe shows you how you can do it.
+Note that the support for move-only method arguments was only introduced to
+gMock in April 2017; in older code, you may find more complex
+[workarounds](#LegacyMoveOnly) for lack of this feature.
+
+Let’s say we are working on a fictional project that lets one post and share
+snippets called “buzzes”. Your code uses these types:
+
+```cpp
+enum class AccessLevel { kInternal, kPublic };
+
+class Buzz {
+ public:
+  explicit Buzz(AccessLevel access) { ... }
+  ...
+};
+
+class Buzzer {
+ public:
+  virtual ~Buzzer() {}
+  virtual std::unique_ptr<Buzz> MakeBuzz(StringPiece text) = 0;
+  virtual bool ShareBuzz(std::unique_ptr<Buzz> buzz, int64_t timestamp) = 0;
+  ...
+};
+```
+
+A `Buzz` object represents a snippet being posted. A class that implements the
+`Buzzer` interface is capable of creating and sharing `Buzz`es. Methods in
+`Buzzer` may return a `unique_ptr<Buzz>` or take a `unique_ptr<Buzz>`. Now we
+need to mock `Buzzer` in our tests.
+
+To mock a method that accepts or returns move-only types, you just use the
+familiar `MOCK_METHOD` syntax as usual:
+
+```cpp
+class MockBuzzer : public Buzzer {
+ public:
+  MOCK_METHOD(std::unique_ptr<Buzz>, MakeBuzz, (StringPiece text), (override));
+  MOCK_METHOD(bool, ShareBuzz, (std::unique_ptr<Buzz> buzz, int64_t timestamp),
+              (override));
+};
+```
+
+Now that we have the mock class defined, we can use it in tests. In the
+following code examples, we assume that we have defined a `MockBuzzer` object
+named `mock_buzzer_`:
+
+```cpp
+  MockBuzzer mock_buzzer_;
+```
+
+First let’s see how we can set expectations on the `MakeBuzz()` method, which
+returns a `unique_ptr<Buzz>`.
+
+As usual, if you set an expectation without an action (i.e. the `.WillOnce()` or
+`.WillRepeatedly()` clause), when that expectation fires, the default action for
+that method will be taken. Since `unique_ptr<>` has a default constructor that
+returns a null `unique_ptr`, that’s what you’ll get if you don’t specify an
+action:
+
+```cpp
+using ::testing::IsNull;
+...
+  // Use the default action.
+  EXPECT_CALL(mock_buzzer_, MakeBuzz("hello"));
+
+  // Triggers the previous EXPECT_CALL.
+  EXPECT_THAT(mock_buzzer_.MakeBuzz("hello"), IsNull());
+```
+
+If you are not happy with the default action, you can tweak it as usual; see
+[Setting Default Actions](#OnCall).
+
+If you just need to return a move-only value, you can use it in combination with
+`WillOnce`. For example:
+
+```cpp
+  EXPECT_CALL(mock_buzzer_, MakeBuzz("hello"))
+      .WillOnce(Return(std::make_unique<Buzz>(AccessLevel::kInternal)));
+  EXPECT_NE(nullptr, mock_buzzer_.MakeBuzz("hello"));
+```
+
+Quiz time! What do you think will happen if a `Return` action is performed more
+than once (e.g. you write `... .WillRepeatedly(Return(std::move(...)));`)? Come
+think of it, after the first time the action runs, the source value will be
+consumed (since it’s a move-only value), so the next time around, there’s no
+value to move from -- you’ll get a run-time error that `Return(std::move(...))`
+can only be run once.
+
+If you need your mock method to do more than just moving a pre-defined value,
+remember that you can always use a lambda or a callable object, which can do
+pretty much anything you want:
+
+```cpp
+  EXPECT_CALL(mock_buzzer_, MakeBuzz("x"))
+      .WillRepeatedly([](StringPiece text) {
+        return std::make_unique<Buzz>(AccessLevel::kInternal);
+      });
+
+  EXPECT_NE(nullptr, mock_buzzer_.MakeBuzz("x"));
+  EXPECT_NE(nullptr, mock_buzzer_.MakeBuzz("x"));
+```
+
+Every time this `EXPECT_CALL` fires, a new `unique_ptr<Buzz>` will be created
+and returned. You cannot do this with `Return(std::make_unique<...>(...))`.
+
+That covers returning move-only values; but how do we work with methods
+accepting move-only arguments? The answer is that they work normally, although
+some actions will not compile when any of method's arguments are move-only. You
+can always use `Return`, or a [lambda or functor](#FunctionsAsActions):
+
+```cpp
+  using ::testing::Unused;
+
+  EXPECT_CALL(mock_buzzer_, ShareBuzz(NotNull(), _)).WillOnce(Return(true));
+  EXPECT_TRUE(mock_buzzer_.ShareBuzz(std::make_unique<Buzz>(AccessLevel::kInternal)),
+              0);
+
+  EXPECT_CALL(mock_buzzer_, ShareBuzz(_, _)).WillOnce(
+      [](std::unique_ptr<Buzz> buzz, Unused) { return buzz != nullptr; });
+  EXPECT_FALSE(mock_buzzer_.ShareBuzz(nullptr, 0));
+```
+
+Many built-in actions (`WithArgs`, `WithoutArgs`,`DeleteArg`, `SaveArg`, ...)
+could in principle support move-only arguments, but the support for this is not
+implemented yet. If this is blocking you, please file a bug.
+
+A few actions (e.g. `DoAll`) copy their arguments internally, so they can never
+work with non-copyable objects; you'll have to use functors instead.
+
+#### Legacy workarounds for move-only types {#LegacyMoveOnly}
+
+Support for move-only function arguments was only introduced to gMock in April
+of 2017. In older code, you may encounter the following workaround for the lack
+of this feature (it is no longer necessary - we're including it just for
+reference):
+
+```cpp
+class MockBuzzer : public Buzzer {
+ public:
+  MOCK_METHOD(bool, DoShareBuzz, (Buzz* buzz, Time timestamp));
+  bool ShareBuzz(std::unique_ptr<Buzz> buzz, Time timestamp) override {
+    return DoShareBuzz(buzz.get(), timestamp);
+  }
+};
+```
+
+The trick is to delegate the `ShareBuzz()` method to a mock method (let’s call
+it `DoShareBuzz()`) that does not take move-only parameters. Then, instead of
+setting expectations on `ShareBuzz()`, you set them on the `DoShareBuzz()` mock
+method:
+
+```cpp
+  MockBuzzer mock_buzzer_;
+  EXPECT_CALL(mock_buzzer_, DoShareBuzz(NotNull(), _));
+
+  // When one calls ShareBuzz() on the MockBuzzer like this, the call is
+  // forwarded to DoShareBuzz(), which is mocked.  Therefore this statement
+  // will trigger the above EXPECT_CALL.
+  mock_buzzer_.ShareBuzz(std::make_unique<Buzz>(AccessLevel::kInternal), 0);
+```
+
+### Making the Compilation Faster
+
+Believe it or not, the *vast majority* of the time spent on compiling a mock
+class is in generating its constructor and destructor, as they perform
+non-trivial tasks (e.g. verification of the expectations). What's more, mock
+methods with different signatures have different types and thus their
+constructors/destructors need to be generated by the compiler separately. As a
+result, if you mock many different types of methods, compiling your mock class
+can get really slow.
+
+If you are experiencing slow compilation, you can move the definition of your
+mock class' constructor and destructor out of the class body and into a `.cc`
+file. This way, even if you `#include` your mock class in N files, the compiler
+only needs to generate its constructor and destructor once, resulting in a much
+faster compilation.
+
+Let's illustrate the idea using an example. Here's the definition of a mock
+class before applying this recipe:
+
+```cpp
+// File mock_foo.h.
+...
+class MockFoo : public Foo {
+ public:
+  // Since we don't declare the constructor or the destructor,
+  // the compiler will generate them in every translation unit
+  // where this mock class is used.
+
+  MOCK_METHOD(int, DoThis, (), (override));
+  MOCK_METHOD(bool, DoThat, (const char* str), (override));
+  ... more mock methods ...
+};
+```
+
+After the change, it would look like:
+
+```cpp
+// File mock_foo.h.
+...
+class MockFoo : public Foo {
+ public:
+  // The constructor and destructor are declared, but not defined, here.
+  MockFoo();
+  virtual ~MockFoo();
+
+  MOCK_METHOD(int, DoThis, (), (override));
+  MOCK_METHOD(bool, DoThat, (const char* str), (override));
+  ... more mock methods ...
+};
+```
+
+and
+
+```cpp
+// File mock_foo.cc.
+#include "path/to/mock_foo.h"
+
+// The definitions may appear trivial, but the functions actually do a
+// lot of things through the constructors/destructors of the member
+// variables used to implement the mock methods.
+MockFoo::MockFoo() {}
+MockFoo::~MockFoo() {}
+```
+
+### Forcing a Verification
+
+When it's being destroyed, your friendly mock object will automatically verify
+that all expectations on it have been satisfied, and will generate googletest
+failures if not. This is convenient as it leaves you with one less thing to
+worry about. That is, unless you are not sure if your mock object will be
+destroyed.
+
+How could it be that your mock object won't eventually be destroyed? Well, it
+might be created on the heap and owned by the code you are testing. Suppose
+there's a bug in that code and it doesn't delete the mock object properly - you
+could end up with a passing test when there's actually a bug.
+
+Using a heap checker is a good idea and can alleviate the concern, but its
+implementation is not 100% reliable. So, sometimes you do want to *force* gMock
+to verify a mock object before it is (hopefully) destructed. You can do this
+with `Mock::VerifyAndClearExpectations(&mock_object)`:
+
+```cpp
+TEST(MyServerTest, ProcessesRequest) {
+  using ::testing::Mock;
+
+  MockFoo* const foo = new MockFoo;
+  EXPECT_CALL(*foo, ...)...;
+  // ... other expectations ...
+
+  // server now owns foo.
+  MyServer server(foo);
+  server.ProcessRequest(...);
+
+  // In case that server's destructor will forget to delete foo,
+  // this will verify the expectations anyway.
+  Mock::VerifyAndClearExpectations(foo);
+}  // server is destroyed when it goes out of scope here.
+```
+
+{: .callout .tip}
+**Tip:** The `Mock::VerifyAndClearExpectations()` function returns a `bool` to
+indicate whether the verification was successful (`true` for yes), so you can
+wrap that function call inside a `ASSERT_TRUE()` if there is no point going
+further when the verification has failed.
+
+Do not set new expectations after verifying and clearing a mock after its use.
+Setting expectations after code that exercises the mock has undefined behavior.
+See [Using Mocks in Tests](gmock_for_dummies.md#using-mocks-in-tests) for more
+information.
+
+### Using Checkpoints {#UsingCheckPoints}
+
+Sometimes you might want to test a mock object's behavior in phases whose sizes
+are each manageable, or you might want to set more detailed expectations about
+which API calls invoke which mock functions.
+
+A technique you can use is to put the expectations in a sequence and insert
+calls to a dummy "checkpoint" function at specific places. Then you can verify
+that the mock function calls do happen at the right time. For example, if you
+are exercising the code:
+
+```cpp
+  Foo(1);
+  Foo(2);
+  Foo(3);
+```
+
+and want to verify that `Foo(1)` and `Foo(3)` both invoke `mock.Bar("a")`, but
+`Foo(2)` doesn't invoke anything, you can write:
+
+```cpp
+using ::testing::MockFunction;
+
+TEST(FooTest, InvokesBarCorrectly) {
+  MyMock mock;
+  // Class MockFunction<F> has exactly one mock method.  It is named
+  // Call() and has type F.
+  MockFunction<void(string check_point_name)> check;
+  {
+    InSequence s;
+
+    EXPECT_CALL(mock, Bar("a"));
+    EXPECT_CALL(check, Call("1"));
+    EXPECT_CALL(check, Call("2"));
+    EXPECT_CALL(mock, Bar("a"));
+  }
+  Foo(1);
+  check.Call("1");
+  Foo(2);
+  check.Call("2");
+  Foo(3);
+}
+```
+
+The expectation spec says that the first `Bar("a")` call must happen before
+checkpoint "1", the second `Bar("a")` call must happen after checkpoint "2", and
+nothing should happen between the two checkpoints. The explicit checkpoints make
+it clear which `Bar("a")` is called by which call to `Foo()`.
+
+### Mocking Destructors
+
+Sometimes you want to make sure a mock object is destructed at the right time,
+e.g. after `bar->A()` is called but before `bar->B()` is called. We already know
+that you can specify constraints on the [order](#OrderedCalls) of mock function
+calls, so all we need to do is to mock the destructor of the mock function.
+
+This sounds simple, except for one problem: a destructor is a special function
+with special syntax and special semantics, and the `MOCK_METHOD` macro doesn't
+work for it:
+
+```cpp
+MOCK_METHOD(void, ~MockFoo, ());  // Won't compile!
+```
+
+The good news is that you can use a simple pattern to achieve the same effect.
+First, add a mock function `Die()` to your mock class and call it in the
+destructor, like this:
+
+```cpp
+class MockFoo : public Foo {
+  ...
+  // Add the following two lines to the mock class.
+  MOCK_METHOD(void, Die, ());
+  ~MockFoo() override { Die(); }
+};
+```
+
+(If the name `Die()` clashes with an existing symbol, choose another name.) Now,
+we have translated the problem of testing when a `MockFoo` object dies to
+testing when its `Die()` method is called:
+
+```cpp
+  MockFoo* foo = new MockFoo;
+  MockBar* bar = new MockBar;
+  ...
+  {
+    InSequence s;
+
+    // Expects *foo to die after bar->A() and before bar->B().
+    EXPECT_CALL(*bar, A());
+    EXPECT_CALL(*foo, Die());
+    EXPECT_CALL(*bar, B());
+  }
+```
+
+And that's that.
+
+### Using gMock and Threads {#UsingThreads}
+
+In a **unit** test, it's best if you could isolate and test a piece of code in a
+single-threaded context. That avoids race conditions and dead locks, and makes
+debugging your test much easier.
+
+Yet most programs are multi-threaded, and sometimes to test something we need to
+pound on it from more than one thread. gMock works for this purpose too.
+
+Remember the steps for using a mock:
+
+1.  Create a mock object `foo`.
+2.  Set its default actions and expectations using `ON_CALL()` and
+    `EXPECT_CALL()`.
+3.  The code under test calls methods of `foo`.
+4.  Optionally, verify and reset the mock.
+5.  Destroy the mock yourself, or let the code under test destroy it. The
+    destructor will automatically verify it.
+
+If you follow the following simple rules, your mocks and threads can live
+happily together:
+
+*   Execute your *test code* (as opposed to the code being tested) in *one*
+    thread. This makes your test easy to follow.
+*   Obviously, you can do step #1 without locking.
+*   When doing step #2 and #5, make sure no other thread is accessing `foo`.
+    Obvious too, huh?
+*   #3 and #4 can be done either in one thread or in multiple threads - anyway
+    you want. gMock takes care of the locking, so you don't have to do any -
+    unless required by your test logic.
+
+If you violate the rules (for example, if you set expectations on a mock while
+another thread is calling its methods), you get undefined behavior. That's not
+fun, so don't do it.
+
+gMock guarantees that the action for a mock function is done in the same thread
+that called the mock function. For example, in
+
+```cpp
+  EXPECT_CALL(mock, Foo(1))
+      .WillOnce(action1);
+  EXPECT_CALL(mock, Foo(2))
+      .WillOnce(action2);
+```
+
+if `Foo(1)` is called in thread 1 and `Foo(2)` is called in thread 2, gMock will
+execute `action1` in thread 1 and `action2` in thread 2.
+
+gMock does *not* impose a sequence on actions performed in different threads
+(doing so may create deadlocks as the actions may need to cooperate). This means
+that the execution of `action1` and `action2` in the above example *may*
+interleave. If this is a problem, you should add proper synchronization logic to
+`action1` and `action2` to make the test thread-safe.
+
+Also, remember that `DefaultValue<T>` is a global resource that potentially
+affects *all* living mock objects in your program. Naturally, you won't want to
+mess with it from multiple threads or when there still are mocks in action.
+
+### Controlling How Much Information gMock Prints
+
+When gMock sees something that has the potential of being an error (e.g. a mock
+function with no expectation is called, a.k.a. an uninteresting call, which is
+allowed but perhaps you forgot to explicitly ban the call), it prints some
+warning messages, including the arguments of the function, the return value, and
+the stack trace. Hopefully this will remind you to take a look and see if there
+is indeed a problem.
+
+Sometimes you are confident that your tests are correct and may not appreciate
+such friendly messages. Some other times, you are debugging your tests or
+learning about the behavior of the code you are testing, and wish you could
+observe every mock call that happens (including argument values, the return
+value, and the stack trace). Clearly, one size doesn't fit all.
+
+You can control how much gMock tells you using the `--gmock_verbose=LEVEL`
+command-line flag, where `LEVEL` is a string with three possible values:
+
+*   `info`: gMock will print all informational messages, warnings, and errors
+    (most verbose). At this setting, gMock will also log any calls to the
+    `ON_CALL/EXPECT_CALL` macros. It will include a stack trace in
+    "uninteresting call" warnings.
+*   `warning`: gMock will print both warnings and errors (less verbose); it will
+    omit the stack traces in "uninteresting call" warnings. This is the default.
+*   `error`: gMock will print errors only (least verbose).
+
+Alternatively, you can adjust the value of that flag from within your tests like
+so:
+
+```cpp
+  ::testing::FLAGS_gmock_verbose = "error";
+```
+
+If you find gMock printing too many stack frames with its informational or
+warning messages, remember that you can control their amount with the
+`--gtest_stack_trace_depth=max_depth` flag.
+
+Now, judiciously use the right flag to enable gMock serve you better!
+
+### Gaining Super Vision into Mock Calls
+
+You have a test using gMock. It fails: gMock tells you some expectations aren't
+satisfied. However, you aren't sure why: Is there a typo somewhere in the
+matchers? Did you mess up the order of the `EXPECT_CALL`s? Or is the code under
+test doing something wrong? How can you find out the cause?
+
+Won't it be nice if you have X-ray vision and can actually see the trace of all
+`EXPECT_CALL`s and mock method calls as they are made? For each call, would you
+like to see its actual argument values and which `EXPECT_CALL` gMock thinks it
+matches? If you still need some help to figure out who made these calls, how
+about being able to see the complete stack trace at each mock call?
+
+You can unlock this power by running your test with the `--gmock_verbose=info`
+flag. For example, given the test program:
+
+```cpp
+#include <gmock/gmock.h>
+
+using ::testing::_;
+using ::testing::HasSubstr;
+using ::testing::Return;
+
+class MockFoo {
+ public:
+  MOCK_METHOD(void, F, (const string& x, const string& y));
+};
+
+TEST(Foo, Bar) {
+  MockFoo mock;
+  EXPECT_CALL(mock, F(_, _)).WillRepeatedly(Return());
+  EXPECT_CALL(mock, F("a", "b"));
+  EXPECT_CALL(mock, F("c", HasSubstr("d")));
+
+  mock.F("a", "good");
+  mock.F("a", "b");
+}
+```
+
+if you run it with `--gmock_verbose=info`, you will see this output:
+
+```shell
+[ RUN       ] Foo.Bar
+
+foo_test.cc:14: EXPECT_CALL(mock, F(_, _)) invoked
+Stack trace: ...
+
+foo_test.cc:15: EXPECT_CALL(mock, F("a", "b")) invoked
+Stack trace: ...
+
+foo_test.cc:16: EXPECT_CALL(mock, F("c", HasSubstr("d"))) invoked
+Stack trace: ...
+
+foo_test.cc:14: Mock function call matches EXPECT_CALL(mock, F(_, _))...
+    Function call: F(@0x7fff7c8dad40"a",@0x7fff7c8dad10"good")
+Stack trace: ...
+
+foo_test.cc:15: Mock function call matches EXPECT_CALL(mock, F("a", "b"))...
+    Function call: F(@0x7fff7c8dada0"a",@0x7fff7c8dad70"b")
+Stack trace: ...
+
+foo_test.cc:16: Failure
+Actual function call count doesn't match EXPECT_CALL(mock, F("c", HasSubstr("d")))...
+         Expected: to be called once
+           Actual: never called - unsatisfied and active
+[  FAILED  ] Foo.Bar
+```
+
+Suppose the bug is that the `"c"` in the third `EXPECT_CALL` is a typo and
+should actually be `"a"`. With the above message, you should see that the actual
+`F("a", "good")` call is matched by the first `EXPECT_CALL`, not the third as
+you thought. From that it should be obvious that the third `EXPECT_CALL` is
+written wrong. Case solved.
+
+If you are interested in the mock call trace but not the stack traces, you can
+combine `--gmock_verbose=info` with `--gtest_stack_trace_depth=0` on the test
+command line.
+
+### Running Tests in Emacs
+
+If you build and run your tests in Emacs using the `M-x google-compile` command
+(as many googletest users do), the source file locations of gMock and googletest
+errors will be highlighted. Just press `<Enter>` on one of them and you'll be
+taken to the offending line. Or, you can just type `C-x`` to jump to the next
+error.
+
+To make it even easier, you can add the following lines to your `~/.emacs` file:
+
+```text
+(global-set-key "\M-m"  'google-compile)  ; m is for make
+(global-set-key [M-down] 'next-error)
+(global-set-key [M-up]  '(lambda () (interactive) (next-error -1)))
+```
+
+Then you can type `M-m` to start a build (if you want to run the test as well,
+just make sure `foo_test.run` or `runtests` is in the build command you supply
+after typing `M-m`), or `M-up`/`M-down` to move back and forth between errors.
+
+## Extending gMock
+
+### Writing New Matchers Quickly {#NewMatchers}
+
+{: .callout .warning}
+WARNING: gMock does not guarantee when or how many times a matcher will be
+invoked. Therefore, all matchers must be functionally pure. See
+[this section](#PureMatchers) for more details.
+
+The `MATCHER*` family of macros can be used to define custom matchers easily.
+The syntax:
+
+```cpp
+MATCHER(name, description_string_expression) { statements; }
+```
+
+will define a matcher with the given name that executes the statements, which
+must return a `bool` to indicate if the match succeeds. Inside the statements,
+you can refer to the value being matched by `arg`, and refer to its type by
+`arg_type`.
+
+The *description string* is a `string`-typed expression that documents what the
+matcher does, and is used to generate the failure message when the match fails.
+It can (and should) reference the special `bool` variable `negation`, and should
+evaluate to the description of the matcher when `negation` is `false`, or that
+of the matcher's negation when `negation` is `true`.
+
+For convenience, we allow the description string to be empty (`""`), in which
+case gMock will use the sequence of words in the matcher name as the
+description.
+
+For example:
+
+```cpp
+MATCHER(IsDivisibleBy7, "") { return (arg % 7) == 0; }
+```
+
+allows you to write
+
+```cpp
+  // Expects mock_foo.Bar(n) to be called where n is divisible by 7.
+  EXPECT_CALL(mock_foo, Bar(IsDivisibleBy7()));
+```
+
+or,
+
+```cpp
+  using ::testing::Not;
+  ...
+  // Verifies that a value is divisible by 7 and the other is not.
+  EXPECT_THAT(some_expression, IsDivisibleBy7());
+  EXPECT_THAT(some_other_expression, Not(IsDivisibleBy7()));
+```
+
+If the above assertions fail, they will print something like:
+
+```shell
+  Value of: some_expression
+  Expected: is divisible by 7
+    Actual: 27
+  ...
+  Value of: some_other_expression
+  Expected: not (is divisible by 7)
+    Actual: 21
+```
+
+where the descriptions `"is divisible by 7"` and `"not (is divisible by 7)"` are
+automatically calculated from the matcher name `IsDivisibleBy7`.
+
+As you may have noticed, the auto-generated descriptions (especially those for
+the negation) may not be so great. You can always override them with a `string`
+expression of your own:
+
+```cpp
+MATCHER(IsDivisibleBy7,
+        absl::StrCat(negation ? "isn't" : "is", " divisible by 7")) {
+  return (arg % 7) == 0;
+}
+```
+
+Optionally, you can stream additional information to a hidden argument named
+`result_listener` to explain the match result. For example, a better definition
+of `IsDivisibleBy7` is:
+
+```cpp
+MATCHER(IsDivisibleBy7, "") {
+  if ((arg % 7) == 0)
+    return true;
+
+  *result_listener << "the remainder is " << (arg % 7);
+  return false;
+}
+```
+
+With this definition, the above assertion will give a better message:
+
+```shell
+  Value of: some_expression
+  Expected: is divisible by 7
+    Actual: 27 (the remainder is 6)
+```
+
+You should let `MatchAndExplain()` print *any additional information* that can
+help a user understand the match result. Note that it should explain why the
+match succeeds in case of a success (unless it's obvious) - this is useful when
+the matcher is used inside `Not()`. There is no need to print the argument value
+itself, as gMock already prints it for you.
+
+{: .callout .note}
+NOTE: The type of the value being matched (`arg_type`) is determined by the
+context in which you use the matcher and is supplied to you by the compiler, so
+you don't need to worry about declaring it (nor can you). This allows the
+matcher to be polymorphic. For example, `IsDivisibleBy7()` can be used to match
+any type where the value of `(arg % 7) == 0` can be implicitly converted to a
+`bool`. In the `Bar(IsDivisibleBy7())` example above, if method `Bar()` takes an
+`int`, `arg_type` will be `int`; if it takes an `unsigned long`, `arg_type` will
+be `unsigned long`; and so on.
+
+### Writing New Parameterized Matchers Quickly
+
+Sometimes you'll want to define a matcher that has parameters. For that you can
+use the macro:
+
+```cpp
+MATCHER_P(name, param_name, description_string) { statements; }
+```
+
+where the description string can be either `""` or a `string` expression that
+references `negation` and `param_name`.
+
+For example:
+
+```cpp
+MATCHER_P(HasAbsoluteValue, value, "") { return abs(arg) == value; }
+```
+
+will allow you to write:
+
+```cpp
+  EXPECT_THAT(Blah("a"), HasAbsoluteValue(n));
+```
+
+which may lead to this message (assuming `n` is 10):
+
+```shell
+  Value of: Blah("a")
+  Expected: has absolute value 10
+    Actual: -9
+```
+
+Note that both the matcher description and its parameter are printed, making the
+message human-friendly.
+
+In the matcher definition body, you can write `foo_type` to reference the type
+of a parameter named `foo`. For example, in the body of
+`MATCHER_P(HasAbsoluteValue, value)` above, you can write `value_type` to refer
+to the type of `value`.
+
+gMock also provides `MATCHER_P2`, `MATCHER_P3`, ..., up to `MATCHER_P10` to
+support multi-parameter matchers:
+
+```cpp
+MATCHER_Pk(name, param_1, ..., param_k, description_string) { statements; }
+```
+
+Please note that the custom description string is for a particular *instance* of
+the matcher, where the parameters have been bound to actual values. Therefore
+usually you'll want the parameter values to be part of the description. gMock
+lets you do that by referencing the matcher parameters in the description string
+expression.
+
+For example,
+
+```cpp
+using ::testing::PrintToString;
+MATCHER_P2(InClosedRange, low, hi,
+           absl::StrFormat("%s in range [%s, %s]", negation ? "isn't" : "is",
+                           PrintToString(low), PrintToString(hi))) {
+  return low <= arg && arg <= hi;
+}
+...
+EXPECT_THAT(3, InClosedRange(4, 6));
+```
+
+would generate a failure that contains the message:
+
+```shell
+  Expected: is in range [4, 6]
+```
+
+If you specify `""` as the description, the failure message will contain the
+sequence of words in the matcher name followed by the parameter values printed
+as a tuple. For example,
+
+```cpp
+  MATCHER_P2(InClosedRange, low, hi, "") { ... }
+  ...
+  EXPECT_THAT(3, InClosedRange(4, 6));
+```
+
+would generate a failure that contains the text:
+
+```shell
+  Expected: in closed range (4, 6)
+```
+
+For the purpose of typing, you can view
+
+```cpp
+MATCHER_Pk(Foo, p1, ..., pk, description_string) { ... }
+```
+
+as shorthand for
+
+```cpp
+template <typename p1_type, ..., typename pk_type>
+FooMatcherPk<p1_type, ..., pk_type>
+Foo(p1_type p1, ..., pk_type pk) { ... }
+```
+
+When you write `Foo(v1, ..., vk)`, the compiler infers the types of the
+parameters `v1`, ..., and `vk` for you. If you are not happy with the result of
+the type inference, you can specify the types by explicitly instantiating the
+template, as in `Foo<long, bool>(5, false)`. As said earlier, you don't get to
+(or need to) specify `arg_type` as that's determined by the context in which the
+matcher is used.
+
+You can assign the result of expression `Foo(p1, ..., pk)` to a variable of type
+`FooMatcherPk<p1_type, ..., pk_type>`. This can be useful when composing
+matchers. Matchers that don't have a parameter or have only one parameter have
+special types: you can assign `Foo()` to a `FooMatcher`-typed variable, and
+assign `Foo(p)` to a `FooMatcherP<p_type>`-typed variable.
+
+While you can instantiate a matcher template with reference types, passing the
+parameters by pointer usually makes your code more readable. If, however, you
+still want to pass a parameter by reference, be aware that in the failure
+message generated by the matcher you will see the value of the referenced object
+but not its address.
+
+You can overload matchers with different numbers of parameters:
+
+```cpp
+MATCHER_P(Blah, a, description_string_1) { ... }
+MATCHER_P2(Blah, a, b, description_string_2) { ... }
+```
+
+While it's tempting to always use the `MATCHER*` macros when defining a new
+matcher, you should also consider implementing the matcher interface directly
+instead (see the recipes that follow), especially if you need to use the matcher
+a lot. While these approaches require more work, they give you more control on
+the types of the value being matched and the matcher parameters, which in
+general leads to better compiler error messages that pay off in the long run.
+They also allow overloading matchers based on parameter types (as opposed to
+just based on the number of parameters).
+
+### Writing New Monomorphic Matchers
+
+A matcher of argument type `T` implements the matcher interface for `T` and does
+two things: it tests whether a value of type `T` matches the matcher, and can
+describe what kind of values it matches. The latter ability is used for
+generating readable error messages when expectations are violated.
+
+A matcher of `T` must declare a typedef like:
+
+```cpp
+using is_gtest_matcher = void;
+```
+
+and supports the following operations:
+
+```cpp
+// Match a value and optionally explain into an ostream.
+bool matched = matcher.MatchAndExplain(value, maybe_os);
+// where `value` is of type `T` and
+// `maybe_os` is of type `std::ostream*`, where it can be null if the caller
+// is not interested in there textual explanation.
+
+matcher.DescribeTo(os);
+matcher.DescribeNegationTo(os);
+// where `os` is of type `std::ostream*`.
+```
+
+If you need a custom matcher but `Truly()` is not a good option (for example,
+you may not be happy with the way `Truly(predicate)` describes itself, or you
+may want your matcher to be polymorphic as `Eq(value)` is), you can define a
+matcher to do whatever you want in two steps: first implement the matcher
+interface, and then define a factory function to create a matcher instance. The
+second step is not strictly needed but it makes the syntax of using the matcher
+nicer.
+
+For example, you can define a matcher to test whether an `int` is divisible by 7
+and then use it like this:
+
+```cpp
+using ::testing::Matcher;
+
+class DivisibleBy7Matcher {
+ public:
+  using is_gtest_matcher = void;
+
+  bool MatchAndExplain(int n, std::ostream*) const {
+    return (n % 7) == 0;
+  }
+
+  void DescribeTo(std::ostream* os) const {
+    *os << "is divisible by 7";
+  }
+
+  void DescribeNegationTo(std::ostream* os) const {
+    *os << "is not divisible by 7";
+  }
+};
+
+Matcher<int> DivisibleBy7() {
+  return DivisibleBy7Matcher();
+}
+
+...
+  EXPECT_CALL(foo, Bar(DivisibleBy7()));
+```
+
+You may improve the matcher message by streaming additional information to the
+`os` argument in `MatchAndExplain()`:
+
+```cpp
+class DivisibleBy7Matcher {
+ public:
+  bool MatchAndExplain(int n, std::ostream* os) const {
+    const int remainder = n % 7;
+    if (remainder != 0 && os != nullptr) {
+      *os << "the remainder is " << remainder;
+    }
+    return remainder == 0;
+  }
+  ...
+};
+```
+
+Then, `EXPECT_THAT(x, DivisibleBy7());` may generate a message like this:
+
+```shell
+Value of: x
+Expected: is divisible by 7
+  Actual: 23 (the remainder is 2)
+```
+
+{: .callout .tip}
+Tip: for convenience, `MatchAndExplain()` can take a `MatchResultListener*`
+instead of `std::ostream*`.
+
+### Writing New Polymorphic Matchers
+
+Expanding what we learned above to *polymorphic* matchers is now just as simple
+as adding templates in the right place.
+
+```cpp
+
+class NotNullMatcher {
+ public:
+  using is_gtest_matcher = void;
+
+  // To implement a polymorphic matcher, we just need to make MatchAndExplain a
+  // template on its first argument.
+
+  // In this example, we want to use NotNull() with any pointer, so
+  // MatchAndExplain() accepts a pointer of any type as its first argument.
+  // In general, you can define MatchAndExplain() as an ordinary method or
+  // a method template, or even overload it.
+  template <typename T>
+  bool MatchAndExplain(T* p, std::ostream*) const {
+    return p != nullptr;
+  }
+
+  // Describes the property of a value matching this matcher.
+  void DescribeTo(std::ostream* os) const { *os << "is not NULL"; }
+
+  // Describes the property of a value NOT matching this matcher.
+  void DescribeNegationTo(std::ostream* os) const { *os << "is NULL"; }
+};
+
+NotNullMatcher NotNull() {
+  return NotNullMatcher();
+}
+
+...
+
+  EXPECT_CALL(foo, Bar(NotNull()));  // The argument must be a non-NULL pointer.
+```
+
+### Legacy Matcher Implementation
+
+Defining matchers used to be somewhat more complicated, in which it required
+several supporting classes and virtual functions. To implement a matcher for
+type `T` using the legacy API you have to derive from `MatcherInterface<T>` and
+call `MakeMatcher` to construct the object.
+
+The interface looks like this:
+
+```cpp
+class MatchResultListener {
+ public:
+  ...
+  // Streams x to the underlying ostream; does nothing if the ostream
+  // is NULL.
+  template <typename T>
+  MatchResultListener& operator<<(const T& x);
+
+  // Returns the underlying ostream.
+  std::ostream* stream();
+};
+
+template <typename T>
+class MatcherInterface {
+ public:
+  virtual ~MatcherInterface();
+
+  // Returns true if and only if the matcher matches x; also explains the match
+  // result to 'listener'.
+  virtual bool MatchAndExplain(T x, MatchResultListener* listener) const = 0;
+
+  // Describes this matcher to an ostream.
+  virtual void DescribeTo(std::ostream* os) const = 0;
+
+  // Describes the negation of this matcher to an ostream.
+  virtual void DescribeNegationTo(std::ostream* os) const;
+};
+```
+
+Fortunately, most of the time you can define a polymorphic matcher easily with
+the help of `MakePolymorphicMatcher()`. Here's how you can define `NotNull()` as
+an example:
+
+```cpp
+using ::testing::MakePolymorphicMatcher;
+using ::testing::MatchResultListener;
+using ::testing::PolymorphicMatcher;
+
+class NotNullMatcher {
+ public:
+  // To implement a polymorphic matcher, first define a COPYABLE class
+  // that has three members MatchAndExplain(), DescribeTo(), and
+  // DescribeNegationTo(), like the following.
+
+  // In this example, we want to use NotNull() with any pointer, so
+  // MatchAndExplain() accepts a pointer of any type as its first argument.
+  // In general, you can define MatchAndExplain() as an ordinary method or
+  // a method template, or even overload it.
+  template <typename T>
+  bool MatchAndExplain(T* p,
+                       MatchResultListener* /* listener */) const {
+    return p != NULL;
+  }
+
+  // Describes the property of a value matching this matcher.
+  void DescribeTo(std::ostream* os) const { *os << "is not NULL"; }
+
+  // Describes the property of a value NOT matching this matcher.
+  void DescribeNegationTo(std::ostream* os) const { *os << "is NULL"; }
+};
+
+// To construct a polymorphic matcher, pass an instance of the class
+// to MakePolymorphicMatcher().  Note the return type.
+PolymorphicMatcher<NotNullMatcher> NotNull() {
+  return MakePolymorphicMatcher(NotNullMatcher());
+}
+
+...
+
+  EXPECT_CALL(foo, Bar(NotNull()));  // The argument must be a non-NULL pointer.
+```
+
+{: .callout .note}
+**Note:** Your polymorphic matcher class does **not** need to inherit from
+`MatcherInterface` or any other class, and its methods do **not** need to be
+virtual.
+
+Like in a monomorphic matcher, you may explain the match result by streaming
+additional information to the `listener` argument in `MatchAndExplain()`.
+
+### Writing New Cardinalities
+
+A cardinality is used in `Times()` to tell gMock how many times you expect a
+call to occur. It doesn't have to be exact. For example, you can say
+`AtLeast(5)` or `Between(2, 4)`.
+
+If the [built-in set](gmock_cheat_sheet.md#CardinalityList) of cardinalities
+doesn't suit you, you are free to define your own by implementing the following
+interface (in namespace `testing`):
+
+```cpp
+class CardinalityInterface {
+ public:
+  virtual ~CardinalityInterface();
+
+  // Returns true if and only if call_count calls will satisfy this cardinality.
+  virtual bool IsSatisfiedByCallCount(int call_count) const = 0;
+
+  // Returns true if and only if call_count calls will saturate this
+  // cardinality.
+  virtual bool IsSaturatedByCallCount(int call_count) const = 0;
+
+  // Describes self to an ostream.
+  virtual void DescribeTo(std::ostream* os) const = 0;
+};
+```
+
+For example, to specify that a call must occur even number of times, you can
+write
+
+```cpp
+using ::testing::Cardinality;
+using ::testing::CardinalityInterface;
+using ::testing::MakeCardinality;
+
+class EvenNumberCardinality : public CardinalityInterface {
+ public:
+  bool IsSatisfiedByCallCount(int call_count) const override {
+    return (call_count % 2) == 0;
+  }
+
+  bool IsSaturatedByCallCount(int call_count) const override {
+    return false;
+  }
+
+  void DescribeTo(std::ostream* os) const {
+    *os << "called even number of times";
+  }
+};
+
+Cardinality EvenNumber() {
+  return MakeCardinality(new EvenNumberCardinality);
+}
+
+...
+  EXPECT_CALL(foo, Bar(3))
+      .Times(EvenNumber());
+```
+
+### Writing New Actions {#QuickNewActions}
+
+If the built-in actions don't work for you, you can easily define your own one.
+All you need is a call operator with a signature compatible with the mocked
+function. So you can use a lambda:
+
+```cpp
+MockFunction<int(int)> mock;
+EXPECT_CALL(mock, Call).WillOnce([](const int input) { return input * 7; });
+EXPECT_EQ(mock.AsStdFunction()(2), 14);
+```
+
+Or a struct with a call operator (even a templated one):
+
+```cpp
+struct MultiplyBy {
+  template <typename T>
+  T operator()(T arg) { return arg * multiplier; }
+
+  int multiplier;
+};
+
+// Then use:
+// EXPECT_CALL(...).WillOnce(MultiplyBy{7});
+```
+
+It's also fine for the callable to take no arguments, ignoring the arguments
+supplied to the mock function:
+
+```cpp
+MockFunction<int(int)> mock;
+EXPECT_CALL(mock, Call).WillOnce([] { return 17; });
+EXPECT_EQ(mock.AsStdFunction()(0), 17);
+```
+
+When used with `WillOnce`, the callable can assume it will be called at most
+once and is allowed to be a move-only type:
+
+```cpp
+// An action that contains move-only types and has an &&-qualified operator,
+// demanding in the type system that it be called at most once. This can be
+// used with WillOnce, but the compiler will reject it if handed to
+// WillRepeatedly.
+struct MoveOnlyAction {
+  std::unique_ptr<int> move_only_state;
+  std::unique_ptr<int> operator()() && { return std::move(move_only_state); }
+};
+
+MockFunction<std::unique_ptr<int>()> mock;
+EXPECT_CALL(mock, Call).WillOnce(MoveOnlyAction{std::make_unique<int>(17)});
+EXPECT_THAT(mock.AsStdFunction()(), Pointee(Eq(17)));
+```
+
+More generally, to use with a mock function whose signature is `R(Args...)` the
+object can be anything convertible to `OnceAction<R(Args...)>` or
+`Action<R(Args...)`>. The difference between the two is that `OnceAction` has
+weaker requirements (`Action` requires a copy-constructible input that can be
+called repeatedly whereas `OnceAction` requires only move-constructible and
+supports `&&`-qualified call operators), but can be used only with `WillOnce`.
+`OnceAction` is typically relevant only when supporting move-only types or
+actions that want a type-system guarantee that they will be called at most once.
+
+Typically the `OnceAction` and `Action` templates need not be referenced
+directly in your actions: a struct or class with a call operator is sufficient,
+as in the examples above. But fancier polymorphic actions that need to know the
+specific return type of the mock function can define templated conversion
+operators to make that possible. See `gmock-actions.h` for examples.
+
+#### Legacy macro-based Actions
+
+Before C++11, the functor-based actions were not supported; the old way of
+writing actions was through a set of `ACTION*` macros. We suggest to avoid them
+in new code; they hide a lot of logic behind the macro, potentially leading to
+harder-to-understand compiler errors. Nevertheless, we cover them here for
+completeness.
+
+By writing
+
+```cpp
+ACTION(name) { statements; }
+```
+
+in a namespace scope (i.e. not inside a class or function), you will define an
+action with the given name that executes the statements. The value returned by
+`statements` will be used as the return value of the action. Inside the
+statements, you can refer to the K-th (0-based) argument of the mock function as
+`argK`. For example:
+
+```cpp
+ACTION(IncrementArg1) { return ++(*arg1); }
+```
+
+allows you to write
+
+```cpp
+... WillOnce(IncrementArg1());
+```
+
+Note that you don't need to specify the types of the mock function arguments.
+Rest assured that your code is type-safe though: you'll get a compiler error if
+`*arg1` doesn't support the `++` operator, or if the type of `++(*arg1)` isn't
+compatible with the mock function's return type.
+
+Another example:
+
+```cpp
+ACTION(Foo) {
+  (*arg2)(5);
+  Blah();
+  *arg1 = 0;
+  return arg0;
+}
+```
+
+defines an action `Foo()` that invokes argument #2 (a function pointer) with 5,
+calls function `Blah()`, sets the value pointed to by argument #1 to 0, and
+returns argument #0.
+
+For more convenience and flexibility, you can also use the following pre-defined
+symbols in the body of `ACTION`:
+
+`argK_type`     | The type of the K-th (0-based) argument of the mock function
+:-------------- | :-----------------------------------------------------------
+`args`          | All arguments of the mock function as a tuple
+`args_type`     | The type of all arguments of the mock function as a tuple
+`return_type`   | The return type of the mock function
+`function_type` | The type of the mock function
+
+For example, when using an `ACTION` as a stub action for mock function:
+
+```cpp
+int DoSomething(bool flag, int* ptr);
+```
+
+we have:
+
+Pre-defined Symbol | Is Bound To
+------------------ | ---------------------------------
+`arg0`             | the value of `flag`
+`arg0_type`        | the type `bool`
+`arg1`             | the value of `ptr`
+`arg1_type`        | the type `int*`
+`args`             | the tuple `(flag, ptr)`
+`args_type`        | the type `std::tuple<bool, int*>`
+`return_type`      | the type `int`
+`function_type`    | the type `int(bool, int*)`
+
+#### Legacy macro-based parameterized Actions
+
+Sometimes you'll want to parameterize an action you define. For that we have
+another macro
+
+```cpp
+ACTION_P(name, param) { statements; }
+```
+
+For example,
+
+```cpp
+ACTION_P(Add, n) { return arg0 + n; }
+```
+
+will allow you to write
+
+```cpp
+// Returns argument #0 + 5.
+... WillOnce(Add(5));
+```
+
+For convenience, we use the term *arguments* for the values used to invoke the
+mock function, and the term *parameters* for the values used to instantiate an
+action.
+
+Note that you don't need to provide the type of the parameter either. Suppose
+the parameter is named `param`, you can also use the gMock-defined symbol
+`param_type` to refer to the type of the parameter as inferred by the compiler.
+For example, in the body of `ACTION_P(Add, n)` above, you can write `n_type` for
+the type of `n`.
+
+gMock also provides `ACTION_P2`, `ACTION_P3`, and etc to support multi-parameter
+actions. For example,
+
+```cpp
+ACTION_P2(ReturnDistanceTo, x, y) {
+  double dx = arg0 - x;
+  double dy = arg1 - y;
+  return sqrt(dx*dx + dy*dy);
+}
+```
+
+lets you write
+
+```cpp
+... WillOnce(ReturnDistanceTo(5.0, 26.5));
+```
+
+You can view `ACTION` as a degenerated parameterized action where the number of
+parameters is 0.
+
+You can also easily define actions overloaded on the number of parameters:
+
+```cpp
+ACTION_P(Plus, a) { ... }
+ACTION_P2(Plus, a, b) { ... }
+```
+
+### Restricting the Type of an Argument or Parameter in an ACTION
+
+For maximum brevity and reusability, the `ACTION*` macros don't ask you to
+provide the types of the mock function arguments and the action parameters.
+Instead, we let the compiler infer the types for us.
+
+Sometimes, however, we may want to be more explicit about the types. There are
+several tricks to do that. For example:
+
+```cpp
+ACTION(Foo) {
+  // Makes sure arg0 can be converted to int.
+  int n = arg0;
+  ... use n instead of arg0 here ...
+}
+
+ACTION_P(Bar, param) {
+  // Makes sure the type of arg1 is const char*.
+  ::testing::StaticAssertTypeEq<const char*, arg1_type>();
+
+  // Makes sure param can be converted to bool.
+  bool flag = param;
+}
+```
+
+where `StaticAssertTypeEq` is a compile-time assertion in googletest that
+verifies two types are the same.
+
+### Writing New Action Templates Quickly
+
+Sometimes you want to give an action explicit template parameters that cannot be
+inferred from its value parameters. `ACTION_TEMPLATE()` supports that and can be
+viewed as an extension to `ACTION()` and `ACTION_P*()`.
+
+The syntax:
+
+```cpp
+ACTION_TEMPLATE(ActionName,
+                HAS_m_TEMPLATE_PARAMS(kind1, name1, ..., kind_m, name_m),
+                AND_n_VALUE_PARAMS(p1, ..., p_n)) { statements; }
+```
+
+defines an action template that takes *m* explicit template parameters and *n*
+value parameters, where *m* is in [1, 10] and *n* is in [0, 10]. `name_i` is the
+name of the *i*-th template parameter, and `kind_i` specifies whether it's a
+`typename`, an integral constant, or a template. `p_i` is the name of the *i*-th
+value parameter.
+
+Example:
+
+```cpp
+// DuplicateArg<k, T>(output) converts the k-th argument of the mock
+// function to type T and copies it to *output.
+ACTION_TEMPLATE(DuplicateArg,
+                // Note the comma between int and k:
+                HAS_2_TEMPLATE_PARAMS(int, k, typename, T),
+                AND_1_VALUE_PARAMS(output)) {
+  *output = T(std::get<k>(args));
+}
+```
+
+To create an instance of an action template, write:
+
+```cpp
+ActionName<t1, ..., t_m>(v1, ..., v_n)
+```
+
+where the `t`s are the template arguments and the `v`s are the value arguments.
+The value argument types are inferred by the compiler. For example:
+
+```cpp
+using ::testing::_;
+...
+  int n;
+  EXPECT_CALL(mock, Foo).WillOnce(DuplicateArg<1, unsigned char>(&n));
+```
+
+If you want to explicitly specify the value argument types, you can provide
+additional template arguments:
+
+```cpp
+ActionName<t1, ..., t_m, u1, ..., u_k>(v1, ..., v_n)
+```
+
+where `u_i` is the desired type of `v_i`.
+
+`ACTION_TEMPLATE` and `ACTION`/`ACTION_P*` can be overloaded on the number of
+value parameters, but not on the number of template parameters. Without the
+restriction, the meaning of the following is unclear:
+
+```cpp
+  OverloadedAction<int, bool>(x);
+```
+
+Are we using a single-template-parameter action where `bool` refers to the type
+of `x`, or a two-template-parameter action where the compiler is asked to infer
+the type of `x`?
+
+### Using the ACTION Object's Type
+
+If you are writing a function that returns an `ACTION` object, you'll need to
+know its type. The type depends on the macro used to define the action and the
+parameter types. The rule is relatively simple:
+
+
+| Given Definition              | Expression          | Has Type              |
+| ----------------------------- | ------------------- | --------------------- |
+| `ACTION(Foo)`                 | `Foo()`             | `FooAction`           |
+| `ACTION_TEMPLATE(Foo, HAS_m_TEMPLATE_PARAMS(...), AND_0_VALUE_PARAMS())` | `Foo<t1, ..., t_m>()` | `FooAction<t1, ..., t_m>` |
+| `ACTION_P(Bar, param)`        | `Bar(int_value)`    | `BarActionP<int>`     |
+| `ACTION_TEMPLATE(Bar, HAS_m_TEMPLATE_PARAMS(...), AND_1_VALUE_PARAMS(p1))` | `Bar<t1, ..., t_m>(int_value)` | `BarActionP<t1, ..., t_m, int>` |
+| `ACTION_P2(Baz, p1, p2)`      | `Baz(bool_value, int_value)` | `BazActionP2<bool, int>` |
+| `ACTION_TEMPLATE(Baz, HAS_m_TEMPLATE_PARAMS(...), AND_2_VALUE_PARAMS(p1, p2))` | `Baz<t1, ..., t_m>(bool_value, int_value)` | `BazActionP2<t1, ..., t_m, bool, int>` |
+| ...                           | ...                 | ...                   |
+
+
+Note that we have to pick different suffixes (`Action`, `ActionP`, `ActionP2`,
+and etc) for actions with different numbers of value parameters, or the action
+definitions cannot be overloaded on the number of them.
+
+### Writing New Monomorphic Actions {#NewMonoActions}
+
+While the `ACTION*` macros are very convenient, sometimes they are
+inappropriate. For example, despite the tricks shown in the previous recipes,
+they don't let you directly specify the types of the mock function arguments and
+the action parameters, which in general leads to unoptimized compiler error
+messages that can baffle unfamiliar users. They also don't allow overloading
+actions based on parameter types without jumping through some hoops.
+
+An alternative to the `ACTION*` macros is to implement
+`::testing::ActionInterface<F>`, where `F` is the type of the mock function in
+which the action will be used. For example:
+
+```cpp
+template <typename F>
+class ActionInterface {
+ public:
+  virtual ~ActionInterface();
+
+  // Performs the action.  Result is the return type of function type
+  // F, and ArgumentTuple is the tuple of arguments of F.
+  //
+
+  // For example, if F is int(bool, const string&), then Result would
+  // be int, and ArgumentTuple would be std::tuple<bool, const string&>.
+  virtual Result Perform(const ArgumentTuple& args) = 0;
+};
+```
+
+```cpp
+using ::testing::_;
+using ::testing::Action;
+using ::testing::ActionInterface;
+using ::testing::MakeAction;
+
+typedef int IncrementMethod(int*);
+
+class IncrementArgumentAction : public ActionInterface<IncrementMethod> {
+ public:
+  int Perform(const std::tuple<int*>& args) override {
+    int* p = std::get<0>(args);  // Grabs the first argument.
+    return *p++;
+  }
+};
+
+Action<IncrementMethod> IncrementArgument() {
+  return MakeAction(new IncrementArgumentAction);
+}
+
+...
+  EXPECT_CALL(foo, Baz(_))
+      .WillOnce(IncrementArgument());
+
+  int n = 5;
+  foo.Baz(&n);  // Should return 5 and change n to 6.
+```
+
+### Writing New Polymorphic Actions {#NewPolyActions}
+
+The previous recipe showed you how to define your own action. This is all good,
+except that you need to know the type of the function in which the action will
+be used. Sometimes that can be a problem. For example, if you want to use the
+action in functions with *different* types (e.g. like `Return()` and
+`SetArgPointee()`).
+
+If an action can be used in several types of mock functions, we say it's
+*polymorphic*. The `MakePolymorphicAction()` function template makes it easy to
+define such an action:
+
+```cpp
+namespace testing {
+template <typename Impl>
+PolymorphicAction<Impl> MakePolymorphicAction(const Impl& impl);
+}  // namespace testing
+```
+
+As an example, let's define an action that returns the second argument in the
+mock function's argument list. The first step is to define an implementation
+class:
+
+```cpp
+class ReturnSecondArgumentAction {
+ public:
+  template <typename Result, typename ArgumentTuple>
+  Result Perform(const ArgumentTuple& args) const {
+    // To get the i-th (0-based) argument, use std::get(args).
+    return std::get<1>(args);
+  }
+};
+```
+
+This implementation class does *not* need to inherit from any particular class.
+What matters is that it must have a `Perform()` method template. This method
+template takes the mock function's arguments as a tuple in a **single**
+argument, and returns the result of the action. It can be either `const` or not,
+but must be invocable with exactly one template argument, which is the result
+type. In other words, you must be able to call `Perform<R>(args)` where `R` is
+the mock function's return type and `args` is its arguments in a tuple.
+
+Next, we use `MakePolymorphicAction()` to turn an instance of the implementation
+class into the polymorphic action we need. It will be convenient to have a
+wrapper for this:
+
+```cpp
+using ::testing::MakePolymorphicAction;
+using ::testing::PolymorphicAction;
+
+PolymorphicAction<ReturnSecondArgumentAction> ReturnSecondArgument() {
+  return MakePolymorphicAction(ReturnSecondArgumentAction());
+}
+```
+
+Now, you can use this polymorphic action the same way you use the built-in ones:
+
+```cpp
+using ::testing::_;
+
+class MockFoo : public Foo {
+ public:
+  MOCK_METHOD(int, DoThis, (bool flag, int n), (override));
+  MOCK_METHOD(string, DoThat, (int x, const char* str1, const char* str2),
+              (override));
+};
+
+  ...
+  MockFoo foo;
+  EXPECT_CALL(foo, DoThis).WillOnce(ReturnSecondArgument());
+  EXPECT_CALL(foo, DoThat).WillOnce(ReturnSecondArgument());
+  ...
+  foo.DoThis(true, 5);  // Will return 5.
+  foo.DoThat(1, "Hi", "Bye");  // Will return "Hi".
+```
+
+### Teaching gMock How to Print Your Values
+
+When an uninteresting or unexpected call occurs, gMock prints the argument
+values and the stack trace to help you debug. Assertion macros like
+`EXPECT_THAT` and `EXPECT_EQ` also print the values in question when the
+assertion fails. gMock and googletest do this using googletest's user-extensible
+value printer.
+
+This printer knows how to print built-in C++ types, native arrays, STL
+containers, and any type that supports the `<<` operator. For other types, it
+prints the raw bytes in the value and hopes that you the user can figure it out.
+[The GoogleTest advanced guide](advanced.md#teaching-googletest-how-to-print-your-values)
+explains how to extend the printer to do a better job at printing your
+particular type than to dump the bytes.
+
+## Useful Mocks Created Using gMock
+
+<!--#include file="includes/g3_testing_LOGs.md"-->
+<!--#include file="includes/g3_mock_callbacks.md"-->
+
+### Mock std::function {#MockFunction}
+
+`std::function` is a general function type introduced in C++11. It is a
+preferred way of passing callbacks to new interfaces. Functions are copyable,
+and are not usually passed around by pointer, which makes them tricky to mock.
+But fear not - `MockFunction` can help you with that.
+
+`MockFunction<R(T1, ..., Tn)>` has a mock method `Call()` with the signature:
+
+```cpp
+  R Call(T1, ..., Tn);
+```
+
+It also has a `AsStdFunction()` method, which creates a `std::function` proxy
+forwarding to Call:
+
+```cpp
+  std::function<R(T1, ..., Tn)> AsStdFunction();
+```
+
+To use `MockFunction`, first create `MockFunction` object and set up
+expectations on its `Call` method. Then pass proxy obtained from
+`AsStdFunction()` to the code you are testing. For example:
+
+```cpp
+TEST(FooTest, RunsCallbackWithBarArgument) {
+  // 1. Create a mock object.
+  MockFunction<int(string)> mock_function;
+
+  // 2. Set expectations on Call() method.
+  EXPECT_CALL(mock_function, Call("bar")).WillOnce(Return(1));
+
+  // 3. Exercise code that uses std::function.
+  Foo(mock_function.AsStdFunction());
+  // Foo's signature can be either of:
+  // void Foo(const std::function<int(string)>& fun);
+  // void Foo(std::function<int(string)> fun);
+
+  // 4. All expectations will be verified when mock_function
+  //     goes out of scope and is destroyed.
+}
+```
+
+Remember that function objects created with `AsStdFunction()` are just
+forwarders. If you create multiple of them, they will share the same set of
+expectations.
+
+Although `std::function` supports unlimited number of arguments, `MockFunction`
+implementation is limited to ten. If you ever hit that limit... well, your
+callback has bigger problems than being mockable. :-)

contrib/googletest/docs/gmock_faq.md

@@ -0,0 +1,390 @@
+# Legacy gMock FAQ
+
+### When I call a method on my mock object, the method for the real object is invoked instead. What's the problem?
+
+In order for a method to be mocked, it must be *virtual*, unless you use the
+[high-perf dependency injection technique](gmock_cook_book.md#MockingNonVirtualMethods).
+
+### Can I mock a variadic function?
+
+You cannot mock a variadic function (i.e. a function taking ellipsis (`...`)
+arguments) directly in gMock.
+
+The problem is that in general, there is *no way* for a mock object to know how
+many arguments are passed to the variadic method, and what the arguments' types
+are. Only the *author of the base class* knows the protocol, and we cannot look
+into his or her head.
+
+Therefore, to mock such a function, the *user* must teach the mock object how to
+figure out the number of arguments and their types. One way to do it is to
+provide overloaded versions of the function.
+
+Ellipsis arguments are inherited from C and not really a C++ feature. They are
+unsafe to use and don't work with arguments that have constructors or
+destructors. Therefore we recommend to avoid them in C++ as much as possible.
+
+### MSVC gives me warning C4301 or C4373 when I define a mock method with a const parameter. Why?
+
+If you compile this using Microsoft Visual C++ 2005 SP1:
+
+```cpp
+class Foo {
+  ...
+  virtual void Bar(const int i) = 0;
+};
+
+class MockFoo : public Foo {
+  ...
+  MOCK_METHOD(void, Bar, (const int i), (override));
+};
+```
+
+You may get the following warning:
+
+```shell
+warning C4301: 'MockFoo::Bar': overriding virtual function only differs from 'Foo::Bar' by const/volatile qualifier
+```
+
+This is a MSVC bug. The same code compiles fine with gcc, for example. If you
+use Visual C++ 2008 SP1, you would get the warning:
+
+```shell
+warning C4373: 'MockFoo::Bar': virtual function overrides 'Foo::Bar', previous versions of the compiler did not override when parameters only differed by const/volatile qualifiers
+```
+
+In C++, if you *declare* a function with a `const` parameter, the `const`
+modifier is ignored. Therefore, the `Foo` base class above is equivalent to:
+
+```cpp
+class Foo {
+  ...
+  virtual void Bar(int i) = 0;  // int or const int?  Makes no difference.
+};
+```
+
+In fact, you can *declare* `Bar()` with an `int` parameter, and define it with a
+`const int` parameter. The compiler will still match them up.
+
+Since making a parameter `const` is meaningless in the method declaration, we
+recommend to remove it in both `Foo` and `MockFoo`. That should workaround the
+VC bug.
+
+Note that we are talking about the *top-level* `const` modifier here. If the
+function parameter is passed by pointer or reference, declaring the pointee or
+referee as `const` is still meaningful. For example, the following two
+declarations are *not* equivalent:
+
+```cpp
+void Bar(int* p);         // Neither p nor *p is const.
+void Bar(const int* p);  // p is not const, but *p is.
+```
+
+### I can't figure out why gMock thinks my expectations are not satisfied. What should I do?
+
+You might want to run your test with `--gmock_verbose=info`. This flag lets
+gMock print a trace of every mock function call it receives. By studying the
+trace, you'll gain insights on why the expectations you set are not met.
+
+If you see the message "The mock function has no default action set, and its
+return type has no default value set.", then try
+[adding a default action](gmock_cheat_sheet.md#OnCall). Due to a known issue,
+unexpected calls on mocks without default actions don't print out a detailed
+comparison between the actual arguments and the expected arguments.
+
+### My program crashed and `ScopedMockLog` spit out tons of messages. Is it a gMock bug?
+
+gMock and `ScopedMockLog` are likely doing the right thing here.
+
+When a test crashes, the failure signal handler will try to log a lot of
+information (the stack trace, and the address map, for example). The messages
+are compounded if you have many threads with depth stacks. When `ScopedMockLog`
+intercepts these messages and finds that they don't match any expectations, it
+prints an error for each of them.
+
+You can learn to ignore the errors, or you can rewrite your expectations to make
+your test more robust, for example, by adding something like:
+
+```cpp
+using ::testing::AnyNumber;
+using ::testing::Not;
+...
+  // Ignores any log not done by us.
+  EXPECT_CALL(log, Log(_, Not(EndsWith("/my_file.cc")), _))
+      .Times(AnyNumber());
+```
+
+### How can I assert that a function is NEVER called?
+
+```cpp
+using ::testing::_;
+...
+  EXPECT_CALL(foo, Bar(_))
+      .Times(0);
+```
+
+### I have a failed test where gMock tells me TWICE that a particular expectation is not satisfied. Isn't this redundant?
+
+When gMock detects a failure, it prints relevant information (the mock function
+arguments, the state of relevant expectations, and etc) to help the user debug.
+If another failure is detected, gMock will do the same, including printing the
+state of relevant expectations.
+
+Sometimes an expectation's state didn't change between two failures, and you'll
+see the same description of the state twice. They are however *not* redundant,
+as they refer to *different points in time*. The fact they are the same *is*
+interesting information.
+
+### I get a heapcheck failure when using a mock object, but using a real object is fine. What can be wrong?
+
+Does the class (hopefully a pure interface) you are mocking have a virtual
+destructor?
+
+Whenever you derive from a base class, make sure its destructor is virtual.
+Otherwise Bad Things will happen. Consider the following code:
+
+```cpp
+class Base {
+ public:
+  // Not virtual, but should be.
+  ~Base() { ... }
+  ...
+};
+
+class Derived : public Base {
+ public:
+  ...
+ private:
+  std::string value_;
+};
+
+...
+  Base* p = new Derived;
+  ...
+  delete p;  // Surprise! ~Base() will be called, but ~Derived() will not
+                 // - value_ is leaked.
+```
+
+By changing `~Base()` to virtual, `~Derived()` will be correctly called when
+`delete p` is executed, and the heap checker will be happy.
+
+### The "newer expectations override older ones" rule makes writing expectations awkward. Why does gMock do that?
+
+When people complain about this, often they are referring to code like:
+
+```cpp
+using ::testing::Return;
+...
+  // foo.Bar() should be called twice, return 1 the first time, and return
+  // 2 the second time.  However, I have to write the expectations in the
+  // reverse order.  This sucks big time!!!
+  EXPECT_CALL(foo, Bar())
+      .WillOnce(Return(2))
+      .RetiresOnSaturation();
+  EXPECT_CALL(foo, Bar())
+      .WillOnce(Return(1))
+      .RetiresOnSaturation();
+```
+
+The problem, is that they didn't pick the **best** way to express the test's
+intent.
+
+By default, expectations don't have to be matched in *any* particular order. If
+you want them to match in a certain order, you need to be explicit. This is
+gMock's (and jMock's) fundamental philosophy: it's easy to accidentally
+over-specify your tests, and we want to make it harder to do so.
+
+There are two better ways to write the test spec. You could either put the
+expectations in sequence:
+
+```cpp
+using ::testing::Return;
+...
+  // foo.Bar() should be called twice, return 1 the first time, and return
+  // 2 the second time.  Using a sequence, we can write the expectations
+  // in their natural order.
+  {
+    InSequence s;
+    EXPECT_CALL(foo, Bar())
+        .WillOnce(Return(1))
+        .RetiresOnSaturation();
+    EXPECT_CALL(foo, Bar())
+        .WillOnce(Return(2))
+        .RetiresOnSaturation();
+  }
+```
+
+or you can put the sequence of actions in the same expectation:
+
+```cpp
+using ::testing::Return;
+...
+  // foo.Bar() should be called twice, return 1 the first time, and return
+  // 2 the second time.
+  EXPECT_CALL(foo, Bar())
+      .WillOnce(Return(1))
+      .WillOnce(Return(2))
+      .RetiresOnSaturation();
+```
+
+Back to the original questions: why does gMock search the expectations (and
+`ON_CALL`s) from back to front? Because this allows a user to set up a mock's
+behavior for the common case early (e.g. in the mock's constructor or the test
+fixture's set-up phase) and customize it with more specific rules later. If
+gMock searches from front to back, this very useful pattern won't be possible.
+
+### gMock prints a warning when a function without EXPECT_CALL is called, even if I have set its behavior using ON_CALL. Would it be reasonable not to show the warning in this case?
+
+When choosing between being neat and being safe, we lean toward the latter. So
+the answer is that we think it's better to show the warning.
+
+Often people write `ON_CALL`s in the mock object's constructor or `SetUp()`, as
+the default behavior rarely changes from test to test. Then in the test body
+they set the expectations, which are often different for each test. Having an
+`ON_CALL` in the set-up part of a test doesn't mean that the calls are expected.
+If there's no `EXPECT_CALL` and the method is called, it's possibly an error. If
+we quietly let the call go through without notifying the user, bugs may creep in
+unnoticed.
+
+If, however, you are sure that the calls are OK, you can write
+
+```cpp
+using ::testing::_;
+...
+  EXPECT_CALL(foo, Bar(_))
+      .WillRepeatedly(...);
+```
+
+instead of
+
+```cpp
+using ::testing::_;
+...
+  ON_CALL(foo, Bar(_))
+      .WillByDefault(...);
+```
+
+This tells gMock that you do expect the calls and no warning should be printed.
+
+Also, you can control the verbosity by specifying `--gmock_verbose=error`. Other
+values are `info` and `warning`. If you find the output too noisy when
+debugging, just choose a less verbose level.
+
+### How can I delete the mock function's argument in an action?
+
+If your mock function takes a pointer argument and you want to delete that
+argument, you can use testing::DeleteArg<N>() to delete the N'th (zero-indexed)
+argument:
+
+```cpp
+using ::testing::_;
+  ...
+  MOCK_METHOD(void, Bar, (X* x, const Y& y));
+  ...
+  EXPECT_CALL(mock_foo_, Bar(_, _))
+      .WillOnce(testing::DeleteArg<0>()));
+```
+
+### How can I perform an arbitrary action on a mock function's argument?
+
+If you find yourself needing to perform some action that's not supported by
+gMock directly, remember that you can define your own actions using
+[`MakeAction()`](#NewMonoActions) or
+[`MakePolymorphicAction()`](#NewPolyActions), or you can write a stub function
+and invoke it using [`Invoke()`](#FunctionsAsActions).
+
+```cpp
+using ::testing::_;
+using ::testing::Invoke;
+  ...
+  MOCK_METHOD(void, Bar, (X* p));
+  ...
+  EXPECT_CALL(mock_foo_, Bar(_))
+      .WillOnce(Invoke(MyAction(...)));
+```
+
+### My code calls a static/global function. Can I mock it?
+
+You can, but you need to make some changes.
+
+In general, if you find yourself needing to mock a static function, it's a sign
+that your modules are too tightly coupled (and less flexible, less reusable,
+less testable, etc). You are probably better off defining a small interface and
+call the function through that interface, which then can be easily mocked. It's
+a bit of work initially, but usually pays for itself quickly.
+
+This Google Testing Blog
+[post](https://testing.googleblog.com/2008/06/defeat-static-cling.html) says it
+excellently. Check it out.
+
+### My mock object needs to do complex stuff. It's a lot of pain to specify the actions. gMock sucks!
+
+I know it's not a question, but you get an answer for free any way. :-)
+
+With gMock, you can create mocks in C++ easily. And people might be tempted to
+use them everywhere. Sometimes they work great, and sometimes you may find them,
+well, a pain to use. So, what's wrong in the latter case?
+
+When you write a test without using mocks, you exercise the code and assert that
+it returns the correct value or that the system is in an expected state. This is
+sometimes called "state-based testing".
+
+Mocks are great for what some call "interaction-based" testing: instead of
+checking the system state at the very end, mock objects verify that they are
+invoked the right way and report an error as soon as it arises, giving you a
+handle on the precise context in which the error was triggered. This is often
+more effective and economical to do than state-based testing.
+
+If you are doing state-based testing and using a test double just to simulate
+the real object, you are probably better off using a fake. Using a mock in this
+case causes pain, as it's not a strong point for mocks to perform complex
+actions. If you experience this and think that mocks suck, you are just not
+using the right tool for your problem. Or, you might be trying to solve the
+wrong problem. :-)
+
+### I got a warning "Uninteresting function call encountered - default action taken.." Should I panic?
+
+By all means, NO! It's just an FYI. :-)
+
+What it means is that you have a mock function, you haven't set any expectations
+on it (by gMock's rule this means that you are not interested in calls to this
+function and therefore it can be called any number of times), and it is called.
+That's OK - you didn't say it's not OK to call the function!
+
+What if you actually meant to disallow this function to be called, but forgot to
+write `EXPECT_CALL(foo, Bar()).Times(0)`? While one can argue that it's the
+user's fault, gMock tries to be nice and prints you a note.
+
+So, when you see the message and believe that there shouldn't be any
+uninteresting calls, you should investigate what's going on. To make your life
+easier, gMock dumps the stack trace when an uninteresting call is encountered.
+From that you can figure out which mock function it is, and how it is called.
+
+### I want to define a custom action. Should I use Invoke() or implement the ActionInterface interface?
+
+Either way is fine - you want to choose the one that's more convenient for your
+circumstance.
+
+Usually, if your action is for a particular function type, defining it using
+`Invoke()` should be easier; if your action can be used in functions of
+different types (e.g. if you are defining `Return(*value*)`),
+`MakePolymorphicAction()` is easiest. Sometimes you want precise control on what
+types of functions the action can be used in, and implementing `ActionInterface`
+is the way to go here. See the implementation of `Return()` in `gmock-actions.h`
+for an example.
+
+### I use SetArgPointee() in WillOnce(), but gcc complains about "conflicting return type specified". What does it mean?
+
+You got this error as gMock has no idea what value it should return when the
+mock method is called. `SetArgPointee()` says what the side effect is, but
+doesn't say what the return value should be. You need `DoAll()` to chain a
+`SetArgPointee()` with a `Return()` that provides a value appropriate to the API
+being mocked.
+
+See this [recipe](gmock_cook_book.md#mocking-side-effects) for more details and
+an example.
+
+### I have a huge mock class, and Microsoft Visual C++ runs out of memory when compiling it. What can I do?
+
+We've noticed that when the `/clr` compiler flag is used, Visual C++ uses 5~6
+times as much memory when compiling a mock class. We suggest to avoid `/clr`
+when compiling native C++ mocks.

contrib/googletest/docs/gmock_for_dummies.md

@@ -0,0 +1,700 @@
+# gMock for Dummies
+
+## What Is gMock?
+
+When you write a prototype or test, often it's not feasible or wise to rely on
+real objects entirely. A **mock object** implements the same interface as a real
+object (so it can be used as one), but lets you specify at run time how it will
+be used and what it should do (which methods will be called? in which order? how
+many times? with what arguments? what will they return? etc).
+
+It is easy to confuse the term *fake objects* with mock objects. Fakes and mocks
+actually mean very different things in the Test-Driven Development (TDD)
+community:
+
+*   **Fake** objects have working implementations, but usually take some
+    shortcut (perhaps to make the operations less expensive), which makes them
+    not suitable for production. An in-memory file system would be an example of
+    a fake.
+*   **Mocks** are objects pre-programmed with *expectations*, which form a
+    specification of the calls they are expected to receive.
+
+If all this seems too abstract for you, don't worry - the most important thing
+to remember is that a mock allows you to check the *interaction* between itself
+and code that uses it. The difference between fakes and mocks shall become much
+clearer once you start to use mocks.
+
+**gMock** is a library (sometimes we also call it a "framework" to make it sound
+cool) for creating mock classes and using them. It does to C++ what
+jMock/EasyMock does to Java (well, more or less).
+
+When using gMock,
+
+1.  first, you use some simple macros to describe the interface you want to
+    mock, and they will expand to the implementation of your mock class;
+2.  next, you create some mock objects and specify its expectations and behavior
+    using an intuitive syntax;
+3.  then you exercise code that uses the mock objects. gMock will catch any
+    violation to the expectations as soon as it arises.
+
+## Why gMock?
+
+While mock objects help you remove unnecessary dependencies in tests and make
+them fast and reliable, using mocks manually in C++ is *hard*:
+
+*   Someone has to implement the mocks. The job is usually tedious and
+    error-prone. No wonder people go great distance to avoid it.
+*   The quality of those manually written mocks is a bit, uh, unpredictable. You
+    may see some really polished ones, but you may also see some that were
+    hacked up in a hurry and have all sorts of ad hoc restrictions.
+*   The knowledge you gained from using one mock doesn't transfer to the next
+    one.
+
+In contrast, Java and Python programmers have some fine mock frameworks (jMock,
+EasyMock, etc), which automate the creation of mocks. As a result, mocking is a
+proven effective technique and widely adopted practice in those communities.
+Having the right tool absolutely makes the difference.
+
+gMock was built to help C++ programmers. It was inspired by jMock and EasyMock,
+but designed with C++'s specifics in mind. It is your friend if any of the
+following problems is bothering you:
+
+*   You are stuck with a sub-optimal design and wish you had done more
+    prototyping before it was too late, but prototyping in C++ is by no means
+    "rapid".
+*   Your tests are slow as they depend on too many libraries or use expensive
+    resources (e.g. a database).
+*   Your tests are brittle as some resources they use are unreliable (e.g. the
+    network).
+*   You want to test how your code handles a failure (e.g. a file checksum
+    error), but it's not easy to cause one.
+*   You need to make sure that your module interacts with other modules in the
+    right way, but it's hard to observe the interaction; therefore you resort to
+    observing the side effects at the end of the action, but it's awkward at
+    best.
+*   You want to "mock out" your dependencies, except that they don't have mock
+    implementations yet; and, frankly, you aren't thrilled by some of those
+    hand-written mocks.
+
+We encourage you to use gMock as
+
+*   a *design* tool, for it lets you experiment with your interface design early
+    and often. More iterations lead to better designs!
+*   a *testing* tool to cut your tests' outbound dependencies and probe the
+    interaction between your module and its collaborators.
+
+## Getting Started
+
+gMock is bundled with googletest.
+
+## A Case for Mock Turtles
+
+Let's look at an example. Suppose you are developing a graphics program that
+relies on a [LOGO](http://en.wikipedia.org/wiki/Logo_programming_language)-like
+API for drawing. How would you test that it does the right thing? Well, you can
+run it and compare the screen with a golden screen snapshot, but let's admit it:
+tests like this are expensive to run and fragile (What if you just upgraded to a
+shiny new graphics card that has better anti-aliasing? Suddenly you have to
+update all your golden images.). It would be too painful if all your tests are
+like this. Fortunately, you learned about
+[Dependency Injection](http://en.wikipedia.org/wiki/Dependency_injection) and know the right thing
+to do: instead of having your application talk to the system API directly, wrap
+the API in an interface (say, `Turtle`) and code to that interface:
+
+```cpp
+class Turtle {
+  ...
+  virtual ~Turtle() {}
+  virtual void PenUp() = 0;
+  virtual void PenDown() = 0;
+  virtual void Forward(int distance) = 0;
+  virtual void Turn(int degrees) = 0;
+  virtual void GoTo(int x, int y) = 0;
+  virtual int GetX() const = 0;
+  virtual int GetY() const = 0;
+};
+```
+
+(Note that the destructor of `Turtle` **must** be virtual, as is the case for
+**all** classes you intend to inherit from - otherwise the destructor of the
+derived class will not be called when you delete an object through a base
+pointer, and you'll get corrupted program states like memory leaks.)
+
+You can control whether the turtle's movement will leave a trace using `PenUp()`
+and `PenDown()`, and control its movement using `Forward()`, `Turn()`, and
+`GoTo()`. Finally, `GetX()` and `GetY()` tell you the current position of the
+turtle.
+
+Your program will normally use a real implementation of this interface. In
+tests, you can use a mock implementation instead. This allows you to easily
+check what drawing primitives your program is calling, with what arguments, and
+in which order. Tests written this way are much more robust (they won't break
+because your new machine does anti-aliasing differently), easier to read and
+maintain (the intent of a test is expressed in the code, not in some binary
+images), and run *much, much faster*.
+
+## Writing the Mock Class
+
+If you are lucky, the mocks you need to use have already been implemented by
+some nice people. If, however, you find yourself in the position to write a mock
+class, relax - gMock turns this task into a fun game! (Well, almost.)
+
+### How to Define It
+
+Using the `Turtle` interface as example, here are the simple steps you need to
+follow:
+
+*   Derive a class `MockTurtle` from `Turtle`.
+*   Take a *virtual* function of `Turtle` (while it's possible to
+    [mock non-virtual methods using templates](gmock_cook_book.md#MockingNonVirtualMethods),
+    it's much more involved).
+*   In the `public:` section of the child class, write `MOCK_METHOD();`
+*   Now comes the fun part: you take the function signature, cut-and-paste it
+    into the macro, and add two commas - one between the return type and the
+    name, another between the name and the argument list.
+*   If you're mocking a const method, add a 4th parameter containing `(const)`
+    (the parentheses are required).
+*   Since you're overriding a virtual method, we suggest adding the `override`
+    keyword. For const methods the 4th parameter becomes `(const, override)`,
+    for non-const methods just `(override)`. This isn't mandatory.
+*   Repeat until all virtual functions you want to mock are done. (It goes
+    without saying that *all* pure virtual methods in your abstract class must
+    be either mocked or overridden.)
+
+After the process, you should have something like:
+
+```cpp
+#include <gmock/gmock.h>  // Brings in gMock.
+
+class MockTurtle : public Turtle {
+ public:
+  ...
+  MOCK_METHOD(void, PenUp, (), (override));
+  MOCK_METHOD(void, PenDown, (), (override));
+  MOCK_METHOD(void, Forward, (int distance), (override));
+  MOCK_METHOD(void, Turn, (int degrees), (override));
+  MOCK_METHOD(void, GoTo, (int x, int y), (override));
+  MOCK_METHOD(int, GetX, (), (const, override));
+  MOCK_METHOD(int, GetY, (), (const, override));
+};
+```
+
+You don't need to define these mock methods somewhere else - the `MOCK_METHOD`
+macro will generate the definitions for you. It's that simple!
+
+### Where to Put It
+
+When you define a mock class, you need to decide where to put its definition.
+Some people put it in a `_test.cc`. This is fine when the interface being mocked
+(say, `Foo`) is owned by the same person or team. Otherwise, when the owner of
+`Foo` changes it, your test could break. (You can't really expect `Foo`'s
+maintainer to fix every test that uses `Foo`, can you?)
+
+Generally, you should not mock classes you don't own. If you must mock such a
+class owned by others, define the mock class in `Foo`'s Bazel package (usually
+the same directory or a `testing` sub-directory), and put it in a `.h` and a
+`cc_library` with `testonly=True`. Then everyone can reference them from their
+tests. If `Foo` ever changes, there is only one copy of `MockFoo` to change, and
+only tests that depend on the changed methods need to be fixed.
+
+Another way to do it: you can introduce a thin layer `FooAdaptor` on top of
+`Foo` and code to this new interface. Since you own `FooAdaptor`, you can absorb
+changes in `Foo` much more easily. While this is more work initially, carefully
+choosing the adaptor interface can make your code easier to write and more
+readable (a net win in the long run), as you can choose `FooAdaptor` to fit your
+specific domain much better than `Foo` does.
+
+## Using Mocks in Tests
+
+Once you have a mock class, using it is easy. The typical work flow is:
+
+1.  Import the gMock names from the `testing` namespace such that you can use
+    them unqualified (You only have to do it once per file). Remember that
+    namespaces are a good idea.
+2.  Create some mock objects.
+3.  Specify your expectations on them (How many times will a method be called?
+    With what arguments? What should it do? etc.).
+4.  Exercise some code that uses the mocks; optionally, check the result using
+    googletest assertions. If a mock method is called more than expected or with
+    wrong arguments, you'll get an error immediately.
+5.  When a mock is destructed, gMock will automatically check whether all
+    expectations on it have been satisfied.
+
+Here's an example:
+
+```cpp
+#include "path/to/mock-turtle.h"
+#include <gmock/gmock.h>
+#include <gtest/gtest.h>
+
+using ::testing::AtLeast;                         // #1
+
+TEST(PainterTest, CanDrawSomething) {
+  MockTurtle turtle;                              // #2
+  EXPECT_CALL(turtle, PenDown())                  // #3
+      .Times(AtLeast(1));
+
+  Painter painter(&turtle);                       // #4
+
+  EXPECT_TRUE(painter.DrawCircle(0, 0, 10));      // #5
+}
+```
+
+As you might have guessed, this test checks that `PenDown()` is called at least
+once. If the `painter` object didn't call this method, your test will fail with
+a message like this:
+
+```text
+path/to/my_test.cc:119: Failure
+Actual function call count doesn't match this expectation:
+Actually: never called;
+Expected: called at least once.
+Stack trace:
+...
+```
+
+**Tip 1:** If you run the test from an Emacs buffer, you can hit `<Enter>` on
+the line number to jump right to the failed expectation.
+
+**Tip 2:** If your mock objects are never deleted, the final verification won't
+happen. Therefore it's a good idea to turn on the heap checker in your tests
+when you allocate mocks on the heap. You get that automatically if you use the
+`gtest_main` library already.
+
+**Important note:** gMock requires expectations to be set **before** the mock
+functions are called, otherwise the behavior is **undefined**. Do not alternate
+between calls to `EXPECT_CALL()` and calls to the mock functions, and do not set
+any expectations on a mock after passing the mock to an API.
+
+This means `EXPECT_CALL()` should be read as expecting that a call will occur
+*in the future*, not that a call has occurred. Why does gMock work like that?
+Well, specifying the expectation beforehand allows gMock to report a violation
+as soon as it rises, when the context (stack trace, etc) is still available.
+This makes debugging much easier.
+
+Admittedly, this test is contrived and doesn't do much. You can easily achieve
+the same effect without using gMock. However, as we shall reveal soon, gMock
+allows you to do *so much more* with the mocks.
+
+## Setting Expectations
+
+The key to using a mock object successfully is to set the *right expectations*
+on it. If you set the expectations too strict, your test will fail as the result
+of unrelated changes. If you set them too loose, bugs can slip through. You want
+to do it just right such that your test can catch exactly the kind of bugs you
+intend it to catch. gMock provides the necessary means for you to do it "just
+right."
+
+### General Syntax
+
+In gMock we use the `EXPECT_CALL()` macro to set an expectation on a mock
+method. The general syntax is:
+
+```cpp
+EXPECT_CALL(mock_object, method(matchers))
+    .Times(cardinality)
+    .WillOnce(action)
+    .WillRepeatedly(action);
+```
+
+The macro has two arguments: first the mock object, and then the method and its
+arguments. Note that the two are separated by a comma (`,`), not a period (`.`).
+(Why using a comma? The answer is that it was necessary for technical reasons.)
+If the method is not overloaded, the macro can also be called without matchers:
+
+```cpp
+EXPECT_CALL(mock_object, non-overloaded-method)
+    .Times(cardinality)
+    .WillOnce(action)
+    .WillRepeatedly(action);
+```
+
+This syntax allows the test writer to specify "called with any arguments"
+without explicitly specifying the number or types of arguments. To avoid
+unintended ambiguity, this syntax may only be used for methods that are not
+overloaded.
+
+Either form of the macro can be followed by some optional *clauses* that provide
+more information about the expectation. We'll discuss how each clause works in
+the coming sections.
+
+This syntax is designed to make an expectation read like English. For example,
+you can probably guess that
+
+```cpp
+using ::testing::Return;
+...
+EXPECT_CALL(turtle, GetX())
+    .Times(5)
+    .WillOnce(Return(100))
+    .WillOnce(Return(150))
+    .WillRepeatedly(Return(200));
+```
+
+says that the `turtle` object's `GetX()` method will be called five times, it
+will return 100 the first time, 150 the second time, and then 200 every time.
+Some people like to call this style of syntax a Domain-Specific Language (DSL).
+
+{: .callout .note}
+**Note:** Why do we use a macro to do this? Well it serves two purposes: first
+it makes expectations easily identifiable (either by `grep` or by a human
+reader), and second it allows gMock to include the source file location of a
+failed expectation in messages, making debugging easier.
+
+### Matchers: What Arguments Do We Expect?
+
+When a mock function takes arguments, we may specify what arguments we are
+expecting, for example:
+
+```cpp
+// Expects the turtle to move forward by 100 units.
+EXPECT_CALL(turtle, Forward(100));
+```
+
+Oftentimes you do not want to be too specific. Remember that talk about tests
+being too rigid? Over specification leads to brittle tests and obscures the
+intent of tests. Therefore we encourage you to specify only what's necessary—no
+more, no less. If you aren't interested in the value of an argument, write `_`
+as the argument, which means "anything goes":
+
+```cpp
+using ::testing::_;
+...
+// Expects that the turtle jumps to somewhere on the x=50 line.
+EXPECT_CALL(turtle, GoTo(50, _));
+```
+
+`_` is an instance of what we call **matchers**. A matcher is like a predicate
+and can test whether an argument is what we'd expect. You can use a matcher
+inside `EXPECT_CALL()` wherever a function argument is expected. `_` is a
+convenient way of saying "any value".
+
+In the above examples, `100` and `50` are also matchers; implicitly, they are
+the same as `Eq(100)` and `Eq(50)`, which specify that the argument must be
+equal (using `operator==`) to the matcher argument. There are many
+[built-in matchers](reference/matchers.md) for common types (as well as
+[custom matchers](gmock_cook_book.md#NewMatchers)); for example:
+
+```cpp
+using ::testing::Ge;
+...
+// Expects the turtle moves forward by at least 100.
+EXPECT_CALL(turtle, Forward(Ge(100)));
+```
+
+If you don't care about *any* arguments, rather than specify `_` for each of
+them you may instead omit the parameter list:
+
+```cpp
+// Expects the turtle to move forward.
+EXPECT_CALL(turtle, Forward);
+// Expects the turtle to jump somewhere.
+EXPECT_CALL(turtle, GoTo);
+```
+
+This works for all non-overloaded methods; if a method is overloaded, you need
+to help gMock resolve which overload is expected by specifying the number of
+arguments and possibly also the
+[types of the arguments](gmock_cook_book.md#SelectOverload).
+
+### Cardinalities: How Many Times Will It Be Called?
+
+The first clause we can specify following an `EXPECT_CALL()` is `Times()`. We
+call its argument a **cardinality** as it tells *how many times* the call should
+occur. It allows us to repeat an expectation many times without actually writing
+it as many times. More importantly, a cardinality can be "fuzzy", just like a
+matcher can be. This allows a user to express the intent of a test exactly.
+
+An interesting special case is when we say `Times(0)`. You may have guessed - it
+means that the function shouldn't be called with the given arguments at all, and
+gMock will report a googletest failure whenever the function is (wrongfully)
+called.
+
+We've seen `AtLeast(n)` as an example of fuzzy cardinalities earlier. For the
+list of built-in cardinalities you can use, see
+[here](gmock_cheat_sheet.md#CardinalityList).
+
+The `Times()` clause can be omitted. **If you omit `Times()`, gMock will infer
+the cardinality for you.** The rules are easy to remember:
+
+*   If **neither** `WillOnce()` **nor** `WillRepeatedly()` is in the
+    `EXPECT_CALL()`, the inferred cardinality is `Times(1)`.
+*   If there are *n* `WillOnce()`'s but **no** `WillRepeatedly()`, where *n* >=
+    1, the cardinality is `Times(n)`.
+*   If there are *n* `WillOnce()`'s and **one** `WillRepeatedly()`, where *n* >=
+    0, the cardinality is `Times(AtLeast(n))`.
+
+**Quick quiz:** what do you think will happen if a function is expected to be
+called twice but actually called four times?
+
+### Actions: What Should It Do?
+
+Remember that a mock object doesn't really have a working implementation? We as
+users have to tell it what to do when a method is invoked. This is easy in
+gMock.
+
+First, if the return type of a mock function is a built-in type or a pointer,
+the function has a **default action** (a `void` function will just return, a
+`bool` function will return `false`, and other functions will return 0). In
+addition, in C++ 11 and above, a mock function whose return type is
+default-constructible (i.e. has a default constructor) has a default action of
+returning a default-constructed value. If you don't say anything, this behavior
+will be used.
+
+Second, if a mock function doesn't have a default action, or the default action
+doesn't suit you, you can specify the action to be taken each time the
+expectation matches using a series of `WillOnce()` clauses followed by an
+optional `WillRepeatedly()`. For example,
+
+```cpp
+using ::testing::Return;
+...
+EXPECT_CALL(turtle, GetX())
+     .WillOnce(Return(100))
+     .WillOnce(Return(200))
+     .WillOnce(Return(300));
+```
+
+says that `turtle.GetX()` will be called *exactly three times* (gMock inferred
+this from how many `WillOnce()` clauses we've written, since we didn't
+explicitly write `Times()`), and will return 100, 200, and 300 respectively.
+
+```cpp
+using ::testing::Return;
+...
+EXPECT_CALL(turtle, GetY())
+     .WillOnce(Return(100))
+     .WillOnce(Return(200))
+     .WillRepeatedly(Return(300));
+```
+
+says that `turtle.GetY()` will be called *at least twice* (gMock knows this as
+we've written two `WillOnce()` clauses and a `WillRepeatedly()` while having no
+explicit `Times()`), will return 100 and 200 respectively the first two times,
+and 300 from the third time on.
+
+Of course, if you explicitly write a `Times()`, gMock will not try to infer the
+cardinality itself. What if the number you specified is larger than there are
+`WillOnce()` clauses? Well, after all `WillOnce()`s are used up, gMock will do
+the *default* action for the function every time (unless, of course, you have a
+`WillRepeatedly()`.).
+
+What can we do inside `WillOnce()` besides `Return()`? You can return a
+reference using `ReturnRef(`*`variable`*`)`, or invoke a pre-defined function,
+among [others](gmock_cook_book.md#using-actions).
+
+**Important note:** The `EXPECT_CALL()` statement evaluates the action clause
+only once, even though the action may be performed many times. Therefore you
+must be careful about side effects. The following may not do what you want:
+
+```cpp
+using ::testing::Return;
+...
+int n = 100;
+EXPECT_CALL(turtle, GetX())
+    .Times(4)
+    .WillRepeatedly(Return(n++));
+```
+
+Instead of returning 100, 101, 102, ..., consecutively, this mock function will
+always return 100 as `n++` is only evaluated once. Similarly, `Return(new Foo)`
+will create a new `Foo` object when the `EXPECT_CALL()` is executed, and will
+return the same pointer every time. If you want the side effect to happen every
+time, you need to define a custom action, which we'll teach in the
+[cook book](gmock_cook_book.md).
+
+Time for another quiz! What do you think the following means?
+
+```cpp
+using ::testing::Return;
+...
+EXPECT_CALL(turtle, GetY())
+    .Times(4)
+    .WillOnce(Return(100));
+```
+
+Obviously `turtle.GetY()` is expected to be called four times. But if you think
+it will return 100 every time, think twice! Remember that one `WillOnce()`
+clause will be consumed each time the function is invoked and the default action
+will be taken afterwards. So the right answer is that `turtle.GetY()` will
+return 100 the first time, but **return 0 from the second time on**, as
+returning 0 is the default action for `int` functions.
+
+### Using Multiple Expectations {#MultiExpectations}
+
+So far we've only shown examples where you have a single expectation. More
+realistically, you'll specify expectations on multiple mock methods which may be
+from multiple mock objects.
+
+By default, when a mock method is invoked, gMock will search the expectations in
+the **reverse order** they are defined, and stop when an active expectation that
+matches the arguments is found (you can think of it as "newer rules override
+older ones."). If the matching expectation cannot take any more calls, you will
+get an upper-bound-violated failure. Here's an example:
+
+```cpp
+using ::testing::_;
+...
+EXPECT_CALL(turtle, Forward(_));  // #1
+EXPECT_CALL(turtle, Forward(10))  // #2
+    .Times(2);
+```
+
+If `Forward(10)` is called three times in a row, the third time it will be an
+error, as the last matching expectation (#2) has been saturated. If, however,
+the third `Forward(10)` call is replaced by `Forward(20)`, then it would be OK,
+as now #1 will be the matching expectation.
+
+{: .callout .note}
+**Note:** Why does gMock search for a match in the *reverse* order of the
+expectations? The reason is that this allows a user to set up the default
+expectations in a mock object's constructor or the test fixture's set-up phase
+and then customize the mock by writing more specific expectations in the test
+body. So, if you have two expectations on the same method, you want to put the
+one with more specific matchers **after** the other, or the more specific rule
+would be shadowed by the more general one that comes after it.
+
+{: .callout .tip}
+**Tip:** It is very common to start with a catch-all expectation for a method
+and `Times(AnyNumber())` (omitting arguments, or with `_` for all arguments, if
+overloaded). This makes any calls to the method expected. This is not necessary
+for methods that are not mentioned at all (these are "uninteresting"), but is
+useful for methods that have some expectations, but for which other calls are
+ok. See
+[Understanding Uninteresting vs Unexpected Calls](gmock_cook_book.md#uninteresting-vs-unexpected).
+
+### Ordered vs Unordered Calls {#OrderedCalls}
+
+By default, an expectation can match a call even though an earlier expectation
+hasn't been satisfied. In other words, the calls don't have to occur in the
+order the expectations are specified.
+
+Sometimes, you may want all the expected calls to occur in a strict order. To
+say this in gMock is easy:
+
+```cpp
+using ::testing::InSequence;
+...
+TEST(FooTest, DrawsLineSegment) {
+  ...
+  {
+    InSequence seq;
+
+    EXPECT_CALL(turtle, PenDown());
+    EXPECT_CALL(turtle, Forward(100));
+    EXPECT_CALL(turtle, PenUp());
+  }
+  Foo();
+}
+```
+
+By creating an object of type `InSequence`, all expectations in its scope are
+put into a *sequence* and have to occur *sequentially*. Since we are just
+relying on the constructor and destructor of this object to do the actual work,
+its name is really irrelevant.
+
+In this example, we test that `Foo()` calls the three expected functions in the
+order as written. If a call is made out-of-order, it will be an error.
+
+(What if you care about the relative order of some of the calls, but not all of
+them? Can you specify an arbitrary partial order? The answer is ... yes! The
+details can be found [here](gmock_cook_book.md#OrderedCalls).)
+
+### All Expectations Are Sticky (Unless Said Otherwise) {#StickyExpectations}
+
+Now let's do a quick quiz to see how well you can use this mock stuff already.
+How would you test that the turtle is asked to go to the origin *exactly twice*
+(you want to ignore any other instructions it receives)?
+
+After you've come up with your answer, take a look at ours and compare notes
+(solve it yourself first - don't cheat!):
+
+```cpp
+using ::testing::_;
+using ::testing::AnyNumber;
+...
+EXPECT_CALL(turtle, GoTo(_, _))  // #1
+     .Times(AnyNumber());
+EXPECT_CALL(turtle, GoTo(0, 0))  // #2
+     .Times(2);
+```
+
+Suppose `turtle.GoTo(0, 0)` is called three times. In the third time, gMock will
+see that the arguments match expectation #2 (remember that we always pick the
+last matching expectation). Now, since we said that there should be only two
+such calls, gMock will report an error immediately. This is basically what we've
+told you in the [Using Multiple Expectations](#MultiExpectations) section above.
+
+This example shows that **expectations in gMock are "sticky" by default**, in
+the sense that they remain active even after we have reached their invocation
+upper bounds. This is an important rule to remember, as it affects the meaning
+of the spec, and is **different** to how it's done in many other mocking
+frameworks (Why'd we do that? Because we think our rule makes the common cases
+easier to express and understand.).
+
+Simple? Let's see if you've really understood it: what does the following code
+say?
+
+```cpp
+using ::testing::Return;
+...
+for (int i = n; i > 0; i--) {
+  EXPECT_CALL(turtle, GetX())
+      .WillOnce(Return(10*i));
+}
+```
+
+If you think it says that `turtle.GetX()` will be called `n` times and will
+return 10, 20, 30, ..., consecutively, think twice! The problem is that, as we
+said, expectations are sticky. So, the second time `turtle.GetX()` is called,
+the last (latest) `EXPECT_CALL()` statement will match, and will immediately
+lead to an "upper bound violated" error - this piece of code is not very useful!
+
+One correct way of saying that `turtle.GetX()` will return 10, 20, 30, ..., is
+to explicitly say that the expectations are *not* sticky. In other words, they
+should *retire* as soon as they are saturated:
+
+```cpp
+using ::testing::Return;
+...
+for (int i = n; i > 0; i--) {
+  EXPECT_CALL(turtle, GetX())
+      .WillOnce(Return(10*i))
+      .RetiresOnSaturation();
+}
+```
+
+And, there's a better way to do it: in this case, we expect the calls to occur
+in a specific order, and we line up the actions to match the order. Since the
+order is important here, we should make it explicit using a sequence:
+
+```cpp
+using ::testing::InSequence;
+using ::testing::Return;
+...
+{
+  InSequence s;
+
+  for (int i = 1; i <= n; i++) {
+    EXPECT_CALL(turtle, GetX())
+        .WillOnce(Return(10*i))
+        .RetiresOnSaturation();
+  }
+}
+```
+
+By the way, the other situation where an expectation may *not* be sticky is when
+it's in a sequence - as soon as another expectation that comes after it in the
+sequence has been used, it automatically retires (and will never be used to
+match any call).
+
+### Uninteresting Calls
+
+A mock object may have many methods, and not all of them are that interesting.
+For example, in some tests we may not care about how many times `GetX()` and
+`GetY()` get called.
+
+In gMock, if you are not interested in a method, just don't say anything about
+it. If a call to this method occurs, you'll see a warning in the test output,
+but it won't be a failure. This is called "naggy" behavior; to change, see
+[The Nice, the Strict, and the Naggy](gmock_cook_book.md#NiceStrictNaggy).

contrib/googletest/docs/index.md

@@ -0,0 +1,22 @@
+# GoogleTest User's Guide
+
+## Welcome to GoogleTest!
+
+GoogleTest is Google's C++ testing and mocking framework. This user's guide has
+the following contents:
+
+*   [GoogleTest Primer](primer.md) - Teaches you how to write simple tests using
+    GoogleTest. Read this first if you are new to GoogleTest.
+*   [GoogleTest Advanced](advanced.md) - Read this when you've finished the
+    Primer and want to utilize GoogleTest to its full potential.
+*   [GoogleTest Samples](samples.md) - Describes some GoogleTest samples.
+*   [GoogleTest FAQ](faq.md) - Have a question? Want some tips? Check here
+    first.
+*   [Mocking for Dummies](gmock_for_dummies.md) - Teaches you how to create mock
+    objects and use them in tests.
+*   [Mocking Cookbook](gmock_cook_book.md) - Includes tips and approaches to
+    common mocking use cases.
+*   [Mocking Cheat Sheet](gmock_cheat_sheet.md) - A handy reference for
+    matchers, actions, invariants, and more.
+*   [Mocking FAQ](gmock_faq.md) - Contains answers to some mocking-specific
+    questions.

contrib/googletest/docs/pkgconfig.md

@@ -0,0 +1,144 @@
+## Using GoogleTest from various build systems
+
+GoogleTest comes with pkg-config files that can be used to determine all
+necessary flags for compiling and linking to GoogleTest (and GoogleMock).
+Pkg-config is a standardised plain-text format containing
+
+*   the includedir (-I) path
+*   necessary macro (-D) definitions
+*   further required flags (-pthread)
+*   the library (-L) path
+*   the library (-l) to link to
+
+All current build systems support pkg-config in one way or another. For all
+examples here we assume you want to compile the sample
+`samples/sample3_unittest.cc`.
+
+### CMake
+
+Using `pkg-config` in CMake is fairly easy:
+
+```cmake
+find_package(PkgConfig)
+pkg_search_module(GTEST REQUIRED gtest_main)
+
+add_executable(testapp)
+target_sources(testapp PRIVATE samples/sample3_unittest.cc)
+target_link_libraries(testapp PRIVATE ${GTEST_LDFLAGS})
+target_compile_options(testapp PRIVATE ${GTEST_CFLAGS})
+
+enable_testing()
+add_test(first_and_only_test testapp)
+```
+
+It is generally recommended that you use `target_compile_options` + `_CFLAGS`
+over `target_include_directories` + `_INCLUDE_DIRS` as the former includes not
+just -I flags (GoogleTest might require a macro indicating to internal headers
+that all libraries have been compiled with threading enabled. In addition,
+GoogleTest might also require `-pthread` in the compiling step, and as such
+splitting the pkg-config `Cflags` variable into include dirs and macros for
+`target_compile_definitions()` might still miss this). The same recommendation
+goes for using `_LDFLAGS` over the more commonplace `_LIBRARIES`, which happens
+to discard `-L` flags and `-pthread`.
+
+### Help! pkg-config can't find GoogleTest!
+
+Let's say you have a `CMakeLists.txt` along the lines of the one in this
+tutorial and you try to run `cmake`. It is very possible that you get a failure
+along the lines of:
+
+```
+-- Checking for one of the modules 'gtest_main'
+CMake Error at /usr/share/cmake/Modules/FindPkgConfig.cmake:640 (message):
+  None of the required 'gtest_main' found
+```
+
+These failures are common if you installed GoogleTest yourself and have not
+sourced it from a distro or other package manager. If so, you need to tell
+pkg-config where it can find the `.pc` files containing the information. Say you
+installed GoogleTest to `/usr/local`, then it might be that the `.pc` files are
+installed under `/usr/local/lib64/pkgconfig`. If you set
+
+```
+export PKG_CONFIG_PATH=/usr/local/lib64/pkgconfig
+```
+
+pkg-config will also try to look in `PKG_CONFIG_PATH` to find `gtest_main.pc`.
+
+### Using pkg-config in a cross-compilation setting
+
+Pkg-config can be used in a cross-compilation setting too. To do this, let's
+assume the final prefix of the cross-compiled installation will be `/usr`, and
+your sysroot is `/home/MYUSER/sysroot`. Configure and install GTest using
+
+```
+mkdir build && cmake -DCMAKE_INSTALL_PREFIX=/usr ..
+```
+
+Install into the sysroot using `DESTDIR`:
+
+```
+make -j install DESTDIR=/home/MYUSER/sysroot
+```
+
+Before we continue, it is recommended to **always** define the following two
+variables for pkg-config in a cross-compilation setting:
+
+```
+export PKG_CONFIG_ALLOW_SYSTEM_CFLAGS=yes
+export PKG_CONFIG_ALLOW_SYSTEM_LIBS=yes
+```
+
+otherwise `pkg-config` will filter `-I` and `-L` flags against standard prefixes
+such as `/usr` (see https://bugs.freedesktop.org/show_bug.cgi?id=28264#c3 for
+reasons why this stripping needs to occur usually).
+
+If you look at the generated pkg-config file, it will look something like
+
+```
+libdir=/usr/lib64
+includedir=/usr/include
+
+Name: gtest
+Description: GoogleTest (without main() function)
+Version: 1.11.0
+URL: https://github.com/google/googletest
+Libs: -L${libdir} -lgtest -lpthread
+Cflags: -I${includedir} -DGTEST_HAS_PTHREAD=1 -lpthread
+```
+
+Notice that the sysroot is not included in `libdir` and `includedir`! If you try
+to run `pkg-config` with the correct
+`PKG_CONFIG_LIBDIR=/home/MYUSER/sysroot/usr/lib64/pkgconfig` against this `.pc`
+file, you will get
+
+```
+$ pkg-config --cflags gtest
+-DGTEST_HAS_PTHREAD=1 -lpthread -I/usr/include
+$ pkg-config --libs gtest
+-L/usr/lib64 -lgtest -lpthread
+```
+
+which is obviously wrong and points to the `CBUILD` and not `CHOST` root. In
+order to use this in a cross-compilation setting, we need to tell pkg-config to
+inject the actual sysroot into `-I` and `-L` variables. Let us now tell
+pkg-config about the actual sysroot
+
+```
+export PKG_CONFIG_DIR=
+export PKG_CONFIG_SYSROOT_DIR=/home/MYUSER/sysroot
+export PKG_CONFIG_LIBDIR=${PKG_CONFIG_SYSROOT_DIR}/usr/lib64/pkgconfig
+```
+
+and running `pkg-config` again we get
+
+```
+$ pkg-config --cflags gtest
+-DGTEST_HAS_PTHREAD=1 -lpthread -I/home/MYUSER/sysroot/usr/include
+$ pkg-config --libs gtest
+-L/home/MYUSER/sysroot/usr/lib64 -lgtest -lpthread
+```
+
+which contains the correct sysroot now. For a more comprehensive guide to also
+including `${CHOST}` in build system calls, see the excellent tutorial by Diego
+Elio Pettenò: <https://autotools.io/pkgconfig/cross-compiling.html>

contrib/googletest/docs/platforms.md

@@ -0,0 +1,8 @@
+# Supported Platforms
+
+GoogleTest follows Google's
+[Foundational C++ Support Policy](https://opensource.google/documentation/policies/cplusplus-support).
+See
+[this table](https://github.com/google/oss-policies-info/blob/main/foundational-cxx-support-matrix.md)
+for a list of currently supported versions compilers, platforms, and build
+tools.

contrib/googletest/docs/primer.md

@@ -0,0 +1,483 @@
+# GoogleTest Primer
+
+## Introduction: Why GoogleTest?
+
+*GoogleTest* helps you write better C++ tests.
+
+GoogleTest is a testing framework developed by the Testing Technology team with
+Google's specific requirements and constraints in mind. Whether you work on
+Linux, Windows, or a Mac, if you write C++ code, GoogleTest can help you. And it
+supports *any* kind of tests, not just unit tests.
+
+So what makes a good test, and how does GoogleTest fit in? We believe:
+
+1.  Tests should be *independent* and *repeatable*. It's a pain to debug a test
+    that succeeds or fails as a result of other tests. GoogleTest isolates the
+    tests by running each of them on a different object. When a test fails,
+    GoogleTest allows you to run it in isolation for quick debugging.
+2.  Tests should be well *organized* and reflect the structure of the tested
+    code. GoogleTest groups related tests into test suites that can share data
+    and subroutines. This common pattern is easy to recognize and makes tests
+    easy to maintain. Such consistency is especially helpful when people switch
+    projects and start to work on a new code base.
+3.  Tests should be *portable* and *reusable*. Google has a lot of code that is
+    platform-neutral; its tests should also be platform-neutral. GoogleTest
+    works on different OSes, with different compilers, with or without
+    exceptions, so GoogleTest tests can work with a variety of configurations.
+4.  When tests fail, they should provide as much *information* about the problem
+    as possible. GoogleTest doesn't stop at the first test failure. Instead, it
+    only stops the current test and continues with the next. You can also set up
+    tests that report non-fatal failures after which the current test continues.
+    Thus, you can detect and fix multiple bugs in a single run-edit-compile
+    cycle.
+5.  The testing framework should liberate test writers from housekeeping chores
+    and let them focus on the test *content*. GoogleTest automatically keeps
+    track of all tests defined, and doesn't require the user to enumerate them
+    in order to run them.
+6.  Tests should be *fast*. With GoogleTest, you can reuse shared resources
+    across tests and pay for the set-up/tear-down only once, without making
+    tests depend on each other.
+
+Since GoogleTest is based on the popular xUnit architecture, you'll feel right
+at home if you've used JUnit or PyUnit before. If not, it will take you about 10
+minutes to learn the basics and get started. So let's go!
+
+## Beware of the Nomenclature
+
+{: .callout .note}
+*Note:* There might be some confusion arising from different definitions of the
+terms *Test*, *Test Case* and *Test Suite*, so beware of misunderstanding these.
+
+Historically, GoogleTest started to use the term *Test Case* for grouping
+related tests, whereas current publications, including International Software
+Testing Qualifications Board ([ISTQB](http://www.istqb.org/)) materials and
+various textbooks on software quality, use the term
+*[Test Suite][istqb test suite]* for this.
+
+The related term *Test*, as it is used in GoogleTest, corresponds to the term
+*[Test Case][istqb test case]* of ISTQB and others.
+
+The term *Test* is commonly of broad enough sense, including ISTQB's definition
+of *Test Case*, so it's not much of a problem here. But the term *Test Case* as
+was used in Google Test is of contradictory sense and thus confusing.
+
+GoogleTest recently started replacing the term *Test Case* with *Test Suite*.
+The preferred API is *TestSuite*. The older TestCase API is being slowly
+deprecated and refactored away.
+
+So please be aware of the different definitions of the terms:
+
+
+Meaning                                                                              | GoogleTest Term         | [ISTQB](http://www.istqb.org/) Term
+:----------------------------------------------------------------------------------- | :---------------------- | :----------------------------------
+Exercise a particular program path with specific input values and verify the results | [TEST()](#simple-tests) | [Test Case][istqb test case]
+
+
+[istqb test case]: http://glossary.istqb.org/en/search/test%20case
+[istqb test suite]: http://glossary.istqb.org/en/search/test%20suite
+
+## Basic Concepts
+
+When using GoogleTest, you start by writing *assertions*, which are statements
+that check whether a condition is true. An assertion's result can be *success*,
+*nonfatal failure*, or *fatal failure*. If a fatal failure occurs, it aborts the
+current function; otherwise the program continues normally.
+
+*Tests* use assertions to verify the tested code's behavior. If a test crashes
+or has a failed assertion, then it *fails*; otherwise it *succeeds*.
+
+A *test suite* contains one or many tests. You should group your tests into test
+suites that reflect the structure of the tested code. When multiple tests in a
+test suite need to share common objects and subroutines, you can put them into a
+*test fixture* class.
+
+A *test program* can contain multiple test suites.
+
+We'll now explain how to write a test program, starting at the individual
+assertion level and building up to tests and test suites.
+
+## Assertions
+
+GoogleTest assertions are macros that resemble function calls. You test a class
+or function by making assertions about its behavior. When an assertion fails,
+GoogleTest prints the assertion's source file and line number location, along
+with a failure message. You may also supply a custom failure message which will
+be appended to GoogleTest's message.
+
+The assertions come in pairs that test the same thing but have different effects
+on the current function. `ASSERT_*` versions generate fatal failures when they
+fail, and **abort the current function**. `EXPECT_*` versions generate nonfatal
+failures, which don't abort the current function. Usually `EXPECT_*` are
+preferred, as they allow more than one failure to be reported in a test.
+However, you should use `ASSERT_*` if it doesn't make sense to continue when the
+assertion in question fails.
+
+Since a failed `ASSERT_*` returns from the current function immediately,
+possibly skipping clean-up code that comes after it, it may cause a space leak.
+Depending on the nature of the leak, it may or may not be worth fixing - so keep
+this in mind if you get a heap checker error in addition to assertion errors.
+
+To provide a custom failure message, simply stream it into the macro using the
+`<<` operator or a sequence of such operators. See the following example, using
+the [`ASSERT_EQ` and `EXPECT_EQ`](reference/assertions.md#EXPECT_EQ) macros to
+verify value equality:
+
+```c++
+ASSERT_EQ(x.size(), y.size()) << "Vectors x and y are of unequal length";
+
+for (int i = 0; i < x.size(); ++i) {
+  EXPECT_EQ(x[i], y[i]) << "Vectors x and y differ at index " << i;
+}
+```
+
+Anything that can be streamed to an `ostream` can be streamed to an assertion
+macro--in particular, C strings and `string` objects. If a wide string
+(`wchar_t*`, `TCHAR*` in `UNICODE` mode on Windows, or `std::wstring`) is
+streamed to an assertion, it will be translated to UTF-8 when printed.
+
+GoogleTest provides a collection of assertions for verifying the behavior of
+your code in various ways. You can check Boolean conditions, compare values
+based on relational operators, verify string values, floating-point values, and
+much more. There are even assertions that enable you to verify more complex
+states by providing custom predicates. For the complete list of assertions
+provided by GoogleTest, see the [Assertions Reference](reference/assertions.md).
+
+## Simple Tests
+
+To create a test:
+
+1.  Use the `TEST()` macro to define and name a test function. These are
+    ordinary C++ functions that don't return a value.
+2.  In this function, along with any valid C++ statements you want to include,
+    use the various GoogleTest assertions to check values.
+3.  The test's result is determined by the assertions; if any assertion in the
+    test fails (either fatally or non-fatally), or if the test crashes, the
+    entire test fails. Otherwise, it succeeds.
+
+```c++
+TEST(TestSuiteName, TestName) {
+  ... test body ...
+}
+```
+
+`TEST()` arguments go from general to specific. The *first* argument is the name
+of the test suite, and the *second* argument is the test's name within the test
+suite. Both names must be valid C++ identifiers, and they should not contain any
+underscores (`_`). A test's *full name* consists of its containing test suite
+and its individual name. Tests from different test suites can have the same
+individual name.
+
+For example, let's take a simple integer function:
+
+```c++
+int Factorial(int n);  // Returns the factorial of n
+```
+
+A test suite for this function might look like:
+
+```c++
+// Tests factorial of 0.
+TEST(FactorialTest, HandlesZeroInput) {
+  EXPECT_EQ(Factorial(0), 1);
+}
+
+// Tests factorial of positive numbers.
+TEST(FactorialTest, HandlesPositiveInput) {
+  EXPECT_EQ(Factorial(1), 1);
+  EXPECT_EQ(Factorial(2), 2);
+  EXPECT_EQ(Factorial(3), 6);
+  EXPECT_EQ(Factorial(8), 40320);
+}
+```
+
+GoogleTest groups the test results by test suites, so logically related tests
+should be in the same test suite; in other words, the first argument to their
+`TEST()` should be the same. In the above example, we have two tests,
+`HandlesZeroInput` and `HandlesPositiveInput`, that belong to the same test
+suite `FactorialTest`.
+
+When naming your test suites and tests, you should follow the same convention as
+for
+[naming functions and classes](https://google.github.io/styleguide/cppguide.html#Function_Names).
+
+**Availability**: Linux, Windows, Mac.
+
+## Test Fixtures: Using the Same Data Configuration for Multiple Tests {#same-data-multiple-tests}
+
+If you find yourself writing two or more tests that operate on similar data, you
+can use a *test fixture*. This allows you to reuse the same configuration of
+objects for several different tests.
+
+To create a fixture:
+
+1.  Derive a class from `::testing::Test` . Start its body with `protected:`, as
+    we'll want to access fixture members from sub-classes.
+2.  Inside the class, declare any objects you plan to use.
+3.  If necessary, write a default constructor or `SetUp()` function to prepare
+    the objects for each test. A common mistake is to spell `SetUp()` as
+    **`Setup()`** with a small `u` - Use `override` in C++11 to make sure you
+    spelled it correctly.
+4.  If necessary, write a destructor or `TearDown()` function to release any
+    resources you allocated in `SetUp()` . To learn when you should use the
+    constructor/destructor and when you should use `SetUp()/TearDown()`, read
+    the [FAQ](faq.md#CtorVsSetUp).
+5.  If needed, define subroutines for your tests to share.
+
+When using a fixture, use `TEST_F()` instead of `TEST()` as it allows you to
+access objects and subroutines in the test fixture:
+
+```c++
+TEST_F(TestFixtureClassName, TestName) {
+  ... test body ...
+}
+```
+
+Unlike `TEST()`, in `TEST_F()` the first argument must be the name of the test
+fixture class. (`_F` stands for "Fixture"). No test suite name is specified for
+this macro.
+
+Unfortunately, the C++ macro system does not allow us to create a single macro
+that can handle both types of tests. Using the wrong macro causes a compiler
+error.
+
+Also, you must first define a test fixture class before using it in a
+`TEST_F()`, or you'll get the compiler error "`virtual outside class
+declaration`".
+
+For each test defined with `TEST_F()`, GoogleTest will create a *fresh* test
+fixture at runtime, immediately initialize it via `SetUp()`, run the test, clean
+up by calling `TearDown()`, and then delete the test fixture. Note that
+different tests in the same test suite have different test fixture objects, and
+GoogleTest always deletes a test fixture before it creates the next one.
+GoogleTest does **not** reuse the same test fixture for multiple tests. Any
+changes one test makes to the fixture do not affect other tests.
+
+As an example, let's write tests for a FIFO queue class named `Queue`, which has
+the following interface:
+
+```c++
+template <typename E>  // E is the element type.
+class Queue {
+ public:
+  Queue();
+  void Enqueue(const E& element);
+  E* Dequeue();  // Returns NULL if the queue is empty.
+  size_t size() const;
+  ...
+};
+```
+
+First, define a fixture class. By convention, you should give it the name
+`FooTest` where `Foo` is the class being tested.
+
+```c++
+class QueueTest : public ::testing::Test {
+ protected:
+  void SetUp() override {
+     // q0_ remains empty
+     q1_.Enqueue(1);
+     q2_.Enqueue(2);
+     q2_.Enqueue(3);
+  }
+
+  // void TearDown() override {}
+
+  Queue<int> q0_;
+  Queue<int> q1_;
+  Queue<int> q2_;
+};
+```
+
+In this case, `TearDown()` is not needed since we don't have to clean up after
+each test, other than what's already done by the destructor.
+
+Now we'll write tests using `TEST_F()` and this fixture.
+
+```c++
+TEST_F(QueueTest, IsEmptyInitially) {
+  EXPECT_EQ(q0_.size(), 0);
+}
+
+TEST_F(QueueTest, DequeueWorks) {
+  int* n = q0_.Dequeue();
+  EXPECT_EQ(n, nullptr);
+
+  n = q1_.Dequeue();
+  ASSERT_NE(n, nullptr);
+  EXPECT_EQ(*n, 1);
+  EXPECT_EQ(q1_.size(), 0);
+  delete n;
+
+  n = q2_.Dequeue();
+  ASSERT_NE(n, nullptr);
+  EXPECT_EQ(*n, 2);
+  EXPECT_EQ(q2_.size(), 1);
+  delete n;
+}
+```
+
+The above uses both `ASSERT_*` and `EXPECT_*` assertions. The rule of thumb is
+to use `EXPECT_*` when you want the test to continue to reveal more errors after
+the assertion failure, and use `ASSERT_*` when continuing after failure doesn't
+make sense. For example, the second assertion in the `Dequeue` test is
+`ASSERT_NE(n, nullptr)`, as we need to dereference the pointer `n` later, which
+would lead to a segfault when `n` is `NULL`.
+
+When these tests run, the following happens:
+
+1.  GoogleTest constructs a `QueueTest` object (let's call it `t1`).
+2.  `t1.SetUp()` initializes `t1`.
+3.  The first test (`IsEmptyInitially`) runs on `t1`.
+4.  `t1.TearDown()` cleans up after the test finishes.
+5.  `t1` is destructed.
+6.  The above steps are repeated on another `QueueTest` object, this time
+    running the `DequeueWorks` test.
+
+**Availability**: Linux, Windows, Mac.
+
+## Invoking the Tests
+
+`TEST()` and `TEST_F()` implicitly register their tests with GoogleTest. So,
+unlike with many other C++ testing frameworks, you don't have to re-list all
+your defined tests in order to run them.
+
+After defining your tests, you can run them with `RUN_ALL_TESTS()`, which
+returns `0` if all the tests are successful, or `1` otherwise. Note that
+`RUN_ALL_TESTS()` runs *all tests* in your link unit--they can be from different
+test suites, or even different source files.
+
+When invoked, the `RUN_ALL_TESTS()` macro:
+
+*   Saves the state of all GoogleTest flags.
+
+*   Creates a test fixture object for the first test.
+
+*   Initializes it via `SetUp()`.
+
+*   Runs the test on the fixture object.
+
+*   Cleans up the fixture via `TearDown()`.
+
+*   Deletes the fixture.
+
+*   Restores the state of all GoogleTest flags.
+
+*   Repeats the above steps for the next test, until all tests have run.
+
+If a fatal failure happens the subsequent steps will be skipped.
+
+{: .callout .important}
+> IMPORTANT: You must **not** ignore the return value of `RUN_ALL_TESTS()`, or
+> you will get a compiler error. The rationale for this design is that the
+> automated testing service determines whether a test has passed based on its
+> exit code, not on its stdout/stderr output; thus your `main()` function must
+> return the value of `RUN_ALL_TESTS()`.
+>
+> Also, you should call `RUN_ALL_TESTS()` only **once**. Calling it more than
+> once conflicts with some advanced GoogleTest features (e.g., thread-safe
+> [death tests](advanced.md#death-tests)) and thus is not supported.
+
+**Availability**: Linux, Windows, Mac.
+
+## Writing the main() Function
+
+Most users should *not* need to write their own `main` function and instead link
+with `gtest_main` (as opposed to with `gtest`), which defines a suitable entry
+point. See the end of this section for details. The remainder of this section
+should only apply when you need to do something custom before the tests run that
+cannot be expressed within the framework of fixtures and test suites.
+
+If you write your own `main` function, it should return the value of
+`RUN_ALL_TESTS()`.
+
+You can start from this boilerplate:
+
+```c++
+#include "this/package/foo.h"
+
+#include <gtest/gtest.h>
+
+namespace my {
+namespace project {
+namespace {
+
+// The fixture for testing class Foo.
+class FooTest : public ::testing::Test {
+ protected:
+  // You can remove any or all of the following functions if their bodies would
+  // be empty.
+
+  FooTest() {
+     // You can do set-up work for each test here.
+  }
+
+  ~FooTest() override {
+     // You can do clean-up work that doesn't throw exceptions here.
+  }
+
+  // If the constructor and destructor are not enough for setting up
+  // and cleaning up each test, you can define the following methods:
+
+  void SetUp() override {
+     // Code here will be called immediately after the constructor (right
+     // before each test).
+  }
+
+  void TearDown() override {
+     // Code here will be called immediately after each test (right
+     // before the destructor).
+  }
+
+  // Class members declared here can be used by all tests in the test suite
+  // for Foo.
+};
+
+// Tests that the Foo::Bar() method does Abc.
+TEST_F(FooTest, MethodBarDoesAbc) {
+  const std::string input_filepath = "this/package/testdata/myinputfile.dat";
+  const std::string output_filepath = "this/package/testdata/myoutputfile.dat";
+  Foo f;
+  EXPECT_EQ(f.Bar(input_filepath, output_filepath), 0);
+}
+
+// Tests that Foo does Xyz.
+TEST_F(FooTest, DoesXyz) {
+  // Exercises the Xyz feature of Foo.
+}
+
+}  // namespace
+}  // namespace project
+}  // namespace my
+
+int main(int argc, char **argv) {
+  ::testing::InitGoogleTest(&argc, argv);
+  return RUN_ALL_TESTS();
+}
+```
+
+The `::testing::InitGoogleTest()` function parses the command line for
+GoogleTest flags, and removes all recognized flags. This allows the user to
+control a test program's behavior via various flags, which we'll cover in the
+[AdvancedGuide](advanced.md). You **must** call this function before calling
+`RUN_ALL_TESTS()`, or the flags won't be properly initialized.
+
+On Windows, `InitGoogleTest()` also works with wide strings, so it can be used
+in programs compiled in `UNICODE` mode as well.
+
+But maybe you think that writing all those `main` functions is too much work? We
+agree with you completely, and that's why Google Test provides a basic
+implementation of main(). If it fits your needs, then just link your test with
+the `gtest_main` library and you are good to go.
+
+{: .callout .note}
+NOTE: `ParseGUnitFlags()` is deprecated in favor of `InitGoogleTest()`.
+
+## Known Limitations
+
+*   Google Test is designed to be thread-safe. The implementation is thread-safe
+    on systems where the `pthreads` library is available. It is currently
+    *unsafe* to use Google Test assertions from two threads concurrently on
+    other systems (e.g. Windows). In most tests this is not an issue as usually
+    the assertions are done in the main thread. If you want to help, you can
+    volunteer to implement the necessary synchronization primitives in
+    `gtest-port.h` for your platform.

contrib/googletest/docs/quickstart-bazel.md

@@ -0,0 +1,153 @@
+# Quickstart: Building with Bazel
+
+This tutorial aims to get you up and running with GoogleTest using the Bazel
+build system. If you're using GoogleTest for the first time or need a refresher,
+we recommend this tutorial as a starting point.
+
+## Prerequisites
+
+To complete this tutorial, you'll need:
+
+*   A compatible operating system (e.g. Linux, macOS, Windows).
+*   A compatible C++ compiler that supports at least C++14.
+*   [Bazel](https://bazel.build/), the preferred build system used by the
+    GoogleTest team.
+
+See [Supported Platforms](platforms.md) for more information about platforms
+compatible with GoogleTest.
+
+If you don't already have Bazel installed, see the
+[Bazel installation guide](https://bazel.build/install).
+
+{: .callout .note} Note: The terminal commands in this tutorial show a Unix
+shell prompt, but the commands work on the Windows command line as well.
+
+## Set up a Bazel workspace
+
+A
+[Bazel workspace](https://docs.bazel.build/versions/main/build-ref.html#workspace)
+is a directory on your filesystem that you use to manage source files for the
+software you want to build. Each workspace directory has a text file named
+`WORKSPACE` which may be empty, or may contain references to external
+dependencies required to build the outputs.
+
+First, create a directory for your workspace:
+
+```
+$ mkdir my_workspace && cd my_workspace
+```
+
+Next, you’ll create the `WORKSPACE` file to specify dependencies. A common and
+recommended way to depend on GoogleTest is to use a
+[Bazel external dependency](https://docs.bazel.build/versions/main/external.html)
+via the
+[`http_archive` rule](https://docs.bazel.build/versions/main/repo/http.html#http_archive).
+To do this, in the root directory of your workspace (`my_workspace/`), create a
+file named `WORKSPACE` with the following contents:
+
+```
+load("@bazel_tools//tools/build_defs/repo:http.bzl", "http_archive")
+
+http_archive(
+  name = "com_google_googletest",
+  urls = ["https://github.com/google/googletest/archive/5ab508a01f9eb089207ee87fd547d290da39d015.zip"],
+  strip_prefix = "googletest-5ab508a01f9eb089207ee87fd547d290da39d015",
+)
+```
+
+The above configuration declares a dependency on GoogleTest which is downloaded
+as a ZIP archive from GitHub. In the above example,
+`5ab508a01f9eb089207ee87fd547d290da39d015` is the Git commit hash of the
+GoogleTest version to use; we recommend updating the hash often to point to the
+latest version. Use a recent hash on the `main` branch.
+
+Now you're ready to build C++ code that uses GoogleTest.
+
+## Create and run a binary
+
+With your Bazel workspace set up, you can now use GoogleTest code within your
+own project.
+
+As an example, create a file named `hello_test.cc` in your `my_workspace`
+directory with the following contents:
+
+```cpp
+#include <gtest/gtest.h>
+
+// Demonstrate some basic assertions.
+TEST(HelloTest, BasicAssertions) {
+  // Expect two strings not to be equal.
+  EXPECT_STRNE("hello", "world");
+  // Expect equality.
+  EXPECT_EQ(7 * 6, 42);
+}
+```
+
+GoogleTest provides [assertions](primer.md#assertions) that you use to test the
+behavior of your code. The above sample includes the main GoogleTest header file
+and demonstrates some basic assertions.
+
+To build the code, create a file named `BUILD` in the same directory with the
+following contents:
+
+```
+cc_test(
+  name = "hello_test",
+  size = "small",
+  srcs = ["hello_test.cc"],
+  deps = ["@com_google_googletest//:gtest_main"],
+)
+```
+
+This `cc_test` rule declares the C++ test binary you want to build, and links to
+GoogleTest (`//:gtest_main`) using the prefix you specified in the `WORKSPACE`
+file (`@com_google_googletest`). For more information about Bazel `BUILD` files,
+see the
+[Bazel C++ Tutorial](https://docs.bazel.build/versions/main/tutorial/cpp.html).
+
+{: .callout .note}
+NOTE: In the example below, we assume Clang or GCC and set `--cxxopt=-std=c++14`
+to ensure that GoogleTest is compiled as C++14 instead of the compiler's default
+setting (which could be C++11). For MSVC, the equivalent would be
+`--cxxopt=/std:c++14`. See [Supported Platforms](platforms.md) for more details
+on supported language versions.
+
+Now you can build and run your test:
+
+<pre>
+<strong>my_workspace$ bazel test --cxxopt=-std=c++14 --test_output=all //:hello_test</strong>
+INFO: Analyzed target //:hello_test (26 packages loaded, 362 targets configured).
+INFO: Found 1 test target...
+INFO: From Testing //:hello_test:
+==================== Test output for //:hello_test:
+Running main() from gmock_main.cc
+[==========] Running 1 test from 1 test suite.
+[----------] Global test environment set-up.
+[----------] 1 test from HelloTest
+[ RUN      ] HelloTest.BasicAssertions
+[       OK ] HelloTest.BasicAssertions (0 ms)
+[----------] 1 test from HelloTest (0 ms total)
+
+[----------] Global test environment tear-down
+[==========] 1 test from 1 test suite ran. (0 ms total)
+[  PASSED  ] 1 test.
+================================================================================
+Target //:hello_test up-to-date:
+  bazel-bin/hello_test
+INFO: Elapsed time: 4.190s, Critical Path: 3.05s
+INFO: 27 processes: 8 internal, 19 linux-sandbox.
+INFO: Build completed successfully, 27 total actions
+//:hello_test                                                     PASSED in 0.1s
+
+INFO: Build completed successfully, 27 total actions
+</pre>
+
+Congratulations! You've successfully built and run a test binary using
+GoogleTest.
+
+## Next steps
+
+*   [Check out the Primer](primer.md) to start learning how to write simple
+    tests.
+*   [See the code samples](samples.md) for more examples showing how to use a
+    variety of GoogleTest features.

contrib/googletest/docs/quickstart-cmake.md

@@ -0,0 +1,157 @@
+# Quickstart: Building with CMake
+
+This tutorial aims to get you up and running with GoogleTest using CMake. If
+you're using GoogleTest for the first time or need a refresher, we recommend
+this tutorial as a starting point. If your project uses Bazel, see the
+[Quickstart for Bazel](quickstart-bazel.md) instead.
+
+## Prerequisites
+
+To complete this tutorial, you'll need:
+
+*   A compatible operating system (e.g. Linux, macOS, Windows).
+*   A compatible C++ compiler that supports at least C++14.
+*   [CMake](https://cmake.org/) and a compatible build tool for building the
+    project.
+    *   Compatible build tools include
+        [Make](https://www.gnu.org/software/make/),
+        [Ninja](https://ninja-build.org/), and others - see
+        [CMake Generators](https://cmake.org/cmake/help/latest/manual/cmake-generators.7.html)
+        for more information.
+
+See [Supported Platforms](platforms.md) for more information about platforms
+compatible with GoogleTest.
+
+If you don't already have CMake installed, see the
+[CMake installation guide](https://cmake.org/install).
+
+{: .callout .note}
+Note: The terminal commands in this tutorial show a Unix shell prompt, but the
+commands work on the Windows command line as well.
+
+## Set up a project
+
+CMake uses a file named `CMakeLists.txt` to configure the build system for a
+project. You'll use this file to set up your project and declare a dependency on
+GoogleTest.
+
+First, create a directory for your project:
+
+```
+$ mkdir my_project && cd my_project
+```
+
+Next, you'll create the `CMakeLists.txt` file and declare a dependency on
+GoogleTest. There are many ways to express dependencies in the CMake ecosystem;
+in this quickstart, you'll use the
+[`FetchContent` CMake module](https://cmake.org/cmake/help/latest/module/FetchContent.html).
+To do this, in your project directory (`my_project`), create a file named
+`CMakeLists.txt` with the following contents:
+
+```cmake
+cmake_minimum_required(VERSION 3.14)
+project(my_project)
+
+# GoogleTest requires at least C++14
+set(CMAKE_CXX_STANDARD 14)
+set(CMAKE_CXX_STANDARD_REQUIRED ON)
+
+include(FetchContent)
+FetchContent_Declare(
+  googletest
+  URL https://github.com/google/googletest/archive/03597a01ee50ed33e9dfd640b249b4be3799d395.zip
+)
+# For Windows: Prevent overriding the parent project's compiler/linker settings
+set(gtest_force_shared_crt ON CACHE BOOL "" FORCE)
+FetchContent_MakeAvailable(googletest)
+```
+
+The above configuration declares a dependency on GoogleTest which is downloaded
+from GitHub. In the above example, `03597a01ee50ed33e9dfd640b249b4be3799d395` is
+the Git commit hash of the GoogleTest version to use; we recommend updating the
+hash often to point to the latest version.
+
+For more information about how to create `CMakeLists.txt` files, see the
+[CMake Tutorial](https://cmake.org/cmake/help/latest/guide/tutorial/index.html).
+
+## Create and run a binary
+
+With GoogleTest declared as a dependency, you can use GoogleTest code within
+your own project.
+
+As an example, create a file named `hello_test.cc` in your `my_project`
+directory with the following contents:
+
+```cpp
+#include <gtest/gtest.h>
+
+// Demonstrate some basic assertions.
+TEST(HelloTest, BasicAssertions) {
+  // Expect two strings not to be equal.
+  EXPECT_STRNE("hello", "world");
+  // Expect equality.
+  EXPECT_EQ(7 * 6, 42);
+}
+```
+
+GoogleTest provides [assertions](primer.md#assertions) that you use to test the
+behavior of your code. The above sample includes the main GoogleTest header file
+and demonstrates some basic assertions.
+
+To build the code, add the following to the end of your `CMakeLists.txt` file:
+
+```cmake
+enable_testing()
+
+add_executable(
+  hello_test
+  hello_test.cc
+)
+target_link_libraries(
+  hello_test
+  GTest::gtest_main
+)
+
+include(GoogleTest)
+gtest_discover_tests(hello_test)
+```
+
+The above configuration enables testing in CMake, declares the C++ test binary
+you want to build (`hello_test`), and links it to GoogleTest (`gtest_main`). The
+last two lines enable CMake's test runner to discover the tests included in the
+binary, using the
+[`GoogleTest` CMake module](https://cmake.org/cmake/help/git-stage/module/GoogleTest.html).
+
+Now you can build and run your test:
+
+<pre>
+<strong>my_project$ cmake -S . -B build</strong>
+-- The C compiler identification is GNU 10.2.1
+-- The CXX compiler identification is GNU 10.2.1
+...
+-- Build files have been written to: .../my_project/build
+
+<strong>my_project$ cmake --build build</strong>
+Scanning dependencies of target gtest
+...
+[100%] Built target gmock_main
+
+<strong>my_project$ cd build && ctest</strong>
+Test project .../my_project/build
+    Start 1: HelloTest.BasicAssertions
+1/1 Test #1: HelloTest.BasicAssertions ........   Passed    0.00 sec
+
+100% tests passed, 0 tests failed out of 1
+
+Total Test time (real) =   0.01 sec
+</pre>
+
+Congratulations! You've successfully built and run a test binary using
+GoogleTest.
+
+## Next steps
+
+*   [Check out the Primer](primer.md) to start learning how to write simple
+    tests.
+*   [See the code samples](samples.md) for more examples showing how to use a
+    variety of GoogleTest features.

contrib/googletest/docs/reference/actions.md

@@ -0,0 +1,115 @@
+# Actions Reference
+
+[**Actions**](../gmock_for_dummies.md#actions-what-should-it-do) specify what a
+mock function should do when invoked. This page lists the built-in actions
+provided by GoogleTest. All actions are defined in the `::testing` namespace.
+
+## Returning a Value
+
+| Action                            | Description                                   |
+| :-------------------------------- | :-------------------------------------------- |
+| `Return()`                        | Return from a `void` mock function.           |
+| `Return(value)`                   | Return `value`. If the type of `value` is     different to the mock function's return type, `value` is converted to the latter type <i>at the time the expectation is set</i>, not when the action is executed. |
+| `ReturnArg<N>()`                  | Return the `N`-th (0-based) argument.         |
+| `ReturnNew<T>(a1, ..., ak)`       | Return `new T(a1, ..., ak)`; a different      object is created each time. |
+| `ReturnNull()`                    | Return a null pointer.                        |
+| `ReturnPointee(ptr)`              | Return the value pointed to by `ptr`.         |
+| `ReturnRef(variable)`             | Return a reference to `variable`.             |
+| `ReturnRefOfCopy(value)`          | Return a reference to a copy of `value`; the  copy lives as long as the action. |
+| `ReturnRoundRobin({a1, ..., ak})` | Each call will return the next `ai` in the list, starting at the beginning when the end of the list is reached. |
+
+## Side Effects
+
+| Action                             | Description                             |
+| :--------------------------------- | :-------------------------------------- |
+| `Assign(&variable, value)` | Assign `value` to variable. |
+| `DeleteArg<N>()` | Delete the `N`-th (0-based) argument, which must be a pointer. |
+| `SaveArg<N>(pointer)` | Save the `N`-th (0-based) argument to `*pointer`. |
+| `SaveArgPointee<N>(pointer)` | Save the value pointed to by the `N`-th (0-based) argument to `*pointer`. |
+| `SetArgReferee<N>(value)` | Assign `value` to the variable referenced by the `N`-th (0-based) argument. |
+| `SetArgPointee<N>(value)` | Assign `value` to the variable pointed by the `N`-th (0-based) argument. |
+| `SetArgumentPointee<N>(value)` | Same as `SetArgPointee<N>(value)`. Deprecated. Will be removed in v1.7.0. |
+| `SetArrayArgument<N>(first, last)` | Copies the elements in source range [`first`, `last`) to the array pointed to by the `N`-th (0-based) argument, which can be either a pointer or an iterator. The action does not take ownership of the elements in the source range. |
+| `SetErrnoAndReturn(error, value)` | Set `errno` to `error` and return `value`. |
+| `Throw(exception)` | Throws the given exception, which can be any copyable value. Available since v1.1.0. |
+
+## Using a Function, Functor, or Lambda as an Action
+
+In the following, by "callable" we mean a free function, `std::function`,
+functor, or lambda.
+
+| Action                              | Description                            |
+| :---------------------------------- | :------------------------------------- |
+| `f` | Invoke `f` with the arguments passed to the mock function, where `f` is a callable. |
+| `Invoke(f)` | Invoke `f` with the arguments passed to the mock function, where `f` can be a global/static function or a functor. |
+| `Invoke(object_pointer, &class::method)` | Invoke the method on the object with the arguments passed to the mock function. |
+| `InvokeWithoutArgs(f)` | Invoke `f`, which can be a global/static function or a functor. `f` must take no arguments. |
+| `InvokeWithoutArgs(object_pointer, &class::method)` | Invoke the method on the object, which takes no arguments. |
+| `InvokeArgument<N>(arg1, arg2, ..., argk)` | Invoke the mock function's `N`-th (0-based) argument, which must be a function or a functor, with the `k` arguments. |
+
+The return value of the invoked function is used as the return value of the
+action.
+
+When defining a callable to be used with `Invoke*()`, you can declare any unused
+parameters as `Unused`:
+
+```cpp
+using ::testing::Invoke;
+double Distance(Unused, double x, double y) { return sqrt(x*x + y*y); }
+...
+EXPECT_CALL(mock, Foo("Hi", _, _)).WillOnce(Invoke(Distance));
+```
+
+`Invoke(callback)` and `InvokeWithoutArgs(callback)` take ownership of
+`callback`, which must be permanent. The type of `callback` must be a base
+callback type instead of a derived one, e.g.
+
+```cpp
+  BlockingClosure* done = new BlockingClosure;
+  ... Invoke(done) ...;  // This won't compile!
+
+  Closure* done2 = new BlockingClosure;
+  ... Invoke(done2) ...;  // This works.
+```
+
+In `InvokeArgument<N>(...)`, if an argument needs to be passed by reference,
+wrap it inside `std::ref()`. For example,
+
+```cpp
+using ::testing::InvokeArgument;
+...
+InvokeArgument<2>(5, string("Hi"), std::ref(foo))
+```
+
+calls the mock function's #2 argument, passing to it `5` and `string("Hi")` by
+value, and `foo` by reference.
+
+## Default Action
+
+| Action        | Description                                            |
+| :------------ | :----------------------------------------------------- |
+| `DoDefault()` | Do the default action (specified by `ON_CALL()` or the built-in one). |
+
+{: .callout .note}
+**Note:** due to technical reasons, `DoDefault()` cannot be used inside a
+composite action - trying to do so will result in a run-time error.
+
+## Composite Actions
+
+| Action                         | Description                                 |
+| :----------------------------- | :------------------------------------------ |
+| `DoAll(a1, a2, ..., an)`       | Do all actions `a1` to `an` and return the result of `an` in each invocation. The first `n - 1` sub-actions must return void and will receive a  readonly view of the arguments. |
+| `IgnoreResult(a)`              | Perform action `a` and ignore its result. `a` must not return void. |
+| `WithArg<N>(a)`                | Pass the `N`-th (0-based) argument of the mock function to action `a` and perform it. |
+| `WithArgs<N1, N2, ..., Nk>(a)` | Pass the selected (0-based) arguments of the mock function to action `a` and perform it. |
+| `WithoutArgs(a)`               | Perform action `a` without any arguments. |
+
+## Defining Actions
+
+| Macro                              | Description                             |
+| :--------------------------------- | :-------------------------------------- |
+| `ACTION(Sum) { return arg0 + arg1; }` | Defines an action `Sum()` to return the sum of the mock function's argument #0 and #1. |
+| `ACTION_P(Plus, n) { return arg0 + n; }` | Defines an action `Plus(n)` to return the sum of the mock function's argument #0 and `n`. |
+| `ACTION_Pk(Foo, p1, ..., pk) { statements; }` | Defines a parameterized action `Foo(p1, ..., pk)` to execute the given `statements`. |
+
+The `ACTION*` macros cannot be used inside a function or class.

contrib/googletest/docs/reference/assertions.md

@@ -0,0 +1,633 @@
+# Assertions Reference
+
+This page lists the assertion macros provided by GoogleTest for verifying code
+behavior. To use them, include the header `gtest/gtest.h`.
+
+The majority of the macros listed below come as a pair with an `EXPECT_` variant
+and an `ASSERT_` variant. Upon failure, `EXPECT_` macros generate nonfatal
+failures and allow the current function to continue running, while `ASSERT_`
+macros generate fatal failures and abort the current function.
+
+All assertion macros support streaming a custom failure message into them with
+the `<<` operator, for example:
+
+```cpp
+EXPECT_TRUE(my_condition) << "My condition is not true";
+```
+
+Anything that can be streamed to an `ostream` can be streamed to an assertion
+macro—in particular, C strings and string objects. If a wide string (`wchar_t*`,
+`TCHAR*` in `UNICODE` mode on Windows, or `std::wstring`) is streamed to an
+assertion, it will be translated to UTF-8 when printed.
+
+## Explicit Success and Failure {#success-failure}
+
+The assertions in this section generate a success or failure directly instead of
+testing a value or expression. These are useful when control flow, rather than a
+Boolean expression, determines the test's success or failure, as shown by the
+following example:
+
+```c++
+switch(expression) {
+  case 1:
+    ... some checks ...
+  case 2:
+    ... some other checks ...
+  default:
+    FAIL() << "We shouldn't get here.";
+}
+```
+
+### SUCCEED {#SUCCEED}
+
+`SUCCEED()`
+
+Generates a success. This *does not* make the overall test succeed. A test is
+considered successful only if none of its assertions fail during its execution.
+
+The `SUCCEED` assertion is purely documentary and currently doesn't generate any
+user-visible output. However, we may add `SUCCEED` messages to GoogleTest output
+in the future.
+
+### FAIL {#FAIL}
+
+`FAIL()`
+
+Generates a fatal failure, which returns from the current function.
+
+Can only be used in functions that return `void`. See
+[Assertion Placement](../advanced.md#assertion-placement) for more information.
+
+### ADD_FAILURE {#ADD_FAILURE}
+
+`ADD_FAILURE()`
+
+Generates a nonfatal failure, which allows the current function to continue
+running.
+
+### ADD_FAILURE_AT {#ADD_FAILURE_AT}
+
+`ADD_FAILURE_AT(`*`file_path`*`,`*`line_number`*`)`
+
+Generates a nonfatal failure at the file and line number specified.
+
+## Generalized Assertion {#generalized}
+
+The following assertion allows [matchers](matchers.md) to be used to verify
+values.
+
+### EXPECT_THAT {#EXPECT_THAT}
+
+`EXPECT_THAT(`*`value`*`,`*`matcher`*`)` \
+`ASSERT_THAT(`*`value`*`,`*`matcher`*`)`
+
+Verifies that *`value`* matches the [matcher](matchers.md) *`matcher`*.
+
+For example, the following code verifies that the string `value1` starts with
+`"Hello"`, `value2` matches a regular expression, and `value3` is between 5 and
+10:
+
+```cpp
+#include <gmock/gmock.h>
+
+using ::testing::AllOf;
+using ::testing::Gt;
+using ::testing::Lt;
+using ::testing::MatchesRegex;
+using ::testing::StartsWith;
+
+...
+EXPECT_THAT(value1, StartsWith("Hello"));
+EXPECT_THAT(value2, MatchesRegex("Line \\d+"));
+ASSERT_THAT(value3, AllOf(Gt(5), Lt(10)));
+```
+
+Matchers enable assertions of this form to read like English and generate
+informative failure messages. For example, if the above assertion on `value1`
+fails, the resulting message will be similar to the following:
+
+```
+Value of: value1
+  Actual: "Hi, world!"
+Expected: starts with "Hello"
+```
+
+GoogleTest provides a built-in library of matchers—see the
+[Matchers Reference](matchers.md). It is also possible to write your own
+matchers—see [Writing New Matchers Quickly](../gmock_cook_book.md#NewMatchers).
+The use of matchers makes `EXPECT_THAT` a powerful, extensible assertion.
+
+*The idea for this assertion was borrowed from Joe Walnes' Hamcrest project,
+which adds `assertThat()` to JUnit.*
+
+## Boolean Conditions {#boolean}
+
+The following assertions test Boolean conditions.
+
+### EXPECT_TRUE {#EXPECT_TRUE}
+
+`EXPECT_TRUE(`*`condition`*`)` \
+`ASSERT_TRUE(`*`condition`*`)`
+
+Verifies that *`condition`* is true.
+
+### EXPECT_FALSE {#EXPECT_FALSE}
+
+`EXPECT_FALSE(`*`condition`*`)` \
+`ASSERT_FALSE(`*`condition`*`)`
+
+Verifies that *`condition`* is false.
+
+## Binary Comparison {#binary-comparison}
+
+The following assertions compare two values. The value arguments must be
+comparable by the assertion's comparison operator, otherwise a compiler error
+will result.
+
+If an argument supports the `<<` operator, it will be called to print the
+argument when the assertion fails. Otherwise, GoogleTest will attempt to print
+them in the best way it can—see
+[Teaching GoogleTest How to Print Your Values](../advanced.md#teaching-googletest-how-to-print-your-values).
+
+Arguments are always evaluated exactly once, so it's OK for the arguments to
+have side effects. However, the argument evaluation order is undefined and
+programs should not depend on any particular argument evaluation order.
+
+These assertions work with both narrow and wide string objects (`string` and
+`wstring`).
+
+See also the [Floating-Point Comparison](#floating-point) assertions to compare
+floating-point numbers and avoid problems caused by rounding.
+
+### EXPECT_EQ {#EXPECT_EQ}
+
+`EXPECT_EQ(`*`val1`*`,`*`val2`*`)` \
+`ASSERT_EQ(`*`val1`*`,`*`val2`*`)`
+
+Verifies that *`val1`*`==`*`val2`*.
+
+Does pointer equality on pointers. If used on two C strings, it tests if they
+are in the same memory location, not if they have the same value. Use
+[`EXPECT_STREQ`](#EXPECT_STREQ) to compare C strings (e.g. `const char*`) by
+value.
+
+When comparing a pointer to `NULL`, use `EXPECT_EQ(`*`ptr`*`, nullptr)` instead
+of `EXPECT_EQ(`*`ptr`*`, NULL)`.
+
+### EXPECT_NE {#EXPECT_NE}
+
+`EXPECT_NE(`*`val1`*`,`*`val2`*`)` \
+`ASSERT_NE(`*`val1`*`,`*`val2`*`)`
+
+Verifies that *`val1`*`!=`*`val2`*.
+
+Does pointer equality on pointers. If used on two C strings, it tests if they
+are in different memory locations, not if they have different values. Use
+[`EXPECT_STRNE`](#EXPECT_STRNE) to compare C strings (e.g. `const char*`) by
+value.
+
+When comparing a pointer to `NULL`, use `EXPECT_NE(`*`ptr`*`, nullptr)` instead
+of `EXPECT_NE(`*`ptr`*`, NULL)`.
+
+### EXPECT_LT {#EXPECT_LT}
+
+`EXPECT_LT(`*`val1`*`,`*`val2`*`)` \
+`ASSERT_LT(`*`val1`*`,`*`val2`*`)`
+
+Verifies that *`val1`*`<`*`val2`*.
+
+### EXPECT_LE {#EXPECT_LE}
+
+`EXPECT_LE(`*`val1`*`,`*`val2`*`)` \
+`ASSERT_LE(`*`val1`*`,`*`val2`*`)`
+
+Verifies that *`val1`*`<=`*`val2`*.
+
+### EXPECT_GT {#EXPECT_GT}
+
+`EXPECT_GT(`*`val1`*`,`*`val2`*`)` \
+`ASSERT_GT(`*`val1`*`,`*`val2`*`)`
+
+Verifies that *`val1`*`>`*`val2`*.
+
+### EXPECT_GE {#EXPECT_GE}
+
+`EXPECT_GE(`*`val1`*`,`*`val2`*`)` \
+`ASSERT_GE(`*`val1`*`,`*`val2`*`)`
+
+Verifies that *`val1`*`>=`*`val2`*.
+
+## String Comparison {#c-strings}
+
+The following assertions compare two **C strings**. To compare two `string`
+objects, use [`EXPECT_EQ`](#EXPECT_EQ) or [`EXPECT_NE`](#EXPECT_NE) instead.
+
+These assertions also accept wide C strings (`wchar_t*`). If a comparison of two
+wide strings fails, their values will be printed as UTF-8 narrow strings.
+
+To compare a C string with `NULL`, use `EXPECT_EQ(`*`c_string`*`, nullptr)` or
+`EXPECT_NE(`*`c_string`*`, nullptr)`.
+
+### EXPECT_STREQ {#EXPECT_STREQ}
+
+`EXPECT_STREQ(`*`str1`*`,`*`str2`*`)` \
+`ASSERT_STREQ(`*`str1`*`,`*`str2`*`)`
+
+Verifies that the two C strings *`str1`* and *`str2`* have the same contents.
+
+### EXPECT_STRNE {#EXPECT_STRNE}
+
+`EXPECT_STRNE(`*`str1`*`,`*`str2`*`)` \
+`ASSERT_STRNE(`*`str1`*`,`*`str2`*`)`
+
+Verifies that the two C strings *`str1`* and *`str2`* have different contents.
+
+### EXPECT_STRCASEEQ {#EXPECT_STRCASEEQ}
+
+`EXPECT_STRCASEEQ(`*`str1`*`,`*`str2`*`)` \
+`ASSERT_STRCASEEQ(`*`str1`*`,`*`str2`*`)`
+
+Verifies that the two C strings *`str1`* and *`str2`* have the same contents,
+ignoring case.
+
+### EXPECT_STRCASENE {#EXPECT_STRCASENE}
+
+`EXPECT_STRCASENE(`*`str1`*`,`*`str2`*`)` \
+`ASSERT_STRCASENE(`*`str1`*`,`*`str2`*`)`
+
+Verifies that the two C strings *`str1`* and *`str2`* have different contents,
+ignoring case.
+
+## Floating-Point Comparison {#floating-point}
+
+The following assertions compare two floating-point values.
+
+Due to rounding errors, it is very unlikely that two floating-point values will
+match exactly, so `EXPECT_EQ` is not suitable. In general, for floating-point
+comparison to make sense, the user needs to carefully choose the error bound.
+
+GoogleTest also provides assertions that use a default error bound based on
+Units in the Last Place (ULPs). To learn more about ULPs, see the article
+[Comparing Floating Point Numbers](https://randomascii.wordpress.com/2012/02/25/comparing-floating-point-numbers-2012-edition/).
+
+### EXPECT_FLOAT_EQ {#EXPECT_FLOAT_EQ}
+
+`EXPECT_FLOAT_EQ(`*`val1`*`,`*`val2`*`)` \
+`ASSERT_FLOAT_EQ(`*`val1`*`,`*`val2`*`)`
+
+Verifies that the two `float` values *`val1`* and *`val2`* are approximately
+equal, to within 4 ULPs from each other.
+
+### EXPECT_DOUBLE_EQ {#EXPECT_DOUBLE_EQ}
+
+`EXPECT_DOUBLE_EQ(`*`val1`*`,`*`val2`*`)` \
+`ASSERT_DOUBLE_EQ(`*`val1`*`,`*`val2`*`)`
+
+Verifies that the two `double` values *`val1`* and *`val2`* are approximately
+equal, to within 4 ULPs from each other.
+
+### EXPECT_NEAR {#EXPECT_NEAR}
+
+`EXPECT_NEAR(`*`val1`*`,`*`val2`*`,`*`abs_error`*`)` \
+`ASSERT_NEAR(`*`val1`*`,`*`val2`*`,`*`abs_error`*`)`
+
+Verifies that the difference between *`val1`* and *`val2`* does not exceed the
+absolute error bound *`abs_error`*.
+
+## Exception Assertions {#exceptions}
+
+The following assertions verify that a piece of code throws, or does not throw,
+an exception. Usage requires exceptions to be enabled in the build environment.
+
+Note that the piece of code under test can be a compound statement, for example:
+
+```cpp
+EXPECT_NO_THROW({
+  int n = 5;
+  DoSomething(&n);
+});
+```
+
+### EXPECT_THROW {#EXPECT_THROW}
+
+`EXPECT_THROW(`*`statement`*`,`*`exception_type`*`)` \
+`ASSERT_THROW(`*`statement`*`,`*`exception_type`*`)`
+
+Verifies that *`statement`* throws an exception of type *`exception_type`*.
+
+### EXPECT_ANY_THROW {#EXPECT_ANY_THROW}
+
+`EXPECT_ANY_THROW(`*`statement`*`)` \
+`ASSERT_ANY_THROW(`*`statement`*`)`
+
+Verifies that *`statement`* throws an exception of any type.
+
+### EXPECT_NO_THROW {#EXPECT_NO_THROW}
+
+`EXPECT_NO_THROW(`*`statement`*`)` \
+`ASSERT_NO_THROW(`*`statement`*`)`
+
+Verifies that *`statement`* does not throw any exception.
+
+## Predicate Assertions {#predicates}
+
+The following assertions enable more complex predicates to be verified while
+printing a more clear failure message than if `EXPECT_TRUE` were used alone.
+
+### EXPECT_PRED* {#EXPECT_PRED}
+
+`EXPECT_PRED1(`*`pred`*`,`*`val1`*`)` \
+`EXPECT_PRED2(`*`pred`*`,`*`val1`*`,`*`val2`*`)` \
+`EXPECT_PRED3(`*`pred`*`,`*`val1`*`,`*`val2`*`,`*`val3`*`)` \
+`EXPECT_PRED4(`*`pred`*`,`*`val1`*`,`*`val2`*`,`*`val3`*`,`*`val4`*`)` \
+`EXPECT_PRED5(`*`pred`*`,`*`val1`*`,`*`val2`*`,`*`val3`*`,`*`val4`*`,`*`val5`*`)`
+
+`ASSERT_PRED1(`*`pred`*`,`*`val1`*`)` \
+`ASSERT_PRED2(`*`pred`*`,`*`val1`*`,`*`val2`*`)` \
+`ASSERT_PRED3(`*`pred`*`,`*`val1`*`,`*`val2`*`,`*`val3`*`)` \
+`ASSERT_PRED4(`*`pred`*`,`*`val1`*`,`*`val2`*`,`*`val3`*`,`*`val4`*`)` \
+`ASSERT_PRED5(`*`pred`*`,`*`val1`*`,`*`val2`*`,`*`val3`*`,`*`val4`*`,`*`val5`*`)`
+
+Verifies that the predicate *`pred`* returns `true` when passed the given values
+as arguments.
+
+The parameter *`pred`* is a function or functor that accepts as many arguments
+as the corresponding macro accepts values. If *`pred`* returns `true` for the
+given arguments, the assertion succeeds, otherwise the assertion fails.
+
+When the assertion fails, it prints the value of each argument. Arguments are
+always evaluated exactly once.
+
+As an example, see the following code:
+
+```cpp
+// Returns true if m and n have no common divisors except 1.
+bool MutuallyPrime(int m, int n) { ... }
+...
+const int a = 3;
+const int b = 4;
+const int c = 10;
+...
+EXPECT_PRED2(MutuallyPrime, a, b);  // Succeeds
+EXPECT_PRED2(MutuallyPrime, b, c);  // Fails
+```
+
+In the above example, the first assertion succeeds, and the second fails with
+the following message:
+
+```
+MutuallyPrime(b, c) is false, where
+b is 4
+c is 10
+```
+
+Note that if the given predicate is an overloaded function or a function
+template, the assertion macro might not be able to determine which version to
+use, and it might be necessary to explicitly specify the type of the function.
+For example, for a Boolean function `IsPositive()` overloaded to take either a
+single `int` or `double` argument, it would be necessary to write one of the
+following:
+
+```cpp
+EXPECT_PRED1(static_cast<bool (*)(int)>(IsPositive), 5);
+EXPECT_PRED1(static_cast<bool (*)(double)>(IsPositive), 3.14);
+```
+
+Writing simply `EXPECT_PRED1(IsPositive, 5);` would result in a compiler error.
+Similarly, to use a template function, specify the template arguments:
+
+```cpp
+template <typename T>
+bool IsNegative(T x) {
+  return x < 0;
+}
+...
+EXPECT_PRED1(IsNegative<int>, -5);  // Must specify type for IsNegative
+```
+
+If a template has multiple parameters, wrap the predicate in parentheses so the
+macro arguments are parsed correctly:
+
+```cpp
+ASSERT_PRED2((MyPredicate<int, int>), 5, 0);
+```
+
+### EXPECT_PRED_FORMAT* {#EXPECT_PRED_FORMAT}
+
+`EXPECT_PRED_FORMAT1(`*`pred_formatter`*`,`*`val1`*`)` \
+`EXPECT_PRED_FORMAT2(`*`pred_formatter`*`,`*`val1`*`,`*`val2`*`)` \
+`EXPECT_PRED_FORMAT3(`*`pred_formatter`*`,`*`val1`*`,`*`val2`*`,`*`val3`*`)` \
+`EXPECT_PRED_FORMAT4(`*`pred_formatter`*`,`*`val1`*`,`*`val2`*`,`*`val3`*`,`*`val4`*`)`
+\
+`EXPECT_PRED_FORMAT5(`*`pred_formatter`*`,`*`val1`*`,`*`val2`*`,`*`val3`*`,`*`val4`*`,`*`val5`*`)`
+
+`ASSERT_PRED_FORMAT1(`*`pred_formatter`*`,`*`val1`*`)` \
+`ASSERT_PRED_FORMAT2(`*`pred_formatter`*`,`*`val1`*`,`*`val2`*`)` \
+`ASSERT_PRED_FORMAT3(`*`pred_formatter`*`,`*`val1`*`,`*`val2`*`,`*`val3`*`)` \
+`ASSERT_PRED_FORMAT4(`*`pred_formatter`*`,`*`val1`*`,`*`val2`*`,`*`val3`*`,`*`val4`*`)`
+\
+`ASSERT_PRED_FORMAT5(`*`pred_formatter`*`,`*`val1`*`,`*`val2`*`,`*`val3`*`,`*`val4`*`,`*`val5`*`)`
+
+Verifies that the predicate *`pred_formatter`* succeeds when passed the given
+values as arguments.
+
+The parameter *`pred_formatter`* is a *predicate-formatter*, which is a function
+or functor with the signature:
+
+```cpp
+testing::AssertionResult PredicateFormatter(const char* expr1,
+                                            const char* expr2,
+                                            ...
+                                            const char* exprn,
+                                            T1 val1,
+                                            T2 val2,
+                                            ...
+                                            Tn valn);
+```
+
+where *`val1`*, *`val2`*, ..., *`valn`* are the values of the predicate
+arguments, and *`expr1`*, *`expr2`*, ..., *`exprn`* are the corresponding
+expressions as they appear in the source code. The types `T1`, `T2`, ..., `Tn`
+can be either value types or reference types; if an argument has type `T`, it
+can be declared as either `T` or `const T&`, whichever is appropriate. For more
+about the return type `testing::AssertionResult`, see
+[Using a Function That Returns an AssertionResult](../advanced.md#using-a-function-that-returns-an-assertionresult).
+
+As an example, see the following code:
+
+```cpp
+// Returns the smallest prime common divisor of m and n,
+// or 1 when m and n are mutually prime.
+int SmallestPrimeCommonDivisor(int m, int n) { ... }
+
+// Returns true if m and n have no common divisors except 1.
+bool MutuallyPrime(int m, int n) { ... }
+
+// A predicate-formatter for asserting that two integers are mutually prime.
+testing::AssertionResult AssertMutuallyPrime(const char* m_expr,
+                                             const char* n_expr,
+                                             int m,
+                                             int n) {
+  if (MutuallyPrime(m, n)) return testing::AssertionSuccess();
+
+  return testing::AssertionFailure() << m_expr << " and " << n_expr
+      << " (" << m << " and " << n << ") are not mutually prime, "
+      << "as they have a common divisor " << SmallestPrimeCommonDivisor(m, n);
+}
+
+...
+const int a = 3;
+const int b = 4;
+const int c = 10;
+...
+EXPECT_PRED_FORMAT2(AssertMutuallyPrime, a, b);  // Succeeds
+EXPECT_PRED_FORMAT2(AssertMutuallyPrime, b, c);  // Fails
+```
+
+In the above example, the final assertion fails and the predicate-formatter
+produces the following failure message:
+
+```
+b and c (4 and 10) are not mutually prime, as they have a common divisor 2
+```
+
+## Windows HRESULT Assertions {#HRESULT}
+
+The following assertions test for `HRESULT` success or failure. For example:
+
+```cpp
+CComPtr<IShellDispatch2> shell;
+ASSERT_HRESULT_SUCCEEDED(shell.CoCreateInstance(L"Shell.Application"));
+CComVariant empty;
+ASSERT_HRESULT_SUCCEEDED(shell->ShellExecute(CComBSTR(url), empty, empty, empty, empty));
+```
+
+The generated output contains the human-readable error message associated with
+the returned `HRESULT` code.
+
+### EXPECT_HRESULT_SUCCEEDED {#EXPECT_HRESULT_SUCCEEDED}
+
+`EXPECT_HRESULT_SUCCEEDED(`*`expression`*`)` \
+`ASSERT_HRESULT_SUCCEEDED(`*`expression`*`)`
+
+Verifies that *`expression`* is a success `HRESULT`.
+
+### EXPECT_HRESULT_FAILED {#EXPECT_HRESULT_FAILED}
+
+`EXPECT_HRESULT_FAILED(`*`expression`*`)` \
+`ASSERT_HRESULT_FAILED(`*`expression`*`)`
+
+Verifies that *`expression`* is a failure `HRESULT`.
+
+## Death Assertions {#death}
+
+The following assertions verify that a piece of code causes the process to
+terminate. For context, see [Death Tests](../advanced.md#death-tests).
+
+These assertions spawn a new process and execute the code under test in that
+process. How that happens depends on the platform and the variable
+`::testing::GTEST_FLAG(death_test_style)`, which is initialized from the
+command-line flag `--gtest_death_test_style`.
+
+*   On POSIX systems, `fork()` (or `clone()` on Linux) is used to spawn the
+    child, after which:
+    *   If the variable's value is `"fast"`, the death test statement is
+        immediately executed.
+    *   If the variable's value is `"threadsafe"`, the child process re-executes
+        the unit test binary just as it was originally invoked, but with some
+        extra flags to cause just the single death test under consideration to
+        be run.
+*   On Windows, the child is spawned using the `CreateProcess()` API, and
+    re-executes the binary to cause just the single death test under
+    consideration to be run - much like the `"threadsafe"` mode on POSIX.
+
+Other values for the variable are illegal and will cause the death test to fail.
+Currently, the flag's default value is
+**`"fast"`**.
+
+If the death test statement runs to completion without dying, the child process
+will nonetheless terminate, and the assertion fails.
+
+Note that the piece of code under test can be a compound statement, for example:
+
+```cpp
+EXPECT_DEATH({
+  int n = 5;
+  DoSomething(&n);
+}, "Error on line .* of DoSomething()");
+```
+
+### EXPECT_DEATH {#EXPECT_DEATH}
+
+`EXPECT_DEATH(`*`statement`*`,`*`matcher`*`)` \
+`ASSERT_DEATH(`*`statement`*`,`*`matcher`*`)`
+
+Verifies that *`statement`* causes the process to terminate with a nonzero exit
+status and produces `stderr` output that matches *`matcher`*.
+
+The parameter *`matcher`* is either a [matcher](matchers.md) for a `const
+std::string&`, or a regular expression (see
+[Regular Expression Syntax](../advanced.md#regular-expression-syntax))—a bare
+string *`s`* (with no matcher) is treated as
+[`ContainsRegex(s)`](matchers.md#string-matchers), **not**
+[`Eq(s)`](matchers.md#generic-comparison).
+
+For example, the following code verifies that calling `DoSomething(42)` causes
+the process to die with an error message that contains the text `My error`:
+
+```cpp
+EXPECT_DEATH(DoSomething(42), "My error");
+```
+
+### EXPECT_DEATH_IF_SUPPORTED {#EXPECT_DEATH_IF_SUPPORTED}
+
+`EXPECT_DEATH_IF_SUPPORTED(`*`statement`*`,`*`matcher`*`)` \
+`ASSERT_DEATH_IF_SUPPORTED(`*`statement`*`,`*`matcher`*`)`
+
+If death tests are supported, behaves the same as
+[`EXPECT_DEATH`](#EXPECT_DEATH). Otherwise, verifies nothing.
+
+### EXPECT_DEBUG_DEATH {#EXPECT_DEBUG_DEATH}
+
+`EXPECT_DEBUG_DEATH(`*`statement`*`,`*`matcher`*`)` \
+`ASSERT_DEBUG_DEATH(`*`statement`*`,`*`matcher`*`)`
+
+In debug mode, behaves the same as [`EXPECT_DEATH`](#EXPECT_DEATH). When not in
+debug mode (i.e. `NDEBUG` is defined), just executes *`statement`*.
+
+### EXPECT_EXIT {#EXPECT_EXIT}
+
+`EXPECT_EXIT(`*`statement`*`,`*`predicate`*`,`*`matcher`*`)` \
+`ASSERT_EXIT(`*`statement`*`,`*`predicate`*`,`*`matcher`*`)`
+
+Verifies that *`statement`* causes the process to terminate with an exit status
+that satisfies *`predicate`*, and produces `stderr` output that matches
+*`matcher`*.
+
+The parameter *`predicate`* is a function or functor that accepts an `int` exit
+status and returns a `bool`. GoogleTest provides two predicates to handle common
+cases:
+
+```cpp
+// Returns true if the program exited normally with the given exit status code.
+::testing::ExitedWithCode(exit_code);
+
+// Returns true if the program was killed by the given signal.
+// Not available on Windows.
+::testing::KilledBySignal(signal_number);
+```
+
+The parameter *`matcher`* is either a [matcher](matchers.md) for a `const
+std::string&`, or a regular expression (see
+[Regular Expression Syntax](../advanced.md#regular-expression-syntax))—a bare
+string *`s`* (with no matcher) is treated as
+[`ContainsRegex(s)`](matchers.md#string-matchers), **not**
+[`Eq(s)`](matchers.md#generic-comparison).
+
+For example, the following code verifies that calling `NormalExit()` causes the
+process to print a message containing the text `Success` to `stderr` and exit
+with exit status code 0:
+
+```cpp
+EXPECT_EXIT(NormalExit(), testing::ExitedWithCode(0), "Success");
+```

contrib/googletest/docs/reference/matchers.md

@@ -0,0 +1,302 @@
+# Matchers Reference
+
+A **matcher** matches a *single* argument. You can use it inside `ON_CALL()` or
+`EXPECT_CALL()`, or use it to validate a value directly using two macros:
+
+| Macro                                | Description                           |
+| :----------------------------------- | :------------------------------------ |
+| `EXPECT_THAT(actual_value, matcher)` | Asserts that `actual_value` matches `matcher`. |
+| `ASSERT_THAT(actual_value, matcher)` | The same as `EXPECT_THAT(actual_value, matcher)`, except that it generates a **fatal** failure. |
+
+{: .callout .warning}
+**WARNING:** Equality matching via `EXPECT_THAT(actual_value, expected_value)`
+is supported, however note that implicit conversions can cause surprising
+results. For example, `EXPECT_THAT(some_bool, "some string")` will compile and
+may pass unintentionally.
+
+**BEST PRACTICE:** Prefer to make the comparison explicit via
+`EXPECT_THAT(actual_value, Eq(expected_value))` or `EXPECT_EQ(actual_value,
+expected_value)`.
+
+Built-in matchers (where `argument` is the function argument, e.g.
+`actual_value` in the example above, or when used in the context of
+`EXPECT_CALL(mock_object, method(matchers))`, the arguments of `method`) are
+divided into several categories. All matchers are defined in the `::testing`
+namespace unless otherwise noted.
+
+## Wildcard
+
+Matcher                     | Description
+:-------------------------- | :-----------------------------------------------
+`_`                         | `argument` can be any value of the correct type.
+`A<type>()` or `An<type>()` | `argument` can be any value of type `type`.
+
+## Generic Comparison
+
+| Matcher                | Description                                         |
+| :--------------------- | :-------------------------------------------------- |
+| `Eq(value)` or `value` | `argument == value`                                 |
+| `Ge(value)`            | `argument >= value`                                 |
+| `Gt(value)`            | `argument > value`                                  |
+| `Le(value)`            | `argument <= value`                                 |
+| `Lt(value)`            | `argument < value`                                  |
+| `Ne(value)`            | `argument != value`                                 |
+| `IsFalse()`            | `argument` evaluates to `false` in a Boolean context. |
+| `IsTrue()`             | `argument` evaluates to `true` in a Boolean context. |
+| `IsNull()`             | `argument` is a `NULL` pointer (raw or smart).      |
+| `NotNull()`            | `argument` is a non-null pointer (raw or smart).    |
+| `Optional(m)`          | `argument` is `optional<>` that contains a value matching `m`. (For testing whether an `optional<>` is set, check for equality with `nullopt`. You may need to use `Eq(nullopt)` if the inner type doesn't have `==`.)|
+| `VariantWith<T>(m)`    | `argument` is `variant<>` that holds the alternative of type T with a value matching `m`. |
+| `Ref(variable)`        | `argument` is a reference to `variable`.            |
+| `TypedEq<type>(value)` | `argument` has type `type` and is equal to `value`. You may need to use this instead of `Eq(value)` when the mock function is overloaded. |
+
+Except `Ref()`, these matchers make a *copy* of `value` in case it's modified or
+destructed later. If the compiler complains that `value` doesn't have a public
+copy constructor, try wrap it in `std::ref()`, e.g.
+`Eq(std::ref(non_copyable_value))`. If you do that, make sure
+`non_copyable_value` is not changed afterwards, or the meaning of your matcher
+will be changed.
+
+`IsTrue` and `IsFalse` are useful when you need to use a matcher, or for types
+that can be explicitly converted to Boolean, but are not implicitly converted to
+Boolean. In other cases, you can use the basic
+[`EXPECT_TRUE` and `EXPECT_FALSE`](assertions.md#boolean) assertions.
+
+## Floating-Point Matchers {#FpMatchers}
+
+| Matcher                          | Description                        |
+| :------------------------------- | :--------------------------------- |
+| `DoubleEq(a_double)`             | `argument` is a `double` value approximately equal to `a_double`, treating two NaNs as unequal. |
+| `FloatEq(a_float)`               | `argument` is a `float` value approximately equal to `a_float`, treating two NaNs as unequal. |
+| `NanSensitiveDoubleEq(a_double)` | `argument` is a `double` value approximately equal to `a_double`, treating two NaNs as equal. |
+| `NanSensitiveFloatEq(a_float)`   | `argument` is a `float` value approximately equal to `a_float`, treating two NaNs as equal. |
+| `IsNan()`   | `argument` is any floating-point type with a NaN value. |
+
+The above matchers use ULP-based comparison (the same as used in googletest).
+They automatically pick a reasonable error bound based on the absolute value of
+the expected value. `DoubleEq()` and `FloatEq()` conform to the IEEE standard,
+which requires comparing two NaNs for equality to return false. The
+`NanSensitive*` version instead treats two NaNs as equal, which is often what a
+user wants.
+
+| Matcher                                           | Description              |
+| :------------------------------------------------ | :----------------------- |
+| `DoubleNear(a_double, max_abs_error)`             | `argument` is a `double` value close to `a_double` (absolute error <= `max_abs_error`), treating two NaNs as unequal. |
+| `FloatNear(a_float, max_abs_error)`               | `argument` is a `float` value close to `a_float` (absolute error <= `max_abs_error`), treating two NaNs as unequal. |
+| `NanSensitiveDoubleNear(a_double, max_abs_error)` | `argument` is a `double` value close to `a_double` (absolute error <= `max_abs_error`), treating two NaNs as equal. |
+| `NanSensitiveFloatNear(a_float, max_abs_error)`   | `argument` is a `float` value close to `a_float` (absolute error <= `max_abs_error`), treating two NaNs as equal. |
+
+## String Matchers
+
+The `argument` can be either a C string or a C++ string object:
+
+| Matcher                 | Description                                        |
+| :---------------------- | :------------------------------------------------- |
+| `ContainsRegex(string)`  | `argument` matches the given regular expression.  |
+| `EndsWith(suffix)`       | `argument` ends with string `suffix`.             |
+| `HasSubstr(string)`      | `argument` contains `string` as a sub-string.     |
+| `IsEmpty()`              | `argument` is an empty string.                    |
+| `MatchesRegex(string)`   | `argument` matches the given regular expression with the match starting at the first character and ending at the last character. |
+| `StartsWith(prefix)`     | `argument` starts with string `prefix`.           |
+| `StrCaseEq(string)`      | `argument` is equal to `string`, ignoring case.   |
+| `StrCaseNe(string)`      | `argument` is not equal to `string`, ignoring case. |
+| `StrEq(string)`          | `argument` is equal to `string`.                  |
+| `StrNe(string)`          | `argument` is not equal to `string`.              |
+| `WhenBase64Unescaped(m)` | `argument` is a base-64 escaped string whose unescaped string matches `m`.  The web-safe format from [RFC 4648](https://www.rfc-editor.org/rfc/rfc4648#section-5) is supported. |
+
+`ContainsRegex()` and `MatchesRegex()` take ownership of the `RE` object. They
+use the regular expression syntax defined
+[here](../advanced.md#regular-expression-syntax). All of these matchers, except
+`ContainsRegex()` and `MatchesRegex()` work for wide strings as well.
+
+## Container Matchers
+
+Most STL-style containers support `==`, so you can use `Eq(expected_container)`
+or simply `expected_container` to match a container exactly. If you want to
+write the elements in-line, match them more flexibly, or get more informative
+messages, you can use:
+
+| Matcher                                   | Description                      |
+| :---------------------------------------- | :------------------------------- |
+| `BeginEndDistanceIs(m)` | `argument` is a container whose `begin()` and `end()` iterators are separated by a number of increments matching `m`. E.g. `BeginEndDistanceIs(2)` or `BeginEndDistanceIs(Lt(2))`. For containers that define a `size()` method, `SizeIs(m)` may be more efficient. |
+| `ContainerEq(container)` | The same as `Eq(container)` except that the failure message also includes which elements are in one container but not the other. |
+| `Contains(e)` | `argument` contains an element that matches `e`, which can be either a value or a matcher. |
+| `Contains(e).Times(n)` | `argument` contains elements that match `e`, which can be either a value or a matcher, and the number of matches is `n`, which can be either a value or a matcher. Unlike the plain `Contains` and `Each` this allows to check for arbitrary occurrences including testing for absence with `Contains(e).Times(0)`. |
+| `Each(e)` | `argument` is a container where *every* element matches `e`, which can be either a value or a matcher. |
+| `ElementsAre(e0, e1, ..., en)` | `argument` has `n + 1` elements, where the *i*-th element matches `ei`, which can be a value or a matcher. |
+| `ElementsAreArray({e0, e1, ..., en})`, `ElementsAreArray(a_container)`, `ElementsAreArray(begin, end)`, `ElementsAreArray(array)`, or `ElementsAreArray(array, count)` | The same as `ElementsAre()` except that the expected element values/matchers come from an initializer list, STL-style container, iterator range, or C-style array. |
+| `IsEmpty()` | `argument` is an empty container (`container.empty()`). |
+| `IsSubsetOf({e0, e1, ..., en})`, `IsSubsetOf(a_container)`, `IsSubsetOf(begin, end)`, `IsSubsetOf(array)`, or `IsSubsetOf(array, count)` | `argument` matches `UnorderedElementsAre(x0, x1, ..., xk)` for some subset `{x0, x1, ..., xk}` of the expected matchers. |
+| `IsSupersetOf({e0, e1, ..., en})`, `IsSupersetOf(a_container)`, `IsSupersetOf(begin, end)`, `IsSupersetOf(array)`, or `IsSupersetOf(array, count)` | Some subset of `argument` matches `UnorderedElementsAre(`expected matchers`)`. |
+| `Pointwise(m, container)`, `Pointwise(m, {e0, e1, ..., en})` | `argument` contains the same number of elements as in `container`, and for all i, (the i-th element in `argument`, the i-th element in `container`) match `m`, which is a matcher on 2-tuples. E.g. `Pointwise(Le(), upper_bounds)` verifies that each element in `argument` doesn't exceed the corresponding element in `upper_bounds`. See more detail below. |
+| `SizeIs(m)` | `argument` is a container whose size matches `m`. E.g. `SizeIs(2)` or `SizeIs(Lt(2))`. |
+| `UnorderedElementsAre(e0, e1, ..., en)` | `argument` has `n + 1` elements, and under *some* permutation of the elements, each element matches an `ei` (for a different `i`), which can be a value or a matcher. |
+| `UnorderedElementsAreArray({e0, e1, ..., en})`, `UnorderedElementsAreArray(a_container)`, `UnorderedElementsAreArray(begin, end)`, `UnorderedElementsAreArray(array)`, or `UnorderedElementsAreArray(array, count)` | The same as `UnorderedElementsAre()` except that the expected element values/matchers come from an initializer list, STL-style container, iterator range, or C-style array. |
+| `UnorderedPointwise(m, container)`, `UnorderedPointwise(m, {e0, e1, ..., en})` | Like `Pointwise(m, container)`, but ignores the order of elements. |
+| `WhenSorted(m)` | When `argument` is sorted using the `<` operator, it matches container matcher `m`. E.g. `WhenSorted(ElementsAre(1, 2, 3))` verifies that `argument` contains elements 1, 2, and 3, ignoring order. |
+| `WhenSortedBy(comparator, m)` | The same as `WhenSorted(m)`, except that the given comparator instead of `<` is used to sort `argument`. E.g. `WhenSortedBy(std::greater(), ElementsAre(3, 2, 1))`. |
+
+**Notes:**
+
+*   These matchers can also match:
+    1.  a native array passed by reference (e.g. in `Foo(const int (&a)[5])`),
+        and
+    2.  an array passed as a pointer and a count (e.g. in `Bar(const T* buffer,
+        int len)` -- see [Multi-argument Matchers](#MultiArgMatchers)).
+*   The array being matched may be multi-dimensional (i.e. its elements can be
+    arrays).
+*   `m` in `Pointwise(m, ...)` and `UnorderedPointwise(m, ...)` should be a
+    matcher for `::std::tuple<T, U>` where `T` and `U` are the element type of
+    the actual container and the expected container, respectively. For example,
+    to compare two `Foo` containers where `Foo` doesn't support `operator==`,
+    one might write:
+
+    ```cpp
+    MATCHER(FooEq, "") {
+      return std::get<0>(arg).Equals(std::get<1>(arg));
+    }
+    ...
+    EXPECT_THAT(actual_foos, Pointwise(FooEq(), expected_foos));
+    ```
+
+## Member Matchers
+
+| Matcher                         | Description                                |
+| :------------------------------ | :----------------------------------------- |
+| `Field(&class::field, m)`       | `argument.field` (or `argument->field` when `argument` is a plain pointer) matches matcher `m`, where `argument` is an object of type _class_. |
+| `Field(field_name, &class::field, m)` | The same as the two-parameter version, but provides a better error message. |
+| `Key(e)`                        | `argument.first` matches `e`, which can be either a value or a matcher. E.g. `Contains(Key(Le(5)))` can verify that a `map` contains a key `<= 5`. |
+| `Pair(m1, m2)`                  | `argument` is an `std::pair` whose `first` field matches `m1` and `second` field matches `m2`. |
+| `FieldsAre(m...)`                   | `argument` is a compatible object where each field matches piecewise with the matchers `m...`. A compatible object is any that supports the `std::tuple_size<Obj>`+`get<I>(obj)` protocol. In C++17 and up this also supports types compatible with structured bindings, like aggregates. |
+| `Property(&class::property, m)` | `argument.property()` (or `argument->property()` when `argument` is a plain pointer) matches matcher `m`, where `argument` is an object of type _class_. The method `property()` must take no argument and be declared as `const`. |
+| `Property(property_name, &class::property, m)` | The same as the two-parameter version, but provides a better error message.
+
+**Notes:**
+
+*   You can use `FieldsAre()` to match any type that supports structured
+    bindings, such as `std::tuple`, `std::pair`, `std::array`, and aggregate
+    types. For example:
+
+    ```cpp
+    std::tuple<int, std::string> my_tuple{7, "hello world"};
+    EXPECT_THAT(my_tuple, FieldsAre(Ge(0), HasSubstr("hello")));
+
+    struct MyStruct {
+      int value = 42;
+      std::string greeting = "aloha";
+    };
+    MyStruct s;
+    EXPECT_THAT(s, FieldsAre(42, "aloha"));
+    ```
+
+*   Don't use `Property()` against member functions that you do not own, because
+    taking addresses of functions is fragile and generally not part of the
+    contract of the function.
+
+## Matching the Result of a Function, Functor, or Callback
+
+| Matcher          | Description                                       |
+| :--------------- | :------------------------------------------------ |
+| `ResultOf(f, m)` | `f(argument)` matches matcher `m`, where `f` is a function or functor. |
+| `ResultOf(result_description, f, m)` | The same as the two-parameter version, but provides a better error message.
+
+## Pointer Matchers
+
+| Matcher                   | Description                                     |
+| :------------------------ | :---------------------------------------------- |
+| `Address(m)`              | the result of `std::addressof(argument)` matches `m`. |
+| `Pointee(m)`              | `argument` (either a smart pointer or a raw pointer) points to a value that matches matcher `m`. |
+| `Pointer(m)`              | `argument` (either a smart pointer or a raw pointer) contains a pointer that matches `m`. `m` will match against the raw pointer regardless of the type of `argument`. |
+| `WhenDynamicCastTo<T>(m)` | when `argument` is passed through `dynamic_cast<T>()`, it matches matcher `m`. |
+
+## Multi-argument Matchers {#MultiArgMatchers}
+
+Technically, all matchers match a *single* value. A "multi-argument" matcher is
+just one that matches a *tuple*. The following matchers can be used to match a
+tuple `(x, y)`:
+
+Matcher | Description
+:------ | :----------
+`Eq()`  | `x == y`
+`Ge()`  | `x >= y`
+`Gt()`  | `x > y`
+`Le()`  | `x <= y`
+`Lt()`  | `x < y`
+`Ne()`  | `x != y`
+
+You can use the following selectors to pick a subset of the arguments (or
+reorder them) to participate in the matching:
+
+| Matcher                    | Description                                     |
+| :------------------------- | :---------------------------------------------- |
+| `AllArgs(m)`               | Equivalent to `m`. Useful as syntactic sugar in `.With(AllArgs(m))`. |
+| `Args<N1, N2, ..., Nk>(m)` | The tuple of the `k` selected (using 0-based indices) arguments matches `m`, e.g. `Args<1, 2>(Eq())`. |
+
+## Composite Matchers
+
+You can make a matcher from one or more other matchers:
+
+| Matcher                          | Description                             |
+| :------------------------------- | :-------------------------------------- |
+| `AllOf(m1, m2, ..., mn)` | `argument` matches all of the matchers `m1` to `mn`. |
+| `AllOfArray({m0, m1, ..., mn})`, `AllOfArray(a_container)`, `AllOfArray(begin, end)`, `AllOfArray(array)`, or `AllOfArray(array, count)` | The same as `AllOf()` except that the matchers come from an initializer list, STL-style container, iterator range, or C-style array. |
+| `AnyOf(m1, m2, ..., mn)` | `argument` matches at least one of the matchers `m1` to `mn`. |
+| `AnyOfArray({m0, m1, ..., mn})`, `AnyOfArray(a_container)`, `AnyOfArray(begin, end)`, `AnyOfArray(array)`, or `AnyOfArray(array, count)` | The same as `AnyOf()` except that the matchers come from an initializer list, STL-style container, iterator range, or C-style array. |
+| `Not(m)` | `argument` doesn't match matcher `m`. |
+| `Conditional(cond, m1, m2)` | Matches matcher `m1` if `cond` evaluates to true, else matches `m2`.|
+
+## Adapters for Matchers
+
+| Matcher                 | Description                           |
+| :---------------------- | :------------------------------------ |
+| `MatcherCast<T>(m)`     | casts matcher `m` to type `Matcher<T>`. |
+| `SafeMatcherCast<T>(m)` | [safely casts](../gmock_cook_book.md#SafeMatcherCast) matcher `m` to type `Matcher<T>`. |
+| `Truly(predicate)`      | `predicate(argument)` returns something considered by C++ to be true, where `predicate` is a function or functor. |
+
+`AddressSatisfies(callback)` and `Truly(callback)` take ownership of `callback`,
+which must be a permanent callback.
+
+## Using Matchers as Predicates {#MatchersAsPredicatesCheat}
+
+| Matcher                       | Description                                 |
+| :---------------------------- | :------------------------------------------ |
+| `Matches(m)(value)` | evaluates to `true` if `value` matches `m`. You can use `Matches(m)` alone as a unary functor. |
+| `ExplainMatchResult(m, value, result_listener)` | evaluates to `true` if `value` matches `m`, explaining the result to `result_listener`. |
+| `Value(value, m)` | evaluates to `true` if `value` matches `m`. |
+
+## Defining Matchers
+
+| Macro                                | Description                           |
+| :----------------------------------- | :------------------------------------ |
+| `MATCHER(IsEven, "") { return (arg % 2) == 0; }` | Defines a matcher `IsEven()` to match an even number. |
+| `MATCHER_P(IsDivisibleBy, n, "") { *result_listener << "where the remainder is " << (arg % n); return (arg % n) == 0; }` | Defines a matcher `IsDivisibleBy(n)` to match a number divisible by `n`. |
+| `MATCHER_P2(IsBetween, a, b, absl::StrCat(negation ? "isn't" : "is", " between ", PrintToString(a), " and ", PrintToString(b))) { return a <= arg && arg <= b; }` | Defines a matcher `IsBetween(a, b)` to match a value in the range [`a`, `b`]. |
+
+**Notes:**
+
+1.  The `MATCHER*` macros cannot be used inside a function or class.
+2.  The matcher body must be *purely functional* (i.e. it cannot have any side
+    effect, and the result must not depend on anything other than the value
+    being matched and the matcher parameters).
+3.  You can use `PrintToString(x)` to convert a value `x` of any type to a
+    string.
+4.  You can use `ExplainMatchResult()` in a custom matcher to wrap another
+    matcher, for example:
+
+    ```cpp
+    MATCHER_P(NestedPropertyMatches, matcher, "") {
+      return ExplainMatchResult(matcher, arg.nested().property(), result_listener);
+    }
+    ```
+
+5.  You can use `DescribeMatcher<>` to describe another matcher. For example:
+
+    ```cpp
+    MATCHER_P(XAndYThat, matcher,
+              "X that " + DescribeMatcher<int>(matcher, negation) +
+                  (negation ? " or" : " and") + " Y that " +
+                  DescribeMatcher<double>(matcher, negation)) {
+      return ExplainMatchResult(matcher, arg.x(), result_listener) &&
+             ExplainMatchResult(matcher, arg.y(), result_listener);
+    }
+    ```

contrib/googletest/docs/reference/mocking.md

@@ -0,0 +1,589 @@
+# Mocking Reference
+
+This page lists the facilities provided by GoogleTest for creating and working
+with mock objects. To use them, include the header
+`gmock/gmock.h`.
+
+## Macros {#macros}
+
+GoogleTest defines the following macros for working with mocks.
+
+### MOCK_METHOD {#MOCK_METHOD}
+
+`MOCK_METHOD(`*`return_type`*`,`*`method_name`*`, (`*`args...`*`));` \
+`MOCK_METHOD(`*`return_type`*`,`*`method_name`*`, (`*`args...`*`),
+(`*`specs...`*`));`
+
+Defines a mock method *`method_name`* with arguments `(`*`args...`*`)` and
+return type *`return_type`* within a mock class.
+
+The parameters of `MOCK_METHOD` mirror the method declaration. The optional
+fourth parameter *`specs...`* is a comma-separated list of qualifiers. The
+following qualifiers are accepted:
+
+| Qualifier                  | Meaning                                      |
+| -------------------------- | -------------------------------------------- |
+| `const`                    | Makes the mocked method a `const` method. Required if overriding a `const` method. |
+| `override`                 | Marks the method with `override`. Recommended if overriding a `virtual` method. |
+| `noexcept`                 | Marks the method with `noexcept`. Required if overriding a `noexcept` method. |
+| `Calltype(`*`calltype`*`)` | Sets the call type for the method, for example `Calltype(STDMETHODCALLTYPE)`. Useful on Windows. |
+| `ref(`*`qualifier`*`)`     | Marks the method with the given reference qualifier, for example `ref(&)` or `ref(&&)`. Required if overriding a method that has a reference qualifier. |
+
+Note that commas in arguments prevent `MOCK_METHOD` from parsing the arguments
+correctly if they are not appropriately surrounded by parentheses. See the
+following example:
+
+```cpp
+class MyMock {
+ public:
+  // The following 2 lines will not compile due to commas in the arguments:
+  MOCK_METHOD(std::pair<bool, int>, GetPair, ());              // Error!
+  MOCK_METHOD(bool, CheckMap, (std::map<int, double>, bool));  // Error!
+
+  // One solution - wrap arguments that contain commas in parentheses:
+  MOCK_METHOD((std::pair<bool, int>), GetPair, ());
+  MOCK_METHOD(bool, CheckMap, ((std::map<int, double>), bool));
+
+  // Another solution - use type aliases:
+  using BoolAndInt = std::pair<bool, int>;
+  MOCK_METHOD(BoolAndInt, GetPair, ());
+  using MapIntDouble = std::map<int, double>;
+  MOCK_METHOD(bool, CheckMap, (MapIntDouble, bool));
+};
+```
+
+`MOCK_METHOD` must be used in the `public:` section of a mock class definition,
+regardless of whether the method being mocked is `public`, `protected`, or
+`private` in the base class.
+
+### EXPECT_CALL {#EXPECT_CALL}
+
+`EXPECT_CALL(`*`mock_object`*`,`*`method_name`*`(`*`matchers...`*`))`
+
+Creates an [expectation](../gmock_for_dummies.md#setting-expectations) that the
+method *`method_name`* of the object *`mock_object`* is called with arguments
+that match the given matchers *`matchers...`*. `EXPECT_CALL` must precede any
+code that exercises the mock object.
+
+The parameter *`matchers...`* is a comma-separated list of
+[matchers](../gmock_for_dummies.md#matchers-what-arguments-do-we-expect) that
+correspond to each argument of the method *`method_name`*. The expectation will
+apply only to calls of *`method_name`* whose arguments match all of the
+matchers. If `(`*`matchers...`*`)` is omitted, the expectation behaves as if
+each argument's matcher were a [wildcard matcher (`_`)](matchers.md#wildcard).
+See the [Matchers Reference](matchers.md) for a list of all built-in matchers.
+
+The following chainable clauses can be used to modify the expectation, and they
+must be used in the following order:
+
+```cpp
+EXPECT_CALL(mock_object, method_name(matchers...))
+    .With(multi_argument_matcher)  // Can be used at most once
+    .Times(cardinality)            // Can be used at most once
+    .InSequence(sequences...)      // Can be used any number of times
+    .After(expectations...)        // Can be used any number of times
+    .WillOnce(action)              // Can be used any number of times
+    .WillRepeatedly(action)        // Can be used at most once
+    .RetiresOnSaturation();        // Can be used at most once
+```
+
+See details for each modifier clause below.
+
+#### With {#EXPECT_CALL.With}
+
+`.With(`*`multi_argument_matcher`*`)`
+
+Restricts the expectation to apply only to mock function calls whose arguments
+as a whole match the multi-argument matcher *`multi_argument_matcher`*.
+
+GoogleTest passes all of the arguments as one tuple into the matcher. The
+parameter *`multi_argument_matcher`* must thus be a matcher of type
+`Matcher<std::tuple<A1, ..., An>>`, where `A1, ..., An` are the types of the
+function arguments.
+
+For example, the following code sets the expectation that
+`my_mock.SetPosition()` is called with any two arguments, the first argument
+being less than the second:
+
+```cpp
+using ::testing::_;
+using ::testing::Lt;
+...
+EXPECT_CALL(my_mock, SetPosition(_, _))
+    .With(Lt());
+```
+
+GoogleTest provides some built-in matchers for 2-tuples, including the `Lt()`
+matcher above. See [Multi-argument Matchers](matchers.md#MultiArgMatchers).
+
+The `With` clause can be used at most once on an expectation and must be the
+first clause.
+
+#### Times {#EXPECT_CALL.Times}
+
+`.Times(`*`cardinality`*`)`
+
+Specifies how many times the mock function call is expected.
+
+The parameter *`cardinality`* represents the number of expected calls and can be
+one of the following, all defined in the `::testing` namespace:
+
+| Cardinality         | Meaning                                             |
+| ------------------- | --------------------------------------------------- |
+| `AnyNumber()`       | The function can be called any number of times.     |
+| `AtLeast(n)`        | The function call is expected at least *n* times.   |
+| `AtMost(n)`         | The function call is expected at most *n* times.    |
+| `Between(m, n)`     | The function call is expected between *m* and *n* times, inclusive. |
+| `Exactly(n)` or `n` | The function call is expected exactly *n* times. If *n* is 0, the call should never happen. |
+
+If the `Times` clause is omitted, GoogleTest infers the cardinality as follows:
+
+*   If neither [`WillOnce`](#EXPECT_CALL.WillOnce) nor
+    [`WillRepeatedly`](#EXPECT_CALL.WillRepeatedly) are specified, the inferred
+    cardinality is `Times(1)`.
+*   If there are *n* `WillOnce` clauses and no `WillRepeatedly` clause, where
+    *n* >= 1, the inferred cardinality is `Times(n)`.
+*   If there are *n* `WillOnce` clauses and one `WillRepeatedly` clause, where
+    *n* >= 0, the inferred cardinality is `Times(AtLeast(n))`.
+
+The `Times` clause can be used at most once on an expectation.
+
+#### InSequence {#EXPECT_CALL.InSequence}
+
+`.InSequence(`*`sequences...`*`)`
+
+Specifies that the mock function call is expected in a certain sequence.
+
+The parameter *`sequences...`* is any number of [`Sequence`](#Sequence) objects.
+Expected calls assigned to the same sequence are expected to occur in the order
+the expectations are declared.
+
+For example, the following code sets the expectation that the `Reset()` method
+of `my_mock` is called before both `GetSize()` and `Describe()`, and `GetSize()`
+and `Describe()` can occur in any order relative to each other:
+
+```cpp
+using ::testing::Sequence;
+Sequence s1, s2;
+...
+EXPECT_CALL(my_mock, Reset())
+    .InSequence(s1, s2);
+EXPECT_CALL(my_mock, GetSize())
+    .InSequence(s1);
+EXPECT_CALL(my_mock, Describe())
+    .InSequence(s2);
+```
+
+The `InSequence` clause can be used any number of times on an expectation.
+
+See also the [`InSequence` class](#InSequence).
+
+#### After {#EXPECT_CALL.After}
+
+`.After(`*`expectations...`*`)`
+
+Specifies that the mock function call is expected to occur after one or more
+other calls.
+
+The parameter *`expectations...`* can be up to five
+[`Expectation`](#Expectation) or [`ExpectationSet`](#ExpectationSet) objects.
+The mock function call is expected to occur after all of the given expectations.
+
+For example, the following code sets the expectation that the `Describe()`
+method of `my_mock` is called only after both `InitX()` and `InitY()` have been
+called.
+
+```cpp
+using ::testing::Expectation;
+...
+Expectation init_x = EXPECT_CALL(my_mock, InitX());
+Expectation init_y = EXPECT_CALL(my_mock, InitY());
+EXPECT_CALL(my_mock, Describe())
+    .After(init_x, init_y);
+```
+
+The `ExpectationSet` object is helpful when the number of prerequisites for an
+expectation is large or variable, for example:
+
+```cpp
+using ::testing::ExpectationSet;
+...
+ExpectationSet all_inits;
+// Collect all expectations of InitElement() calls
+for (int i = 0; i < element_count; i++) {
+  all_inits += EXPECT_CALL(my_mock, InitElement(i));
+}
+EXPECT_CALL(my_mock, Describe())
+    .After(all_inits);  // Expect Describe() call after all InitElement() calls
+```
+
+The `After` clause can be used any number of times on an expectation.
+
+#### WillOnce {#EXPECT_CALL.WillOnce}
+
+`.WillOnce(`*`action`*`)`
+
+Specifies the mock function's actual behavior when invoked, for a single
+matching function call.
+
+The parameter *`action`* represents the
+[action](../gmock_for_dummies.md#actions-what-should-it-do) that the function
+call will perform. See the [Actions Reference](actions.md) for a list of
+built-in actions.
+
+The use of `WillOnce` implicitly sets a cardinality on the expectation when
+`Times` is not specified. See [`Times`](#EXPECT_CALL.Times).
+
+Each matching function call will perform the next action in the order declared.
+For example, the following code specifies that `my_mock.GetNumber()` is expected
+to be called exactly 3 times and will return `1`, `2`, and `3` respectively on
+the first, second, and third calls:
+
+```cpp
+using ::testing::Return;
+...
+EXPECT_CALL(my_mock, GetNumber())
+    .WillOnce(Return(1))
+    .WillOnce(Return(2))
+    .WillOnce(Return(3));
+```
+
+The `WillOnce` clause can be used any number of times on an expectation. Unlike
+`WillRepeatedly`, the action fed to each `WillOnce` call will be called at most
+once, so may be a move-only type and/or have an `&&`-qualified call operator.
+
+#### WillRepeatedly {#EXPECT_CALL.WillRepeatedly}
+
+`.WillRepeatedly(`*`action`*`)`
+
+Specifies the mock function's actual behavior when invoked, for all subsequent
+matching function calls. Takes effect after the actions specified in the
+[`WillOnce`](#EXPECT_CALL.WillOnce) clauses, if any, have been performed.
+
+The parameter *`action`* represents the
+[action](../gmock_for_dummies.md#actions-what-should-it-do) that the function
+call will perform. See the [Actions Reference](actions.md) for a list of
+built-in actions.
+
+The use of `WillRepeatedly` implicitly sets a cardinality on the expectation
+when `Times` is not specified. See [`Times`](#EXPECT_CALL.Times).
+
+If any `WillOnce` clauses have been specified, matching function calls will
+perform those actions before the action specified by `WillRepeatedly`. See the
+following example:
+
+```cpp
+using ::testing::Return;
+...
+EXPECT_CALL(my_mock, GetName())
+    .WillRepeatedly(Return("John Doe"));  // Return "John Doe" on all calls
+
+EXPECT_CALL(my_mock, GetNumber())
+    .WillOnce(Return(42))        // Return 42 on the first call
+    .WillRepeatedly(Return(7));  // Return 7 on all subsequent calls
+```
+
+The `WillRepeatedly` clause can be used at most once on an expectation.
+
+#### RetiresOnSaturation {#EXPECT_CALL.RetiresOnSaturation}
+
+`.RetiresOnSaturation()`
+
+Indicates that the expectation will no longer be active after the expected
+number of matching function calls has been reached.
+
+The `RetiresOnSaturation` clause is only meaningful for expectations with an
+upper-bounded cardinality. The expectation will *retire* (no longer match any
+function calls) after it has been *saturated* (the upper bound has been
+reached). See the following example:
+
+```cpp
+using ::testing::_;
+using ::testing::AnyNumber;
+...
+EXPECT_CALL(my_mock, SetNumber(_))  // Expectation 1
+    .Times(AnyNumber());
+EXPECT_CALL(my_mock, SetNumber(7))  // Expectation 2
+    .Times(2)
+    .RetiresOnSaturation();
+```
+
+In the above example, the first two calls to `my_mock.SetNumber(7)` match
+expectation 2, which then becomes inactive and no longer matches any calls. A
+third call to `my_mock.SetNumber(7)` would then match expectation 1. Without
+`RetiresOnSaturation()` on expectation 2, a third call to `my_mock.SetNumber(7)`
+would match expectation 2 again, producing a failure since the limit of 2 calls
+was exceeded.
+
+The `RetiresOnSaturation` clause can be used at most once on an expectation and
+must be the last clause.
+
+### ON_CALL {#ON_CALL}
+
+`ON_CALL(`*`mock_object`*`,`*`method_name`*`(`*`matchers...`*`))`
+
+Defines what happens when the method *`method_name`* of the object
+*`mock_object`* is called with arguments that match the given matchers
+*`matchers...`*. Requires a modifier clause to specify the method's behavior.
+*Does not* set any expectations that the method will be called.
+
+The parameter *`matchers...`* is a comma-separated list of
+[matchers](../gmock_for_dummies.md#matchers-what-arguments-do-we-expect) that
+correspond to each argument of the method *`method_name`*. The `ON_CALL`
+specification will apply only to calls of *`method_name`* whose arguments match
+all of the matchers. If `(`*`matchers...`*`)` is omitted, the behavior is as if
+each argument's matcher were a [wildcard matcher (`_`)](matchers.md#wildcard).
+See the [Matchers Reference](matchers.md) for a list of all built-in matchers.
+
+The following chainable clauses can be used to set the method's behavior, and
+they must be used in the following order:
+
+```cpp
+ON_CALL(mock_object, method_name(matchers...))
+    .With(multi_argument_matcher)  // Can be used at most once
+    .WillByDefault(action);        // Required
+```
+
+See details for each modifier clause below.
+
+#### With {#ON_CALL.With}
+
+`.With(`*`multi_argument_matcher`*`)`
+
+Restricts the specification to only mock function calls whose arguments as a
+whole match the multi-argument matcher *`multi_argument_matcher`*.
+
+GoogleTest passes all of the arguments as one tuple into the matcher. The
+parameter *`multi_argument_matcher`* must thus be a matcher of type
+`Matcher<std::tuple<A1, ..., An>>`, where `A1, ..., An` are the types of the
+function arguments.
+
+For example, the following code sets the default behavior when
+`my_mock.SetPosition()` is called with any two arguments, the first argument
+being less than the second:
+
+```cpp
+using ::testing::_;
+using ::testing::Lt;
+using ::testing::Return;
+...
+ON_CALL(my_mock, SetPosition(_, _))
+    .With(Lt())
+    .WillByDefault(Return(true));
+```
+
+GoogleTest provides some built-in matchers for 2-tuples, including the `Lt()`
+matcher above. See [Multi-argument Matchers](matchers.md#MultiArgMatchers).
+
+The `With` clause can be used at most once with each `ON_CALL` statement.
+
+#### WillByDefault {#ON_CALL.WillByDefault}
+
+`.WillByDefault(`*`action`*`)`
+
+Specifies the default behavior of a matching mock function call.
+
+The parameter *`action`* represents the
+[action](../gmock_for_dummies.md#actions-what-should-it-do) that the function
+call will perform. See the [Actions Reference](actions.md) for a list of
+built-in actions.
+
+For example, the following code specifies that by default, a call to
+`my_mock.Greet()` will return `"hello"`:
+
+```cpp
+using ::testing::Return;
+...
+ON_CALL(my_mock, Greet())
+    .WillByDefault(Return("hello"));
+```
+
+The action specified by `WillByDefault` is superseded by the actions specified
+on a matching `EXPECT_CALL` statement, if any. See the
+[`WillOnce`](#EXPECT_CALL.WillOnce) and
+[`WillRepeatedly`](#EXPECT_CALL.WillRepeatedly) clauses of `EXPECT_CALL`.
+
+The `WillByDefault` clause must be used exactly once with each `ON_CALL`
+statement.
+
+## Classes {#classes}
+
+GoogleTest defines the following classes for working with mocks.
+
+### DefaultValue {#DefaultValue}
+
+`::testing::DefaultValue<T>`
+
+Allows a user to specify the default value for a type `T` that is both copyable
+and publicly destructible (i.e. anything that can be used as a function return
+type). For mock functions with a return type of `T`, this default value is
+returned from function calls that do not specify an action.
+
+Provides the static methods `Set()`, `SetFactory()`, and `Clear()` to manage the
+default value:
+
+```cpp
+// Sets the default value to be returned. T must be copy constructible.
+DefaultValue<T>::Set(value);
+
+// Sets a factory. Will be invoked on demand. T must be move constructible.
+T MakeT();
+DefaultValue<T>::SetFactory(&MakeT);
+
+// Unsets the default value.
+DefaultValue<T>::Clear();
+```
+
+### NiceMock {#NiceMock}
+
+`::testing::NiceMock<T>`
+
+Represents a mock object that suppresses warnings on
+[uninteresting calls](../gmock_cook_book.md#uninteresting-vs-unexpected). The
+template parameter `T` is any mock class, except for another `NiceMock`,
+`NaggyMock`, or `StrictMock`.
+
+Usage of `NiceMock<T>` is analogous to usage of `T`. `NiceMock<T>` is a subclass
+of `T`, so it can be used wherever an object of type `T` is accepted. In
+addition, `NiceMock<T>` can be constructed with any arguments that a constructor
+of `T` accepts.
+
+For example, the following code suppresses warnings on the mock `my_mock` of
+type `MockClass` if a method other than `DoSomething()` is called:
+
+```cpp
+using ::testing::NiceMock;
+...
+NiceMock<MockClass> my_mock("some", "args");
+EXPECT_CALL(my_mock, DoSomething());
+... code that uses my_mock ...
+```
+
+`NiceMock<T>` only works for mock methods defined using the `MOCK_METHOD` macro
+directly in the definition of class `T`. If a mock method is defined in a base
+class of `T`, a warning might still be generated.
+
+`NiceMock<T>` might not work correctly if the destructor of `T` is not virtual.
+
+### NaggyMock {#NaggyMock}
+
+`::testing::NaggyMock<T>`
+
+Represents a mock object that generates warnings on
+[uninteresting calls](../gmock_cook_book.md#uninteresting-vs-unexpected). The
+template parameter `T` is any mock class, except for another `NiceMock`,
+`NaggyMock`, or `StrictMock`.
+
+Usage of `NaggyMock<T>` is analogous to usage of `T`. `NaggyMock<T>` is a
+subclass of `T`, so it can be used wherever an object of type `T` is accepted.
+In addition, `NaggyMock<T>` can be constructed with any arguments that a
+constructor of `T` accepts.
+
+For example, the following code generates warnings on the mock `my_mock` of type
+`MockClass` if a method other than `DoSomething()` is called:
+
+```cpp
+using ::testing::NaggyMock;
+...
+NaggyMock<MockClass> my_mock("some", "args");
+EXPECT_CALL(my_mock, DoSomething());
+... code that uses my_mock ...
+```
+
+Mock objects of type `T` by default behave the same way as `NaggyMock<T>`.
+
+### StrictMock {#StrictMock}
+
+`::testing::StrictMock<T>`
+
+Represents a mock object that generates test failures on
+[uninteresting calls](../gmock_cook_book.md#uninteresting-vs-unexpected). The
+template parameter `T` is any mock class, except for another `NiceMock`,
+`NaggyMock`, or `StrictMock`.
+
+Usage of `StrictMock<T>` is analogous to usage of `T`. `StrictMock<T>` is a
+subclass of `T`, so it can be used wherever an object of type `T` is accepted.
+In addition, `StrictMock<T>` can be constructed with any arguments that a
+constructor of `T` accepts.
+
+For example, the following code generates a test failure on the mock `my_mock`
+of type `MockClass` if a method other than `DoSomething()` is called:
+
+```cpp
+using ::testing::StrictMock;
+...
+StrictMock<MockClass> my_mock("some", "args");
+EXPECT_CALL(my_mock, DoSomething());
+... code that uses my_mock ...
+```
+
+`StrictMock<T>` only works for mock methods defined using the `MOCK_METHOD`
+macro directly in the definition of class `T`. If a mock method is defined in a
+base class of `T`, a failure might not be generated.
+
+`StrictMock<T>` might not work correctly if the destructor of `T` is not
+virtual.
+
+### Sequence {#Sequence}
+
+`::testing::Sequence`
+
+Represents a chronological sequence of expectations. See the
+[`InSequence`](#EXPECT_CALL.InSequence) clause of `EXPECT_CALL` for usage.
+
+### InSequence {#InSequence}
+
+`::testing::InSequence`
+
+An object of this type causes all expectations encountered in its scope to be
+put in an anonymous sequence.
+
+This allows more convenient expression of multiple expectations in a single
+sequence:
+
+```cpp
+using ::testing::InSequence;
+{
+  InSequence seq;
+
+  // The following are expected to occur in the order declared.
+  EXPECT_CALL(...);
+  EXPECT_CALL(...);
+  ...
+  EXPECT_CALL(...);
+}
+```
+
+The name of the `InSequence` object does not matter.
+
+### Expectation {#Expectation}
+
+`::testing::Expectation`
+
+Represents a mock function call expectation as created by
+[`EXPECT_CALL`](#EXPECT_CALL):
+
+```cpp
+using ::testing::Expectation;
+Expectation my_expectation = EXPECT_CALL(...);
+```
+
+Useful for specifying sequences of expectations; see the
+[`After`](#EXPECT_CALL.After) clause of `EXPECT_CALL`.
+
+### ExpectationSet {#ExpectationSet}
+
+`::testing::ExpectationSet`
+
+Represents a set of mock function call expectations.
+
+Use the `+=` operator to add [`Expectation`](#Expectation) objects to the set:
+
+```cpp
+using ::testing::ExpectationSet;
+ExpectationSet my_expectations;
+my_expectations += EXPECT_CALL(...);
+```
+
+Useful for specifying sequences of expectations; see the
+[`After`](#EXPECT_CALL.After) clause of `EXPECT_CALL`.

contrib/googletest/docs/reference/testing.md

@@ -0,0 +1,1432 @@
+# Testing Reference
+
+<!--* toc_depth: 3 *-->
+
+This page lists the facilities provided by GoogleTest for writing test programs.
+To use them, include the header `gtest/gtest.h`.
+
+## Macros
+
+GoogleTest defines the following macros for writing tests.
+
+### TEST {#TEST}
+
+<pre>
+TEST(<em>TestSuiteName</em>, <em>TestName</em>) {
+  ... <em>statements</em> ...
+}
+</pre>
+
+Defines an individual test named *`TestName`* in the test suite
+*`TestSuiteName`*, consisting of the given statements.
+
+Both arguments *`TestSuiteName`* and *`TestName`* must be valid C++ identifiers
+and must not contain underscores (`_`). Tests in different test suites can have
+the same individual name.
+
+The statements within the test body can be any code under test.
+[Assertions](assertions.md) used within the test body determine the outcome of
+the test.
+
+### TEST_F {#TEST_F}
+
+<pre>
+TEST_F(<em>TestFixtureName</em>, <em>TestName</em>) {
+  ... <em>statements</em> ...
+}
+</pre>
+
+Defines an individual test named *`TestName`* that uses the test fixture class
+*`TestFixtureName`*. The test suite name is *`TestFixtureName`*.
+
+Both arguments *`TestFixtureName`* and *`TestName`* must be valid C++
+identifiers and must not contain underscores (`_`). *`TestFixtureName`* must be
+the name of a test fixture class—see
+[Test Fixtures](../primer.md#same-data-multiple-tests).
+
+The statements within the test body can be any code under test.
+[Assertions](assertions.md) used within the test body determine the outcome of
+the test.
+
+### TEST_P {#TEST_P}
+
+<pre>
+TEST_P(<em>TestFixtureName</em>, <em>TestName</em>) {
+  ... <em>statements</em> ...
+}
+</pre>
+
+Defines an individual value-parameterized test named *`TestName`* that uses the
+test fixture class *`TestFixtureName`*. The test suite name is
+*`TestFixtureName`*.
+
+Both arguments *`TestFixtureName`* and *`TestName`* must be valid C++
+identifiers and must not contain underscores (`_`). *`TestFixtureName`* must be
+the name of a value-parameterized test fixture class—see
+[Value-Parameterized Tests](../advanced.md#value-parameterized-tests).
+
+The statements within the test body can be any code under test. Within the test
+body, the test parameter can be accessed with the `GetParam()` function (see
+[`WithParamInterface`](#WithParamInterface)). For example:
+
+```cpp
+TEST_P(MyTestSuite, DoesSomething) {
+  ...
+  EXPECT_TRUE(DoSomething(GetParam()));
+  ...
+}
+```
+
+[Assertions](assertions.md) used within the test body determine the outcome of
+the test.
+
+See also [`INSTANTIATE_TEST_SUITE_P`](#INSTANTIATE_TEST_SUITE_P).
+
+### INSTANTIATE_TEST_SUITE_P {#INSTANTIATE_TEST_SUITE_P}
+
+`INSTANTIATE_TEST_SUITE_P(`*`InstantiationName`*`,`*`TestSuiteName`*`,`*`param_generator`*`)`
+\
+`INSTANTIATE_TEST_SUITE_P(`*`InstantiationName`*`,`*`TestSuiteName`*`,`*`param_generator`*`,`*`name_generator`*`)`
+
+Instantiates the value-parameterized test suite *`TestSuiteName`* (defined with
+[`TEST_P`](#TEST_P)).
+
+The argument *`InstantiationName`* is a unique name for the instantiation of the
+test suite, to distinguish between multiple instantiations. In test output, the
+instantiation name is added as a prefix to the test suite name
+*`TestSuiteName`*.
+
+The argument *`param_generator`* is one of the following GoogleTest-provided
+functions that generate the test parameters, all defined in the `::testing`
+namespace:
+
+<span id="param-generators"></span>
+
+| Parameter Generator | Behavior                                             |
+| ------------------- | ---------------------------------------------------- |
+| `Range(begin, end [, step])` | Yields values `{begin, begin+step, begin+step+step, ...}`. The values do not include `end`. `step` defaults to 1. |
+| `Values(v1, v2, ..., vN)`    | Yields values `{v1, v2, ..., vN}`.          |
+| `ValuesIn(container)` or `ValuesIn(begin,end)` | Yields values from a C-style array, an STL-style container, or an iterator range `[begin, end)`. |
+| `Bool()`                     | Yields sequence `{false, true}`.            |
+| `Combine(g1, g2, ..., gN)`   | Yields as `std::tuple` *n*-tuples all combinations (Cartesian product) of the values generated by the given *n* generators `g1`, `g2`, ..., `gN`. |
+| `ConvertGenerator<T>(g)`     | Yields values generated by generator `g`, `static_cast` to `T`. |
+
+The optional last argument *`name_generator`* is a function or functor that
+generates custom test name suffixes based on the test parameters. The function
+must accept an argument of type
+[`TestParamInfo<class ParamType>`](#TestParamInfo) and return a `std::string`.
+The test name suffix can only contain alphanumeric characters and underscores.
+GoogleTest provides [`PrintToStringParamName`](#PrintToStringParamName), or a
+custom function can be used for more control:
+
+```cpp
+INSTANTIATE_TEST_SUITE_P(
+    MyInstantiation, MyTestSuite,
+    testing::Values(...),
+    [](const testing::TestParamInfo<MyTestSuite::ParamType>& info) {
+      // Can use info.param here to generate the test suffix
+      std::string name = ...
+      return name;
+    });
+```
+
+For more information, see
+[Value-Parameterized Tests](../advanced.md#value-parameterized-tests).
+
+See also
+[`GTEST_ALLOW_UNINSTANTIATED_PARAMETERIZED_TEST`](#GTEST_ALLOW_UNINSTANTIATED_PARAMETERIZED_TEST).
+
+### TYPED_TEST_SUITE {#TYPED_TEST_SUITE}
+
+`TYPED_TEST_SUITE(`*`TestFixtureName`*`,`*`Types`*`)`
+
+Defines a typed test suite based on the test fixture *`TestFixtureName`*. The
+test suite name is *`TestFixtureName`*.
+
+The argument *`TestFixtureName`* is a fixture class template, parameterized by a
+type, for example:
+
+```cpp
+template <typename T>
+class MyFixture : public testing::Test {
+ public:
+  ...
+  using List = std::list<T>;
+  static T shared_;
+  T value_;
+};
+```
+
+The argument *`Types`* is a [`Types`](#Types) object representing the list of
+types to run the tests on, for example:
+
+```cpp
+using MyTypes = ::testing::Types<char, int, unsigned int>;
+TYPED_TEST_SUITE(MyFixture, MyTypes);
+```
+
+The type alias (`using` or `typedef`) is necessary for the `TYPED_TEST_SUITE`
+macro to parse correctly.
+
+See also [`TYPED_TEST`](#TYPED_TEST) and
+[Typed Tests](../advanced.md#typed-tests) for more information.
+
+### TYPED_TEST {#TYPED_TEST}
+
+<pre>
+TYPED_TEST(<em>TestSuiteName</em>, <em>TestName</em>) {
+  ... <em>statements</em> ...
+}
+</pre>
+
+Defines an individual typed test named *`TestName`* in the typed test suite
+*`TestSuiteName`*. The test suite must be defined with
+[`TYPED_TEST_SUITE`](#TYPED_TEST_SUITE).
+
+Within the test body, the special name `TypeParam` refers to the type parameter,
+and `TestFixture` refers to the fixture class. See the following example:
+
+```cpp
+TYPED_TEST(MyFixture, Example) {
+  // Inside a test, refer to the special name TypeParam to get the type
+  // parameter.  Since we are inside a derived class template, C++ requires
+  // us to visit the members of MyFixture via 'this'.
+  TypeParam n = this->value_;
+
+  // To visit static members of the fixture, add the 'TestFixture::'
+  // prefix.
+  n += TestFixture::shared_;
+
+  // To refer to typedefs in the fixture, add the 'typename TestFixture::'
+  // prefix. The 'typename' is required to satisfy the compiler.
+  typename TestFixture::List values;
+
+  values.push_back(n);
+  ...
+}
+```
+
+For more information, see [Typed Tests](../advanced.md#typed-tests).
+
+### TYPED_TEST_SUITE_P {#TYPED_TEST_SUITE_P}
+
+`TYPED_TEST_SUITE_P(`*`TestFixtureName`*`)`
+
+Defines a type-parameterized test suite based on the test fixture
+*`TestFixtureName`*. The test suite name is *`TestFixtureName`*.
+
+The argument *`TestFixtureName`* is a fixture class template, parameterized by a
+type. See [`TYPED_TEST_SUITE`](#TYPED_TEST_SUITE) for an example.
+
+See also [`TYPED_TEST_P`](#TYPED_TEST_P) and
+[Type-Parameterized Tests](../advanced.md#type-parameterized-tests) for more
+information.
+
+### TYPED_TEST_P {#TYPED_TEST_P}
+
+<pre>
+TYPED_TEST_P(<em>TestSuiteName</em>, <em>TestName</em>) {
+  ... <em>statements</em> ...
+}
+</pre>
+
+Defines an individual type-parameterized test named *`TestName`* in the
+type-parameterized test suite *`TestSuiteName`*. The test suite must be defined
+with [`TYPED_TEST_SUITE_P`](#TYPED_TEST_SUITE_P).
+
+Within the test body, the special name `TypeParam` refers to the type parameter,
+and `TestFixture` refers to the fixture class. See [`TYPED_TEST`](#TYPED_TEST)
+for an example.
+
+See also [`REGISTER_TYPED_TEST_SUITE_P`](#REGISTER_TYPED_TEST_SUITE_P) and
+[Type-Parameterized Tests](../advanced.md#type-parameterized-tests) for more
+information.
+
+### REGISTER_TYPED_TEST_SUITE_P {#REGISTER_TYPED_TEST_SUITE_P}
+
+`REGISTER_TYPED_TEST_SUITE_P(`*`TestSuiteName`*`,`*`TestNames...`*`)`
+
+Registers the type-parameterized tests *`TestNames...`* of the test suite
+*`TestSuiteName`*. The test suite and tests must be defined with
+[`TYPED_TEST_SUITE_P`](#TYPED_TEST_SUITE_P) and [`TYPED_TEST_P`](#TYPED_TEST_P).
+
+For example:
+
+```cpp
+// Define the test suite and tests.
+TYPED_TEST_SUITE_P(MyFixture);
+TYPED_TEST_P(MyFixture, HasPropertyA) { ... }
+TYPED_TEST_P(MyFixture, HasPropertyB) { ... }
+
+// Register the tests in the test suite.
+REGISTER_TYPED_TEST_SUITE_P(MyFixture, HasPropertyA, HasPropertyB);
+```
+
+See also [`INSTANTIATE_TYPED_TEST_SUITE_P`](#INSTANTIATE_TYPED_TEST_SUITE_P) and
+[Type-Parameterized Tests](../advanced.md#type-parameterized-tests) for more
+information.
+
+### INSTANTIATE_TYPED_TEST_SUITE_P {#INSTANTIATE_TYPED_TEST_SUITE_P}
+
+`INSTANTIATE_TYPED_TEST_SUITE_P(`*`InstantiationName`*`,`*`TestSuiteName`*`,`*`Types`*`)`
+
+Instantiates the type-parameterized test suite *`TestSuiteName`*. The test suite
+must be registered with
+[`REGISTER_TYPED_TEST_SUITE_P`](#REGISTER_TYPED_TEST_SUITE_P).
+
+The argument *`InstantiationName`* is a unique name for the instantiation of the
+test suite, to distinguish between multiple instantiations. In test output, the
+instantiation name is added as a prefix to the test suite name
+*`TestSuiteName`*.
+
+The argument *`Types`* is a [`Types`](#Types) object representing the list of
+types to run the tests on, for example:
+
+```cpp
+using MyTypes = ::testing::Types<char, int, unsigned int>;
+INSTANTIATE_TYPED_TEST_SUITE_P(MyInstantiation, MyFixture, MyTypes);
+```
+
+The type alias (`using` or `typedef`) is necessary for the
+`INSTANTIATE_TYPED_TEST_SUITE_P` macro to parse correctly.
+
+For more information, see
+[Type-Parameterized Tests](../advanced.md#type-parameterized-tests).
+
+### FRIEND_TEST {#FRIEND_TEST}
+
+`FRIEND_TEST(`*`TestSuiteName`*`,`*`TestName`*`)`
+
+Within a class body, declares an individual test as a friend of the class,
+enabling the test to access private class members.
+
+If the class is defined in a namespace, then in order to be friends of the
+class, test fixtures and tests must be defined in the exact same namespace,
+without inline or anonymous namespaces.
+
+For example, if the class definition looks like the following:
+
+```cpp
+namespace my_namespace {
+
+class MyClass {
+  friend class MyClassTest;
+  FRIEND_TEST(MyClassTest, HasPropertyA);
+  FRIEND_TEST(MyClassTest, HasPropertyB);
+  ... definition of class MyClass ...
+};
+
+}  // namespace my_namespace
+```
+
+Then the test code should look like:
+
+```cpp
+namespace my_namespace {
+
+class MyClassTest : public testing::Test {
+  ...
+};
+
+TEST_F(MyClassTest, HasPropertyA) { ... }
+TEST_F(MyClassTest, HasPropertyB) { ... }
+
+}  // namespace my_namespace
+```
+
+See [Testing Private Code](../advanced.md#testing-private-code) for more
+information.
+
+### SCOPED_TRACE {#SCOPED_TRACE}
+
+`SCOPED_TRACE(`*`message`*`)`
+
+Causes the current file name, line number, and the given message *`message`* to
+be added to the failure message for each assertion failure that occurs in the
+scope.
+
+For more information, see
+[Adding Traces to Assertions](../advanced.md#adding-traces-to-assertions).
+
+See also the [`ScopedTrace` class](#ScopedTrace).
+
+### GTEST_SKIP {#GTEST_SKIP}
+
+`GTEST_SKIP()`
+
+Prevents further test execution at runtime.
+
+Can be used in individual test cases or in the `SetUp()` methods of test
+environments or test fixtures (classes derived from the
+[`Environment`](#Environment) or [`Test`](#Test) classes). If used in a global
+test environment `SetUp()` method, it skips all tests in the test program. If
+used in a test fixture `SetUp()` method, it skips all tests in the corresponding
+test suite.
+
+Similar to assertions, `GTEST_SKIP` allows streaming a custom message into it.
+
+See [Skipping Test Execution](../advanced.md#skipping-test-execution) for more
+information.
+
+### GTEST_ALLOW_UNINSTANTIATED_PARAMETERIZED_TEST {#GTEST_ALLOW_UNINSTANTIATED_PARAMETERIZED_TEST}
+
+`GTEST_ALLOW_UNINSTANTIATED_PARAMETERIZED_TEST(`*`TestSuiteName`*`)`
+
+Allows the value-parameterized test suite *`TestSuiteName`* to be
+uninstantiated.
+
+By default, every [`TEST_P`](#TEST_P) call without a corresponding
+[`INSTANTIATE_TEST_SUITE_P`](#INSTANTIATE_TEST_SUITE_P) call causes a failing
+test in the test suite `GoogleTestVerification`.
+`GTEST_ALLOW_UNINSTANTIATED_PARAMETERIZED_TEST` suppresses this failure for the
+given test suite.
+
+## Classes and types
+
+GoogleTest defines the following classes and types to help with writing tests.
+
+### AssertionResult {#AssertionResult}
+
+`testing::AssertionResult`
+
+A class for indicating whether an assertion was successful.
+
+When the assertion wasn't successful, the `AssertionResult` object stores a
+non-empty failure message that can be retrieved with the object's `message()`
+method.
+
+To create an instance of this class, use one of the factory functions
+[`AssertionSuccess()`](#AssertionSuccess) or
+[`AssertionFailure()`](#AssertionFailure).
+
+### AssertionException {#AssertionException}
+
+`testing::AssertionException`
+
+Exception which can be thrown from
+[`TestEventListener::OnTestPartResult`](#TestEventListener::OnTestPartResult).
+
+### EmptyTestEventListener {#EmptyTestEventListener}
+
+`testing::EmptyTestEventListener`
+
+Provides an empty implementation of all methods in the
+[`TestEventListener`](#TestEventListener) interface, such that a subclass only
+needs to override the methods it cares about.
+
+### Environment {#Environment}
+
+`testing::Environment`
+
+Represents a global test environment. See
+[Global Set-Up and Tear-Down](../advanced.md#global-set-up-and-tear-down).
+
+#### Protected Methods {#Environment-protected}
+
+##### SetUp {#Environment::SetUp}
+
+`virtual void Environment::SetUp()`
+
+Override this to define how to set up the environment.
+
+##### TearDown {#Environment::TearDown}
+
+`virtual void Environment::TearDown()`
+
+Override this to define how to tear down the environment.
+
+### ScopedTrace {#ScopedTrace}
+
+`testing::ScopedTrace`
+
+An instance of this class causes a trace to be included in every test failure
+message generated by code in the scope of the lifetime of the `ScopedTrace`
+instance. The effect is undone with the destruction of the instance.
+
+The `ScopedTrace` constructor has the following form:
+
+```cpp
+template <typename T>
+ScopedTrace(const char* file, int line, const T& message)
+```
+
+Example usage:
+
+```cpp
+testing::ScopedTrace trace("file.cc", 123, "message");
+```
+
+The resulting trace includes the given source file path and line number, and the
+given message. The `message` argument can be anything streamable to
+`std::ostream`.
+
+See also [`SCOPED_TRACE`](#SCOPED_TRACE).
+
+### Test {#Test}
+
+`testing::Test`
+
+The abstract class that all tests inherit from. `Test` is not copyable.
+
+#### Public Methods {#Test-public}
+
+##### SetUpTestSuite {#Test::SetUpTestSuite}
+
+`static void Test::SetUpTestSuite()`
+
+Performs shared setup for all tests in the test suite. GoogleTest calls
+`SetUpTestSuite()` before running the first test in the test suite.
+
+##### TearDownTestSuite {#Test::TearDownTestSuite}
+
+`static void Test::TearDownTestSuite()`
+
+Performs shared teardown for all tests in the test suite. GoogleTest calls
+`TearDownTestSuite()` after running the last test in the test suite.
+
+##### HasFatalFailure {#Test::HasFatalFailure}
+
+`static bool Test::HasFatalFailure()`
+
+Returns true if and only if the current test has a fatal failure.
+
+##### HasNonfatalFailure {#Test::HasNonfatalFailure}
+
+`static bool Test::HasNonfatalFailure()`
+
+Returns true if and only if the current test has a nonfatal failure.
+
+##### HasFailure {#Test::HasFailure}
+
+`static bool Test::HasFailure()`
+
+Returns true if and only if the current test has any failure, either fatal or
+nonfatal.
+
+##### IsSkipped {#Test::IsSkipped}
+
+`static bool Test::IsSkipped()`
+
+Returns true if and only if the current test was skipped.
+
+##### RecordProperty {#Test::RecordProperty}
+
+`static void Test::RecordProperty(const std::string& key, const std::string&
+value)` \
+`static void Test::RecordProperty(const std::string& key, int value)`
+
+Logs a property for the current test, test suite, or entire invocation of the
+test program. Only the last value for a given key is logged.
+
+The key must be a valid XML attribute name, and cannot conflict with the ones
+already used by GoogleTest (`name`, `file`, `line`, `status`, `time`,
+`classname`, `type_param`, and `value_param`).
+
+`RecordProperty` is `public static` so it can be called from utility functions
+that are not members of the test fixture.
+
+Calls to `RecordProperty` made during the lifespan of the test (from the moment
+its constructor starts to the moment its destructor finishes) are output in XML
+as attributes of the `<testcase>` element. Properties recorded from a fixture's
+`SetUpTestSuite` or `TearDownTestSuite` methods are logged as attributes of the
+corresponding `<testsuite>` element. Calls to `RecordProperty` made in the
+global context (before or after invocation of `RUN_ALL_TESTS` or from the
+`SetUp`/`TearDown` methods of registered `Environment` objects) are output as
+attributes of the `<testsuites>` element.
+
+#### Protected Methods {#Test-protected}
+
+##### SetUp {#Test::SetUp}
+
+`virtual void Test::SetUp()`
+
+Override this to perform test fixture setup. GoogleTest calls `SetUp()` before
+running each individual test.
+
+##### TearDown {#Test::TearDown}
+
+`virtual void Test::TearDown()`
+
+Override this to perform test fixture teardown. GoogleTest calls `TearDown()`
+after running each individual test.
+
+### TestWithParam {#TestWithParam}
+
+`testing::TestWithParam<T>`
+
+A convenience class which inherits from both [`Test`](#Test) and
+[`WithParamInterface<T>`](#WithParamInterface).
+
+### TestSuite {#TestSuite}
+
+Represents a test suite. `TestSuite` is not copyable.
+
+#### Public Methods {#TestSuite-public}
+
+##### name {#TestSuite::name}
+
+`const char* TestSuite::name() const`
+
+Gets the name of the test suite.
+
+##### type_param {#TestSuite::type_param}
+
+`const char* TestSuite::type_param() const`
+
+Returns the name of the parameter type, or `NULL` if this is not a typed or
+type-parameterized test suite. See [Typed Tests](../advanced.md#typed-tests) and
+[Type-Parameterized Tests](../advanced.md#type-parameterized-tests).
+
+##### should_run {#TestSuite::should_run}
+
+`bool TestSuite::should_run() const`
+
+Returns true if any test in this test suite should run.
+
+##### successful_test_count {#TestSuite::successful_test_count}
+
+`int TestSuite::successful_test_count() const`
+
+Gets the number of successful tests in this test suite.
+
+##### skipped_test_count {#TestSuite::skipped_test_count}
+
+`int TestSuite::skipped_test_count() const`
+
+Gets the number of skipped tests in this test suite.
+
+##### failed_test_count {#TestSuite::failed_test_count}
+
+`int TestSuite::failed_test_count() const`
+
+Gets the number of failed tests in this test suite.
+
+##### reportable_disabled_test_count {#TestSuite::reportable_disabled_test_count}
+
+`int TestSuite::reportable_disabled_test_count() const`
+
+Gets the number of disabled tests that will be reported in the XML report.
+
+##### disabled_test_count {#TestSuite::disabled_test_count}
+
+`int TestSuite::disabled_test_count() const`
+
+Gets the number of disabled tests in this test suite.
+
+##### reportable_test_count {#TestSuite::reportable_test_count}
+
+`int TestSuite::reportable_test_count() const`
+
+Gets the number of tests to be printed in the XML report.
+
+##### test_to_run_count {#TestSuite::test_to_run_count}
+
+`int TestSuite::test_to_run_count() const`
+
+Get the number of tests in this test suite that should run.
+
+##### total_test_count {#TestSuite::total_test_count}
+
+`int TestSuite::total_test_count() const`
+
+Gets the number of all tests in this test suite.
+
+##### Passed {#TestSuite::Passed}
+
+`bool TestSuite::Passed() const`
+
+Returns true if and only if the test suite passed.
+
+##### Failed {#TestSuite::Failed}
+
+`bool TestSuite::Failed() const`
+
+Returns true if and only if the test suite failed.
+
+##### elapsed_time {#TestSuite::elapsed_time}
+
+`TimeInMillis TestSuite::elapsed_time() const`
+
+Returns the elapsed time, in milliseconds.
+
+##### start_timestamp {#TestSuite::start_timestamp}
+
+`TimeInMillis TestSuite::start_timestamp() const`
+
+Gets the time of the test suite start, in ms from the start of the UNIX epoch.
+
+##### GetTestInfo {#TestSuite::GetTestInfo}
+
+`const TestInfo* TestSuite::GetTestInfo(int i) const`
+
+Returns the [`TestInfo`](#TestInfo) for the `i`-th test among all the tests. `i`
+can range from 0 to `total_test_count() - 1`. If `i` is not in that range,
+returns `NULL`.
+
+##### ad_hoc_test_result {#TestSuite::ad_hoc_test_result}
+
+`const TestResult& TestSuite::ad_hoc_test_result() const`
+
+Returns the [`TestResult`](#TestResult) that holds test properties recorded
+during execution of `SetUpTestSuite` and `TearDownTestSuite`.
+
+### TestInfo {#TestInfo}
+
+`testing::TestInfo`
+
+Stores information about a test.
+
+#### Public Methods {#TestInfo-public}
+
+##### test_suite_name {#TestInfo::test_suite_name}
+
+`const char* TestInfo::test_suite_name() const`
+
+Returns the test suite name.
+
+##### name {#TestInfo::name}
+
+`const char* TestInfo::name() const`
+
+Returns the test name.
+
+##### type_param {#TestInfo::type_param}
+
+`const char* TestInfo::type_param() const`
+
+Returns the name of the parameter type, or `NULL` if this is not a typed or
+type-parameterized test. See [Typed Tests](../advanced.md#typed-tests) and
+[Type-Parameterized Tests](../advanced.md#type-parameterized-tests).
+
+##### value_param {#TestInfo::value_param}
+
+`const char* TestInfo::value_param() const`
+
+Returns the text representation of the value parameter, or `NULL` if this is not
+a value-parameterized test. See
+[Value-Parameterized Tests](../advanced.md#value-parameterized-tests).
+
+##### file {#TestInfo::file}
+
+`const char* TestInfo::file() const`
+
+Returns the file name where this test is defined.
+
+##### line {#TestInfo::line}
+
+`int TestInfo::line() const`
+
+Returns the line where this test is defined.
+
+##### is_in_another_shard {#TestInfo::is_in_another_shard}
+
+`bool TestInfo::is_in_another_shard() const`
+
+Returns true if this test should not be run because it's in another shard.
+
+##### should_run {#TestInfo::should_run}
+
+`bool TestInfo::should_run() const`
+
+Returns true if this test should run, that is if the test is not disabled (or it
+is disabled but the `also_run_disabled_tests` flag has been specified) and its
+full name matches the user-specified filter.
+
+GoogleTest allows the user to filter the tests by their full names. Only the
+tests that match the filter will run. See
+[Running a Subset of the Tests](../advanced.md#running-a-subset-of-the-tests)
+for more information.
+
+##### is_reportable {#TestInfo::is_reportable}
+
+`bool TestInfo::is_reportable() const`
+
+Returns true if and only if this test will appear in the XML report.
+
+##### result {#TestInfo::result}
+
+`const TestResult* TestInfo::result() const`
+
+Returns the result of the test. See [`TestResult`](#TestResult).
+
+### TestParamInfo {#TestParamInfo}
+
+`testing::TestParamInfo<T>`
+
+Describes a parameter to a value-parameterized test. The type `T` is the type of
+the parameter.
+
+Contains the fields `param` and `index` which hold the value of the parameter
+and its integer index respectively.
+
+### UnitTest {#UnitTest}
+
+`testing::UnitTest`
+
+This class contains information about the test program.
+
+`UnitTest` is a singleton class. The only instance is created when
+`UnitTest::GetInstance()` is first called. This instance is never deleted.
+
+`UnitTest` is not copyable.
+
+#### Public Methods {#UnitTest-public}
+
+##### GetInstance {#UnitTest::GetInstance}
+
+`static UnitTest* UnitTest::GetInstance()`
+
+Gets the singleton `UnitTest` object. The first time this method is called, a
+`UnitTest` object is constructed and returned. Consecutive calls will return the
+same object.
+
+##### original_working_dir {#UnitTest::original_working_dir}
+
+`const char* UnitTest::original_working_dir() const`
+
+Returns the working directory when the first [`TEST()`](#TEST) or
+[`TEST_F()`](#TEST_F) was executed. The `UnitTest` object owns the string.
+
+##### current_test_suite {#UnitTest::current_test_suite}
+
+`const TestSuite* UnitTest::current_test_suite() const`
+
+Returns the [`TestSuite`](#TestSuite) object for the test that's currently
+running, or `NULL` if no test is running.
+
+##### current_test_info {#UnitTest::current_test_info}
+
+`const TestInfo* UnitTest::current_test_info() const`
+
+Returns the [`TestInfo`](#TestInfo) object for the test that's currently
+running, or `NULL` if no test is running.
+
+##### random_seed {#UnitTest::random_seed}
+
+`int UnitTest::random_seed() const`
+
+Returns the random seed used at the start of the current test run.
+
+##### successful_test_suite_count {#UnitTest::successful_test_suite_count}
+
+`int UnitTest::successful_test_suite_count() const`
+
+Gets the number of successful test suites.
+
+##### failed_test_suite_count {#UnitTest::failed_test_suite_count}
+
+`int UnitTest::failed_test_suite_count() const`
+
+Gets the number of failed test suites.
+
+##### total_test_suite_count {#UnitTest::total_test_suite_count}
+
+`int UnitTest::total_test_suite_count() const`
+
+Gets the number of all test suites.
+
+##### test_suite_to_run_count {#UnitTest::test_suite_to_run_count}
+
+`int UnitTest::test_suite_to_run_count() const`
+
+Gets the number of all test suites that contain at least one test that should
+run.
+
+##### successful_test_count {#UnitTest::successful_test_count}
+
+`int UnitTest::successful_test_count() const`
+
+Gets the number of successful tests.
+
+##### skipped_test_count {#UnitTest::skipped_test_count}
+
+`int UnitTest::skipped_test_count() const`
+
+Gets the number of skipped tests.
+
+##### failed_test_count {#UnitTest::failed_test_count}
+
+`int UnitTest::failed_test_count() const`
+
+Gets the number of failed tests.
+
+##### reportable_disabled_test_count {#UnitTest::reportable_disabled_test_count}
+
+`int UnitTest::reportable_disabled_test_count() const`
+
+Gets the number of disabled tests that will be reported in the XML report.
+
+##### disabled_test_count {#UnitTest::disabled_test_count}
+
+`int UnitTest::disabled_test_count() const`
+
+Gets the number of disabled tests.
+
+##### reportable_test_count {#UnitTest::reportable_test_count}
+
+`int UnitTest::reportable_test_count() const`
+
+Gets the number of tests to be printed in the XML report.
+
+##### total_test_count {#UnitTest::total_test_count}
+
+`int UnitTest::total_test_count() const`
+
+Gets the number of all tests.
+
+##### test_to_run_count {#UnitTest::test_to_run_count}
+
+`int UnitTest::test_to_run_count() const`
+
+Gets the number of tests that should run.
+
+##### start_timestamp {#UnitTest::start_timestamp}
+
+`TimeInMillis UnitTest::start_timestamp() const`
+
+Gets the time of the test program start, in ms from the start of the UNIX epoch.
+
+##### elapsed_time {#UnitTest::elapsed_time}
+
+`TimeInMillis UnitTest::elapsed_time() const`
+
+Gets the elapsed time, in milliseconds.
+
+##### Passed {#UnitTest::Passed}
+
+`bool UnitTest::Passed() const`
+
+Returns true if and only if the unit test passed (i.e. all test suites passed).
+
+##### Failed {#UnitTest::Failed}
+
+`bool UnitTest::Failed() const`
+
+Returns true if and only if the unit test failed (i.e. some test suite failed or
+something outside of all tests failed).
+
+##### GetTestSuite {#UnitTest::GetTestSuite}
+
+`const TestSuite* UnitTest::GetTestSuite(int i) const`
+
+Gets the [`TestSuite`](#TestSuite) object for the `i`-th test suite among all
+the test suites. `i` can range from 0 to `total_test_suite_count() - 1`. If `i`
+is not in that range, returns `NULL`.
+
+##### ad_hoc_test_result {#UnitTest::ad_hoc_test_result}
+
+`const TestResult& UnitTest::ad_hoc_test_result() const`
+
+Returns the [`TestResult`](#TestResult) containing information on test failures
+and properties logged outside of individual test suites.
+
+##### listeners {#UnitTest::listeners}
+
+`TestEventListeners& UnitTest::listeners()`
+
+Returns the list of event listeners that can be used to track events inside
+GoogleTest. See [`TestEventListeners`](#TestEventListeners).
+
+### TestEventListener {#TestEventListener}
+
+`testing::TestEventListener`
+
+The interface for tracing execution of tests. The methods below are listed in
+the order the corresponding events are fired.
+
+#### Public Methods {#TestEventListener-public}
+
+##### OnTestProgramStart {#TestEventListener::OnTestProgramStart}
+
+`virtual void TestEventListener::OnTestProgramStart(const UnitTest& unit_test)`
+
+Fired before any test activity starts.
+
+##### OnTestIterationStart {#TestEventListener::OnTestIterationStart}
+
+`virtual void TestEventListener::OnTestIterationStart(const UnitTest& unit_test,
+int iteration)`
+
+Fired before each iteration of tests starts. There may be more than one
+iteration if `GTEST_FLAG(repeat)` is set. `iteration` is the iteration index,
+starting from 0.
+
+##### OnEnvironmentsSetUpStart {#TestEventListener::OnEnvironmentsSetUpStart}
+
+`virtual void TestEventListener::OnEnvironmentsSetUpStart(const UnitTest&
+unit_test)`
+
+Fired before environment set-up for each iteration of tests starts.
+
+##### OnEnvironmentsSetUpEnd {#TestEventListener::OnEnvironmentsSetUpEnd}
+
+`virtual void TestEventListener::OnEnvironmentsSetUpEnd(const UnitTest&
+unit_test)`
+
+Fired after environment set-up for each iteration of tests ends.
+
+##### OnTestSuiteStart {#TestEventListener::OnTestSuiteStart}
+
+`virtual void TestEventListener::OnTestSuiteStart(const TestSuite& test_suite)`
+
+Fired before the test suite starts.
+
+##### OnTestStart {#TestEventListener::OnTestStart}
+
+`virtual void TestEventListener::OnTestStart(const TestInfo& test_info)`
+
+Fired before the test starts.
+
+##### OnTestPartResult {#TestEventListener::OnTestPartResult}
+
+`virtual void TestEventListener::OnTestPartResult(const TestPartResult&
+test_part_result)`
+
+Fired after a failed assertion or a `SUCCEED()` invocation. If you want to throw
+an exception from this function to skip to the next test, it must be an
+[`AssertionException`](#AssertionException) or inherited from it.
+
+##### OnTestEnd {#TestEventListener::OnTestEnd}
+
+`virtual void TestEventListener::OnTestEnd(const TestInfo& test_info)`
+
+Fired after the test ends.
+
+##### OnTestSuiteEnd {#TestEventListener::OnTestSuiteEnd}
+
+`virtual void TestEventListener::OnTestSuiteEnd(const TestSuite& test_suite)`
+
+Fired after the test suite ends.
+
+##### OnEnvironmentsTearDownStart {#TestEventListener::OnEnvironmentsTearDownStart}
+
+`virtual void TestEventListener::OnEnvironmentsTearDownStart(const UnitTest&
+unit_test)`
+
+Fired before environment tear-down for each iteration of tests starts.
+
+##### OnEnvironmentsTearDownEnd {#TestEventListener::OnEnvironmentsTearDownEnd}
+
+`virtual void TestEventListener::OnEnvironmentsTearDownEnd(const UnitTest&
+unit_test)`
+
+Fired after environment tear-down for each iteration of tests ends.
+
+##### OnTestIterationEnd {#TestEventListener::OnTestIterationEnd}
+
+`virtual void TestEventListener::OnTestIterationEnd(const UnitTest& unit_test,
+int iteration)`
+
+Fired after each iteration of tests finishes.
+
+##### OnTestProgramEnd {#TestEventListener::OnTestProgramEnd}
+
+`virtual void TestEventListener::OnTestProgramEnd(const UnitTest& unit_test)`
+
+Fired after all test activities have ended.
+
+### TestEventListeners {#TestEventListeners}
+
+`testing::TestEventListeners`
+
+Lets users add listeners to track events in GoogleTest.
+
+#### Public Methods {#TestEventListeners-public}
+
+##### Append {#TestEventListeners::Append}
+
+`void TestEventListeners::Append(TestEventListener* listener)`
+
+Appends an event listener to the end of the list. GoogleTest assumes ownership
+of the listener (i.e. it will delete the listener when the test program
+finishes).
+
+##### Release {#TestEventListeners::Release}
+
+`TestEventListener* TestEventListeners::Release(TestEventListener* listener)`
+
+Removes the given event listener from the list and returns it. It then becomes
+the caller's responsibility to delete the listener. Returns `NULL` if the
+listener is not found in the list.
+
+##### default_result_printer {#TestEventListeners::default_result_printer}
+
+`TestEventListener* TestEventListeners::default_result_printer() const`
+
+Returns the standard listener responsible for the default console output. Can be
+removed from the listeners list to shut down default console output. Note that
+removing this object from the listener list with
+[`Release()`](#TestEventListeners::Release) transfers its ownership to the
+caller and makes this function return `NULL` the next time.
+
+##### default_xml_generator {#TestEventListeners::default_xml_generator}
+
+`TestEventListener* TestEventListeners::default_xml_generator() const`
+
+Returns the standard listener responsible for the default XML output controlled
+by the `--gtest_output=xml` flag. Can be removed from the listeners list by
+users who want to shut down the default XML output controlled by this flag and
+substitute it with custom one. Note that removing this object from the listener
+list with [`Release()`](#TestEventListeners::Release) transfers its ownership to
+the caller and makes this function return `NULL` the next time.
+
+### TestPartResult {#TestPartResult}
+
+`testing::TestPartResult`
+
+A copyable object representing the result of a test part (i.e. an assertion or
+an explicit `FAIL()`, `ADD_FAILURE()`, or `SUCCESS()`).
+
+#### Public Methods {#TestPartResult-public}
+
+##### type {#TestPartResult::type}
+
+`Type TestPartResult::type() const`
+
+Gets the outcome of the test part.
+
+The return type `Type` is an enum defined as follows:
+
+```cpp
+enum Type {
+  kSuccess,          // Succeeded.
+  kNonFatalFailure,  // Failed but the test can continue.
+  kFatalFailure,     // Failed and the test should be terminated.
+  kSkip              // Skipped.
+};
+```
+
+##### file_name {#TestPartResult::file_name}
+
+`const char* TestPartResult::file_name() const`
+
+Gets the name of the source file where the test part took place, or `NULL` if
+it's unknown.
+
+##### line_number {#TestPartResult::line_number}
+
+`int TestPartResult::line_number() const`
+
+Gets the line in the source file where the test part took place, or `-1` if it's
+unknown.
+
+##### summary {#TestPartResult::summary}
+
+`const char* TestPartResult::summary() const`
+
+Gets the summary of the failure message.
+
+##### message {#TestPartResult::message}
+
+`const char* TestPartResult::message() const`
+
+Gets the message associated with the test part.
+
+##### skipped {#TestPartResult::skipped}
+
+`bool TestPartResult::skipped() const`
+
+Returns true if and only if the test part was skipped.
+
+##### passed {#TestPartResult::passed}
+
+`bool TestPartResult::passed() const`
+
+Returns true if and only if the test part passed.
+
+##### nonfatally_failed {#TestPartResult::nonfatally_failed}
+
+`bool TestPartResult::nonfatally_failed() const`
+
+Returns true if and only if the test part non-fatally failed.
+
+##### fatally_failed {#TestPartResult::fatally_failed}
+
+`bool TestPartResult::fatally_failed() const`
+
+Returns true if and only if the test part fatally failed.
+
+##### failed {#TestPartResult::failed}
+
+`bool TestPartResult::failed() const`
+
+Returns true if and only if the test part failed.
+
+### TestProperty {#TestProperty}
+
+`testing::TestProperty`
+
+A copyable object representing a user-specified test property which can be
+output as a key/value string pair.
+
+#### Public Methods {#TestProperty-public}
+
+##### key {#key}
+
+`const char* key() const`
+
+Gets the user-supplied key.
+
+##### value {#value}
+
+`const char* value() const`
+
+Gets the user-supplied value.
+
+##### SetValue {#SetValue}
+
+`void SetValue(const std::string& new_value)`
+
+Sets a new value, overriding the previous one.
+
+### TestResult {#TestResult}
+
+`testing::TestResult`
+
+Contains information about the result of a single test.
+
+`TestResult` is not copyable.
+
+#### Public Methods {#TestResult-public}
+
+##### total_part_count {#TestResult::total_part_count}
+
+`int TestResult::total_part_count() const`
+
+Gets the number of all test parts. This is the sum of the number of successful
+test parts and the number of failed test parts.
+
+##### test_property_count {#TestResult::test_property_count}
+
+`int TestResult::test_property_count() const`
+
+Returns the number of test properties.
+
+##### Passed {#TestResult::Passed}
+
+`bool TestResult::Passed() const`
+
+Returns true if and only if the test passed (i.e. no test part failed).
+
+##### Skipped {#TestResult::Skipped}
+
+`bool TestResult::Skipped() const`
+
+Returns true if and only if the test was skipped.
+
+##### Failed {#TestResult::Failed}
+
+`bool TestResult::Failed() const`
+
+Returns true if and only if the test failed.
+
+##### HasFatalFailure {#TestResult::HasFatalFailure}
+
+`bool TestResult::HasFatalFailure() const`
+
+Returns true if and only if the test fatally failed.
+
+##### HasNonfatalFailure {#TestResult::HasNonfatalFailure}
+
+`bool TestResult::HasNonfatalFailure() const`
+
+Returns true if and only if the test has a non-fatal failure.
+
+##### elapsed_time {#TestResult::elapsed_time}
+
+`TimeInMillis TestResult::elapsed_time() const`
+
+Returns the elapsed time, in milliseconds.
+
+##### start_timestamp {#TestResult::start_timestamp}
+
+`TimeInMillis TestResult::start_timestamp() const`
+
+Gets the time of the test case start, in ms from the start of the UNIX epoch.
+
+##### GetTestPartResult {#TestResult::GetTestPartResult}
+
+`const TestPartResult& TestResult::GetTestPartResult(int i) const`
+
+Returns the [`TestPartResult`](#TestPartResult) for the `i`-th test part result
+among all the results. `i` can range from 0 to `total_part_count() - 1`. If `i`
+is not in that range, aborts the program.
+
+##### GetTestProperty {#TestResult::GetTestProperty}
+
+`const TestProperty& TestResult::GetTestProperty(int i) const`
+
+Returns the [`TestProperty`](#TestProperty) object for the `i`-th test property.
+`i` can range from 0 to `test_property_count() - 1`. If `i` is not in that
+range, aborts the program.
+
+### TimeInMillis {#TimeInMillis}
+
+`testing::TimeInMillis`
+
+An integer type representing time in milliseconds.
+
+### Types {#Types}
+
+`testing::Types<T...>`
+
+Represents a list of types for use in typed tests and type-parameterized tests.
+
+The template argument `T...` can be any number of types, for example:
+
+```
+testing::Types<char, int, unsigned int>
+```
+
+See [Typed Tests](../advanced.md#typed-tests) and
+[Type-Parameterized Tests](../advanced.md#type-parameterized-tests) for more
+information.
+
+### WithParamInterface {#WithParamInterface}
+
+`testing::WithParamInterface<T>`
+
+The pure interface class that all value-parameterized tests inherit from.
+
+A value-parameterized test fixture class must inherit from both [`Test`](#Test)
+and `WithParamInterface`. In most cases that just means inheriting from
+[`TestWithParam`](#TestWithParam), but more complicated test hierarchies may
+need to inherit from `Test` and `WithParamInterface` at different levels.
+
+This interface defines the type alias `ParamType` for the parameter type `T` and
+has support for accessing the test parameter value via the `GetParam()` method:
+
+```
+static const ParamType& GetParam()
+```
+
+For more information, see
+[Value-Parameterized Tests](../advanced.md#value-parameterized-tests).
+
+## Functions
+
+GoogleTest defines the following functions to help with writing and running
+tests.
+
+### InitGoogleTest {#InitGoogleTest}
+
+`void testing::InitGoogleTest(int* argc, char** argv)` \
+`void testing::InitGoogleTest(int* argc, wchar_t** argv)` \
+`void testing::InitGoogleTest()`
+
+Initializes GoogleTest. This must be called before calling
+[`RUN_ALL_TESTS()`](#RUN_ALL_TESTS). In particular, it parses the command line
+for the flags that GoogleTest recognizes. Whenever a GoogleTest flag is seen, it
+is removed from `argv`, and `*argc` is decremented.
+
+No value is returned. Instead, the GoogleTest flag variables are updated.
+
+The `InitGoogleTest(int* argc, wchar_t** argv)` overload can be used in Windows
+programs compiled in `UNICODE` mode.
+
+The argument-less `InitGoogleTest()` overload can be used on Arduino/embedded
+platforms where there is no `argc`/`argv`.
+
+### AddGlobalTestEnvironment {#AddGlobalTestEnvironment}
+
+`Environment* testing::AddGlobalTestEnvironment(Environment* env)`
+
+Adds a test environment to the test program. Must be called before
+[`RUN_ALL_TESTS()`](#RUN_ALL_TESTS) is called. See
+[Global Set-Up and Tear-Down](../advanced.md#global-set-up-and-tear-down) for
+more information.
+
+See also [`Environment`](#Environment).
+
+### RegisterTest {#RegisterTest}
+
+```cpp
+template <typename Factory>
+TestInfo* testing::RegisterTest(const char* test_suite_name, const char* test_name,
+                                  const char* type_param, const char* value_param,
+                                  const char* file, int line, Factory factory)
+```
+
+Dynamically registers a test with the framework.
+
+The `factory` argument is a factory callable (move-constructible) object or
+function pointer that creates a new instance of the `Test` object. It handles
+ownership to the caller. The signature of the callable is `Fixture*()`, where
+`Fixture` is the test fixture class for the test. All tests registered with the
+same `test_suite_name` must return the same fixture type. This is checked at
+runtime.
+
+The framework will infer the fixture class from the factory and will call the
+`SetUpTestSuite` and `TearDownTestSuite` methods for it.
+
+Must be called before [`RUN_ALL_TESTS()`](#RUN_ALL_TESTS) is invoked, otherwise
+behavior is undefined.
+
+See
+[Registering tests programmatically](../advanced.md#registering-tests-programmatically)
+for more information.
+
+### RUN_ALL_TESTS {#RUN_ALL_TESTS}
+
+`int RUN_ALL_TESTS()`
+
+Use this function in `main()` to run all tests. It returns `0` if all tests are
+successful, or `1` otherwise.
+
+`RUN_ALL_TESTS()` should be invoked after the command line has been parsed by
+[`InitGoogleTest()`](#InitGoogleTest).
+
+This function was formerly a macro; thus, it is in the global namespace and has
+an all-caps name.
+
+### AssertionSuccess {#AssertionSuccess}
+
+`AssertionResult testing::AssertionSuccess()`
+
+Creates a successful assertion result. See
+[`AssertionResult`](#AssertionResult).
+
+### AssertionFailure {#AssertionFailure}
+
+`AssertionResult testing::AssertionFailure()`
+
+Creates a failed assertion result. Use the `<<` operator to store a failure
+message:
+
+```cpp
+testing::AssertionFailure() << "My failure message";
+```
+
+See [`AssertionResult`](#AssertionResult).
+
+### StaticAssertTypeEq {#StaticAssertTypeEq}
+
+`testing::StaticAssertTypeEq<T1, T2>()`
+
+Compile-time assertion for type equality. Compiles if and only if `T1` and `T2`
+are the same type. The value it returns is irrelevant.
+
+See [Type Assertions](../advanced.md#type-assertions) for more information.
+
+### PrintToString {#PrintToString}
+
+`std::string testing::PrintToString(x)`
+
+Prints any value `x` using GoogleTest's value printer.
+
+See
+[Teaching GoogleTest How to Print Your Values](../advanced.md#teaching-googletest-how-to-print-your-values)
+for more information.
+
+### PrintToStringParamName {#PrintToStringParamName}
+
+`std::string testing::PrintToStringParamName(TestParamInfo<T>& info)`
+
+A built-in parameterized test name generator which returns the result of
+[`PrintToString`](#PrintToString) called on `info.param`. Does not work when the
+test parameter is a `std::string` or C string. See
+[Specifying Names for Value-Parameterized Test Parameters](../advanced.md#specifying-names-for-value-parameterized-test-parameters)
+for more information.
+
+See also [`TestParamInfo`](#TestParamInfo) and
+[`INSTANTIATE_TEST_SUITE_P`](#INSTANTIATE_TEST_SUITE_P).

contrib/googletest/docs/samples.md

@@ -0,0 +1,22 @@
+# Googletest Samples
+
+If you're like us, you'd like to look at
+[googletest samples.](https://github.com/google/googletest/blob/main/googletest/samples)
+The sample directory has a number of well-commented samples showing how to use a
+variety of googletest features.
+
+*   Sample #1 shows the basic steps of using googletest to test C++ functions.
+*   Sample #2 shows a more complex unit test for a class with multiple member
+    functions.
+*   Sample #3 uses a test fixture.
+*   Sample #4 teaches you how to use googletest and `googletest.h` together to
+    get the best of both libraries.
+*   Sample #5 puts shared testing logic in a base test fixture, and reuses it in
+    derived fixtures.
+*   Sample #6 demonstrates type-parameterized tests.
+*   Sample #7 teaches the basics of value-parameterized tests.
+*   Sample #8 shows using `Combine()` in value-parameterized tests.
+*   Sample #9 shows use of the listener API to modify Google Test's console
+    output and the use of its reflection API to inspect test results.
+*   Sample #10 shows use of the listener API to implement a primitive memory
+    leak checker.

contrib/googletest/googlemock/CMakeLists.txt

@@ -0,0 +1,209 @@
+########################################################################
+# Note: CMake support is community-based. The maintainers do not use CMake
+# internally.
+#
+# CMake build script for Google Mock.
+#
+# To run the tests for Google Mock itself on Linux, use 'make test' or
+# ctest.  You can select which tests to run using 'ctest -R regex'.
+# For more options, run 'ctest --help'.
+
+option(gmock_build_tests "Build all of Google Mock's own tests." OFF)
+
+# A directory to find Google Test sources.
+if (EXISTS "${CMAKE_CURRENT_SOURCE_DIR}/gtest/CMakeLists.txt")
+  set(gtest_dir gtest)
+else()
+  set(gtest_dir ../googletest)
+endif()
+
+# Defines pre_project_set_up_hermetic_build() and set_up_hermetic_build().
+include("${gtest_dir}/cmake/hermetic_build.cmake" OPTIONAL)
+
+if (COMMAND pre_project_set_up_hermetic_build)
+  # Google Test also calls hermetic setup functions from add_subdirectory,
+  # although its changes will not affect things at the current scope.
+  pre_project_set_up_hermetic_build()
+endif()
+
+########################################################################
+#
+# Project-wide settings
+
+# Name of the project.
+#
+# CMake files in this project can refer to the root source directory
+# as ${gmock_SOURCE_DIR} and to the root binary directory as
+# ${gmock_BINARY_DIR}.
+# Language "C" is required for find_package(Threads).
+cmake_minimum_required(VERSION 3.13)
+project(gmock VERSION ${GOOGLETEST_VERSION} LANGUAGES CXX C)
+
+if (COMMAND set_up_hermetic_build)
+  set_up_hermetic_build()
+endif()
+
+# Instructs CMake to process Google Test's CMakeLists.txt and add its
+# targets to the current scope.  We are placing Google Test's binary
+# directory in a subdirectory of our own as VC compilation may break
+# if they are the same (the default).
+add_subdirectory("${gtest_dir}" "${gmock_BINARY_DIR}/${gtest_dir}")
+
+
+# These commands only run if this is the main project
+if(CMAKE_PROJECT_NAME STREQUAL "gmock" OR CMAKE_PROJECT_NAME STREQUAL "googletest-distribution")
+  # BUILD_SHARED_LIBS is a standard CMake variable, but we declare it here to
+  # make it prominent in the GUI.
+  option(BUILD_SHARED_LIBS "Build shared libraries (DLLs)." OFF)
+else()
+  mark_as_advanced(gmock_build_tests)
+endif()
+
+# Although Google Test's CMakeLists.txt calls this function, the
+# changes there don't affect the current scope.  Therefore we have to
+# call it again here.
+config_compiler_and_linker()  # from ${gtest_dir}/cmake/internal_utils.cmake
+
+# Adds Google Mock's and Google Test's header directories to the search path.
+set(gmock_build_include_dirs
+  "${gmock_SOURCE_DIR}/include"
+  "${gmock_SOURCE_DIR}"
+  "${gtest_SOURCE_DIR}/include"
+  # This directory is needed to build directly from Google Test sources.
+  "${gtest_SOURCE_DIR}")
+include_directories(${gmock_build_include_dirs})
+
+########################################################################
+#
+# Defines the gmock & gmock_main libraries.  User tests should link
+# with one of them.
+
+# Google Mock libraries.  We build them using more strict warnings than what
+# are used for other targets, to ensure that Google Mock can be compiled by
+# a user aggressive about warnings.
+if (MSVC)
+  cxx_library(gmock
+              "${cxx_strict}"
+              "${gtest_dir}/src/gtest-all.cc"
+              src/gmock-all.cc)
+
+  cxx_library(gmock_main
+              "${cxx_strict}"
+              "${gtest_dir}/src/gtest-all.cc"
+              src/gmock-all.cc
+              src/gmock_main.cc)
+else()
+  cxx_library(gmock "${cxx_strict}" src/gmock-all.cc)
+  target_link_libraries(gmock PUBLIC gtest)
+  set_target_properties(gmock PROPERTIES VERSION ${GOOGLETEST_VERSION})
+  cxx_library(gmock_main "${cxx_strict}" src/gmock_main.cc)
+  target_link_libraries(gmock_main PUBLIC gmock)
+  set_target_properties(gmock_main PROPERTIES VERSION ${GOOGLETEST_VERSION})
+endif()
+
+string(REPLACE ";" "$<SEMICOLON>" dirs "${gmock_build_include_dirs}")
+target_include_directories(gmock SYSTEM INTERFACE
+  "$<BUILD_INTERFACE:${dirs}>"
+  "$<INSTALL_INTERFACE:$<INSTALL_PREFIX>/${CMAKE_INSTALL_INCLUDEDIR}>")
+target_include_directories(gmock_main SYSTEM INTERFACE
+  "$<BUILD_INTERFACE:${dirs}>"
+  "$<INSTALL_INTERFACE:$<INSTALL_PREFIX>/${CMAKE_INSTALL_INCLUDEDIR}>")
+
+########################################################################
+#
+# Install rules
+install_project(gmock gmock_main)
+
+########################################################################
+#
+# Google Mock's own tests.
+#
+# You can skip this section if you aren't interested in testing
+# Google Mock itself.
+#
+# The tests are not built by default.  To build them, set the
+# gmock_build_tests option to ON.  You can do it by running ccmake
+# or specifying the -Dgmock_build_tests=ON flag when running cmake.
+
+if (gmock_build_tests)
+  # This must be set in the root directory for the tests to be run by
+  # 'make test' or ctest.
+  enable_testing()
+
+  if (MINGW OR CYGWIN)
+    add_compile_options("-Wa,-mbig-obj")
+  endif()
+
+  ############################################################
+  # C++ tests built with standard compiler flags.
+
+  cxx_test(gmock-actions_test gmock_main)
+  cxx_test(gmock-cardinalities_test gmock_main)
+  cxx_test(gmock_ex_test gmock_main)
+  cxx_test(gmock-function-mocker_test gmock_main)
+  cxx_test(gmock-internal-utils_test gmock_main)
+  cxx_test(gmock-matchers-arithmetic_test gmock_main)
+  cxx_test(gmock-matchers-comparisons_test gmock_main)
+  cxx_test(gmock-matchers-containers_test gmock_main)
+  cxx_test(gmock-matchers-misc_test gmock_main)
+  cxx_test(gmock-more-actions_test gmock_main)
+  cxx_test(gmock-nice-strict_test gmock_main)
+  cxx_test(gmock-port_test gmock_main)
+  cxx_test(gmock-spec-builders_test gmock_main)
+  cxx_test(gmock_link_test gmock_main test/gmock_link2_test.cc)
+  cxx_test(gmock_test gmock_main)
+
+  if (DEFINED GTEST_HAS_PTHREAD)
+    cxx_test(gmock_stress_test gmock)
+  endif()
+
+  # gmock_all_test is commented to save time building and running tests.
+  # Uncomment if necessary.
+  # cxx_test(gmock_all_test gmock_main)
+
+  ############################################################
+  # C++ tests built with non-standard compiler flags.
+
+  if (MSVC)
+    cxx_library(gmock_main_no_exception "${cxx_no_exception}"
+      "${gtest_dir}/src/gtest-all.cc" src/gmock-all.cc src/gmock_main.cc)
+
+    cxx_library(gmock_main_no_rtti "${cxx_no_rtti}"
+      "${gtest_dir}/src/gtest-all.cc" src/gmock-all.cc src/gmock_main.cc)
+
+  else()
+    cxx_library(gmock_main_no_exception "${cxx_no_exception}" src/gmock_main.cc)
+    target_link_libraries(gmock_main_no_exception PUBLIC gmock)
+
+    cxx_library(gmock_main_no_rtti "${cxx_no_rtti}" src/gmock_main.cc)
+    target_link_libraries(gmock_main_no_rtti PUBLIC gmock)
+  endif()
+  cxx_test_with_flags(gmock-more-actions_no_exception_test "${cxx_no_exception}"
+    gmock_main_no_exception test/gmock-more-actions_test.cc)
+
+  cxx_test_with_flags(gmock_no_rtti_test "${cxx_no_rtti}"
+    gmock_main_no_rtti test/gmock-spec-builders_test.cc)
+
+  cxx_shared_library(shared_gmock_main "${cxx_default}"
+    "${gtest_dir}/src/gtest-all.cc" src/gmock-all.cc src/gmock_main.cc)
+
+  # Tests that a binary can be built with Google Mock as a shared library.  On
+  # some system configurations, it may not possible to run the binary without
+  # knowing more details about the system configurations. We do not try to run
+  # this binary. To get a more robust shared library coverage, configure with
+  # -DBUILD_SHARED_LIBS=ON.
+  cxx_executable_with_flags(shared_gmock_test_ "${cxx_default}"
+    shared_gmock_main test/gmock-spec-builders_test.cc)
+  set_target_properties(shared_gmock_test_
+    PROPERTIES
+    COMPILE_DEFINITIONS "GTEST_LINKED_AS_SHARED_LIBRARY=1")
+
+  ############################################################
+  # Python tests.
+
+  cxx_executable(gmock_leak_test_ test gmock_main)
+  py_test(gmock_leak_test)
+
+  cxx_executable(gmock_output_test_ test gmock)
+  py_test(gmock_output_test)
+endif()

contrib/googletest/googlemock/README.md

@@ -0,0 +1,40 @@
+# Googletest Mocking (gMock) Framework
+
+### Overview
+
+Google's framework for writing and using C++ mock classes. It can help you
+derive better designs of your system and write better tests.
+
+It is inspired by:
+
+*   [jMock](http://www.jmock.org/)
+*   [EasyMock](http://www.easymock.org/)
+*   [Hamcrest](http://code.google.com/p/hamcrest/)
+
+It is designed with C++'s specifics in mind.
+
+gMock:
+
+-   Provides a declarative syntax for defining mocks.
+-   Can define partial (hybrid) mocks, which are a cross of real and mock
+    objects.
+-   Handles functions of arbitrary types and overloaded functions.
+-   Comes with a rich set of matchers for validating function arguments.
+-   Uses an intuitive syntax for controlling the behavior of a mock.
+-   Does automatic verification of expectations (no record-and-replay needed).
+-   Allows arbitrary (partial) ordering constraints on function calls to be
+    expressed.
+-   Lets a user extend it by defining new matchers and actions.
+-   Does not use exceptions.
+-   Is easy to learn and use.
+
+Details and examples can be found here:
+
+*   [gMock for Dummies](https://google.github.io/googletest/gmock_for_dummies.html)
+*   [Legacy gMock FAQ](https://google.github.io/googletest/gmock_faq.html)
+*   [gMock Cookbook](https://google.github.io/googletest/gmock_cook_book.html)
+*   [gMock Cheat Sheet](https://google.github.io/googletest/gmock_cheat_sheet.html)
+
+GoogleMock is a part of
+[GoogleTest C++ testing framework](http://github.com/google/googletest/) and a
+subject to the same requirements.

contrib/googletest/googlemock/cmake/gmock.pc.in

@@ -0,0 +1,10 @@
+libdir=@CMAKE_INSTALL_FULL_LIBDIR@
+includedir=@CMAKE_INSTALL_FULL_INCLUDEDIR@
+
+Name: gmock
+Description: GoogleMock (without main() function)
+Version: @PROJECT_VERSION@
+URL: https://github.com/google/googletest
+Requires: gtest = @PROJECT_VERSION@
+Libs: -L${libdir} -lgmock @CMAKE_THREAD_LIBS_INIT@
+Cflags: -I${includedir} @GTEST_HAS_PTHREAD_MACRO@

contrib/googletest/googlemock/cmake/gmock_main.pc.in

@@ -0,0 +1,10 @@
+libdir=@CMAKE_INSTALL_FULL_LIBDIR@
+includedir=@CMAKE_INSTALL_FULL_INCLUDEDIR@
+
+Name: gmock_main
+Description: GoogleMock (with main() function)
+Version: @PROJECT_VERSION@
+URL: https://github.com/google/googletest
+Requires: gmock = @PROJECT_VERSION@
+Libs: -L${libdir} -lgmock_main @CMAKE_THREAD_LIBS_INIT@
+Cflags: -I${includedir} @GTEST_HAS_PTHREAD_MACRO@

contrib/googletest/googlemock/include/gmock/gmock-actions.h

@@ -0,0 +1,2297 @@
+// Copyright 2007, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+// Google Mock - a framework for writing C++ mock classes.
+//
+// The ACTION* family of macros can be used in a namespace scope to
+// define custom actions easily.  The syntax:
+//
+//   ACTION(name) { statements; }
+//
+// will define an action with the given name that executes the
+// statements.  The value returned by the statements will be used as
+// the return value of the action.  Inside the statements, you can
+// refer to the K-th (0-based) argument of the mock function by
+// 'argK', and refer to its type by 'argK_type'.  For example:
+//
+//   ACTION(IncrementArg1) {
+//     arg1_type temp = arg1;
+//     return ++(*temp);
+//   }
+//
+// allows you to write
+//
+//   ...WillOnce(IncrementArg1());
+//
+// You can also refer to the entire argument tuple and its type by
+// 'args' and 'args_type', and refer to the mock function type and its
+// return type by 'function_type' and 'return_type'.
+//
+// Note that you don't need to specify the types of the mock function
+// arguments.  However rest assured that your code is still type-safe:
+// you'll get a compiler error if *arg1 doesn't support the ++
+// operator, or if the type of ++(*arg1) isn't compatible with the
+// mock function's return type, for example.
+//
+// Sometimes you'll want to parameterize the action.   For that you can use
+// another macro:
+//
+//   ACTION_P(name, param_name) { statements; }
+//
+// For example:
+//
+//   ACTION_P(Add, n) { return arg0 + n; }
+//
+// will allow you to write:
+//
+//   ...WillOnce(Add(5));
+//
+// Note that you don't need to provide the type of the parameter
+// either.  If you need to reference the type of a parameter named
+// 'foo', you can write 'foo_type'.  For example, in the body of
+// ACTION_P(Add, n) above, you can write 'n_type' to refer to the type
+// of 'n'.
+//
+// We also provide ACTION_P2, ACTION_P3, ..., up to ACTION_P10 to support
+// multi-parameter actions.
+//
+// For the purpose of typing, you can view
+//
+//   ACTION_Pk(Foo, p1, ..., pk) { ... }
+//
+// as shorthand for
+//
+//   template <typename p1_type, ..., typename pk_type>
+//   FooActionPk<p1_type, ..., pk_type> Foo(p1_type p1, ..., pk_type pk) { ... }
+//
+// In particular, you can provide the template type arguments
+// explicitly when invoking Foo(), as in Foo<long, bool>(5, false);
+// although usually you can rely on the compiler to infer the types
+// for you automatically.  You can assign the result of expression
+// Foo(p1, ..., pk) to a variable of type FooActionPk<p1_type, ...,
+// pk_type>.  This can be useful when composing actions.
+//
+// You can also overload actions with different numbers of parameters:
+//
+//   ACTION_P(Plus, a) { ... }
+//   ACTION_P2(Plus, a, b) { ... }
+//
+// While it's tempting to always use the ACTION* macros when defining
+// a new action, you should also consider implementing ActionInterface
+// or using MakePolymorphicAction() instead, especially if you need to
+// use the action a lot.  While these approaches require more work,
+// they give you more control on the types of the mock function
+// arguments and the action parameters, which in general leads to
+// better compiler error messages that pay off in the long run.  They
+// also allow overloading actions based on parameter types (as opposed
+// to just based on the number of parameters).
+//
+// CAVEAT:
+//
+// ACTION*() can only be used in a namespace scope as templates cannot be
+// declared inside of a local class.
+// Users can, however, define any local functors (e.g. a lambda) that
+// can be used as actions.
+//
+// MORE INFORMATION:
+//
+// To learn more about using these macros, please search for 'ACTION' on
+// https://github.com/google/googletest/blob/main/docs/gmock_cook_book.md
+
+// IWYU pragma: private, include "gmock/gmock.h"
+// IWYU pragma: friend gmock/.*
+
+#ifndef GOOGLEMOCK_INCLUDE_GMOCK_GMOCK_ACTIONS_H_
+#define GOOGLEMOCK_INCLUDE_GMOCK_GMOCK_ACTIONS_H_
+
+#ifndef _WIN32_WCE
+#include <errno.h>
+#endif
+
+#include <algorithm>
+#include <functional>
+#include <memory>
+#include <string>
+#include <tuple>
+#include <type_traits>
+#include <utility>
+
+#include "gmock/internal/gmock-internal-utils.h"
+#include "gmock/internal/gmock-port.h"
+#include "gmock/internal/gmock-pp.h"
+
+GTEST_DISABLE_MSC_WARNINGS_PUSH_(4100)
+
+namespace testing {
+
+// To implement an action Foo, define:
+//   1. a class FooAction that implements the ActionInterface interface, and
+//   2. a factory function that creates an Action object from a
+//      const FooAction*.
+//
+// The two-level delegation design follows that of Matcher, providing
+// consistency for extension developers.  It also eases ownership
+// management as Action objects can now be copied like plain values.
+
+namespace internal {
+
+// BuiltInDefaultValueGetter<T, true>::Get() returns a
+// default-constructed T value.  BuiltInDefaultValueGetter<T,
+// false>::Get() crashes with an error.
+//
+// This primary template is used when kDefaultConstructible is true.
+template <typename T, bool kDefaultConstructible>
+struct BuiltInDefaultValueGetter {
+  static T Get() { return T(); }
+};
+template <typename T>
+struct BuiltInDefaultValueGetter<T, false> {
+  static T Get() {
+    Assert(false, __FILE__, __LINE__,
+           "Default action undefined for the function return type.");
+    return internal::Invalid<T>();
+    // The above statement will never be reached, but is required in
+    // order for this function to compile.
+  }
+};
+
+// BuiltInDefaultValue<T>::Get() returns the "built-in" default value
+// for type T, which is NULL when T is a raw pointer type, 0 when T is
+// a numeric type, false when T is bool, or "" when T is string or
+// std::string.  In addition, in C++11 and above, it turns a
+// default-constructed T value if T is default constructible.  For any
+// other type T, the built-in default T value is undefined, and the
+// function will abort the process.
+template <typename T>
+class BuiltInDefaultValue {
+ public:
+  // This function returns true if and only if type T has a built-in default
+  // value.
+  static bool Exists() { return ::std::is_default_constructible<T>::value; }
+
+  static T Get() {
+    return BuiltInDefaultValueGetter<
+        T, ::std::is_default_constructible<T>::value>::Get();
+  }
+};
+
+// This partial specialization says that we use the same built-in
+// default value for T and const T.
+template <typename T>
+class BuiltInDefaultValue<const T> {
+ public:
+  static bool Exists() { return BuiltInDefaultValue<T>::Exists(); }
+  static T Get() { return BuiltInDefaultValue<T>::Get(); }
+};
+
+// This partial specialization defines the default values for pointer
+// types.
+template <typename T>
+class BuiltInDefaultValue<T*> {
+ public:
+  static bool Exists() { return true; }
+  static T* Get() { return nullptr; }
+};
+
+// The following specializations define the default values for
+// specific types we care about.
+#define GMOCK_DEFINE_DEFAULT_ACTION_FOR_RETURN_TYPE_(type, value) \
+  template <>                                                     \
+  class BuiltInDefaultValue<type> {                               \
+   public:                                                        \
+    static bool Exists() { return true; }                         \
+    static type Get() { return value; }                           \
+  }
+
+GMOCK_DEFINE_DEFAULT_ACTION_FOR_RETURN_TYPE_(void, );  // NOLINT
+GMOCK_DEFINE_DEFAULT_ACTION_FOR_RETURN_TYPE_(::std::string, "");
+GMOCK_DEFINE_DEFAULT_ACTION_FOR_RETURN_TYPE_(bool, false);
+GMOCK_DEFINE_DEFAULT_ACTION_FOR_RETURN_TYPE_(unsigned char, '\0');
+GMOCK_DEFINE_DEFAULT_ACTION_FOR_RETURN_TYPE_(signed char, '\0');
+GMOCK_DEFINE_DEFAULT_ACTION_FOR_RETURN_TYPE_(char, '\0');
+
+// There's no need for a default action for signed wchar_t, as that
+// type is the same as wchar_t for gcc, and invalid for MSVC.
+//
+// There's also no need for a default action for unsigned wchar_t, as
+// that type is the same as unsigned int for gcc, and invalid for
+// MSVC.
+#if GMOCK_WCHAR_T_IS_NATIVE_
+GMOCK_DEFINE_DEFAULT_ACTION_FOR_RETURN_TYPE_(wchar_t, 0U);  // NOLINT
+#endif
+
+GMOCK_DEFINE_DEFAULT_ACTION_FOR_RETURN_TYPE_(unsigned short, 0U);  // NOLINT
+GMOCK_DEFINE_DEFAULT_ACTION_FOR_RETURN_TYPE_(signed short, 0);     // NOLINT
+GMOCK_DEFINE_DEFAULT_ACTION_FOR_RETURN_TYPE_(unsigned int, 0U);
+GMOCK_DEFINE_DEFAULT_ACTION_FOR_RETURN_TYPE_(signed int, 0);
+GMOCK_DEFINE_DEFAULT_ACTION_FOR_RETURN_TYPE_(unsigned long, 0UL);     // NOLINT
+GMOCK_DEFINE_DEFAULT_ACTION_FOR_RETURN_TYPE_(signed long, 0L);        // NOLINT
+GMOCK_DEFINE_DEFAULT_ACTION_FOR_RETURN_TYPE_(unsigned long long, 0);  // NOLINT
+GMOCK_DEFINE_DEFAULT_ACTION_FOR_RETURN_TYPE_(signed long long, 0);    // NOLINT
+GMOCK_DEFINE_DEFAULT_ACTION_FOR_RETURN_TYPE_(float, 0);
+GMOCK_DEFINE_DEFAULT_ACTION_FOR_RETURN_TYPE_(double, 0);
+
+#undef GMOCK_DEFINE_DEFAULT_ACTION_FOR_RETURN_TYPE_
+
+// Partial implementations of metaprogramming types from the standard library
+// not available in C++11.
+
+template <typename P>
+struct negation
+    // NOLINTNEXTLINE
+    : std::integral_constant<bool, bool(!P::value)> {};
+
+// Base case: with zero predicates the answer is always true.
+template <typename...>
+struct conjunction : std::true_type {};
+
+// With a single predicate, the answer is that predicate.
+template <typename P1>
+struct conjunction<P1> : P1 {};
+
+// With multiple predicates the answer is the first predicate if that is false,
+// and we recurse otherwise.
+template <typename P1, typename... Ps>
+struct conjunction<P1, Ps...>
+    : std::conditional<bool(P1::value), conjunction<Ps...>, P1>::type {};
+
+template <typename...>
+struct disjunction : std::false_type {};
+
+template <typename P1>
+struct disjunction<P1> : P1 {};
+
+template <typename P1, typename... Ps>
+struct disjunction<P1, Ps...>
+    // NOLINTNEXTLINE
+    : std::conditional<!bool(P1::value), disjunction<Ps...>, P1>::type {};
+
+template <typename...>
+using void_t = void;
+
+// Detects whether an expression of type `From` can be implicitly converted to
+// `To` according to [conv]. In C++17, [conv]/3 defines this as follows:
+//
+//     An expression e can be implicitly converted to a type T if and only if
+//     the declaration T t=e; is well-formed, for some invented temporary
+//     variable t ([dcl.init]).
+//
+// [conv]/2 implies we can use function argument passing to detect whether this
+// initialization is valid.
+//
+// Note that this is distinct from is_convertible, which requires this be valid:
+//
+//     To test() {
+//       return declval<From>();
+//     }
+//
+// In particular, is_convertible doesn't give the correct answer when `To` and
+// `From` are the same non-moveable type since `declval<From>` will be an rvalue
+// reference, defeating the guaranteed copy elision that would otherwise make
+// this function work.
+//
+// REQUIRES: `From` is not cv void.
+template <typename From, typename To>
+struct is_implicitly_convertible {
+ private:
+  // A function that accepts a parameter of type T. This can be called with type
+  // U successfully only if U is implicitly convertible to T.
+  template <typename T>
+  static void Accept(T);
+
+  // A function that creates a value of type T.
+  template <typename T>
+  static T Make();
+
+  // An overload be selected when implicit conversion from T to To is possible.
+  template <typename T, typename = decltype(Accept<To>(Make<T>()))>
+  static std::true_type TestImplicitConversion(int);
+
+  // A fallback overload selected in all other cases.
+  template <typename T>
+  static std::false_type TestImplicitConversion(...);
+
+ public:
+  using type = decltype(TestImplicitConversion<From>(0));
+  static constexpr bool value = type::value;
+};
+
+// Like std::invoke_result_t from C++17, but works only for objects with call
+// operators (not e.g. member function pointers, which we don't need specific
+// support for in OnceAction because std::function deals with them).
+template <typename F, typename... Args>
+using call_result_t = decltype(std::declval<F>()(std::declval<Args>()...));
+
+template <typename Void, typename R, typename F, typename... Args>
+struct is_callable_r_impl : std::false_type {};
+
+// Specialize the struct for those template arguments where call_result_t is
+// well-formed. When it's not, the generic template above is chosen, resulting
+// in std::false_type.
+template <typename R, typename F, typename... Args>
+struct is_callable_r_impl<void_t<call_result_t<F, Args...>>, R, F, Args...>
+    : std::conditional<
+          std::is_void<R>::value,  //
+          std::true_type,          //
+          is_implicitly_convertible<call_result_t<F, Args...>, R>>::type {};
+
+// Like std::is_invocable_r from C++17, but works only for objects with call
+// operators. See the note on call_result_t.
+template <typename R, typename F, typename... Args>
+using is_callable_r = is_callable_r_impl<void, R, F, Args...>;
+
+// Like std::as_const from C++17.
+template <typename T>
+typename std::add_const<T>::type& as_const(T& t) {
+  return t;
+}
+
+}  // namespace internal
+
+// Specialized for function types below.
+template <typename F>
+class OnceAction;
+
+// An action that can only be used once.
+//
+// This is accepted by WillOnce, which doesn't require the underlying action to
+// be copy-constructible (only move-constructible), and promises to invoke it as
+// an rvalue reference. This allows the action to work with move-only types like
+// std::move_only_function in a type-safe manner.
+//
+// For example:
+//
+//     // Assume we have some API that needs to accept a unique pointer to some
+//     // non-copyable object Foo.
+//     void AcceptUniquePointer(std::unique_ptr<Foo> foo);
+//
+//     // We can define an action that provides a Foo to that API. Because It
+//     // has to give away its unique pointer, it must not be called more than
+//     // once, so its call operator is &&-qualified.
+//     struct ProvideFoo {
+//       std::unique_ptr<Foo> foo;
+//
+//       void operator()() && {
+//         AcceptUniquePointer(std::move(Foo));
+//       }
+//     };
+//
+//     // This action can be used with WillOnce.
+//     EXPECT_CALL(mock, Call)
+//         .WillOnce(ProvideFoo{std::make_unique<Foo>(...)});
+//
+//     // But a call to WillRepeatedly will fail to compile. This is correct,
+//     // since the action cannot correctly be used repeatedly.
+//     EXPECT_CALL(mock, Call)
+//         .WillRepeatedly(ProvideFoo{std::make_unique<Foo>(...)});
+//
+// A less-contrived example would be an action that returns an arbitrary type,
+// whose &&-qualified call operator is capable of dealing with move-only types.
+template <typename Result, typename... Args>
+class OnceAction<Result(Args...)> final {
+ private:
+  // True iff we can use the given callable type (or lvalue reference) directly
+  // via StdFunctionAdaptor.
+  template <typename Callable>
+  using IsDirectlyCompatible = internal::conjunction<
+      // It must be possible to capture the callable in StdFunctionAdaptor.
+      std::is_constructible<typename std::decay<Callable>::type, Callable>,
+      // The callable must be compatible with our signature.
+      internal::is_callable_r<Result, typename std::decay<Callable>::type,
+                              Args...>>;
+
+  // True iff we can use the given callable type via StdFunctionAdaptor once we
+  // ignore incoming arguments.
+  template <typename Callable>
+  using IsCompatibleAfterIgnoringArguments = internal::conjunction<
+      // It must be possible to capture the callable in a lambda.
+      std::is_constructible<typename std::decay<Callable>::type, Callable>,
+      // The callable must be invocable with zero arguments, returning something
+      // convertible to Result.
+      internal::is_callable_r<Result, typename std::decay<Callable>::type>>;
+
+ public:
+  // Construct from a callable that is directly compatible with our mocked
+  // signature: it accepts our function type's arguments and returns something
+  // convertible to our result type.
+  template <typename Callable,
+            typename std::enable_if<
+                internal::conjunction<
+                    // Teach clang on macOS that we're not talking about a
+                    // copy/move constructor here. Otherwise it gets confused
+                    // when checking the is_constructible requirement of our
+                    // traits above.
+                    internal::negation<std::is_same<
+                        OnceAction, typename std::decay<Callable>::type>>,
+                    IsDirectlyCompatible<Callable>>  //
+                ::value,
+                int>::type = 0>
+  OnceAction(Callable&& callable)  // NOLINT
+      : function_(StdFunctionAdaptor<typename std::decay<Callable>::type>(
+            {}, std::forward<Callable>(callable))) {}
+
+  // As above, but for a callable that ignores the mocked function's arguments.
+  template <typename Callable,
+            typename std::enable_if<
+                internal::conjunction<
+                    // Teach clang on macOS that we're not talking about a
+                    // copy/move constructor here. Otherwise it gets confused
+                    // when checking the is_constructible requirement of our
+                    // traits above.
+                    internal::negation<std::is_same<
+                        OnceAction, typename std::decay<Callable>::type>>,
+                    // Exclude callables for which the overload above works.
+                    // We'd rather provide the arguments if possible.
+                    internal::negation<IsDirectlyCompatible<Callable>>,
+                    IsCompatibleAfterIgnoringArguments<Callable>>::value,
+                int>::type = 0>
+  OnceAction(Callable&& callable)  // NOLINT
+                                   // Call the constructor above with a callable
+                                   // that ignores the input arguments.
+      : OnceAction(IgnoreIncomingArguments<typename std::decay<Callable>::type>{
+            std::forward<Callable>(callable)}) {}
+
+  // We are naturally copyable because we store only an std::function, but
+  // semantically we should not be copyable.
+  OnceAction(const OnceAction&) = delete;
+  OnceAction& operator=(const OnceAction&) = delete;
+  OnceAction(OnceAction&&) = default;
+
+  // Invoke the underlying action callable with which we were constructed,
+  // handing it the supplied arguments.
+  Result Call(Args... args) && {
+    return function_(std::forward<Args>(args)...);
+  }
+
+ private:
+  // An adaptor that wraps a callable that is compatible with our signature and
+  // being invoked as an rvalue reference so that it can be used as an
+  // StdFunctionAdaptor. This throws away type safety, but that's fine because
+  // this is only used by WillOnce, which we know calls at most once.
+  //
+  // Once we have something like std::move_only_function from C++23, we can do
+  // away with this.
+  template <typename Callable>
+  class StdFunctionAdaptor final {
+   public:
+    // A tag indicating that the (otherwise universal) constructor is accepting
+    // the callable itself, instead of e.g. stealing calls for the move
+    // constructor.
+    struct CallableTag final {};
+
+    template <typename F>
+    explicit StdFunctionAdaptor(CallableTag, F&& callable)
+        : callable_(std::make_shared<Callable>(std::forward<F>(callable))) {}
+
+    // Rather than explicitly returning Result, we return whatever the wrapped
+    // callable returns. This allows for compatibility with existing uses like
+    // the following, when the mocked function returns void:
+    //
+    //     EXPECT_CALL(mock_fn_, Call)
+    //         .WillOnce([&] {
+    //            [...]
+    //            return 0;
+    //         });
+    //
+    // Such a callable can be turned into std::function<void()>. If we use an
+    // explicit return type of Result here then it *doesn't* work with
+    // std::function, because we'll get a "void function should not return a
+    // value" error.
+    //
+    // We need not worry about incompatible result types because the SFINAE on
+    // OnceAction already checks this for us. std::is_invocable_r_v itself makes
+    // the same allowance for void result types.
+    template <typename... ArgRefs>
+    internal::call_result_t<Callable, ArgRefs...> operator()(
+        ArgRefs&&... args) const {
+      return std::move(*callable_)(std::forward<ArgRefs>(args)...);
+    }
+
+   private:
+    // We must put the callable on the heap so that we are copyable, which
+    // std::function needs.
+    std::shared_ptr<Callable> callable_;
+  };
+
+  // An adaptor that makes a callable that accepts zero arguments callable with
+  // our mocked arguments.
+  template <typename Callable>
+  struct IgnoreIncomingArguments {
+    internal::call_result_t<Callable> operator()(Args&&...) {
+      return std::move(callable)();
+    }
+
+    Callable callable;
+  };
+
+  std::function<Result(Args...)> function_;
+};
+
+// When an unexpected function call is encountered, Google Mock will
+// let it return a default value if the user has specified one for its
+// return type, or if the return type has a built-in default value;
+// otherwise Google Mock won't know what value to return and will have
+// to abort the process.
+//
+// The DefaultValue<T> class allows a user to specify the
+// default value for a type T that is both copyable and publicly
+// destructible (i.e. anything that can be used as a function return
+// type).  The usage is:
+//
+//   // Sets the default value for type T to be foo.
+//   DefaultValue<T>::Set(foo);
+template <typename T>
+class DefaultValue {
+ public:
+  // Sets the default value for type T; requires T to be
+  // copy-constructable and have a public destructor.
+  static void Set(T x) {
+    delete producer_;
+    producer_ = new FixedValueProducer(x);
+  }
+
+  // Provides a factory function to be called to generate the default value.
+  // This method can be used even if T is only move-constructible, but it is not
+  // limited to that case.
+  typedef T (*FactoryFunction)();
+  static void SetFactory(FactoryFunction factory) {
+    delete producer_;
+    producer_ = new FactoryValueProducer(factory);
+  }
+
+  // Unsets the default value for type T.
+  static void Clear() {
+    delete producer_;
+    producer_ = nullptr;
+  }
+
+  // Returns true if and only if the user has set the default value for type T.
+  static bool IsSet() { return producer_ != nullptr; }
+
+  // Returns true if T has a default return value set by the user or there
+  // exists a built-in default value.
+  static bool Exists() {
+    return IsSet() || internal::BuiltInDefaultValue<T>::Exists();
+  }
+
+  // Returns the default value for type T if the user has set one;
+  // otherwise returns the built-in default value. Requires that Exists()
+  // is true, which ensures that the return value is well-defined.
+  static T Get() {
+    return producer_ == nullptr ? internal::BuiltInDefaultValue<T>::Get()
+                                : producer_->Produce();
+  }
+
+ private:
+  class ValueProducer {
+   public:
+    virtual ~ValueProducer() = default;
+    virtual T Produce() = 0;
+  };
+
+  class FixedValueProducer : public ValueProducer {
+   public:
+    explicit FixedValueProducer(T value) : value_(value) {}
+    T Produce() override { return value_; }
+
+   private:
+    const T value_;
+    FixedValueProducer(const FixedValueProducer&) = delete;
+    FixedValueProducer& operator=(const FixedValueProducer&) = delete;
+  };
+
+  class FactoryValueProducer : public ValueProducer {
+   public:
+    explicit FactoryValueProducer(FactoryFunction factory)
+        : factory_(factory) {}
+    T Produce() override { return factory_(); }
+
+   private:
+    const FactoryFunction factory_;
+    FactoryValueProducer(const FactoryValueProducer&) = delete;
+    FactoryValueProducer& operator=(const FactoryValueProducer&) = delete;
+  };
+
+  static ValueProducer* producer_;
+};
+
+// This partial specialization allows a user to set default values for
+// reference types.
+template <typename T>
+class DefaultValue<T&> {
+ public:
+  // Sets the default value for type T&.
+  static void Set(T& x) {  // NOLINT
+    address_ = &x;
+  }
+
+  // Unsets the default value for type T&.
+  static void Clear() { address_ = nullptr; }
+
+  // Returns true if and only if the user has set the default value for type T&.
+  static bool IsSet() { return address_ != nullptr; }
+
+  // Returns true if T has a default return value set by the user or there
+  // exists a built-in default value.
+  static bool Exists() {
+    return IsSet() || internal::BuiltInDefaultValue<T&>::Exists();
+  }
+
+  // Returns the default value for type T& if the user has set one;
+  // otherwise returns the built-in default value if there is one;
+  // otherwise aborts the process.
+  static T& Get() {
+    return address_ == nullptr ? internal::BuiltInDefaultValue<T&>::Get()
+                               : *address_;
+  }
+
+ private:
+  static T* address_;
+};
+
+// This specialization allows DefaultValue<void>::Get() to
+// compile.
+template <>
+class DefaultValue<void> {
+ public:
+  static bool Exists() { return true; }
+  static void Get() {}
+};
+
+// Points to the user-set default value for type T.
+template <typename T>
+typename DefaultValue<T>::ValueProducer* DefaultValue<T>::producer_ = nullptr;
+
+// Points to the user-set default value for type T&.
+template <typename T>
+T* DefaultValue<T&>::address_ = nullptr;
+
+// Implement this interface to define an action for function type F.
+template <typename F>
+class ActionInterface {
+ public:
+  typedef typename internal::Function<F>::Result Result;
+  typedef typename internal::Function<F>::ArgumentTuple ArgumentTuple;
+
+  ActionInterface() = default;
+  virtual ~ActionInterface() = default;
+
+  // Performs the action.  This method is not const, as in general an
+  // action can have side effects and be stateful.  For example, a
+  // get-the-next-element-from-the-collection action will need to
+  // remember the current element.
+  virtual Result Perform(const ArgumentTuple& args) = 0;
+
+ private:
+  ActionInterface(const ActionInterface&) = delete;
+  ActionInterface& operator=(const ActionInterface&) = delete;
+};
+
+template <typename F>
+class Action;
+
+// An Action<R(Args...)> is a copyable and IMMUTABLE (except by assignment)
+// object that represents an action to be taken when a mock function of type
+// R(Args...) is called. The implementation of Action<T> is just a
+// std::shared_ptr to const ActionInterface<T>. Don't inherit from Action! You
+// can view an object implementing ActionInterface<F> as a concrete action
+// (including its current state), and an Action<F> object as a handle to it.
+template <typename R, typename... Args>
+class Action<R(Args...)> {
+ private:
+  using F = R(Args...);
+
+  // Adapter class to allow constructing Action from a legacy ActionInterface.
+  // New code should create Actions from functors instead.
+  struct ActionAdapter {
+    // Adapter must be copyable to satisfy std::function requirements.
+    ::std::shared_ptr<ActionInterface<F>> impl_;
+
+    template <typename... InArgs>
+    typename internal::Function<F>::Result operator()(InArgs&&... args) {
+      return impl_->Perform(
+          ::std::forward_as_tuple(::std::forward<InArgs>(args)...));
+    }
+  };
+
+  template <typename G>
+  using IsCompatibleFunctor = std::is_constructible<std::function<F>, G>;
+
+ public:
+  typedef typename internal::Function<F>::Result Result;
+  typedef typename internal::Function<F>::ArgumentTuple ArgumentTuple;
+
+  // Constructs a null Action.  Needed for storing Action objects in
+  // STL containers.
+  Action() = default;
+
+  // Construct an Action from a specified callable.
+  // This cannot take std::function directly, because then Action would not be
+  // directly constructible from lambda (it would require two conversions).
+  template <
+      typename G,
+      typename = typename std::enable_if<internal::disjunction<
+          IsCompatibleFunctor<G>, std::is_constructible<std::function<Result()>,
+                                                        G>>::value>::type>
+  Action(G&& fun) {  // NOLINT
+    Init(::std::forward<G>(fun), IsCompatibleFunctor<G>());
+  }
+
+  // Constructs an Action from its implementation.
+  explicit Action(ActionInterface<F>* impl)
+      : fun_(ActionAdapter{::std::shared_ptr<ActionInterface<F>>(impl)}) {}
+
+  // This constructor allows us to turn an Action<Func> object into an
+  // Action<F>, as long as F's arguments can be implicitly converted
+  // to Func's and Func's return type can be implicitly converted to F's.
+  template <typename Func>
+  Action(const Action<Func>& action)  // NOLINT
+      : fun_(action.fun_) {}
+
+  // Returns true if and only if this is the DoDefault() action.
+  bool IsDoDefault() const { return fun_ == nullptr; }
+
+  // Performs the action.  Note that this method is const even though
+  // the corresponding method in ActionInterface is not.  The reason
+  // is that a const Action<F> means that it cannot be re-bound to
+  // another concrete action, not that the concrete action it binds to
+  // cannot change state.  (Think of the difference between a const
+  // pointer and a pointer to const.)
+  Result Perform(ArgumentTuple args) const {
+    if (IsDoDefault()) {
+      internal::IllegalDoDefault(__FILE__, __LINE__);
+    }
+    return internal::Apply(fun_, ::std::move(args));
+  }
+
+  // An action can be used as a OnceAction, since it's obviously safe to call it
+  // once.
+  operator OnceAction<F>() const {  // NOLINT
+    // Return a OnceAction-compatible callable that calls Perform with the
+    // arguments it is provided. We could instead just return fun_, but then
+    // we'd need to handle the IsDoDefault() case separately.
+    struct OA {
+      Action<F> action;
+
+      R operator()(Args... args) && {
+        return action.Perform(
+            std::forward_as_tuple(std::forward<Args>(args)...));
+      }
+    };
+
+    return OA{*this};
+  }
+
+ private:
+  template <typename G>
+  friend class Action;
+
+  template <typename G>
+  void Init(G&& g, ::std::true_type) {
+    fun_ = ::std::forward<G>(g);
+  }
+
+  template <typename G>
+  void Init(G&& g, ::std::false_type) {
+    fun_ = IgnoreArgs<typename ::std::decay<G>::type>{::std::forward<G>(g)};
+  }
+
+  template <typename FunctionImpl>
+  struct IgnoreArgs {
+    template <typename... InArgs>
+    Result operator()(const InArgs&...) const {
+      return function_impl();
+    }
+
+    FunctionImpl function_impl;
+  };
+
+  // fun_ is an empty function if and only if this is the DoDefault() action.
+  ::std::function<F> fun_;
+};
+
+// The PolymorphicAction class template makes it easy to implement a
+// polymorphic action (i.e. an action that can be used in mock
+// functions of than one type, e.g. Return()).
+//
+// To define a polymorphic action, a user first provides a COPYABLE
+// implementation class that has a Perform() method template:
+//
+//   class FooAction {
+//    public:
+//     template <typename Result, typename ArgumentTuple>
+//     Result Perform(const ArgumentTuple& args) const {
+//       // Processes the arguments and returns a result, using
+//       // std::get<N>(args) to get the N-th (0-based) argument in the tuple.
+//     }
+//     ...
+//   };
+//
+// Then the user creates the polymorphic action using
+// MakePolymorphicAction(object) where object has type FooAction.  See
+// the definition of Return(void) and SetArgumentPointee<N>(value) for
+// complete examples.
+template <typename Impl>
+class PolymorphicAction {
+ public:
+  explicit PolymorphicAction(const Impl& impl) : impl_(impl) {}
+
+  template <typename F>
+  operator Action<F>() const {
+    return Action<F>(new MonomorphicImpl<F>(impl_));
+  }
+
+ private:
+  template <typename F>
+  class MonomorphicImpl : public ActionInterface<F> {
+   public:
+    typedef typename internal::Function<F>::Result Result;
+    typedef typename internal::Function<F>::ArgumentTuple ArgumentTuple;
+
+    explicit MonomorphicImpl(const Impl& impl) : impl_(impl) {}
+
+    Result Perform(const ArgumentTuple& args) override {
+      return impl_.template Perform<Result>(args);
+    }
+
+   private:
+    Impl impl_;
+  };
+
+  Impl impl_;
+};
+
+// Creates an Action from its implementation and returns it.  The
+// created Action object owns the implementation.
+template <typename F>
+Action<F> MakeAction(ActionInterface<F>* impl) {
+  return Action<F>(impl);
+}
+
+// Creates a polymorphic action from its implementation.  This is
+// easier to use than the PolymorphicAction<Impl> constructor as it
+// doesn't require you to explicitly write the template argument, e.g.
+//
+//   MakePolymorphicAction(foo);
+// vs
+//   PolymorphicAction<TypeOfFoo>(foo);
+template <typename Impl>
+inline PolymorphicAction<Impl> MakePolymorphicAction(const Impl& impl) {
+  return PolymorphicAction<Impl>(impl);
+}
+
+namespace internal {
+
+// Helper struct to specialize ReturnAction to execute a move instead of a copy
+// on return. Useful for move-only types, but could be used on any type.
+template <typename T>
+struct ByMoveWrapper {
+  explicit ByMoveWrapper(T value) : payload(std::move(value)) {}
+  T payload;
+};
+
+// The general implementation of Return(R). Specializations follow below.
+template <typename R>
+class ReturnAction final {
+ public:
+  explicit ReturnAction(R value) : value_(std::move(value)) {}
+
+  template <typename U, typename... Args,
+            typename = typename std::enable_if<conjunction<
+                // See the requirements documented on Return.
+                negation<std::is_same<void, U>>,  //
+                negation<std::is_reference<U>>,   //
+                std::is_convertible<R, U>,        //
+                std::is_move_constructible<U>>::value>::type>
+  operator OnceAction<U(Args...)>() && {  // NOLINT
+    return Impl<U>(std::move(value_));
+  }
+
+  template <typename U, typename... Args,
+            typename = typename std::enable_if<conjunction<
+                // See the requirements documented on Return.
+                negation<std::is_same<void, U>>,   //
+                negation<std::is_reference<U>>,    //
+                std::is_convertible<const R&, U>,  //
+                std::is_copy_constructible<U>>::value>::type>
+  operator Action<U(Args...)>() const {  // NOLINT
+    return Impl<U>(value_);
+  }
+
+ private:
+  // Implements the Return(x) action for a mock function that returns type U.
+  template <typename U>
+  class Impl final {
+   public:
+    // The constructor used when the return value is allowed to move from the
+    // input value (i.e. we are converting to OnceAction).
+    explicit Impl(R&& input_value)
+        : state_(new State(std::move(input_value))) {}
+
+    // The constructor used when the return value is not allowed to move from
+    // the input value (i.e. we are converting to Action).
+    explicit Impl(const R& input_value) : state_(new State(input_value)) {}
+
+    U operator()() && { return std::move(state_->value); }
+    U operator()() const& { return state_->value; }
+
+   private:
+    // We put our state on the heap so that the compiler-generated copy/move
+    // constructors work correctly even when U is a reference-like type. This is
+    // necessary only because we eagerly create State::value (see the note on
+    // that symbol for details). If we instead had only the input value as a
+    // member then the default constructors would work fine.
+    //
+    // For example, when R is std::string and U is std::string_view, value is a
+    // reference to the string backed by input_value. The copy constructor would
+    // copy both, so that we wind up with a new input_value object (with the
+    // same contents) and a reference to the *old* input_value object rather
+    // than the new one.
+    struct State {
+      explicit State(const R& input_value_in)
+          : input_value(input_value_in),
+            // Make an implicit conversion to Result before initializing the U
+            // object we store, avoiding calling any explicit constructor of U
+            // from R.
+            //
+            // This simulates the language rules: a function with return type U
+            // that does `return R()` requires R to be implicitly convertible to
+            // U, and uses that path for the conversion, even U Result has an
+            // explicit constructor from R.
+            value(ImplicitCast_<U>(internal::as_const(input_value))) {}
+
+      // As above, but for the case where we're moving from the ReturnAction
+      // object because it's being used as a OnceAction.
+      explicit State(R&& input_value_in)
+          : input_value(std::move(input_value_in)),
+            // For the same reason as above we make an implicit conversion to U
+            // before initializing the value.
+            //
+            // Unlike above we provide the input value as an rvalue to the
+            // implicit conversion because this is a OnceAction: it's fine if it
+            // wants to consume the input value.
+            value(ImplicitCast_<U>(std::move(input_value))) {}
+
+      // A copy of the value originally provided by the user. We retain this in
+      // addition to the value of the mock function's result type below in case
+      // the latter is a reference-like type. See the std::string_view example
+      // in the documentation on Return.
+      R input_value;
+
+      // The value we actually return, as the type returned by the mock function
+      // itself.
+      //
+      // We eagerly initialize this here, rather than lazily doing the implicit
+      // conversion automatically each time Perform is called, for historical
+      // reasons: in 2009-11, commit a070cbd91c (Google changelist 13540126)
+      // made the Action<U()> conversion operator eagerly convert the R value to
+      // U, but without keeping the R alive. This broke the use case discussed
+      // in the documentation for Return, making reference-like types such as
+      // std::string_view not safe to use as U where the input type R is a
+      // value-like type such as std::string.
+      //
+      // The example the commit gave was not very clear, nor was the issue
+      // thread (https://github.com/google/googlemock/issues/86), but it seems
+      // the worry was about reference-like input types R that flatten to a
+      // value-like type U when being implicitly converted. An example of this
+      // is std::vector<bool>::reference, which is often a proxy type with an
+      // reference to the underlying vector:
+      //
+      //     // Helper method: have the mock function return bools according
+      //     // to the supplied script.
+      //     void SetActions(MockFunction<bool(size_t)>& mock,
+      //                     const std::vector<bool>& script) {
+      //       for (size_t i = 0; i < script.size(); ++i) {
+      //         EXPECT_CALL(mock, Call(i)).WillOnce(Return(script[i]));
+      //       }
+      //     }
+      //
+      //     TEST(Foo, Bar) {
+      //       // Set actions using a temporary vector, whose operator[]
+      //       // returns proxy objects that references that will be
+      //       // dangling once the call to SetActions finishes and the
+      //       // vector is destroyed.
+      //       MockFunction<bool(size_t)> mock;
+      //       SetActions(mock, {false, true});
+      //
+      //       EXPECT_FALSE(mock.AsStdFunction()(0));
+      //       EXPECT_TRUE(mock.AsStdFunction()(1));
+      //     }
+      //
+      // This eager conversion helps with a simple case like this, but doesn't
+      // fully make these types work in general. For example the following still
+      // uses a dangling reference:
+      //
+      //     TEST(Foo, Baz) {
+      //       MockFunction<std::vector<std::string>()> mock;
+      //
+      //       // Return the same vector twice, and then the empty vector
+      //       // thereafter.
+      //       auto action = Return(std::initializer_list<std::string>{
+      //           "taco", "burrito",
+      //       });
+      //
+      //       EXPECT_CALL(mock, Call)
+      //           .WillOnce(action)
+      //           .WillOnce(action)
+      //           .WillRepeatedly(Return(std::vector<std::string>{}));
+      //
+      //       EXPECT_THAT(mock.AsStdFunction()(),
+      //                   ElementsAre("taco", "burrito"));
+      //       EXPECT_THAT(mock.AsStdFunction()(),
+      //                   ElementsAre("taco", "burrito"));
+      //       EXPECT_THAT(mock.AsStdFunction()(), IsEmpty());
+      //     }
+      //
+      U value;
+    };
+
+    const std::shared_ptr<State> state_;
+  };
+
+  R value_;
+};
+
+// A specialization of ReturnAction<R> when R is ByMoveWrapper<T> for some T.
+//
+// This version applies the type system-defeating hack of moving from T even in
+// the const call operator, checking at runtime that it isn't called more than
+// once, since the user has declared their intent to do so by using ByMove.
+template <typename T>
+class ReturnAction<ByMoveWrapper<T>> final {
+ public:
+  explicit ReturnAction(ByMoveWrapper<T> wrapper)
+      : state_(new State(std::move(wrapper.payload))) {}
+
+  T operator()() const {
+    GTEST_CHECK_(!state_->called)
+        << "A ByMove() action must be performed at most once.";
+
+    state_->called = true;
+    return std::move(state_->value);
+  }
+
+ private:
+  // We store our state on the heap so that we are copyable as required by
+  // Action, despite the fact that we are stateful and T may not be copyable.
+  struct State {
+    explicit State(T&& value_in) : value(std::move(value_in)) {}
+
+    T value;
+    bool called = false;
+  };
+
+  const std::shared_ptr<State> state_;
+};
+
+// Implements the ReturnNull() action.
+class ReturnNullAction {
+ public:
+  // Allows ReturnNull() to be used in any pointer-returning function. In C++11
+  // this is enforced by returning nullptr, and in non-C++11 by asserting a
+  // pointer type on compile time.
+  template <typename Result, typename ArgumentTuple>
+  static Result Perform(const ArgumentTuple&) {
+    return nullptr;
+  }
+};
+
+// Implements the Return() action.
+class ReturnVoidAction {
+ public:
+  // Allows Return() to be used in any void-returning function.
+  template <typename Result, typename ArgumentTuple>
+  static void Perform(const ArgumentTuple&) {
+    static_assert(std::is_void<Result>::value, "Result should be void.");
+  }
+};
+
+// Implements the polymorphic ReturnRef(x) action, which can be used
+// in any function that returns a reference to the type of x,
+// regardless of the argument types.
+template <typename T>
+class ReturnRefAction {
+ public:
+  // Constructs a ReturnRefAction object from the reference to be returned.
+  explicit ReturnRefAction(T& ref) : ref_(ref) {}  // NOLINT
+
+  // This template type conversion operator allows ReturnRef(x) to be
+  // used in ANY function that returns a reference to x's type.
+  template <typename F>
+  operator Action<F>() const {
+    typedef typename Function<F>::Result Result;
+    // Asserts that the function return type is a reference.  This
+    // catches the user error of using ReturnRef(x) when Return(x)
+    // should be used, and generates some helpful error message.
+    static_assert(std::is_reference<Result>::value,
+                  "use Return instead of ReturnRef to return a value");
+    return Action<F>(new Impl<F>(ref_));
+  }
+
+ private:
+  // Implements the ReturnRef(x) action for a particular function type F.
+  template <typename F>
+  class Impl : public ActionInterface<F> {
+   public:
+    typedef typename Function<F>::Result Result;
+    typedef typename Function<F>::ArgumentTuple ArgumentTuple;
+
+    explicit Impl(T& ref) : ref_(ref) {}  // NOLINT
+
+    Result Perform(const ArgumentTuple&) override { return ref_; }
+
+   private:
+    T& ref_;
+  };
+
+  T& ref_;
+};
+
+// Implements the polymorphic ReturnRefOfCopy(x) action, which can be
+// used in any function that returns a reference to the type of x,
+// regardless of the argument types.
+template <typename T>
+class ReturnRefOfCopyAction {
+ public:
+  // Constructs a ReturnRefOfCopyAction object from the reference to
+  // be returned.
+  explicit ReturnRefOfCopyAction(const T& value) : value_(value) {}  // NOLINT
+
+  // This template type conversion operator allows ReturnRefOfCopy(x) to be
+  // used in ANY function that returns a reference to x's type.
+  template <typename F>
+  operator Action<F>() const {
+    typedef typename Function<F>::Result Result;
+    // Asserts that the function return type is a reference.  This
+    // catches the user error of using ReturnRefOfCopy(x) when Return(x)
+    // should be used, and generates some helpful error message.
+    static_assert(std::is_reference<Result>::value,
+                  "use Return instead of ReturnRefOfCopy to return a value");
+    return Action<F>(new Impl<F>(value_));
+  }
+
+ private:
+  // Implements the ReturnRefOfCopy(x) action for a particular function type F.
+  template <typename F>
+  class Impl : public ActionInterface<F> {
+   public:
+    typedef typename Function<F>::Result Result;
+    typedef typename Function<F>::ArgumentTuple ArgumentTuple;
+
+    explicit Impl(const T& value) : value_(value) {}  // NOLINT
+
+    Result Perform(const ArgumentTuple&) override { return value_; }
+
+   private:
+    T value_;
+  };
+
+  const T value_;
+};
+
+// Implements the polymorphic ReturnRoundRobin(v) action, which can be
+// used in any function that returns the element_type of v.
+template <typename T>
+class ReturnRoundRobinAction {
+ public:
+  explicit ReturnRoundRobinAction(std::vector<T> values) {
+    GTEST_CHECK_(!values.empty())
+        << "ReturnRoundRobin requires at least one element.";
+    state_->values = std::move(values);
+  }
+
+  template <typename... Args>
+  T operator()(Args&&...) const {
+    return state_->Next();
+  }
+
+ private:
+  struct State {
+    T Next() {
+      T ret_val = values[i++];
+      if (i == values.size()) i = 0;
+      return ret_val;
+    }
+
+    std::vector<T> values;
+    size_t i = 0;
+  };
+  std::shared_ptr<State> state_ = std::make_shared<State>();
+};
+
+// Implements the polymorphic DoDefault() action.
+class DoDefaultAction {
+ public:
+  // This template type conversion operator allows DoDefault() to be
+  // used in any function.
+  template <typename F>
+  operator Action<F>() const {
+    return Action<F>();
+  }  // NOLINT
+};
+
+// Implements the Assign action to set a given pointer referent to a
+// particular value.
+template <typename T1, typename T2>
+class AssignAction {
+ public:
+  AssignAction(T1* ptr, T2 value) : ptr_(ptr), value_(value) {}
+
+  template <typename Result, typename ArgumentTuple>
+  void Perform(const ArgumentTuple& /* args */) const {
+    *ptr_ = value_;
+  }
+
+ private:
+  T1* const ptr_;
+  const T2 value_;
+};
+
+#ifndef GTEST_OS_WINDOWS_MOBILE
+
+// Implements the SetErrnoAndReturn action to simulate return from
+// various system calls and libc functions.
+template <typename T>
+class SetErrnoAndReturnAction {
+ public:
+  SetErrnoAndReturnAction(int errno_value, T result)
+      : errno_(errno_value), result_(result) {}
+  template <typename Result, typename ArgumentTuple>
+  Result Perform(const ArgumentTuple& /* args */) const {
+    errno = errno_;
+    return result_;
+  }
+
+ private:
+  const int errno_;
+  const T result_;
+};
+
+#endif  // !GTEST_OS_WINDOWS_MOBILE
+
+// Implements the SetArgumentPointee<N>(x) action for any function
+// whose N-th argument (0-based) is a pointer to x's type.
+template <size_t N, typename A, typename = void>
+struct SetArgumentPointeeAction {
+  A value;
+
+  template <typename... Args>
+  void operator()(const Args&... args) const {
+    *::std::get<N>(std::tie(args...)) = value;
+  }
+};
+
+// Implements the Invoke(object_ptr, &Class::Method) action.
+template <class Class, typename MethodPtr>
+struct InvokeMethodAction {
+  Class* const obj_ptr;
+  const MethodPtr method_ptr;
+
+  template <typename... Args>
+  auto operator()(Args&&... args) const
+      -> decltype((obj_ptr->*method_ptr)(std::forward<Args>(args)...)) {
+    return (obj_ptr->*method_ptr)(std::forward<Args>(args)...);
+  }
+};
+
+// Implements the InvokeWithoutArgs(f) action.  The template argument
+// FunctionImpl is the implementation type of f, which can be either a
+// function pointer or a functor.  InvokeWithoutArgs(f) can be used as an
+// Action<F> as long as f's type is compatible with F.
+template <typename FunctionImpl>
+struct InvokeWithoutArgsAction {
+  FunctionImpl function_impl;
+
+  // Allows InvokeWithoutArgs(f) to be used as any action whose type is
+  // compatible with f.
+  template <typename... Args>
+  auto operator()(const Args&...) -> decltype(function_impl()) {
+    return function_impl();
+  }
+};
+
+// Implements the InvokeWithoutArgs(object_ptr, &Class::Method) action.
+template <class Class, typename MethodPtr>
+struct InvokeMethodWithoutArgsAction {
+  Class* const obj_ptr;
+  const MethodPtr method_ptr;
+
+  using ReturnType =
+      decltype((std::declval<Class*>()->*std::declval<MethodPtr>())());
+
+  template <typename... Args>
+  ReturnType operator()(const Args&...) const {
+    return (obj_ptr->*method_ptr)();
+  }
+};
+
+// Implements the IgnoreResult(action) action.
+template <typename A>
+class IgnoreResultAction {
+ public:
+  explicit IgnoreResultAction(const A& action) : action_(action) {}
+
+  template <typename F>
+  operator Action<F>() const {
+    // Assert statement belongs here because this is the best place to verify
+    // conditions on F. It produces the clearest error messages
+    // in most compilers.
+    // Impl really belongs in this scope as a local class but can't
+    // because MSVC produces duplicate symbols in different translation units
+    // in this case. Until MS fixes that bug we put Impl into the class scope
+    // and put the typedef both here (for use in assert statement) and
+    // in the Impl class. But both definitions must be the same.
+    typedef typename internal::Function<F>::Result Result;
+
+    // Asserts at compile time that F returns void.
+    static_assert(std::is_void<Result>::value, "Result type should be void.");
+
+    return Action<F>(new Impl<F>(action_));
+  }
+
+ private:
+  template <typename F>
+  class Impl : public ActionInterface<F> {
+   public:
+    typedef typename internal::Function<F>::Result Result;
+    typedef typename internal::Function<F>::ArgumentTuple ArgumentTuple;
+
+    explicit Impl(const A& action) : action_(action) {}
+
+    void Perform(const ArgumentTuple& args) override {
+      // Performs the action and ignores its result.
+      action_.Perform(args);
+    }
+
+   private:
+    // Type OriginalFunction is the same as F except that its return
+    // type is IgnoredValue.
+    typedef
+        typename internal::Function<F>::MakeResultIgnoredValue OriginalFunction;
+
+    const Action<OriginalFunction> action_;
+  };
+
+  const A action_;
+};
+
+template <typename InnerAction, size_t... I>
+struct WithArgsAction {
+  InnerAction inner_action;
+
+  // The signature of the function as seen by the inner action, given an out
+  // action with the given result and argument types.
+  template <typename R, typename... Args>
+  using InnerSignature =
+      R(typename std::tuple_element<I, std::tuple<Args...>>::type...);
+
+  // Rather than a call operator, we must define conversion operators to
+  // particular action types. This is necessary for embedded actions like
+  // DoDefault(), which rely on an action conversion operators rather than
+  // providing a call operator because even with a particular set of arguments
+  // they don't have a fixed return type.
+
+  template <
+      typename R, typename... Args,
+      typename std::enable_if<
+          std::is_convertible<InnerAction,
+                              // Unfortunately we can't use the InnerSignature
+                              // alias here; MSVC complains about the I
+                              // parameter pack not being expanded (error C3520)
+                              // despite it being expanded in the type alias.
+                              // TupleElement is also an MSVC workaround.
+                              // See its definition for details.
+                              OnceAction<R(internal::TupleElement<
+                                           I, std::tuple<Args...>>...)>>::value,
+          int>::type = 0>
+  operator OnceAction<R(Args...)>() && {  // NOLINT
+    struct OA {
+      OnceAction<InnerSignature<R, Args...>> inner_action;
+
+      R operator()(Args&&... args) && {
+        return std::move(inner_action)
+            .Call(std::get<I>(
+                std::forward_as_tuple(std::forward<Args>(args)...))...);
+      }
+    };
+
+    return OA{std::move(inner_action)};
+  }
+
+  template <
+      typename R, typename... Args,
+      typename std::enable_if<
+          std::is_convertible<const InnerAction&,
+                              // Unfortunately we can't use the InnerSignature
+                              // alias here; MSVC complains about the I
+                              // parameter pack not being expanded (error C3520)
+                              // despite it being expanded in the type alias.
+                              // TupleElement is also an MSVC workaround.
+                              // See its definition for details.
+                              Action<R(internal::TupleElement<
+                                       I, std::tuple<Args...>>...)>>::value,
+          int>::type = 0>
+  operator Action<R(Args...)>() const {  // NOLINT
+    Action<InnerSignature<R, Args...>> converted(inner_action);
+
+    return [converted](Args&&... args) -> R {
+      return converted.Perform(std::forward_as_tuple(
+          std::get<I>(std::forward_as_tuple(std::forward<Args>(args)...))...));
+    };
+  }
+};
+
+template <typename... Actions>
+class DoAllAction;
+
+// Base case: only a single action.
+template <typename FinalAction>
+class DoAllAction<FinalAction> {
+ public:
+  struct UserConstructorTag {};
+
+  template <typename T>
+  explicit DoAllAction(UserConstructorTag, T&& action)
+      : final_action_(std::forward<T>(action)) {}
+
+  // Rather than a call operator, we must define conversion operators to
+  // particular action types. This is necessary for embedded actions like
+  // DoDefault(), which rely on an action conversion operators rather than
+  // providing a call operator because even with a particular set of arguments
+  // they don't have a fixed return type.
+
+  template <typename R, typename... Args,
+            typename std::enable_if<
+                std::is_convertible<FinalAction, OnceAction<R(Args...)>>::value,
+                int>::type = 0>
+  operator OnceAction<R(Args...)>() && {  // NOLINT
+    return std::move(final_action_);
+  }
+
+  template <
+      typename R, typename... Args,
+      typename std::enable_if<
+          std::is_convertible<const FinalAction&, Action<R(Args...)>>::value,
+          int>::type = 0>
+  operator Action<R(Args...)>() const {  // NOLINT
+    return final_action_;
+  }
+
+ private:
+  FinalAction final_action_;
+};
+
+// Recursive case: support N actions by calling the initial action and then
+// calling through to the base class containing N-1 actions.
+template <typename InitialAction, typename... OtherActions>
+class DoAllAction<InitialAction, OtherActions...>
+    : private DoAllAction<OtherActions...> {
+ private:
+  using Base = DoAllAction<OtherActions...>;
+
+  // The type of reference that should be provided to an initial action for a
+  // mocked function parameter of type T.
+  //
+  // There are two quirks here:
+  //
+  //  *  Unlike most forwarding functions, we pass scalars through by value.
+  //     This isn't strictly necessary because an lvalue reference would work
+  //     fine too and be consistent with other non-reference types, but it's
+  //     perhaps less surprising.
+  //
+  //     For example if the mocked function has signature void(int), then it
+  //     might seem surprising for the user's initial action to need to be
+  //     convertible to Action<void(const int&)>. This is perhaps less
+  //     surprising for a non-scalar type where there may be a performance
+  //     impact, or it might even be impossible, to pass by value.
+  //
+  //  *  More surprisingly, `const T&` is often not a const reference type.
+  //     By the reference collapsing rules in C++17 [dcl.ref]/6, if T refers to
+  //     U& or U&& for some non-scalar type U, then InitialActionArgType<T> is
+  //     U&. In other words, we may hand over a non-const reference.
+  //
+  //     So for example, given some non-scalar type Obj we have the following
+  //     mappings:
+  //
+  //            T               InitialActionArgType<T>
+  //         -------            -----------------------
+  //         Obj                const Obj&
+  //         Obj&               Obj&
+  //         Obj&&              Obj&
+  //         const Obj          const Obj&
+  //         const Obj&         const Obj&
+  //         const Obj&&        const Obj&
+  //
+  //     In other words, the initial actions get a mutable view of an non-scalar
+  //     argument if and only if the mock function itself accepts a non-const
+  //     reference type. They are never given an rvalue reference to an
+  //     non-scalar type.
+  //
+  //     This situation makes sense if you imagine use with a matcher that is
+  //     designed to write through a reference. For example, if the caller wants
+  //     to fill in a reference argument and then return a canned value:
+  //
+  //         EXPECT_CALL(mock, Call)
+  //             .WillOnce(DoAll(SetArgReferee<0>(17), Return(19)));
+  //
+  template <typename T>
+  using InitialActionArgType =
+      typename std::conditional<std::is_scalar<T>::value, T, const T&>::type;
+
+ public:
+  struct UserConstructorTag {};
+
+  template <typename T, typename... U>
+  explicit DoAllAction(UserConstructorTag, T&& initial_action,
+                       U&&... other_actions)
+      : Base({}, std::forward<U>(other_actions)...),
+        initial_action_(std::forward<T>(initial_action)) {}
+
+  template <typename R, typename... Args,
+            typename std::enable_if<
+                conjunction<
+                    // Both the initial action and the rest must support
+                    // conversion to OnceAction.
+                    std::is_convertible<
+                        InitialAction,
+                        OnceAction<void(InitialActionArgType<Args>...)>>,
+                    std::is_convertible<Base, OnceAction<R(Args...)>>>::value,
+                int>::type = 0>
+  operator OnceAction<R(Args...)>() && {  // NOLINT
+    // Return an action that first calls the initial action with arguments
+    // filtered through InitialActionArgType, then forwards arguments directly
+    // to the base class to deal with the remaining actions.
+    struct OA {
+      OnceAction<void(InitialActionArgType<Args>...)> initial_action;
+      OnceAction<R(Args...)> remaining_actions;
+
+      R operator()(Args... args) && {
+        std::move(initial_action)
+            .Call(static_cast<InitialActionArgType<Args>>(args)...);
+
+        return std::move(remaining_actions).Call(std::forward<Args>(args)...);
+      }
+    };
+
+    return OA{
+        std::move(initial_action_),
+        std::move(static_cast<Base&>(*this)),
+    };
+  }
+
+  template <
+      typename R, typename... Args,
+      typename std::enable_if<
+          conjunction<
+              // Both the initial action and the rest must support conversion to
+              // Action.
+              std::is_convertible<const InitialAction&,
+                                  Action<void(InitialActionArgType<Args>...)>>,
+              std::is_convertible<const Base&, Action<R(Args...)>>>::value,
+          int>::type = 0>
+  operator Action<R(Args...)>() const {  // NOLINT
+    // Return an action that first calls the initial action with arguments
+    // filtered through InitialActionArgType, then forwards arguments directly
+    // to the base class to deal with the remaining actions.
+    struct OA {
+      Action<void(InitialActionArgType<Args>...)> initial_action;
+      Action<R(Args...)> remaining_actions;
+
+      R operator()(Args... args) const {
+        initial_action.Perform(std::forward_as_tuple(
+            static_cast<InitialActionArgType<Args>>(args)...));
+
+        return remaining_actions.Perform(
+            std::forward_as_tuple(std::forward<Args>(args)...));
+      }
+    };
+
+    return OA{
+        initial_action_,
+        static_cast<const Base&>(*this),
+    };
+  }
+
+ private:
+  InitialAction initial_action_;
+};
+
+template <typename T, typename... Params>
+struct ReturnNewAction {
+  T* operator()() const {
+    return internal::Apply(
+        [](const Params&... unpacked_params) {
+          return new T(unpacked_params...);
+        },
+        params);
+  }
+  std::tuple<Params...> params;
+};
+
+template <size_t k>
+struct ReturnArgAction {
+  template <typename... Args,
+            typename = typename std::enable_if<(k < sizeof...(Args))>::type>
+  auto operator()(Args&&... args) const -> decltype(std::get<k>(
+      std::forward_as_tuple(std::forward<Args>(args)...))) {
+    return std::get<k>(std::forward_as_tuple(std::forward<Args>(args)...));
+  }
+};
+
+template <size_t k, typename Ptr>
+struct SaveArgAction {
+  Ptr pointer;
+
+  template <typename... Args>
+  void operator()(const Args&... args) const {
+    *pointer = std::get<k>(std::tie(args...));
+  }
+};
+
+template <size_t k, typename Ptr>
+struct SaveArgPointeeAction {
+  Ptr pointer;
+
+  template <typename... Args>
+  void operator()(const Args&... args) const {
+    *pointer = *std::get<k>(std::tie(args...));
+  }
+};
+
+template <size_t k, typename T>
+struct SetArgRefereeAction {
+  T value;
+
+  template <typename... Args>
+  void operator()(Args&&... args) const {
+    using argk_type =
+        typename ::std::tuple_element<k, std::tuple<Args...>>::type;
+    static_assert(std::is_lvalue_reference<argk_type>::value,
+                  "Argument must be a reference type.");
+    std::get<k>(std::tie(args...)) = value;
+  }
+};
+
+template <size_t k, typename I1, typename I2>
+struct SetArrayArgumentAction {
+  I1 first;
+  I2 last;
+
+  template <typename... Args>
+  void operator()(const Args&... args) const {
+    auto value = std::get<k>(std::tie(args...));
+    for (auto it = first; it != last; ++it, (void)++value) {
+      *value = *it;
+    }
+  }
+};
+
+template <size_t k>
+struct DeleteArgAction {
+  template <typename... Args>
+  void operator()(const Args&... args) const {
+    delete std::get<k>(std::tie(args...));
+  }
+};
+
+template <typename Ptr>
+struct ReturnPointeeAction {
+  Ptr pointer;
+  template <typename... Args>
+  auto operator()(const Args&...) const -> decltype(*pointer) {
+    return *pointer;
+  }
+};
+
+#if GTEST_HAS_EXCEPTIONS
+template <typename T>
+struct ThrowAction {
+  T exception;
+  // We use a conversion operator to adapt to any return type.
+  template <typename R, typename... Args>
+  operator Action<R(Args...)>() const {  // NOLINT
+    T copy = exception;
+    return [copy](Args...) -> R { throw copy; };
+  }
+};
+#endif  // GTEST_HAS_EXCEPTIONS
+
+}  // namespace internal
+
+// An Unused object can be implicitly constructed from ANY value.
+// This is handy when defining actions that ignore some or all of the
+// mock function arguments.  For example, given
+//
+//   MOCK_METHOD3(Foo, double(const string& label, double x, double y));
+//   MOCK_METHOD3(Bar, double(int index, double x, double y));
+//
+// instead of
+//
+//   double DistanceToOriginWithLabel(const string& label, double x, double y) {
+//     return sqrt(x*x + y*y);
+//   }
+//   double DistanceToOriginWithIndex(int index, double x, double y) {
+//     return sqrt(x*x + y*y);
+//   }
+//   ...
+//   EXPECT_CALL(mock, Foo("abc", _, _))
+//       .WillOnce(Invoke(DistanceToOriginWithLabel));
+//   EXPECT_CALL(mock, Bar(5, _, _))
+//       .WillOnce(Invoke(DistanceToOriginWithIndex));
+//
+// you could write
+//
+//   // We can declare any uninteresting argument as Unused.
+//   double DistanceToOrigin(Unused, double x, double y) {
+//     return sqrt(x*x + y*y);
+//   }
+//   ...
+//   EXPECT_CALL(mock, Foo("abc", _, _)).WillOnce(Invoke(DistanceToOrigin));
+//   EXPECT_CALL(mock, Bar(5, _, _)).WillOnce(Invoke(DistanceToOrigin));
+typedef internal::IgnoredValue Unused;
+
+// Creates an action that does actions a1, a2, ..., sequentially in
+// each invocation. All but the last action will have a readonly view of the
+// arguments.
+template <typename... Action>
+internal::DoAllAction<typename std::decay<Action>::type...> DoAll(
+    Action&&... action) {
+  return internal::DoAllAction<typename std::decay<Action>::type...>(
+      {}, std::forward<Action>(action)...);
+}
+
+// WithArg<k>(an_action) creates an action that passes the k-th
+// (0-based) argument of the mock function to an_action and performs
+// it.  It adapts an action accepting one argument to one that accepts
+// multiple arguments.  For convenience, we also provide
+// WithArgs<k>(an_action) (defined below) as a synonym.
+template <size_t k, typename InnerAction>
+internal::WithArgsAction<typename std::decay<InnerAction>::type, k> WithArg(
+    InnerAction&& action) {
+  return {std::forward<InnerAction>(action)};
+}
+
+// WithArgs<N1, N2, ..., Nk>(an_action) creates an action that passes
+// the selected arguments of the mock function to an_action and
+// performs it.  It serves as an adaptor between actions with
+// different argument lists.
+template <size_t k, size_t... ks, typename InnerAction>
+internal::WithArgsAction<typename std::decay<InnerAction>::type, k, ks...>
+WithArgs(InnerAction&& action) {
+  return {std::forward<InnerAction>(action)};
+}
+
+// WithoutArgs(inner_action) can be used in a mock function with a
+// non-empty argument list to perform inner_action, which takes no
+// argument.  In other words, it adapts an action accepting no
+// argument to one that accepts (and ignores) arguments.
+template <typename InnerAction>
+internal::WithArgsAction<typename std::decay<InnerAction>::type> WithoutArgs(
+    InnerAction&& action) {
+  return {std::forward<InnerAction>(action)};
+}
+
+// Creates an action that returns a value.
+//
+// The returned type can be used with a mock function returning a non-void,
+// non-reference type U as follows:
+//
+//  *  If R is convertible to U and U is move-constructible, then the action can
+//     be used with WillOnce.
+//
+//  *  If const R& is convertible to U and U is copy-constructible, then the
+//     action can be used with both WillOnce and WillRepeatedly.
+//
+// The mock expectation contains the R value from which the U return value is
+// constructed (a move/copy of the argument to Return). This means that the R
+// value will survive at least until the mock object's expectations are cleared
+// or the mock object is destroyed, meaning that U can safely be a
+// reference-like type such as std::string_view:
+//
+//     // The mock function returns a view of a copy of the string fed to
+//     // Return. The view is valid even after the action is performed.
+//     MockFunction<std::string_view()> mock;
+//     EXPECT_CALL(mock, Call).WillOnce(Return(std::string("taco")));
+//     const std::string_view result = mock.AsStdFunction()();
+//     EXPECT_EQ("taco", result);
+//
+template <typename R>
+internal::ReturnAction<R> Return(R value) {
+  return internal::ReturnAction<R>(std::move(value));
+}
+
+// Creates an action that returns NULL.
+inline PolymorphicAction<internal::ReturnNullAction> ReturnNull() {
+  return MakePolymorphicAction(internal::ReturnNullAction());
+}
+
+// Creates an action that returns from a void function.
+inline PolymorphicAction<internal::ReturnVoidAction> Return() {
+  return MakePolymorphicAction(internal::ReturnVoidAction());
+}
+
+// Creates an action that returns the reference to a variable.
+template <typename R>
+inline internal::ReturnRefAction<R> ReturnRef(R& x) {  // NOLINT
+  return internal::ReturnRefAction<R>(x);
+}
+
+// Prevent using ReturnRef on reference to temporary.
+template <typename R, R* = nullptr>
+internal::ReturnRefAction<R> ReturnRef(R&&) = delete;
+
+// Creates an action that returns the reference to a copy of the
+// argument.  The copy is created when the action is constructed and
+// lives as long as the action.
+template <typename R>
+inline internal::ReturnRefOfCopyAction<R> ReturnRefOfCopy(const R& x) {
+  return internal::ReturnRefOfCopyAction<R>(x);
+}
+
+// DEPRECATED: use Return(x) directly with WillOnce.
+//
+// Modifies the parent action (a Return() action) to perform a move of the
+// argument instead of a copy.
+// Return(ByMove()) actions can only be executed once and will assert this
+// invariant.
+template <typename R>
+internal::ByMoveWrapper<R> ByMove(R x) {
+  return internal::ByMoveWrapper<R>(std::move(x));
+}
+
+// Creates an action that returns an element of `vals`. Calling this action will
+// repeatedly return the next value from `vals` until it reaches the end and
+// will restart from the beginning.
+template <typename T>
+internal::ReturnRoundRobinAction<T> ReturnRoundRobin(std::vector<T> vals) {
+  return internal::ReturnRoundRobinAction<T>(std::move(vals));
+}
+
+// Creates an action that returns an element of `vals`. Calling this action will
+// repeatedly return the next value from `vals` until it reaches the end and
+// will restart from the beginning.
+template <typename T>
+internal::ReturnRoundRobinAction<T> ReturnRoundRobin(
+    std::initializer_list<T> vals) {
+  return internal::ReturnRoundRobinAction<T>(std::vector<T>(vals));
+}
+
+// Creates an action that does the default action for the give mock function.
+inline internal::DoDefaultAction DoDefault() {
+  return internal::DoDefaultAction();
+}
+
+// Creates an action that sets the variable pointed by the N-th
+// (0-based) function argument to 'value'.
+template <size_t N, typename T>
+internal::SetArgumentPointeeAction<N, T> SetArgPointee(T value) {
+  return {std::move(value)};
+}
+
+// The following version is DEPRECATED.
+template <size_t N, typename T>
+internal::SetArgumentPointeeAction<N, T> SetArgumentPointee(T value) {
+  return {std::move(value)};
+}
+
+// Creates an action that sets a pointer referent to a given value.
+template <typename T1, typename T2>
+PolymorphicAction<internal::AssignAction<T1, T2>> Assign(T1* ptr, T2 val) {
+  return MakePolymorphicAction(internal::AssignAction<T1, T2>(ptr, val));
+}
+
+#ifndef GTEST_OS_WINDOWS_MOBILE
+
+// Creates an action that sets errno and returns the appropriate error.
+template <typename T>
+PolymorphicAction<internal::SetErrnoAndReturnAction<T>> SetErrnoAndReturn(
+    int errval, T result) {
+  return MakePolymorphicAction(
+      internal::SetErrnoAndReturnAction<T>(errval, result));
+}
+
+#endif  // !GTEST_OS_WINDOWS_MOBILE
+
+// Various overloads for Invoke().
+
+// Legacy function.
+// Actions can now be implicitly constructed from callables. No need to create
+// wrapper objects.
+// This function exists for backwards compatibility.
+template <typename FunctionImpl>
+typename std::decay<FunctionImpl>::type Invoke(FunctionImpl&& function_impl) {
+  return std::forward<FunctionImpl>(function_impl);
+}
+
+// Creates an action that invokes the given method on the given object
+// with the mock function's arguments.
+template <class Class, typename MethodPtr>
+internal::InvokeMethodAction<Class, MethodPtr> Invoke(Class* obj_ptr,
+                                                      MethodPtr method_ptr) {
+  return {obj_ptr, method_ptr};
+}
+
+// Creates an action that invokes 'function_impl' with no argument.
+template <typename FunctionImpl>
+internal::InvokeWithoutArgsAction<typename std::decay<FunctionImpl>::type>
+InvokeWithoutArgs(FunctionImpl function_impl) {
+  return {std::move(function_impl)};
+}
+
+// Creates an action that invokes the given method on the given object
+// with no argument.
+template <class Class, typename MethodPtr>
+internal::InvokeMethodWithoutArgsAction<Class, MethodPtr> InvokeWithoutArgs(
+    Class* obj_ptr, MethodPtr method_ptr) {
+  return {obj_ptr, method_ptr};
+}
+
+// Creates an action that performs an_action and throws away its
+// result.  In other words, it changes the return type of an_action to
+// void.  an_action MUST NOT return void, or the code won't compile.
+template <typename A>
+inline internal::IgnoreResultAction<A> IgnoreResult(const A& an_action) {
+  return internal::IgnoreResultAction<A>(an_action);
+}
+
+// Creates a reference wrapper for the given L-value.  If necessary,
+// you can explicitly specify the type of the reference.  For example,
+// suppose 'derived' is an object of type Derived, ByRef(derived)
+// would wrap a Derived&.  If you want to wrap a const Base& instead,
+// where Base is a base class of Derived, just write:
+//
+//   ByRef<const Base>(derived)
+//
+// N.B. ByRef is redundant with std::ref, std::cref and std::reference_wrapper.
+// However, it may still be used for consistency with ByMove().
+template <typename T>
+inline ::std::reference_wrapper<T> ByRef(T& l_value) {  // NOLINT
+  return ::std::reference_wrapper<T>(l_value);
+}
+
+// The ReturnNew<T>(a1, a2, ..., a_k) action returns a pointer to a new
+// instance of type T, constructed on the heap with constructor arguments
+// a1, a2, ..., and a_k. The caller assumes ownership of the returned value.
+template <typename T, typename... Params>
+internal::ReturnNewAction<T, typename std::decay<Params>::type...> ReturnNew(
+    Params&&... params) {
+  return {std::forward_as_tuple(std::forward<Params>(params)...)};
+}
+
+// Action ReturnArg<k>() returns the k-th argument of the mock function.
+template <size_t k>
+internal::ReturnArgAction<k> ReturnArg() {
+  return {};
+}
+
+// Action SaveArg<k>(pointer) saves the k-th (0-based) argument of the
+// mock function to *pointer.
+template <size_t k, typename Ptr>
+internal::SaveArgAction<k, Ptr> SaveArg(Ptr pointer) {
+  return {pointer};
+}
+
+// Action SaveArgPointee<k>(pointer) saves the value pointed to
+// by the k-th (0-based) argument of the mock function to *pointer.
+template <size_t k, typename Ptr>
+internal::SaveArgPointeeAction<k, Ptr> SaveArgPointee(Ptr pointer) {
+  return {pointer};
+}
+
+// Action SetArgReferee<k>(value) assigns 'value' to the variable
+// referenced by the k-th (0-based) argument of the mock function.
+template <size_t k, typename T>
+internal::SetArgRefereeAction<k, typename std::decay<T>::type> SetArgReferee(
+    T&& value) {
+  return {std::forward<T>(value)};
+}
+
+// Action SetArrayArgument<k>(first, last) copies the elements in
+// source range [first, last) to the array pointed to by the k-th
+// (0-based) argument, which can be either a pointer or an
+// iterator. The action does not take ownership of the elements in the
+// source range.
+template <size_t k, typename I1, typename I2>
+internal::SetArrayArgumentAction<k, I1, I2> SetArrayArgument(I1 first,
+                                                             I2 last) {
+  return {first, last};
+}
+
+// Action DeleteArg<k>() deletes the k-th (0-based) argument of the mock
+// function.
+template <size_t k>
+internal::DeleteArgAction<k> DeleteArg() {
+  return {};
+}
+
+// This action returns the value pointed to by 'pointer'.
+template <typename Ptr>
+internal::ReturnPointeeAction<Ptr> ReturnPointee(Ptr pointer) {
+  return {pointer};
+}
+
+// Action Throw(exception) can be used in a mock function of any type
+// to throw the given exception.  Any copyable value can be thrown.
+#if GTEST_HAS_EXCEPTIONS
+template <typename T>
+internal::ThrowAction<typename std::decay<T>::type> Throw(T&& exception) {
+  return {std::forward<T>(exception)};
+}
+#endif  // GTEST_HAS_EXCEPTIONS
+
+namespace internal {
+
+// A macro from the ACTION* family (defined later in gmock-generated-actions.h)
+// defines an action that can be used in a mock function.  Typically,
+// these actions only care about a subset of the arguments of the mock
+// function.  For example, if such an action only uses the second
+// argument, it can be used in any mock function that takes >= 2
+// arguments where the type of the second argument is compatible.
+//
+// Therefore, the action implementation must be prepared to take more
+// arguments than it needs.  The ExcessiveArg type is used to
+// represent those excessive arguments.  In order to keep the compiler
+// error messages tractable, we define it in the testing namespace
+// instead of testing::internal.  However, this is an INTERNAL TYPE
+// and subject to change without notice, so a user MUST NOT USE THIS
+// TYPE DIRECTLY.
+struct ExcessiveArg {};
+
+// Builds an implementation of an Action<> for some particular signature, using
+// a class defined by an ACTION* macro.
+template <typename F, typename Impl>
+struct ActionImpl;
+
+template <typename Impl>
+struct ImplBase {
+  struct Holder {
+    // Allows each copy of the Action<> to get to the Impl.
+    explicit operator const Impl&() const { return *ptr; }
+    std::shared_ptr<Impl> ptr;
+  };
+  using type = typename std::conditional<std::is_constructible<Impl>::value,
+                                         Impl, Holder>::type;
+};
+
+template <typename R, typename... Args, typename Impl>
+struct ActionImpl<R(Args...), Impl> : ImplBase<Impl>::type {
+  using Base = typename ImplBase<Impl>::type;
+  using function_type = R(Args...);
+  using args_type = std::tuple<Args...>;
+
+  ActionImpl() = default;  // Only defined if appropriate for Base.
+  explicit ActionImpl(std::shared_ptr<Impl> impl) : Base{std::move(impl)} {}
+
+  R operator()(Args&&... arg) const {
+    static constexpr size_t kMaxArgs =
+        sizeof...(Args) <= 10 ? sizeof...(Args) : 10;
+    return Apply(MakeIndexSequence<kMaxArgs>{},
+                 MakeIndexSequence<10 - kMaxArgs>{},
+                 args_type{std::forward<Args>(arg)...});
+  }
+
+  template <std::size_t... arg_id, std::size_t... excess_id>
+  R Apply(IndexSequence<arg_id...>, IndexSequence<excess_id...>,
+          const args_type& args) const {
+    // Impl need not be specific to the signature of action being implemented;
+    // only the implementing function body needs to have all of the specific
+    // types instantiated.  Up to 10 of the args that are provided by the
+    // args_type get passed, followed by a dummy of unspecified type for the
+    // remainder up to 10 explicit args.
+    static constexpr ExcessiveArg kExcessArg{};
+    return static_cast<const Impl&>(*this)
+        .template gmock_PerformImpl<
+            /*function_type=*/function_type, /*return_type=*/R,
+            /*args_type=*/args_type,
+            /*argN_type=*/
+            typename std::tuple_element<arg_id, args_type>::type...>(
+            /*args=*/args, std::get<arg_id>(args)...,
+            ((void)excess_id, kExcessArg)...);
+  }
+};
+
+// Stores a default-constructed Impl as part of the Action<>'s
+// std::function<>. The Impl should be trivial to copy.
+template <typename F, typename Impl>
+::testing::Action<F> MakeAction() {
+  return ::testing::Action<F>(ActionImpl<F, Impl>());
+}
+
+// Stores just the one given instance of Impl.
+template <typename F, typename Impl>
+::testing::Action<F> MakeAction(std::shared_ptr<Impl> impl) {
+  return ::testing::Action<F>(ActionImpl<F, Impl>(std::move(impl)));
+}
+
+#define GMOCK_INTERNAL_ARG_UNUSED(i, data, el) \
+  , const arg##i##_type& arg##i GTEST_ATTRIBUTE_UNUSED_
+#define GMOCK_ACTION_ARG_TYPES_AND_NAMES_UNUSED_                 \
+  const args_type& args GTEST_ATTRIBUTE_UNUSED_ GMOCK_PP_REPEAT( \
+      GMOCK_INTERNAL_ARG_UNUSED, , 10)
+
+#define GMOCK_INTERNAL_ARG(i, data, el) , const arg##i##_type& arg##i
+#define GMOCK_ACTION_ARG_TYPES_AND_NAMES_ \
+  const args_type& args GMOCK_PP_REPEAT(GMOCK_INTERNAL_ARG, , 10)
+
+#define GMOCK_INTERNAL_TEMPLATE_ARG(i, data, el) , typename arg##i##_type
+#define GMOCK_ACTION_TEMPLATE_ARGS_NAMES_ \
+  GMOCK_PP_TAIL(GMOCK_PP_REPEAT(GMOCK_INTERNAL_TEMPLATE_ARG, , 10))
+
+#define GMOCK_INTERNAL_TYPENAME_PARAM(i, data, param) , typename param##_type
+#define GMOCK_ACTION_TYPENAME_PARAMS_(params) \
+  GMOCK_PP_TAIL(GMOCK_PP_FOR_EACH(GMOCK_INTERNAL_TYPENAME_PARAM, , params))
+
+#define GMOCK_INTERNAL_TYPE_PARAM(i, data, param) , param##_type
+#define GMOCK_ACTION_TYPE_PARAMS_(params) \
+  GMOCK_PP_TAIL(GMOCK_PP_FOR_EACH(GMOCK_INTERNAL_TYPE_PARAM, , params))
+
+#define GMOCK_INTERNAL_TYPE_GVALUE_PARAM(i, data, param) \
+  , param##_type gmock_p##i
+#define GMOCK_ACTION_TYPE_GVALUE_PARAMS_(params) \
+  GMOCK_PP_TAIL(GMOCK_PP_FOR_EACH(GMOCK_INTERNAL_TYPE_GVALUE_PARAM, , params))
+
+#define GMOCK_INTERNAL_GVALUE_PARAM(i, data, param) \
+  , std::forward<param##_type>(gmock_p##i)
+#define GMOCK_ACTION_GVALUE_PARAMS_(params) \
+  GMOCK_PP_TAIL(GMOCK_PP_FOR_EACH(GMOCK_INTERNAL_GVALUE_PARAM, , params))
+
+#define GMOCK_INTERNAL_INIT_PARAM(i, data, param) \
+  , param(::std::forward<param##_type>(gmock_p##i))
+#define GMOCK_ACTION_INIT_PARAMS_(params) \
+  GMOCK_PP_TAIL(GMOCK_PP_FOR_EACH(GMOCK_INTERNAL_INIT_PARAM, , params))
+
+#define GMOCK_INTERNAL_FIELD_PARAM(i, data, param) param##_type param;
+#define GMOCK_ACTION_FIELD_PARAMS_(params) \
+  GMOCK_PP_FOR_EACH(GMOCK_INTERNAL_FIELD_PARAM, , params)
+
+#define GMOCK_INTERNAL_ACTION(name, full_name, params)                         \
+  template <GMOCK_ACTION_TYPENAME_PARAMS_(params)>                             \
+  class full_name {                                                            \
+   public:                                                                     \
+    explicit full_name(GMOCK_ACTION_TYPE_GVALUE_PARAMS_(params))               \
+        : impl_(std::make_shared<gmock_Impl>(                                  \
+              GMOCK_ACTION_GVALUE_PARAMS_(params))) {}                         \
+    full_name(const full_name&) = default;                                     \
+    full_name(full_name&&) noexcept = default;                                 \
+    template <typename F>                                                      \
+    operator ::testing::Action<F>() const {                                    \
+      return ::testing::internal::MakeAction<F>(impl_);                        \
+    }                                                                          \
+                                                                               \
+   private:                                                                    \
+    class gmock_Impl {                                                         \
+     public:                                                                   \
+      explicit gmock_Impl(GMOCK_ACTION_TYPE_GVALUE_PARAMS_(params))            \
+          : GMOCK_ACTION_INIT_PARAMS_(params) {}                               \
+      template <typename function_type, typename return_type,                  \
+                typename args_type, GMOCK_ACTION_TEMPLATE_ARGS_NAMES_>         \
+      return_type gmock_PerformImpl(GMOCK_ACTION_ARG_TYPES_AND_NAMES_) const;  \
+      GMOCK_ACTION_FIELD_PARAMS_(params)                                       \
+    };                                                                         \
+    std::shared_ptr<const gmock_Impl> impl_;                                   \
+  };                                                                           \
+  template <GMOCK_ACTION_TYPENAME_PARAMS_(params)>                             \
+  inline full_name<GMOCK_ACTION_TYPE_PARAMS_(params)> name(                    \
+      GMOCK_ACTION_TYPE_GVALUE_PARAMS_(params)) GTEST_MUST_USE_RESULT_;        \
+  template <GMOCK_ACTION_TYPENAME_PARAMS_(params)>                             \
+  inline full_name<GMOCK_ACTION_TYPE_PARAMS_(params)> name(                    \
+      GMOCK_ACTION_TYPE_GVALUE_PARAMS_(params)) {                              \
+    return full_name<GMOCK_ACTION_TYPE_PARAMS_(params)>(                       \
+        GMOCK_ACTION_GVALUE_PARAMS_(params));                                  \
+  }                                                                            \
+  template <GMOCK_ACTION_TYPENAME_PARAMS_(params)>                             \
+  template <typename function_type, typename return_type, typename args_type,  \
+            GMOCK_ACTION_TEMPLATE_ARGS_NAMES_>                                 \
+  return_type                                                                  \
+  full_name<GMOCK_ACTION_TYPE_PARAMS_(params)>::gmock_Impl::gmock_PerformImpl( \
+      GMOCK_ACTION_ARG_TYPES_AND_NAMES_UNUSED_) const
+
+}  // namespace internal
+
+// Similar to GMOCK_INTERNAL_ACTION, but no bound parameters are stored.
+#define ACTION(name)                                                          \
+  class name##Action {                                                        \
+   public:                                                                    \
+    explicit name##Action() noexcept {}                                       \
+    name##Action(const name##Action&) noexcept {}                             \
+    template <typename F>                                                     \
+    operator ::testing::Action<F>() const {                                   \
+      return ::testing::internal::MakeAction<F, gmock_Impl>();                \
+    }                                                                         \
+                                                                              \
+   private:                                                                   \
+    class gmock_Impl {                                                        \
+     public:                                                                  \
+      template <typename function_type, typename return_type,                 \
+                typename args_type, GMOCK_ACTION_TEMPLATE_ARGS_NAMES_>        \
+      return_type gmock_PerformImpl(GMOCK_ACTION_ARG_TYPES_AND_NAMES_) const; \
+    };                                                                        \
+  };                                                                          \
+  inline name##Action name() GTEST_MUST_USE_RESULT_;                          \
+  inline name##Action name() { return name##Action(); }                       \
+  template <typename function_type, typename return_type, typename args_type, \
+            GMOCK_ACTION_TEMPLATE_ARGS_NAMES_>                                \
+  return_type name##Action::gmock_Impl::gmock_PerformImpl(                    \
+      GMOCK_ACTION_ARG_TYPES_AND_NAMES_UNUSED_) const
+
+#define ACTION_P(name, ...) \
+  GMOCK_INTERNAL_ACTION(name, name##ActionP, (__VA_ARGS__))
+
+#define ACTION_P2(name, ...) \
+  GMOCK_INTERNAL_ACTION(name, name##ActionP2, (__VA_ARGS__))
+
+#define ACTION_P3(name, ...) \
+  GMOCK_INTERNAL_ACTION(name, name##ActionP3, (__VA_ARGS__))
+
+#define ACTION_P4(name, ...) \
+  GMOCK_INTERNAL_ACTION(name, name##ActionP4, (__VA_ARGS__))
+
+#define ACTION_P5(name, ...) \
+  GMOCK_INTERNAL_ACTION(name, name##ActionP5, (__VA_ARGS__))
+
+#define ACTION_P6(name, ...) \
+  GMOCK_INTERNAL_ACTION(name, name##ActionP6, (__VA_ARGS__))
+
+#define ACTION_P7(name, ...) \
+  GMOCK_INTERNAL_ACTION(name, name##ActionP7, (__VA_ARGS__))
+
+#define ACTION_P8(name, ...) \
+  GMOCK_INTERNAL_ACTION(name, name##ActionP8, (__VA_ARGS__))
+
+#define ACTION_P9(name, ...) \
+  GMOCK_INTERNAL_ACTION(name, name##ActionP9, (__VA_ARGS__))
+
+#define ACTION_P10(name, ...) \
+  GMOCK_INTERNAL_ACTION(name, name##ActionP10, (__VA_ARGS__))
+
+}  // namespace testing
+
+GTEST_DISABLE_MSC_WARNINGS_POP_()  // 4100
+
+#endif  // GOOGLEMOCK_INCLUDE_GMOCK_GMOCK_ACTIONS_H_

contrib/googletest/googlemock/include/gmock/gmock-cardinalities.h

@@ -0,0 +1,159 @@
+// Copyright 2007, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+// Google Mock - a framework for writing C++ mock classes.
+//
+// This file implements some commonly used cardinalities.  More
+// cardinalities can be defined by the user implementing the
+// CardinalityInterface interface if necessary.
+
+// IWYU pragma: private, include "gmock/gmock.h"
+// IWYU pragma: friend gmock/.*
+
+#ifndef GOOGLEMOCK_INCLUDE_GMOCK_GMOCK_CARDINALITIES_H_
+#define GOOGLEMOCK_INCLUDE_GMOCK_GMOCK_CARDINALITIES_H_
+
+#include <limits.h>
+
+#include <memory>
+#include <ostream>  // NOLINT
+
+#include "gmock/internal/gmock-port.h"
+#include "gtest/gtest.h"
+
+GTEST_DISABLE_MSC_WARNINGS_PUSH_(4251 \
+/* class A needs to have dll-interface to be used by clients of class B */)
+
+namespace testing {
+
+// To implement a cardinality Foo, define:
+//   1. a class FooCardinality that implements the
+//      CardinalityInterface interface, and
+//   2. a factory function that creates a Cardinality object from a
+//      const FooCardinality*.
+//
+// The two-level delegation design follows that of Matcher, providing
+// consistency for extension developers.  It also eases ownership
+// management as Cardinality objects can now be copied like plain values.
+
+// The implementation of a cardinality.
+class CardinalityInterface {
+ public:
+  virtual ~CardinalityInterface() = default;
+
+  // Conservative estimate on the lower/upper bound of the number of
+  // calls allowed.
+  virtual int ConservativeLowerBound() const { return 0; }
+  virtual int ConservativeUpperBound() const { return INT_MAX; }
+
+  // Returns true if and only if call_count calls will satisfy this
+  // cardinality.
+  virtual bool IsSatisfiedByCallCount(int call_count) const = 0;
+
+  // Returns true if and only if call_count calls will saturate this
+  // cardinality.
+  virtual bool IsSaturatedByCallCount(int call_count) const = 0;
+
+  // Describes self to an ostream.
+  virtual void DescribeTo(::std::ostream* os) const = 0;
+};
+
+// A Cardinality is a copyable and IMMUTABLE (except by assignment)
+// object that specifies how many times a mock function is expected to
+// be called.  The implementation of Cardinality is just a std::shared_ptr
+// to const CardinalityInterface. Don't inherit from Cardinality!
+class GTEST_API_ Cardinality {
+ public:
+  // Constructs a null cardinality.  Needed for storing Cardinality
+  // objects in STL containers.
+  Cardinality() = default;
+
+  // Constructs a Cardinality from its implementation.
+  explicit Cardinality(const CardinalityInterface* impl) : impl_(impl) {}
+
+  // Conservative estimate on the lower/upper bound of the number of
+  // calls allowed.
+  int ConservativeLowerBound() const { return impl_->ConservativeLowerBound(); }
+  int ConservativeUpperBound() const { return impl_->ConservativeUpperBound(); }
+
+  // Returns true if and only if call_count calls will satisfy this
+  // cardinality.
+  bool IsSatisfiedByCallCount(int call_count) const {
+    return impl_->IsSatisfiedByCallCount(call_count);
+  }
+
+  // Returns true if and only if call_count calls will saturate this
+  // cardinality.
+  bool IsSaturatedByCallCount(int call_count) const {
+    return impl_->IsSaturatedByCallCount(call_count);
+  }
+
+  // Returns true if and only if call_count calls will over-saturate this
+  // cardinality, i.e. exceed the maximum number of allowed calls.
+  bool IsOverSaturatedByCallCount(int call_count) const {
+    return impl_->IsSaturatedByCallCount(call_count) &&
+           !impl_->IsSatisfiedByCallCount(call_count);
+  }
+
+  // Describes self to an ostream
+  void DescribeTo(::std::ostream* os) const { impl_->DescribeTo(os); }
+
+  // Describes the given actual call count to an ostream.
+  static void DescribeActualCallCountTo(int actual_call_count,
+                                        ::std::ostream* os);
+
+ private:
+  std::shared_ptr<const CardinalityInterface> impl_;
+};
+
+// Creates a cardinality that allows at least n calls.
+GTEST_API_ Cardinality AtLeast(int n);
+
+// Creates a cardinality that allows at most n calls.
+GTEST_API_ Cardinality AtMost(int n);
+
+// Creates a cardinality that allows any number of calls.
+GTEST_API_ Cardinality AnyNumber();
+
+// Creates a cardinality that allows between min and max calls.
+GTEST_API_ Cardinality Between(int min, int max);
+
+// Creates a cardinality that allows exactly n calls.
+GTEST_API_ Cardinality Exactly(int n);
+
+// Creates a cardinality from its implementation.
+inline Cardinality MakeCardinality(const CardinalityInterface* c) {
+  return Cardinality(c);
+}
+
+}  // namespace testing
+
+GTEST_DISABLE_MSC_WARNINGS_POP_()  //  4251
+
+#endif  // GOOGLEMOCK_INCLUDE_GMOCK_GMOCK_CARDINALITIES_H_

contrib/googletest/googlemock/include/gmock/gmock-function-mocker.h

@@ -0,0 +1,518 @@
+// Copyright 2007, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+// Google Mock - a framework for writing C++ mock classes.
+//
+// This file implements MOCK_METHOD.
+
+// IWYU pragma: private, include "gmock/gmock.h"
+// IWYU pragma: friend gmock/.*
+
+#ifndef GOOGLEMOCK_INCLUDE_GMOCK_GMOCK_FUNCTION_MOCKER_H_
+#define GOOGLEMOCK_INCLUDE_GMOCK_GMOCK_FUNCTION_MOCKER_H_
+
+#include <type_traits>  // IWYU pragma: keep
+#include <utility>      // IWYU pragma: keep
+
+#include "gmock/gmock-spec-builders.h"
+#include "gmock/internal/gmock-internal-utils.h"
+#include "gmock/internal/gmock-pp.h"
+
+namespace testing {
+namespace internal {
+template <typename T>
+using identity_t = T;
+
+template <typename Pattern>
+struct ThisRefAdjuster {
+  template <typename T>
+  using AdjustT = typename std::conditional<
+      std::is_const<typename std::remove_reference<Pattern>::type>::value,
+      typename std::conditional<std::is_lvalue_reference<Pattern>::value,
+                                const T&, const T&&>::type,
+      typename std::conditional<std::is_lvalue_reference<Pattern>::value, T&,
+                                T&&>::type>::type;
+
+  template <typename MockType>
+  static AdjustT<MockType> Adjust(const MockType& mock) {
+    return static_cast<AdjustT<MockType>>(const_cast<MockType&>(mock));
+  }
+};
+
+constexpr bool PrefixOf(const char* a, const char* b) {
+  return *a == 0 || (*a == *b && internal::PrefixOf(a + 1, b + 1));
+}
+
+template <int N, int M>
+constexpr bool StartsWith(const char (&prefix)[N], const char (&str)[M]) {
+  return N <= M && internal::PrefixOf(prefix, str);
+}
+
+template <int N, int M>
+constexpr bool EndsWith(const char (&suffix)[N], const char (&str)[M]) {
+  return N <= M && internal::PrefixOf(suffix, str + M - N);
+}
+
+template <int N, int M>
+constexpr bool Equals(const char (&a)[N], const char (&b)[M]) {
+  return N == M && internal::PrefixOf(a, b);
+}
+
+template <int N>
+constexpr bool ValidateSpec(const char (&spec)[N]) {
+  return internal::Equals("const", spec) ||
+         internal::Equals("override", spec) ||
+         internal::Equals("final", spec) ||
+         internal::Equals("noexcept", spec) ||
+         (internal::StartsWith("noexcept(", spec) &&
+          internal::EndsWith(")", spec)) ||
+         internal::Equals("ref(&)", spec) ||
+         internal::Equals("ref(&&)", spec) ||
+         (internal::StartsWith("Calltype(", spec) &&
+          internal::EndsWith(")", spec));
+}
+
+}  // namespace internal
+
+// The style guide prohibits "using" statements in a namespace scope
+// inside a header file.  However, the FunctionMocker class template
+// is meant to be defined in the ::testing namespace.  The following
+// line is just a trick for working around a bug in MSVC 8.0, which
+// cannot handle it if we define FunctionMocker in ::testing.
+using internal::FunctionMocker;
+}  // namespace testing
+
+#define MOCK_METHOD(...)                                               \
+  GMOCK_INTERNAL_WARNING_PUSH()                                        \
+  GMOCK_INTERNAL_WARNING_CLANG(ignored, "-Wunused-member-function")    \
+  GMOCK_PP_VARIADIC_CALL(GMOCK_INTERNAL_MOCK_METHOD_ARG_, __VA_ARGS__) \
+  GMOCK_INTERNAL_WARNING_POP()
+
+#define GMOCK_INTERNAL_MOCK_METHOD_ARG_1(...) \
+  GMOCK_INTERNAL_WRONG_ARITY(__VA_ARGS__)
+
+#define GMOCK_INTERNAL_MOCK_METHOD_ARG_2(...) \
+  GMOCK_INTERNAL_WRONG_ARITY(__VA_ARGS__)
+
+#define GMOCK_INTERNAL_MOCK_METHOD_ARG_3(_Ret, _MethodName, _Args) \
+  GMOCK_INTERNAL_MOCK_METHOD_ARG_4(_Ret, _MethodName, _Args, ())
+
+#define GMOCK_INTERNAL_MOCK_METHOD_ARG_4(_Ret, _MethodName, _Args, _Spec)  \
+  GMOCK_INTERNAL_ASSERT_PARENTHESIS(_Args);                                \
+  GMOCK_INTERNAL_ASSERT_PARENTHESIS(_Spec);                                \
+  GMOCK_INTERNAL_ASSERT_VALID_SIGNATURE(                                   \
+      GMOCK_PP_NARG0 _Args, GMOCK_INTERNAL_SIGNATURE(_Ret, _Args));        \
+  GMOCK_INTERNAL_ASSERT_VALID_SPEC(_Spec)                                  \
+  GMOCK_INTERNAL_MOCK_METHOD_IMPL(                                         \
+      GMOCK_PP_NARG0 _Args, _MethodName, GMOCK_INTERNAL_HAS_CONST(_Spec),  \
+      GMOCK_INTERNAL_HAS_OVERRIDE(_Spec), GMOCK_INTERNAL_HAS_FINAL(_Spec), \
+      GMOCK_INTERNAL_GET_NOEXCEPT_SPEC(_Spec),                             \
+      GMOCK_INTERNAL_GET_CALLTYPE_SPEC(_Spec),                             \
+      GMOCK_INTERNAL_GET_REF_SPEC(_Spec),                                  \
+      (GMOCK_INTERNAL_SIGNATURE(_Ret, _Args)))
+
+#define GMOCK_INTERNAL_MOCK_METHOD_ARG_5(...) \
+  GMOCK_INTERNAL_WRONG_ARITY(__VA_ARGS__)
+
+#define GMOCK_INTERNAL_MOCK_METHOD_ARG_6(...) \
+  GMOCK_INTERNAL_WRONG_ARITY(__VA_ARGS__)
+
+#define GMOCK_INTERNAL_MOCK_METHOD_ARG_7(...) \
+  GMOCK_INTERNAL_WRONG_ARITY(__VA_ARGS__)
+
+#define GMOCK_INTERNAL_WRONG_ARITY(...)                                      \
+  static_assert(                                                             \
+      false,                                                                 \
+      "MOCK_METHOD must be called with 3 or 4 arguments. _Ret, "             \
+      "_MethodName, _Args and optionally _Spec. _Args and _Spec must be "    \
+      "enclosed in parentheses. If _Ret is a type with unprotected commas, " \
+      "it must also be enclosed in parentheses.")
+
+#define GMOCK_INTERNAL_ASSERT_PARENTHESIS(_Tuple) \
+  static_assert(                                  \
+      GMOCK_PP_IS_ENCLOSED_PARENS(_Tuple),        \
+      GMOCK_PP_STRINGIZE(_Tuple) " should be enclosed in parentheses.")
+
+#define GMOCK_INTERNAL_ASSERT_VALID_SIGNATURE(_N, ...)                 \
+  static_assert(                                                       \
+      std::is_function<__VA_ARGS__>::value,                            \
+      "Signature must be a function type, maybe return type contains " \
+      "unprotected comma.");                                           \
+  static_assert(                                                       \
+      ::testing::tuple_size<typename ::testing::internal::Function<    \
+              __VA_ARGS__>::ArgumentTuple>::value == _N,               \
+      "This method does not take " GMOCK_PP_STRINGIZE(                 \
+          _N) " arguments. Parenthesize all types with unprotected commas.")
+
+#define GMOCK_INTERNAL_ASSERT_VALID_SPEC(_Spec) \
+  GMOCK_PP_FOR_EACH(GMOCK_INTERNAL_ASSERT_VALID_SPEC_ELEMENT, ~, _Spec)
+
+#define GMOCK_INTERNAL_MOCK_METHOD_IMPL(_N, _MethodName, _Constness,           \
+                                        _Override, _Final, _NoexceptSpec,      \
+                                        _CallType, _RefSpec, _Signature)       \
+  typename ::testing::internal::Function<GMOCK_PP_REMOVE_PARENS(               \
+      _Signature)>::Result                                                     \
+  GMOCK_INTERNAL_EXPAND(_CallType)                                             \
+      _MethodName(GMOCK_PP_REPEAT(GMOCK_INTERNAL_PARAMETER, _Signature, _N))   \
+          GMOCK_PP_IF(_Constness, const, )                                     \
+              _RefSpec _NoexceptSpec GMOCK_PP_IF(_Override, override, )        \
+                  GMOCK_PP_IF(_Final, final, ) {                               \
+    GMOCK_MOCKER_(_N, _Constness, _MethodName)                                 \
+        .SetOwnerAndName(this, #_MethodName);                                  \
+    return GMOCK_MOCKER_(_N, _Constness, _MethodName)                          \
+        .Invoke(GMOCK_PP_REPEAT(GMOCK_INTERNAL_FORWARD_ARG, _Signature, _N));  \
+  }                                                                            \
+  ::testing::MockSpec<GMOCK_PP_REMOVE_PARENS(_Signature)> gmock_##_MethodName( \
+      GMOCK_PP_REPEAT(GMOCK_INTERNAL_MATCHER_PARAMETER, _Signature, _N))       \
+      GMOCK_PP_IF(_Constness, const, ) _RefSpec {                              \
+    GMOCK_MOCKER_(_N, _Constness, _MethodName).RegisterOwner(this);            \
+    return GMOCK_MOCKER_(_N, _Constness, _MethodName)                          \
+        .With(GMOCK_PP_REPEAT(GMOCK_INTERNAL_MATCHER_ARGUMENT, , _N));         \
+  }                                                                            \
+  ::testing::MockSpec<GMOCK_PP_REMOVE_PARENS(_Signature)> gmock_##_MethodName( \
+      const ::testing::internal::WithoutMatchers&,                             \
+      GMOCK_PP_IF(_Constness, const, )::testing::internal::Function<           \
+          GMOCK_PP_REMOVE_PARENS(_Signature)>*) const _RefSpec _NoexceptSpec { \
+    return ::testing::internal::ThisRefAdjuster<GMOCK_PP_IF(                   \
+        _Constness, const, ) int _RefSpec>::Adjust(*this)                      \
+        .gmock_##_MethodName(GMOCK_PP_REPEAT(                                  \
+            GMOCK_INTERNAL_A_MATCHER_ARGUMENT, _Signature, _N));               \
+  }                                                                            \
+  mutable ::testing::FunctionMocker<GMOCK_PP_REMOVE_PARENS(_Signature)>        \
+  GMOCK_MOCKER_(_N, _Constness, _MethodName)
+
+#define GMOCK_INTERNAL_EXPAND(...) __VA_ARGS__
+
+// Valid modifiers.
+#define GMOCK_INTERNAL_HAS_CONST(_Tuple) \
+  GMOCK_PP_HAS_COMMA(GMOCK_PP_FOR_EACH(GMOCK_INTERNAL_DETECT_CONST, ~, _Tuple))
+
+#define GMOCK_INTERNAL_HAS_OVERRIDE(_Tuple) \
+  GMOCK_PP_HAS_COMMA(                       \
+      GMOCK_PP_FOR_EACH(GMOCK_INTERNAL_DETECT_OVERRIDE, ~, _Tuple))
+
+#define GMOCK_INTERNAL_HAS_FINAL(_Tuple) \
+  GMOCK_PP_HAS_COMMA(GMOCK_PP_FOR_EACH(GMOCK_INTERNAL_DETECT_FINAL, ~, _Tuple))
+
+#define GMOCK_INTERNAL_GET_NOEXCEPT_SPEC(_Tuple) \
+  GMOCK_PP_FOR_EACH(GMOCK_INTERNAL_NOEXCEPT_SPEC_IF_NOEXCEPT, ~, _Tuple)
+
+#define GMOCK_INTERNAL_NOEXCEPT_SPEC_IF_NOEXCEPT(_i, _, _elem)          \
+  GMOCK_PP_IF(                                                          \
+      GMOCK_PP_HAS_COMMA(GMOCK_INTERNAL_DETECT_NOEXCEPT(_i, _, _elem)), \
+      _elem, )
+
+#define GMOCK_INTERNAL_GET_CALLTYPE_SPEC(_Tuple) \
+  GMOCK_PP_FOR_EACH(GMOCK_INTERNAL_CALLTYPE_SPEC_IF_CALLTYPE, ~, _Tuple)
+
+#define GMOCK_INTERNAL_CALLTYPE_SPEC_IF_CALLTYPE(_i, _, _elem)          \
+  GMOCK_PP_IF(                                                          \
+      GMOCK_PP_HAS_COMMA(GMOCK_INTERNAL_DETECT_CALLTYPE(_i, _, _elem)), \
+      GMOCK_PP_CAT(GMOCK_INTERNAL_UNPACK_, _elem), )
+
+#define GMOCK_INTERNAL_GET_REF_SPEC(_Tuple) \
+  GMOCK_PP_FOR_EACH(GMOCK_INTERNAL_REF_SPEC_IF_REF, ~, _Tuple)
+
+#define GMOCK_INTERNAL_REF_SPEC_IF_REF(_i, _, _elem)                       \
+  GMOCK_PP_IF(GMOCK_PP_HAS_COMMA(GMOCK_INTERNAL_DETECT_REF(_i, _, _elem)), \
+              GMOCK_PP_CAT(GMOCK_INTERNAL_UNPACK_, _elem), )
+
+#ifdef GMOCK_INTERNAL_STRICT_SPEC_ASSERT
+#define GMOCK_INTERNAL_ASSERT_VALID_SPEC_ELEMENT(_i, _, _elem) \
+  static_assert(                                                     \
+      ::testing::internal::ValidateSpec(GMOCK_PP_STRINGIZE(_elem)),  \
+      "Token \'" GMOCK_PP_STRINGIZE(                                 \
+          _elem) "\' cannot be recognized as a valid specification " \
+                 "modifier. Is a ',' missing?");
+#else
+#define GMOCK_INTERNAL_ASSERT_VALID_SPEC_ELEMENT(_i, _, _elem)                 \
+  static_assert(                                                               \
+      (GMOCK_PP_HAS_COMMA(GMOCK_INTERNAL_DETECT_CONST(_i, _, _elem)) +         \
+       GMOCK_PP_HAS_COMMA(GMOCK_INTERNAL_DETECT_OVERRIDE(_i, _, _elem)) +      \
+       GMOCK_PP_HAS_COMMA(GMOCK_INTERNAL_DETECT_FINAL(_i, _, _elem)) +         \
+       GMOCK_PP_HAS_COMMA(GMOCK_INTERNAL_DETECT_NOEXCEPT(_i, _, _elem)) +      \
+       GMOCK_PP_HAS_COMMA(GMOCK_INTERNAL_DETECT_REF(_i, _, _elem)) +           \
+       GMOCK_PP_HAS_COMMA(GMOCK_INTERNAL_DETECT_CALLTYPE(_i, _, _elem))) == 1, \
+      GMOCK_PP_STRINGIZE(                                                      \
+          _elem) " cannot be recognized as a valid specification modifier.");
+#endif  // GMOCK_INTERNAL_STRICT_SPEC_ASSERT
+
+// Modifiers implementation.
+#define GMOCK_INTERNAL_DETECT_CONST(_i, _, _elem) \
+  GMOCK_PP_CAT(GMOCK_INTERNAL_DETECT_CONST_I_, _elem)
+
+#define GMOCK_INTERNAL_DETECT_CONST_I_const ,
+
+#define GMOCK_INTERNAL_DETECT_OVERRIDE(_i, _, _elem) \
+  GMOCK_PP_CAT(GMOCK_INTERNAL_DETECT_OVERRIDE_I_, _elem)
+
+#define GMOCK_INTERNAL_DETECT_OVERRIDE_I_override ,
+
+#define GMOCK_INTERNAL_DETECT_FINAL(_i, _, _elem) \
+  GMOCK_PP_CAT(GMOCK_INTERNAL_DETECT_FINAL_I_, _elem)
+
+#define GMOCK_INTERNAL_DETECT_FINAL_I_final ,
+
+#define GMOCK_INTERNAL_DETECT_NOEXCEPT(_i, _, _elem) \
+  GMOCK_PP_CAT(GMOCK_INTERNAL_DETECT_NOEXCEPT_I_, _elem)
+
+#define GMOCK_INTERNAL_DETECT_NOEXCEPT_I_noexcept ,
+
+#define GMOCK_INTERNAL_DETECT_REF(_i, _, _elem) \
+  GMOCK_PP_CAT(GMOCK_INTERNAL_DETECT_REF_I_, _elem)
+
+#define GMOCK_INTERNAL_DETECT_REF_I_ref ,
+
+#define GMOCK_INTERNAL_UNPACK_ref(x) x
+
+#define GMOCK_INTERNAL_DETECT_CALLTYPE(_i, _, _elem) \
+  GMOCK_PP_CAT(GMOCK_INTERNAL_DETECT_CALLTYPE_I_, _elem)
+
+#define GMOCK_INTERNAL_DETECT_CALLTYPE_I_Calltype ,
+
+#define GMOCK_INTERNAL_UNPACK_Calltype(...) __VA_ARGS__
+
+// Note: The use of `identity_t` here allows _Ret to represent return types that
+// would normally need to be specified in a different way. For example, a method
+// returning a function pointer must be written as
+//
+// fn_ptr_return_t (*method(method_args_t...))(fn_ptr_args_t...)
+//
+// But we only support placing the return type at the beginning. To handle this,
+// we wrap all calls in identity_t, so that a declaration will be expanded to
+//
+// identity_t<fn_ptr_return_t (*)(fn_ptr_args_t...)> method(method_args_t...)
+//
+// This allows us to work around the syntactic oddities of function/method
+// types.
+#define GMOCK_INTERNAL_SIGNATURE(_Ret, _Args)                                 \
+  ::testing::internal::identity_t<GMOCK_PP_IF(GMOCK_PP_IS_BEGIN_PARENS(_Ret), \
+                                              GMOCK_PP_REMOVE_PARENS,         \
+                                              GMOCK_PP_IDENTITY)(_Ret)>(      \
+      GMOCK_PP_FOR_EACH(GMOCK_INTERNAL_GET_TYPE, _, _Args))
+
+#define GMOCK_INTERNAL_GET_TYPE(_i, _, _elem)                          \
+  GMOCK_PP_COMMA_IF(_i)                                                \
+  GMOCK_PP_IF(GMOCK_PP_IS_BEGIN_PARENS(_elem), GMOCK_PP_REMOVE_PARENS, \
+              GMOCK_PP_IDENTITY)                                       \
+  (_elem)
+
+#define GMOCK_INTERNAL_PARAMETER(_i, _Signature, _)            \
+  GMOCK_PP_COMMA_IF(_i)                                        \
+  GMOCK_INTERNAL_ARG_O(_i, GMOCK_PP_REMOVE_PARENS(_Signature)) \
+  gmock_a##_i
+
+#define GMOCK_INTERNAL_FORWARD_ARG(_i, _Signature, _) \
+  GMOCK_PP_COMMA_IF(_i)                               \
+  ::std::forward<GMOCK_INTERNAL_ARG_O(                \
+      _i, GMOCK_PP_REMOVE_PARENS(_Signature))>(gmock_a##_i)
+
+#define GMOCK_INTERNAL_MATCHER_PARAMETER(_i, _Signature, _)        \
+  GMOCK_PP_COMMA_IF(_i)                                            \
+  GMOCK_INTERNAL_MATCHER_O(_i, GMOCK_PP_REMOVE_PARENS(_Signature)) \
+  gmock_a##_i
+
+#define GMOCK_INTERNAL_MATCHER_ARGUMENT(_i, _1, _2) \
+  GMOCK_PP_COMMA_IF(_i)                             \
+  gmock_a##_i
+
+#define GMOCK_INTERNAL_A_MATCHER_ARGUMENT(_i, _Signature, _) \
+  GMOCK_PP_COMMA_IF(_i)                                      \
+  ::testing::A<GMOCK_INTERNAL_ARG_O(_i, GMOCK_PP_REMOVE_PARENS(_Signature))>()
+
+#define GMOCK_INTERNAL_ARG_O(_i, ...) \
+  typename ::testing::internal::Function<__VA_ARGS__>::template Arg<_i>::type
+
+#define GMOCK_INTERNAL_MATCHER_O(_i, ...)                          \
+  const ::testing::Matcher<typename ::testing::internal::Function< \
+      __VA_ARGS__>::template Arg<_i>::type>&
+
+#define MOCK_METHOD0(m, ...) GMOCK_INTERNAL_MOCK_METHODN(, , m, 0, __VA_ARGS__)
+#define MOCK_METHOD1(m, ...) GMOCK_INTERNAL_MOCK_METHODN(, , m, 1, __VA_ARGS__)
+#define MOCK_METHOD2(m, ...) GMOCK_INTERNAL_MOCK_METHODN(, , m, 2, __VA_ARGS__)
+#define MOCK_METHOD3(m, ...) GMOCK_INTERNAL_MOCK_METHODN(, , m, 3, __VA_ARGS__)
+#define MOCK_METHOD4(m, ...) GMOCK_INTERNAL_MOCK_METHODN(, , m, 4, __VA_ARGS__)
+#define MOCK_METHOD5(m, ...) GMOCK_INTERNAL_MOCK_METHODN(, , m, 5, __VA_ARGS__)
+#define MOCK_METHOD6(m, ...) GMOCK_INTERNAL_MOCK_METHODN(, , m, 6, __VA_ARGS__)
+#define MOCK_METHOD7(m, ...) GMOCK_INTERNAL_MOCK_METHODN(, , m, 7, __VA_ARGS__)
+#define MOCK_METHOD8(m, ...) GMOCK_INTERNAL_MOCK_METHODN(, , m, 8, __VA_ARGS__)
+#define MOCK_METHOD9(m, ...) GMOCK_INTERNAL_MOCK_METHODN(, , m, 9, __VA_ARGS__)
+#define MOCK_METHOD10(m, ...) \
+  GMOCK_INTERNAL_MOCK_METHODN(, , m, 10, __VA_ARGS__)
+
+#define MOCK_CONST_METHOD0(m, ...) \
+  GMOCK_INTERNAL_MOCK_METHODN(const, , m, 0, __VA_ARGS__)
+#define MOCK_CONST_METHOD1(m, ...) \
+  GMOCK_INTERNAL_MOCK_METHODN(const, , m, 1, __VA_ARGS__)
+#define MOCK_CONST_METHOD2(m, ...) \
+  GMOCK_INTERNAL_MOCK_METHODN(const, , m, 2, __VA_ARGS__)
+#define MOCK_CONST_METHOD3(m, ...) \
+  GMOCK_INTERNAL_MOCK_METHODN(const, , m, 3, __VA_ARGS__)
+#define MOCK_CONST_METHOD4(m, ...) \
+  GMOCK_INTERNAL_MOCK_METHODN(const, , m, 4, __VA_ARGS__)
+#define MOCK_CONST_METHOD5(m, ...) \
+  GMOCK_INTERNAL_MOCK_METHODN(const, , m, 5, __VA_ARGS__)
+#define MOCK_CONST_METHOD6(m, ...) \
+  GMOCK_INTERNAL_MOCK_METHODN(const, , m, 6, __VA_ARGS__)
+#define MOCK_CONST_METHOD7(m, ...) \
+  GMOCK_INTERNAL_MOCK_METHODN(const, , m, 7, __VA_ARGS__)
+#define MOCK_CONST_METHOD8(m, ...) \
+  GMOCK_INTERNAL_MOCK_METHODN(const, , m, 8, __VA_ARGS__)
+#define MOCK_CONST_METHOD9(m, ...) \
+  GMOCK_INTERNAL_MOCK_METHODN(const, , m, 9, __VA_ARGS__)
+#define MOCK_CONST_METHOD10(m, ...) \
+  GMOCK_INTERNAL_MOCK_METHODN(const, , m, 10, __VA_ARGS__)
+
+#define MOCK_METHOD0_T(m, ...) MOCK_METHOD0(m, __VA_ARGS__)
+#define MOCK_METHOD1_T(m, ...) MOCK_METHOD1(m, __VA_ARGS__)
+#define MOCK_METHOD2_T(m, ...) MOCK_METHOD2(m, __VA_ARGS__)
+#define MOCK_METHOD3_T(m, ...) MOCK_METHOD3(m, __VA_ARGS__)
+#define MOCK_METHOD4_T(m, ...) MOCK_METHOD4(m, __VA_ARGS__)
+#define MOCK_METHOD5_T(m, ...) MOCK_METHOD5(m, __VA_ARGS__)
+#define MOCK_METHOD6_T(m, ...) MOCK_METHOD6(m, __VA_ARGS__)
+#define MOCK_METHOD7_T(m, ...) MOCK_METHOD7(m, __VA_ARGS__)
+#define MOCK_METHOD8_T(m, ...) MOCK_METHOD8(m, __VA_ARGS__)
+#define MOCK_METHOD9_T(m, ...) MOCK_METHOD9(m, __VA_ARGS__)
+#define MOCK_METHOD10_T(m, ...) MOCK_METHOD10(m, __VA_ARGS__)
+
+#define MOCK_CONST_METHOD0_T(m, ...) MOCK_CONST_METHOD0(m, __VA_ARGS__)
+#define MOCK_CONST_METHOD1_T(m, ...) MOCK_CONST_METHOD1(m, __VA_ARGS__)
+#define MOCK_CONST_METHOD2_T(m, ...) MOCK_CONST_METHOD2(m, __VA_ARGS__)
+#define MOCK_CONST_METHOD3_T(m, ...) MOCK_CONST_METHOD3(m, __VA_ARGS__)
+#define MOCK_CONST_METHOD4_T(m, ...) MOCK_CONST_METHOD4(m, __VA_ARGS__)
+#define MOCK_CONST_METHOD5_T(m, ...) MOCK_CONST_METHOD5(m, __VA_ARGS__)
+#define MOCK_CONST_METHOD6_T(m, ...) MOCK_CONST_METHOD6(m, __VA_ARGS__)
+#define MOCK_CONST_METHOD7_T(m, ...) MOCK_CONST_METHOD7(m, __VA_ARGS__)
+#define MOCK_CONST_METHOD8_T(m, ...) MOCK_CONST_METHOD8(m, __VA_ARGS__)
+#define MOCK_CONST_METHOD9_T(m, ...) MOCK_CONST_METHOD9(m, __VA_ARGS__)
+#define MOCK_CONST_METHOD10_T(m, ...) MOCK_CONST_METHOD10(m, __VA_ARGS__)
+
+#define MOCK_METHOD0_WITH_CALLTYPE(ct, m, ...) \
+  GMOCK_INTERNAL_MOCK_METHODN(, ct, m, 0, __VA_ARGS__)
+#define MOCK_METHOD1_WITH_CALLTYPE(ct, m, ...) \
+  GMOCK_INTERNAL_MOCK_METHODN(, ct, m, 1, __VA_ARGS__)
+#define MOCK_METHOD2_WITH_CALLTYPE(ct, m, ...) \
+  GMOCK_INTERNAL_MOCK_METHODN(, ct, m, 2, __VA_ARGS__)
+#define MOCK_METHOD3_WITH_CALLTYPE(ct, m, ...) \
+  GMOCK_INTERNAL_MOCK_METHODN(, ct, m, 3, __VA_ARGS__)
+#define MOCK_METHOD4_WITH_CALLTYPE(ct, m, ...) \
+  GMOCK_INTERNAL_MOCK_METHODN(, ct, m, 4, __VA_ARGS__)
+#define MOCK_METHOD5_WITH_CALLTYPE(ct, m, ...) \
+  GMOCK_INTERNAL_MOCK_METHODN(, ct, m, 5, __VA_ARGS__)
+#define MOCK_METHOD6_WITH_CALLTYPE(ct, m, ...) \
+  GMOCK_INTERNAL_MOCK_METHODN(, ct, m, 6, __VA_ARGS__)
+#define MOCK_METHOD7_WITH_CALLTYPE(ct, m, ...) \
+  GMOCK_INTERNAL_MOCK_METHODN(, ct, m, 7, __VA_ARGS__)
+#define MOCK_METHOD8_WITH_CALLTYPE(ct, m, ...) \
+  GMOCK_INTERNAL_MOCK_METHODN(, ct, m, 8, __VA_ARGS__)
+#define MOCK_METHOD9_WITH_CALLTYPE(ct, m, ...) \
+  GMOCK_INTERNAL_MOCK_METHODN(, ct, m, 9, __VA_ARGS__)
+#define MOCK_METHOD10_WITH_CALLTYPE(ct, m, ...) \
+  GMOCK_INTERNAL_MOCK_METHODN(, ct, m, 10, __VA_ARGS__)
+
+#define MOCK_CONST_METHOD0_WITH_CALLTYPE(ct, m, ...) \
+  GMOCK_INTERNAL_MOCK_METHODN(const, ct, m, 0, __VA_ARGS__)
+#define MOCK_CONST_METHOD1_WITH_CALLTYPE(ct, m, ...) \
+  GMOCK_INTERNAL_MOCK_METHODN(const, ct, m, 1, __VA_ARGS__)
+#define MOCK_CONST_METHOD2_WITH_CALLTYPE(ct, m, ...) \
+  GMOCK_INTERNAL_MOCK_METHODN(const, ct, m, 2, __VA_ARGS__)
+#define MOCK_CONST_METHOD3_WITH_CALLTYPE(ct, m, ...) \
+  GMOCK_INTERNAL_MOCK_METHODN(const, ct, m, 3, __VA_ARGS__)
+#define MOCK_CONST_METHOD4_WITH_CALLTYPE(ct, m, ...) \
+  GMOCK_INTERNAL_MOCK_METHODN(const, ct, m, 4, __VA_ARGS__)
+#define MOCK_CONST_METHOD5_WITH_CALLTYPE(ct, m, ...) \
+  GMOCK_INTERNAL_MOCK_METHODN(const, ct, m, 5, __VA_ARGS__)
+#define MOCK_CONST_METHOD6_WITH_CALLTYPE(ct, m, ...) \
+  GMOCK_INTERNAL_MOCK_METHODN(const, ct, m, 6, __VA_ARGS__)
+#define MOCK_CONST_METHOD7_WITH_CALLTYPE(ct, m, ...) \
+  GMOCK_INTERNAL_MOCK_METHODN(const, ct, m, 7, __VA_ARGS__)
+#define MOCK_CONST_METHOD8_WITH_CALLTYPE(ct, m, ...) \
+  GMOCK_INTERNAL_MOCK_METHODN(const, ct, m, 8, __VA_ARGS__)
+#define MOCK_CONST_METHOD9_WITH_CALLTYPE(ct, m, ...) \
+  GMOCK_INTERNAL_MOCK_METHODN(const, ct, m, 9, __VA_ARGS__)
+#define MOCK_CONST_METHOD10_WITH_CALLTYPE(ct, m, ...) \
+  GMOCK_INTERNAL_MOCK_METHODN(const, ct, m, 10, __VA_ARGS__)
+
+#define MOCK_METHOD0_T_WITH_CALLTYPE(ct, m, ...) \
+  MOCK_METHOD0_WITH_CALLTYPE(ct, m, __VA_ARGS__)
+#define MOCK_METHOD1_T_WITH_CALLTYPE(ct, m, ...) \
+  MOCK_METHOD1_WITH_CALLTYPE(ct, m, __VA_ARGS__)
+#define MOCK_METHOD2_T_WITH_CALLTYPE(ct, m, ...) \
+  MOCK_METHOD2_WITH_CALLTYPE(ct, m, __VA_ARGS__)
+#define MOCK_METHOD3_T_WITH_CALLTYPE(ct, m, ...) \
+  MOCK_METHOD3_WITH_CALLTYPE(ct, m, __VA_ARGS__)
+#define MOCK_METHOD4_T_WITH_CALLTYPE(ct, m, ...) \
+  MOCK_METHOD4_WITH_CALLTYPE(ct, m, __VA_ARGS__)
+#define MOCK_METHOD5_T_WITH_CALLTYPE(ct, m, ...) \
+  MOCK_METHOD5_WITH_CALLTYPE(ct, m, __VA_ARGS__)
+#define MOCK_METHOD6_T_WITH_CALLTYPE(ct, m, ...) \
+  MOCK_METHOD6_WITH_CALLTYPE(ct, m, __VA_ARGS__)
+#define MOCK_METHOD7_T_WITH_CALLTYPE(ct, m, ...) \
+  MOCK_METHOD7_WITH_CALLTYPE(ct, m, __VA_ARGS__)
+#define MOCK_METHOD8_T_WITH_CALLTYPE(ct, m, ...) \
+  MOCK_METHOD8_WITH_CALLTYPE(ct, m, __VA_ARGS__)
+#define MOCK_METHOD9_T_WITH_CALLTYPE(ct, m, ...) \
+  MOCK_METHOD9_WITH_CALLTYPE(ct, m, __VA_ARGS__)
+#define MOCK_METHOD10_T_WITH_CALLTYPE(ct, m, ...) \
+  MOCK_METHOD10_WITH_CALLTYPE(ct, m, __VA_ARGS__)
+
+#define MOCK_CONST_METHOD0_T_WITH_CALLTYPE(ct, m, ...) \
+  MOCK_CONST_METHOD0_WITH_CALLTYPE(ct, m, __VA_ARGS__)
+#define MOCK_CONST_METHOD1_T_WITH_CALLTYPE(ct, m, ...) \
+  MOCK_CONST_METHOD1_WITH_CALLTYPE(ct, m, __VA_ARGS__)
+#define MOCK_CONST_METHOD2_T_WITH_CALLTYPE(ct, m, ...) \
+  MOCK_CONST_METHOD2_WITH_CALLTYPE(ct, m, __VA_ARGS__)
+#define MOCK_CONST_METHOD3_T_WITH_CALLTYPE(ct, m, ...) \
+  MOCK_CONST_METHOD3_WITH_CALLTYPE(ct, m, __VA_ARGS__)
+#define MOCK_CONST_METHOD4_T_WITH_CALLTYPE(ct, m, ...) \
+  MOCK_CONST_METHOD4_WITH_CALLTYPE(ct, m, __VA_ARGS__)
+#define MOCK_CONST_METHOD5_T_WITH_CALLTYPE(ct, m, ...) \
+  MOCK_CONST_METHOD5_WITH_CALLTYPE(ct, m, __VA_ARGS__)
+#define MOCK_CONST_METHOD6_T_WITH_CALLTYPE(ct, m, ...) \
+  MOCK_CONST_METHOD6_WITH_CALLTYPE(ct, m, __VA_ARGS__)
+#define MOCK_CONST_METHOD7_T_WITH_CALLTYPE(ct, m, ...) \
+  MOCK_CONST_METHOD7_WITH_CALLTYPE(ct, m, __VA_ARGS__)
+#define MOCK_CONST_METHOD8_T_WITH_CALLTYPE(ct, m, ...) \
+  MOCK_CONST_METHOD8_WITH_CALLTYPE(ct, m, __VA_ARGS__)
+#define MOCK_CONST_METHOD9_T_WITH_CALLTYPE(ct, m, ...) \
+  MOCK_CONST_METHOD9_WITH_CALLTYPE(ct, m, __VA_ARGS__)
+#define MOCK_CONST_METHOD10_T_WITH_CALLTYPE(ct, m, ...) \
+  MOCK_CONST_METHOD10_WITH_CALLTYPE(ct, m, __VA_ARGS__)
+
+#define GMOCK_INTERNAL_MOCK_METHODN(constness, ct, Method, args_num, ...) \
+  GMOCK_INTERNAL_ASSERT_VALID_SIGNATURE(                                  \
+      args_num, ::testing::internal::identity_t<__VA_ARGS__>);            \
+  GMOCK_INTERNAL_MOCK_METHOD_IMPL(                                        \
+      args_num, Method, GMOCK_PP_NARG0(constness), 0, 0, , ct, ,          \
+      (::testing::internal::identity_t<__VA_ARGS__>))
+
+#define GMOCK_MOCKER_(arity, constness, Method) \
+  GTEST_CONCAT_TOKEN_(gmock##constness##arity##_##Method##_, __LINE__)
+
+#endif  // GOOGLEMOCK_INCLUDE_GMOCK_GMOCK_FUNCTION_MOCKER_H_

contrib/googletest/googlemock/include/gmock/gmock-matchers.h

@@ -0,0 +1,5623 @@
+// Copyright 2007, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+// Google Mock - a framework for writing C++ mock classes.
+//
+// The MATCHER* family of macros can be used in a namespace scope to
+// define custom matchers easily.
+//
+// Basic Usage
+// ===========
+//
+// The syntax
+//
+//   MATCHER(name, description_string) { statements; }
+//
+// defines a matcher with the given name that executes the statements,
+// which must return a bool to indicate if the match succeeds.  Inside
+// the statements, you can refer to the value being matched by 'arg',
+// and refer to its type by 'arg_type'.
+//
+// The description string documents what the matcher does, and is used
+// to generate the failure message when the match fails.  Since a
+// MATCHER() is usually defined in a header file shared by multiple
+// C++ source files, we require the description to be a C-string
+// literal to avoid possible side effects.  It can be empty, in which
+// case we'll use the sequence of words in the matcher name as the
+// description.
+//
+// For example:
+//
+//   MATCHER(IsEven, "") { return (arg % 2) == 0; }
+//
+// allows you to write
+//
+//   // Expects mock_foo.Bar(n) to be called where n is even.
+//   EXPECT_CALL(mock_foo, Bar(IsEven()));
+//
+// or,
+//
+//   // Verifies that the value of some_expression is even.
+//   EXPECT_THAT(some_expression, IsEven());
+//
+// If the above assertion fails, it will print something like:
+//
+//   Value of: some_expression
+//   Expected: is even
+//     Actual: 7
+//
+// where the description "is even" is automatically calculated from the
+// matcher name IsEven.
+//
+// Argument Type
+// =============
+//
+// Note that the type of the value being matched (arg_type) is
+// determined by the context in which you use the matcher and is
+// supplied to you by the compiler, so you don't need to worry about
+// declaring it (nor can you).  This allows the matcher to be
+// polymorphic.  For example, IsEven() can be used to match any type
+// where the value of "(arg % 2) == 0" can be implicitly converted to
+// a bool.  In the "Bar(IsEven())" example above, if method Bar()
+// takes an int, 'arg_type' will be int; if it takes an unsigned long,
+// 'arg_type' will be unsigned long; and so on.
+//
+// Parameterizing Matchers
+// =======================
+//
+// Sometimes you'll want to parameterize the matcher.  For that you
+// can use another macro:
+//
+//   MATCHER_P(name, param_name, description_string) { statements; }
+//
+// For example:
+//
+//   MATCHER_P(HasAbsoluteValue, value, "") { return abs(arg) == value; }
+//
+// will allow you to write:
+//
+//   EXPECT_THAT(Blah("a"), HasAbsoluteValue(n));
+//
+// which may lead to this message (assuming n is 10):
+//
+//   Value of: Blah("a")
+//   Expected: has absolute value 10
+//     Actual: -9
+//
+// Note that both the matcher description and its parameter are
+// printed, making the message human-friendly.
+//
+// In the matcher definition body, you can write 'foo_type' to
+// reference the type of a parameter named 'foo'.  For example, in the
+// body of MATCHER_P(HasAbsoluteValue, value) above, you can write
+// 'value_type' to refer to the type of 'value'.
+//
+// We also provide MATCHER_P2, MATCHER_P3, ..., up to MATCHER_P$n to
+// support multi-parameter matchers.
+//
+// Describing Parameterized Matchers
+// =================================
+//
+// The last argument to MATCHER*() is a string-typed expression.  The
+// expression can reference all of the matcher's parameters and a
+// special bool-typed variable named 'negation'.  When 'negation' is
+// false, the expression should evaluate to the matcher's description;
+// otherwise it should evaluate to the description of the negation of
+// the matcher.  For example,
+//
+//   using testing::PrintToString;
+//
+//   MATCHER_P2(InClosedRange, low, hi,
+//       std::string(negation ? "is not" : "is") + " in range [" +
+//       PrintToString(low) + ", " + PrintToString(hi) + "]") {
+//     return low <= arg && arg <= hi;
+//   }
+//   ...
+//   EXPECT_THAT(3, InClosedRange(4, 6));
+//   EXPECT_THAT(3, Not(InClosedRange(2, 4)));
+//
+// would generate two failures that contain the text:
+//
+//   Expected: is in range [4, 6]
+//   ...
+//   Expected: is not in range [2, 4]
+//
+// If you specify "" as the description, the failure message will
+// contain the sequence of words in the matcher name followed by the
+// parameter values printed as a tuple.  For example,
+//
+//   MATCHER_P2(InClosedRange, low, hi, "") { ... }
+//   ...
+//   EXPECT_THAT(3, InClosedRange(4, 6));
+//   EXPECT_THAT(3, Not(InClosedRange(2, 4)));
+//
+// would generate two failures that contain the text:
+//
+//   Expected: in closed range (4, 6)
+//   ...
+//   Expected: not (in closed range (2, 4))
+//
+// Types of Matcher Parameters
+// ===========================
+//
+// For the purpose of typing, you can view
+//
+//   MATCHER_Pk(Foo, p1, ..., pk, description_string) { ... }
+//
+// as shorthand for
+//
+//   template <typename p1_type, ..., typename pk_type>
+//   FooMatcherPk<p1_type, ..., pk_type>
+//   Foo(p1_type p1, ..., pk_type pk) { ... }
+//
+// When you write Foo(v1, ..., vk), the compiler infers the types of
+// the parameters v1, ..., and vk for you.  If you are not happy with
+// the result of the type inference, you can specify the types by
+// explicitly instantiating the template, as in Foo<long, bool>(5,
+// false).  As said earlier, you don't get to (or need to) specify
+// 'arg_type' as that's determined by the context in which the matcher
+// is used.  You can assign the result of expression Foo(p1, ..., pk)
+// to a variable of type FooMatcherPk<p1_type, ..., pk_type>.  This
+// can be useful when composing matchers.
+//
+// While you can instantiate a matcher template with reference types,
+// passing the parameters by pointer usually makes your code more
+// readable.  If, however, you still want to pass a parameter by
+// reference, be aware that in the failure message generated by the
+// matcher you will see the value of the referenced object but not its
+// address.
+//
+// Explaining Match Results
+// ========================
+//
+// Sometimes the matcher description alone isn't enough to explain why
+// the match has failed or succeeded.  For example, when expecting a
+// long string, it can be very helpful to also print the diff between
+// the expected string and the actual one.  To achieve that, you can
+// optionally stream additional information to a special variable
+// named result_listener, whose type is a pointer to class
+// MatchResultListener:
+//
+//   MATCHER_P(EqualsLongString, str, "") {
+//     if (arg == str) return true;
+//
+//     *result_listener << "the difference: "
+///                     << DiffStrings(str, arg);
+//     return false;
+//   }
+//
+// Overloading Matchers
+// ====================
+//
+// You can overload matchers with different numbers of parameters:
+//
+//   MATCHER_P(Blah, a, description_string1) { ... }
+//   MATCHER_P2(Blah, a, b, description_string2) { ... }
+//
+// Caveats
+// =======
+//
+// When defining a new matcher, you should also consider implementing
+// MatcherInterface or using MakePolymorphicMatcher().  These
+// approaches require more work than the MATCHER* macros, but also
+// give you more control on the types of the value being matched and
+// the matcher parameters, which may leads to better compiler error
+// messages when the matcher is used wrong.  They also allow
+// overloading matchers based on parameter types (as opposed to just
+// based on the number of parameters).
+//
+// MATCHER*() can only be used in a namespace scope as templates cannot be
+// declared inside of a local class.
+//
+// More Information
+// ================
+//
+// To learn more about using these macros, please search for 'MATCHER'
+// on
+// https://github.com/google/googletest/blob/main/docs/gmock_cook_book.md
+//
+// This file also implements some commonly used argument matchers.  More
+// matchers can be defined by the user implementing the
+// MatcherInterface<T> interface if necessary.
+//
+// See googletest/include/gtest/gtest-matchers.h for the definition of class
+// Matcher, class MatcherInterface, and others.
+
+// IWYU pragma: private, include "gmock/gmock.h"
+// IWYU pragma: friend gmock/.*
+
+#ifndef GOOGLEMOCK_INCLUDE_GMOCK_GMOCK_MATCHERS_H_
+#define GOOGLEMOCK_INCLUDE_GMOCK_GMOCK_MATCHERS_H_
+
+#include <algorithm>
+#include <cmath>
+#include <exception>
+#include <functional>
+#include <initializer_list>
+#include <ios>
+#include <iterator>
+#include <limits>
+#include <memory>
+#include <ostream>  // NOLINT
+#include <sstream>
+#include <string>
+#include <type_traits>
+#include <utility>
+#include <vector>
+
+#include "gmock/internal/gmock-internal-utils.h"
+#include "gmock/internal/gmock-port.h"
+#include "gmock/internal/gmock-pp.h"
+#include "gtest/gtest.h"
+
+// MSVC warning C5046 is new as of VS2017 version 15.8.
+#if defined(_MSC_VER) && _MSC_VER >= 1915
+#define GMOCK_MAYBE_5046_ 5046
+#else
+#define GMOCK_MAYBE_5046_
+#endif
+
+GTEST_DISABLE_MSC_WARNINGS_PUSH_(
+    4251 GMOCK_MAYBE_5046_ /* class A needs to have dll-interface to be used by
+                              clients of class B */
+    /* Symbol involving type with internal linkage not defined */)
+
+namespace testing {
+
+// To implement a matcher Foo for type T, define:
+//   1. a class FooMatcherImpl that implements the
+//      MatcherInterface<T> interface, and
+//   2. a factory function that creates a Matcher<T> object from a
+//      FooMatcherImpl*.
+//
+// The two-level delegation design makes it possible to allow a user
+// to write "v" instead of "Eq(v)" where a Matcher is expected, which
+// is impossible if we pass matchers by pointers.  It also eases
+// ownership management as Matcher objects can now be copied like
+// plain values.
+
+// A match result listener that stores the explanation in a string.
+class StringMatchResultListener : public MatchResultListener {
+ public:
+  StringMatchResultListener() : MatchResultListener(&ss_) {}
+
+  // Returns the explanation accumulated so far.
+  std::string str() const { return ss_.str(); }
+
+  // Clears the explanation accumulated so far.
+  void Clear() { ss_.str(""); }
+
+ private:
+  ::std::stringstream ss_;
+
+  StringMatchResultListener(const StringMatchResultListener&) = delete;
+  StringMatchResultListener& operator=(const StringMatchResultListener&) =
+      delete;
+};
+
+// Anything inside the 'internal' namespace IS INTERNAL IMPLEMENTATION
+// and MUST NOT BE USED IN USER CODE!!!
+namespace internal {
+
+// The MatcherCastImpl class template is a helper for implementing
+// MatcherCast().  We need this helper in order to partially
+// specialize the implementation of MatcherCast() (C++ allows
+// class/struct templates to be partially specialized, but not
+// function templates.).
+
+// This general version is used when MatcherCast()'s argument is a
+// polymorphic matcher (i.e. something that can be converted to a
+// Matcher but is not one yet; for example, Eq(value)) or a value (for
+// example, "hello").
+template <typename T, typename M>
+class MatcherCastImpl {
+ public:
+  static Matcher<T> Cast(const M& polymorphic_matcher_or_value) {
+    // M can be a polymorphic matcher, in which case we want to use
+    // its conversion operator to create Matcher<T>.  Or it can be a value
+    // that should be passed to the Matcher<T>'s constructor.
+    //
+    // We can't call Matcher<T>(polymorphic_matcher_or_value) when M is a
+    // polymorphic matcher because it'll be ambiguous if T has an implicit
+    // constructor from M (this usually happens when T has an implicit
+    // constructor from any type).
+    //
+    // It won't work to unconditionally implicit_cast
+    // polymorphic_matcher_or_value to Matcher<T> because it won't trigger
+    // a user-defined conversion from M to T if one exists (assuming M is
+    // a value).
+    return CastImpl(polymorphic_matcher_or_value,
+                    std::is_convertible<M, Matcher<T>>{},
+                    std::is_convertible<M, T>{});
+  }
+
+ private:
+  template <bool Ignore>
+  static Matcher<T> CastImpl(const M& polymorphic_matcher_or_value,
+                             std::true_type /* convertible_to_matcher */,
+                             std::integral_constant<bool, Ignore>) {
+    // M is implicitly convertible to Matcher<T>, which means that either
+    // M is a polymorphic matcher or Matcher<T> has an implicit constructor
+    // from M.  In both cases using the implicit conversion will produce a
+    // matcher.
+    //
+    // Even if T has an implicit constructor from M, it won't be called because
+    // creating Matcher<T> would require a chain of two user-defined conversions
+    // (first to create T from M and then to create Matcher<T> from T).
+    return polymorphic_matcher_or_value;
+  }
+
+  // M can't be implicitly converted to Matcher<T>, so M isn't a polymorphic
+  // matcher. It's a value of a type implicitly convertible to T. Use direct
+  // initialization to create a matcher.
+  static Matcher<T> CastImpl(const M& value,
+                             std::false_type /* convertible_to_matcher */,
+                             std::true_type /* convertible_to_T */) {
+    return Matcher<T>(ImplicitCast_<T>(value));
+  }
+
+  // M can't be implicitly converted to either Matcher<T> or T. Attempt to use
+  // polymorphic matcher Eq(value) in this case.
+  //
+  // Note that we first attempt to perform an implicit cast on the value and
+  // only fall back to the polymorphic Eq() matcher afterwards because the
+  // latter calls bool operator==(const Lhs& lhs, const Rhs& rhs) in the end
+  // which might be undefined even when Rhs is implicitly convertible to Lhs
+  // (e.g. std::pair<const int, int> vs. std::pair<int, int>).
+  //
+  // We don't define this method inline as we need the declaration of Eq().
+  static Matcher<T> CastImpl(const M& value,
+                             std::false_type /* convertible_to_matcher */,
+                             std::false_type /* convertible_to_T */);
+};
+
+// This more specialized version is used when MatcherCast()'s argument
+// is already a Matcher.  This only compiles when type T can be
+// statically converted to type U.
+template <typename T, typename U>
+class MatcherCastImpl<T, Matcher<U>> {
+ public:
+  static Matcher<T> Cast(const Matcher<U>& source_matcher) {
+    return Matcher<T>(new Impl(source_matcher));
+  }
+
+ private:
+  class Impl : public MatcherInterface<T> {
+   public:
+    explicit Impl(const Matcher<U>& source_matcher)
+        : source_matcher_(source_matcher) {}
+
+    // We delegate the matching logic to the source matcher.
+    bool MatchAndExplain(T x, MatchResultListener* listener) const override {
+      using FromType = typename std::remove_cv<typename std::remove_pointer<
+          typename std::remove_reference<T>::type>::type>::type;
+      using ToType = typename std::remove_cv<typename std::remove_pointer<
+          typename std::remove_reference<U>::type>::type>::type;
+      // Do not allow implicitly converting base*/& to derived*/&.
+      static_assert(
+          // Do not trigger if only one of them is a pointer. That implies a
+          // regular conversion and not a down_cast.
+          (std::is_pointer<typename std::remove_reference<T>::type>::value !=
+           std::is_pointer<typename std::remove_reference<U>::type>::value) ||
+              std::is_same<FromType, ToType>::value ||
+              !std::is_base_of<FromType, ToType>::value,
+          "Can't implicitly convert from <base> to <derived>");
+
+      // Do the cast to `U` explicitly if necessary.
+      // Otherwise, let implicit conversions do the trick.
+      using CastType =
+          typename std::conditional<std::is_convertible<T&, const U&>::value,
+                                    T&, U>::type;
+
+      return source_matcher_.MatchAndExplain(static_cast<CastType>(x),
+                                             listener);
+    }
+
+    void DescribeTo(::std::ostream* os) const override {
+      source_matcher_.DescribeTo(os);
+    }
+
+    void DescribeNegationTo(::std::ostream* os) const override {
+      source_matcher_.DescribeNegationTo(os);
+    }
+
+   private:
+    const Matcher<U> source_matcher_;
+  };
+};
+
+// This even more specialized version is used for efficiently casting
+// a matcher to its own type.
+template <typename T>
+class MatcherCastImpl<T, Matcher<T>> {
+ public:
+  static Matcher<T> Cast(const Matcher<T>& matcher) { return matcher; }
+};
+
+// Template specialization for parameterless Matcher.
+template <typename Derived>
+class MatcherBaseImpl {
+ public:
+  MatcherBaseImpl() = default;
+
+  template <typename T>
+  operator ::testing::Matcher<T>() const {  // NOLINT(runtime/explicit)
+    return ::testing::Matcher<T>(new
+                                 typename Derived::template gmock_Impl<T>());
+  }
+};
+
+// Template specialization for Matcher with parameters.
+template <template <typename...> class Derived, typename... Ts>
+class MatcherBaseImpl<Derived<Ts...>> {
+ public:
+  // Mark the constructor explicit for single argument T to avoid implicit
+  // conversions.
+  template <typename E = std::enable_if<sizeof...(Ts) == 1>,
+            typename E::type* = nullptr>
+  explicit MatcherBaseImpl(Ts... params)
+      : params_(std::forward<Ts>(params)...) {}
+  template <typename E = std::enable_if<sizeof...(Ts) != 1>,
+            typename = typename E::type>
+  MatcherBaseImpl(Ts... params)  // NOLINT
+      : params_(std::forward<Ts>(params)...) {}
+
+  template <typename F>
+  operator ::testing::Matcher<F>() const {  // NOLINT(runtime/explicit)
+    return Apply<F>(MakeIndexSequence<sizeof...(Ts)>{});
+  }
+
+ private:
+  template <typename F, std::size_t... tuple_ids>
+  ::testing::Matcher<F> Apply(IndexSequence<tuple_ids...>) const {
+    return ::testing::Matcher<F>(
+        new typename Derived<Ts...>::template gmock_Impl<F>(
+            std::get<tuple_ids>(params_)...));
+  }
+
+  const std::tuple<Ts...> params_;
+};
+
+}  // namespace internal
+
+// In order to be safe and clear, casting between different matcher
+// types is done explicitly via MatcherCast<T>(m), which takes a
+// matcher m and returns a Matcher<T>.  It compiles only when T can be
+// statically converted to the argument type of m.
+template <typename T, typename M>
+inline Matcher<T> MatcherCast(const M& matcher) {
+  return internal::MatcherCastImpl<T, M>::Cast(matcher);
+}
+
+// This overload handles polymorphic matchers and values only since
+// monomorphic matchers are handled by the next one.
+template <typename T, typename M>
+inline Matcher<T> SafeMatcherCast(const M& polymorphic_matcher_or_value) {
+  return MatcherCast<T>(polymorphic_matcher_or_value);
+}
+
+// This overload handles monomorphic matchers.
+//
+// In general, if type T can be implicitly converted to type U, we can
+// safely convert a Matcher<U> to a Matcher<T> (i.e. Matcher is
+// contravariant): just keep a copy of the original Matcher<U>, convert the
+// argument from type T to U, and then pass it to the underlying Matcher<U>.
+// The only exception is when U is a reference and T is not, as the
+// underlying Matcher<U> may be interested in the argument's address, which
+// is not preserved in the conversion from T to U.
+template <typename T, typename U>
+inline Matcher<T> SafeMatcherCast(const Matcher<U>& matcher) {
+  // Enforce that T can be implicitly converted to U.
+  static_assert(std::is_convertible<const T&, const U&>::value,
+                "T must be implicitly convertible to U");
+  // Enforce that we are not converting a non-reference type T to a reference
+  // type U.
+  static_assert(std::is_reference<T>::value || !std::is_reference<U>::value,
+                "cannot convert non reference arg to reference");
+  // In case both T and U are arithmetic types, enforce that the
+  // conversion is not lossy.
+  typedef GTEST_REMOVE_REFERENCE_AND_CONST_(T) RawT;
+  typedef GTEST_REMOVE_REFERENCE_AND_CONST_(U) RawU;
+  constexpr bool kTIsOther = GMOCK_KIND_OF_(RawT) == internal::kOther;
+  constexpr bool kUIsOther = GMOCK_KIND_OF_(RawU) == internal::kOther;
+  static_assert(
+      kTIsOther || kUIsOther ||
+          (internal::LosslessArithmeticConvertible<RawT, RawU>::value),
+      "conversion of arithmetic types must be lossless");
+  return MatcherCast<T>(matcher);
+}
+
+// A<T>() returns a matcher that matches any value of type T.
+template <typename T>
+Matcher<T> A();
+
+// Anything inside the 'internal' namespace IS INTERNAL IMPLEMENTATION
+// and MUST NOT BE USED IN USER CODE!!!
+namespace internal {
+
+// If the explanation is not empty, prints it to the ostream.
+inline void PrintIfNotEmpty(const std::string& explanation,
+                            ::std::ostream* os) {
+  if (!explanation.empty() && os != nullptr) {
+    *os << ", " << explanation;
+  }
+}
+
+// Returns true if the given type name is easy to read by a human.
+// This is used to decide whether printing the type of a value might
+// be helpful.
+inline bool IsReadableTypeName(const std::string& type_name) {
+  // We consider a type name readable if it's short or doesn't contain
+  // a template or function type.
+  return (type_name.length() <= 20 ||
+          type_name.find_first_of("<(") == std::string::npos);
+}
+
+// Matches the value against the given matcher, prints the value and explains
+// the match result to the listener. Returns the match result.
+// 'listener' must not be NULL.
+// Value cannot be passed by const reference, because some matchers take a
+// non-const argument.
+template <typename Value, typename T>
+bool MatchPrintAndExplain(Value& value, const Matcher<T>& matcher,
+                          MatchResultListener* listener) {
+  if (!listener->IsInterested()) {
+    // If the listener is not interested, we do not need to construct the
+    // inner explanation.
+    return matcher.Matches(value);
+  }
+
+  StringMatchResultListener inner_listener;
+  const bool match = matcher.MatchAndExplain(value, &inner_listener);
+
+  UniversalPrint(value, listener->stream());
+#if GTEST_HAS_RTTI
+  const std::string& type_name = GetTypeName<Value>();
+  if (IsReadableTypeName(type_name))
+    *listener->stream() << " (of type " << type_name << ")";
+#endif
+  PrintIfNotEmpty(inner_listener.str(), listener->stream());
+
+  return match;
+}
+
+// An internal helper class for doing compile-time loop on a tuple's
+// fields.
+template <size_t N>
+class TuplePrefix {
+ public:
+  // TuplePrefix<N>::Matches(matcher_tuple, value_tuple) returns true
+  // if and only if the first N fields of matcher_tuple matches
+  // the first N fields of value_tuple, respectively.
+  template <typename MatcherTuple, typename ValueTuple>
+  static bool Matches(const MatcherTuple& matcher_tuple,
+                      const ValueTuple& value_tuple) {
+    return TuplePrefix<N - 1>::Matches(matcher_tuple, value_tuple) &&
+           std::get<N - 1>(matcher_tuple).Matches(std::get<N - 1>(value_tuple));
+  }
+
+  // TuplePrefix<N>::ExplainMatchFailuresTo(matchers, values, os)
+  // describes failures in matching the first N fields of matchers
+  // against the first N fields of values.  If there is no failure,
+  // nothing will be streamed to os.
+  template <typename MatcherTuple, typename ValueTuple>
+  static void ExplainMatchFailuresTo(const MatcherTuple& matchers,
+                                     const ValueTuple& values,
+                                     ::std::ostream* os) {
+    // First, describes failures in the first N - 1 fields.
+    TuplePrefix<N - 1>::ExplainMatchFailuresTo(matchers, values, os);
+
+    // Then describes the failure (if any) in the (N - 1)-th (0-based)
+    // field.
+    typename std::tuple_element<N - 1, MatcherTuple>::type matcher =
+        std::get<N - 1>(matchers);
+    typedef typename std::tuple_element<N - 1, ValueTuple>::type Value;
+    const Value& value = std::get<N - 1>(values);
+    StringMatchResultListener listener;
+    if (!matcher.MatchAndExplain(value, &listener)) {
+      *os << "  Expected arg #" << N - 1 << ": ";
+      std::get<N - 1>(matchers).DescribeTo(os);
+      *os << "\n           Actual: ";
+      // We remove the reference in type Value to prevent the
+      // universal printer from printing the address of value, which
+      // isn't interesting to the user most of the time.  The
+      // matcher's MatchAndExplain() method handles the case when
+      // the address is interesting.
+      internal::UniversalPrint(value, os);
+      PrintIfNotEmpty(listener.str(), os);
+      *os << "\n";
+    }
+  }
+};
+
+// The base case.
+template <>
+class TuplePrefix<0> {
+ public:
+  template <typename MatcherTuple, typename ValueTuple>
+  static bool Matches(const MatcherTuple& /* matcher_tuple */,
+                      const ValueTuple& /* value_tuple */) {
+    return true;
+  }
+
+  template <typename MatcherTuple, typename ValueTuple>
+  static void ExplainMatchFailuresTo(const MatcherTuple& /* matchers */,
+                                     const ValueTuple& /* values */,
+                                     ::std::ostream* /* os */) {}
+};
+
+// TupleMatches(matcher_tuple, value_tuple) returns true if and only if
+// all matchers in matcher_tuple match the corresponding fields in
+// value_tuple.  It is a compiler error if matcher_tuple and
+// value_tuple have different number of fields or incompatible field
+// types.
+template <typename MatcherTuple, typename ValueTuple>
+bool TupleMatches(const MatcherTuple& matcher_tuple,
+                  const ValueTuple& value_tuple) {
+  // Makes sure that matcher_tuple and value_tuple have the same
+  // number of fields.
+  static_assert(std::tuple_size<MatcherTuple>::value ==
+                    std::tuple_size<ValueTuple>::value,
+                "matcher and value have different numbers of fields");
+  return TuplePrefix<std::tuple_size<ValueTuple>::value>::Matches(matcher_tuple,
+                                                                  value_tuple);
+}
+
+// Describes failures in matching matchers against values.  If there
+// is no failure, nothing will be streamed to os.
+template <typename MatcherTuple, typename ValueTuple>
+void ExplainMatchFailureTupleTo(const MatcherTuple& matchers,
+                                const ValueTuple& values, ::std::ostream* os) {
+  TuplePrefix<std::tuple_size<MatcherTuple>::value>::ExplainMatchFailuresTo(
+      matchers, values, os);
+}
+
+// TransformTupleValues and its helper.
+//
+// TransformTupleValuesHelper hides the internal machinery that
+// TransformTupleValues uses to implement a tuple traversal.
+template <typename Tuple, typename Func, typename OutIter>
+class TransformTupleValuesHelper {
+ private:
+  typedef ::std::tuple_size<Tuple> TupleSize;
+
+ public:
+  // For each member of tuple 't', taken in order, evaluates '*out++ = f(t)'.
+  // Returns the final value of 'out' in case the caller needs it.
+  static OutIter Run(Func f, const Tuple& t, OutIter out) {
+    return IterateOverTuple<Tuple, TupleSize::value>()(f, t, out);
+  }
+
+ private:
+  template <typename Tup, size_t kRemainingSize>
+  struct IterateOverTuple {
+    OutIter operator()(Func f, const Tup& t, OutIter out) const {
+      *out++ = f(::std::get<TupleSize::value - kRemainingSize>(t));
+      return IterateOverTuple<Tup, kRemainingSize - 1>()(f, t, out);
+    }
+  };
+  template <typename Tup>
+  struct IterateOverTuple<Tup, 0> {
+    OutIter operator()(Func /* f */, const Tup& /* t */, OutIter out) const {
+      return out;
+    }
+  };
+};
+
+// Successively invokes 'f(element)' on each element of the tuple 't',
+// appending each result to the 'out' iterator. Returns the final value
+// of 'out'.
+template <typename Tuple, typename Func, typename OutIter>
+OutIter TransformTupleValues(Func f, const Tuple& t, OutIter out) {
+  return TransformTupleValuesHelper<Tuple, Func, OutIter>::Run(f, t, out);
+}
+
+// Implements _, a matcher that matches any value of any
+// type.  This is a polymorphic matcher, so we need a template type
+// conversion operator to make it appearing as a Matcher<T> for any
+// type T.
+class AnythingMatcher {
+ public:
+  using is_gtest_matcher = void;
+
+  template <typename T>
+  bool MatchAndExplain(const T& /* x */, std::ostream* /* listener */) const {
+    return true;
+  }
+  void DescribeTo(std::ostream* os) const { *os << "is anything"; }
+  void DescribeNegationTo(::std::ostream* os) const {
+    // This is mostly for completeness' sake, as it's not very useful
+    // to write Not(A<bool>()).  However we cannot completely rule out
+    // such a possibility, and it doesn't hurt to be prepared.
+    *os << "never matches";
+  }
+};
+
+// Implements the polymorphic IsNull() matcher, which matches any raw or smart
+// pointer that is NULL.
+class IsNullMatcher {
+ public:
+  template <typename Pointer>
+  bool MatchAndExplain(const Pointer& p,
+                       MatchResultListener* /* listener */) const {
+    return p == nullptr;
+  }
+
+  void DescribeTo(::std::ostream* os) const { *os << "is NULL"; }
+  void DescribeNegationTo(::std::ostream* os) const { *os << "isn't NULL"; }
+};
+
+// Implements the polymorphic NotNull() matcher, which matches any raw or smart
+// pointer that is not NULL.
+class NotNullMatcher {
+ public:
+  template <typename Pointer>
+  bool MatchAndExplain(const Pointer& p,
+                       MatchResultListener* /* listener */) const {
+    return p != nullptr;
+  }
+
+  void DescribeTo(::std::ostream* os) const { *os << "isn't NULL"; }
+  void DescribeNegationTo(::std::ostream* os) const { *os << "is NULL"; }
+};
+
+// Ref(variable) matches any argument that is a reference to
+// 'variable'.  This matcher is polymorphic as it can match any
+// super type of the type of 'variable'.
+//
+// The RefMatcher template class implements Ref(variable).  It can
+// only be instantiated with a reference type.  This prevents a user
+// from mistakenly using Ref(x) to match a non-reference function
+// argument.  For example, the following will righteously cause a
+// compiler error:
+//
+//   int n;
+//   Matcher<int> m1 = Ref(n);   // This won't compile.
+//   Matcher<int&> m2 = Ref(n);  // This will compile.
+template <typename T>
+class RefMatcher;
+
+template <typename T>
+class RefMatcher<T&> {
+  // Google Mock is a generic framework and thus needs to support
+  // mocking any function types, including those that take non-const
+  // reference arguments.  Therefore the template parameter T (and
+  // Super below) can be instantiated to either a const type or a
+  // non-const type.
+ public:
+  // RefMatcher() takes a T& instead of const T&, as we want the
+  // compiler to catch using Ref(const_value) as a matcher for a
+  // non-const reference.
+  explicit RefMatcher(T& x) : object_(x) {}  // NOLINT
+
+  template <typename Super>
+  operator Matcher<Super&>() const {
+    // By passing object_ (type T&) to Impl(), which expects a Super&,
+    // we make sure that Super is a super type of T.  In particular,
+    // this catches using Ref(const_value) as a matcher for a
+    // non-const reference, as you cannot implicitly convert a const
+    // reference to a non-const reference.
+    return MakeMatcher(new Impl<Super>(object_));
+  }
+
+ private:
+  template <typename Super>
+  class Impl : public MatcherInterface<Super&> {
+   public:
+    explicit Impl(Super& x) : object_(x) {}  // NOLINT
+
+    // MatchAndExplain() takes a Super& (as opposed to const Super&)
+    // in order to match the interface MatcherInterface<Super&>.
+    bool MatchAndExplain(Super& x,
+                         MatchResultListener* listener) const override {
+      *listener << "which is located @" << static_cast<const void*>(&x);
+      return &x == &object_;
+    }
+
+    void DescribeTo(::std::ostream* os) const override {
+      *os << "references the variable ";
+      UniversalPrinter<Super&>::Print(object_, os);
+    }
+
+    void DescribeNegationTo(::std::ostream* os) const override {
+      *os << "does not reference the variable ";
+      UniversalPrinter<Super&>::Print(object_, os);
+    }
+
+   private:
+    const Super& object_;
+  };
+
+  T& object_;
+};
+
+// Polymorphic helper functions for narrow and wide string matchers.
+inline bool CaseInsensitiveCStringEquals(const char* lhs, const char* rhs) {
+  return String::CaseInsensitiveCStringEquals(lhs, rhs);
+}
+
+inline bool CaseInsensitiveCStringEquals(const wchar_t* lhs,
+                                         const wchar_t* rhs) {
+  return String::CaseInsensitiveWideCStringEquals(lhs, rhs);
+}
+
+// String comparison for narrow or wide strings that can have embedded NUL
+// characters.
+template <typename StringType>
+bool CaseInsensitiveStringEquals(const StringType& s1, const StringType& s2) {
+  // Are the heads equal?
+  if (!CaseInsensitiveCStringEquals(s1.c_str(), s2.c_str())) {
+    return false;
+  }
+
+  // Skip the equal heads.
+  const typename StringType::value_type nul = 0;
+  const size_t i1 = s1.find(nul), i2 = s2.find(nul);
+
+  // Are we at the end of either s1 or s2?
+  if (i1 == StringType::npos || i2 == StringType::npos) {
+    return i1 == i2;
+  }
+
+  // Are the tails equal?
+  return CaseInsensitiveStringEquals(s1.substr(i1 + 1), s2.substr(i2 + 1));
+}
+
+// String matchers.
+
+// Implements equality-based string matchers like StrEq, StrCaseNe, and etc.
+template <typename StringType>
+class StrEqualityMatcher {
+ public:
+  StrEqualityMatcher(StringType str, bool expect_eq, bool case_sensitive)
+      : string_(std::move(str)),
+        expect_eq_(expect_eq),
+        case_sensitive_(case_sensitive) {}
+
+#if GTEST_INTERNAL_HAS_STRING_VIEW
+  bool MatchAndExplain(const internal::StringView& s,
+                       MatchResultListener* listener) const {
+    // This should fail to compile if StringView is used with wide
+    // strings.
+    const StringType& str = std::string(s);
+    return MatchAndExplain(str, listener);
+  }
+#endif  // GTEST_INTERNAL_HAS_STRING_VIEW
+
+  // Accepts pointer types, particularly:
+  //   const char*
+  //   char*
+  //   const wchar_t*
+  //   wchar_t*
+  template <typename CharType>
+  bool MatchAndExplain(CharType* s, MatchResultListener* listener) const {
+    if (s == nullptr) {
+      return !expect_eq_;
+    }
+    return MatchAndExplain(StringType(s), listener);
+  }
+
+  // Matches anything that can convert to StringType.
+  //
+  // This is a template, not just a plain function with const StringType&,
+  // because StringView has some interfering non-explicit constructors.
+  template <typename MatcheeStringType>
+  bool MatchAndExplain(const MatcheeStringType& s,
+                       MatchResultListener* /* listener */) const {
+    const StringType s2(s);
+    const bool eq = case_sensitive_ ? s2 == string_
+                                    : CaseInsensitiveStringEquals(s2, string_);
+    return expect_eq_ == eq;
+  }
+
+  void DescribeTo(::std::ostream* os) const {
+    DescribeToHelper(expect_eq_, os);
+  }
+
+  void DescribeNegationTo(::std::ostream* os) const {
+    DescribeToHelper(!expect_eq_, os);
+  }
+
+ private:
+  void DescribeToHelper(bool expect_eq, ::std::ostream* os) const {
+    *os << (expect_eq ? "is " : "isn't ");
+    *os << "equal to ";
+    if (!case_sensitive_) {
+      *os << "(ignoring case) ";
+    }
+    UniversalPrint(string_, os);
+  }
+
+  const StringType string_;
+  const bool expect_eq_;
+  const bool case_sensitive_;
+};
+
+// Implements the polymorphic HasSubstr(substring) matcher, which
+// can be used as a Matcher<T> as long as T can be converted to a
+// string.
+template <typename StringType>
+class HasSubstrMatcher {
+ public:
+  explicit HasSubstrMatcher(const StringType& substring)
+      : substring_(substring) {}
+
+#if GTEST_INTERNAL_HAS_STRING_VIEW
+  bool MatchAndExplain(const internal::StringView& s,
+                       MatchResultListener* listener) const {
+    // This should fail to compile if StringView is used with wide
+    // strings.
+    const StringType& str = std::string(s);
+    return MatchAndExplain(str, listener);
+  }
+#endif  // GTEST_INTERNAL_HAS_STRING_VIEW
+
+  // Accepts pointer types, particularly:
+  //   const char*
+  //   char*
+  //   const wchar_t*
+  //   wchar_t*
+  template <typename CharType>
+  bool MatchAndExplain(CharType* s, MatchResultListener* listener) const {
+    return s != nullptr && MatchAndExplain(StringType(s), listener);
+  }
+
+  // Matches anything that can convert to StringType.
+  //
+  // This is a template, not just a plain function with const StringType&,
+  // because StringView has some interfering non-explicit constructors.
+  template <typename MatcheeStringType>
+  bool MatchAndExplain(const MatcheeStringType& s,
+                       MatchResultListener* /* listener */) const {
+    return StringType(s).find(substring_) != StringType::npos;
+  }
+
+  // Describes what this matcher matches.
+  void DescribeTo(::std::ostream* os) const {
+    *os << "has substring ";
+    UniversalPrint(substring_, os);
+  }
+
+  void DescribeNegationTo(::std::ostream* os) const {
+    *os << "has no substring ";
+    UniversalPrint(substring_, os);
+  }
+
+ private:
+  const StringType substring_;
+};
+
+// Implements the polymorphic StartsWith(substring) matcher, which
+// can be used as a Matcher<T> as long as T can be converted to a
+// string.
+template <typename StringType>
+class StartsWithMatcher {
+ public:
+  explicit StartsWithMatcher(const StringType& prefix) : prefix_(prefix) {}
+
+#if GTEST_INTERNAL_HAS_STRING_VIEW
+  bool MatchAndExplain(const internal::StringView& s,
+                       MatchResultListener* listener) const {
+    // This should fail to compile if StringView is used with wide
+    // strings.
+    const StringType& str = std::string(s);
+    return MatchAndExplain(str, listener);
+  }
+#endif  // GTEST_INTERNAL_HAS_STRING_VIEW
+
+  // Accepts pointer types, particularly:
+  //   const char*
+  //   char*
+  //   const wchar_t*
+  //   wchar_t*
+  template <typename CharType>
+  bool MatchAndExplain(CharType* s, MatchResultListener* listener) const {
+    return s != nullptr && MatchAndExplain(StringType(s), listener);
+  }
+
+  // Matches anything that can convert to StringType.
+  //
+  // This is a template, not just a plain function with const StringType&,
+  // because StringView has some interfering non-explicit constructors.
+  template <typename MatcheeStringType>
+  bool MatchAndExplain(const MatcheeStringType& s,
+                       MatchResultListener* /* listener */) const {
+    const StringType& s2(s);
+    return s2.length() >= prefix_.length() &&
+           s2.substr(0, prefix_.length()) == prefix_;
+  }
+
+  void DescribeTo(::std::ostream* os) const {
+    *os << "starts with ";
+    UniversalPrint(prefix_, os);
+  }
+
+  void DescribeNegationTo(::std::ostream* os) const {
+    *os << "doesn't start with ";
+    UniversalPrint(prefix_, os);
+  }
+
+ private:
+  const StringType prefix_;
+};
+
+// Implements the polymorphic EndsWith(substring) matcher, which
+// can be used as a Matcher<T> as long as T can be converted to a
+// string.
+template <typename StringType>
+class EndsWithMatcher {
+ public:
+  explicit EndsWithMatcher(const StringType& suffix) : suffix_(suffix) {}
+
+#if GTEST_INTERNAL_HAS_STRING_VIEW
+  bool MatchAndExplain(const internal::StringView& s,
+                       MatchResultListener* listener) const {
+    // This should fail to compile if StringView is used with wide
+    // strings.
+    const StringType& str = std::string(s);
+    return MatchAndExplain(str, listener);
+  }
+#endif  // GTEST_INTERNAL_HAS_STRING_VIEW
+
+  // Accepts pointer types, particularly:
+  //   const char*
+  //   char*
+  //   const wchar_t*
+  //   wchar_t*
+  template <typename CharType>
+  bool MatchAndExplain(CharType* s, MatchResultListener* listener) const {
+    return s != nullptr && MatchAndExplain(StringType(s), listener);
+  }
+
+  // Matches anything that can convert to StringType.
+  //
+  // This is a template, not just a plain function with const StringType&,
+  // because StringView has some interfering non-explicit constructors.
+  template <typename MatcheeStringType>
+  bool MatchAndExplain(const MatcheeStringType& s,
+                       MatchResultListener* /* listener */) const {
+    const StringType& s2(s);
+    return s2.length() >= suffix_.length() &&
+           s2.substr(s2.length() - suffix_.length()) == suffix_;
+  }
+
+  void DescribeTo(::std::ostream* os) const {
+    *os << "ends with ";
+    UniversalPrint(suffix_, os);
+  }
+
+  void DescribeNegationTo(::std::ostream* os) const {
+    *os << "doesn't end with ";
+    UniversalPrint(suffix_, os);
+  }
+
+ private:
+  const StringType suffix_;
+};
+
+// Implements the polymorphic WhenBase64Unescaped(matcher) matcher, which can be
+// used as a Matcher<T> as long as T can be converted to a string.
+class WhenBase64UnescapedMatcher {
+ public:
+  using is_gtest_matcher = void;
+
+  explicit WhenBase64UnescapedMatcher(
+      const Matcher<const std::string&>& internal_matcher)
+      : internal_matcher_(internal_matcher) {}
+
+  // Matches anything that can convert to std::string.
+  template <typename MatcheeStringType>
+  bool MatchAndExplain(const MatcheeStringType& s,
+                       MatchResultListener* listener) const {
+    const std::string s2(s);  // NOLINT (needed for working with string_view).
+    std::string unescaped;
+    if (!internal::Base64Unescape(s2, &unescaped)) {
+      if (listener != nullptr) {
+        *listener << "is not a valid base64 escaped string";
+      }
+      return false;
+    }
+    return MatchPrintAndExplain(unescaped, internal_matcher_, listener);
+  }
+
+  void DescribeTo(::std::ostream* os) const {
+    *os << "matches after Base64Unescape ";
+    internal_matcher_.DescribeTo(os);
+  }
+
+  void DescribeNegationTo(::std::ostream* os) const {
+    *os << "does not match after Base64Unescape ";
+    internal_matcher_.DescribeTo(os);
+  }
+
+ private:
+  const Matcher<const std::string&> internal_matcher_;
+};
+
+// Implements a matcher that compares the two fields of a 2-tuple
+// using one of the ==, <=, <, etc, operators.  The two fields being
+// compared don't have to have the same type.
+//
+// The matcher defined here is polymorphic (for example, Eq() can be
+// used to match a std::tuple<int, short>, a std::tuple<const long&, double>,
+// etc).  Therefore we use a template type conversion operator in the
+// implementation.
+template <typename D, typename Op>
+class PairMatchBase {
+ public:
+  template <typename T1, typename T2>
+  operator Matcher<::std::tuple<T1, T2>>() const {
+    return Matcher<::std::tuple<T1, T2>>(new Impl<const ::std::tuple<T1, T2>&>);
+  }
+  template <typename T1, typename T2>
+  operator Matcher<const ::std::tuple<T1, T2>&>() const {
+    return MakeMatcher(new Impl<const ::std::tuple<T1, T2>&>);
+  }
+
+ private:
+  static ::std::ostream& GetDesc(::std::ostream& os) {  // NOLINT
+    return os << D::Desc();
+  }
+
+  template <typename Tuple>
+  class Impl : public MatcherInterface<Tuple> {
+   public:
+    bool MatchAndExplain(Tuple args,
+                         MatchResultListener* /* listener */) const override {
+      return Op()(::std::get<0>(args), ::std::get<1>(args));
+    }
+    void DescribeTo(::std::ostream* os) const override {
+      *os << "are " << GetDesc;
+    }
+    void DescribeNegationTo(::std::ostream* os) const override {
+      *os << "aren't " << GetDesc;
+    }
+  };
+};
+
+class Eq2Matcher : public PairMatchBase<Eq2Matcher, std::equal_to<>> {
+ public:
+  static const char* Desc() { return "an equal pair"; }
+};
+class Ne2Matcher : public PairMatchBase<Ne2Matcher, std::not_equal_to<>> {
+ public:
+  static const char* Desc() { return "an unequal pair"; }
+};
+class Lt2Matcher : public PairMatchBase<Lt2Matcher, std::less<>> {
+ public:
+  static const char* Desc() { return "a pair where the first < the second"; }
+};
+class Gt2Matcher : public PairMatchBase<Gt2Matcher, std::greater<>> {
+ public:
+  static const char* Desc() { return "a pair where the first > the second"; }
+};
+class Le2Matcher : public PairMatchBase<Le2Matcher, std::less_equal<>> {
+ public:
+  static const char* Desc() { return "a pair where the first <= the second"; }
+};
+class Ge2Matcher : public PairMatchBase<Ge2Matcher, std::greater_equal<>> {
+ public:
+  static const char* Desc() { return "a pair where the first >= the second"; }
+};
+
+// Implements the Not(...) matcher for a particular argument type T.
+// We do not nest it inside the NotMatcher class template, as that
+// will prevent different instantiations of NotMatcher from sharing
+// the same NotMatcherImpl<T> class.
+template <typename T>
+class NotMatcherImpl : public MatcherInterface<const T&> {
+ public:
+  explicit NotMatcherImpl(const Matcher<T>& matcher) : matcher_(matcher) {}
+
+  bool MatchAndExplain(const T& x,
+                       MatchResultListener* listener) const override {
+    return !matcher_.MatchAndExplain(x, listener);
+  }
+
+  void DescribeTo(::std::ostream* os) const override {
+    matcher_.DescribeNegationTo(os);
+  }
+
+  void DescribeNegationTo(::std::ostream* os) const override {
+    matcher_.DescribeTo(os);
+  }
+
+ private:
+  const Matcher<T> matcher_;
+};
+
+// Implements the Not(m) matcher, which matches a value that doesn't
+// match matcher m.
+template <typename InnerMatcher>
+class NotMatcher {
+ public:
+  explicit NotMatcher(InnerMatcher matcher) : matcher_(matcher) {}
+
+  // This template type conversion operator allows Not(m) to be used
+  // to match any type m can match.
+  template <typename T>
+  operator Matcher<T>() const {
+    return Matcher<T>(new NotMatcherImpl<T>(SafeMatcherCast<T>(matcher_)));
+  }
+
+ private:
+  InnerMatcher matcher_;
+};
+
+// Implements the AllOf(m1, m2) matcher for a particular argument type
+// T. We do not nest it inside the BothOfMatcher class template, as
+// that will prevent different instantiations of BothOfMatcher from
+// sharing the same BothOfMatcherImpl<T> class.
+template <typename T>
+class AllOfMatcherImpl : public MatcherInterface<const T&> {
+ public:
+  explicit AllOfMatcherImpl(std::vector<Matcher<T>> matchers)
+      : matchers_(std::move(matchers)) {}
+
+  void DescribeTo(::std::ostream* os) const override {
+    *os << "(";
+    for (size_t i = 0; i < matchers_.size(); ++i) {
+      if (i != 0) *os << ") and (";
+      matchers_[i].DescribeTo(os);
+    }
+    *os << ")";
+  }
+
+  void DescribeNegationTo(::std::ostream* os) const override {
+    *os << "(";
+    for (size_t i = 0; i < matchers_.size(); ++i) {
+      if (i != 0) *os << ") or (";
+      matchers_[i].DescribeNegationTo(os);
+    }
+    *os << ")";
+  }
+
+  bool MatchAndExplain(const T& x,
+                       MatchResultListener* listener) const override {
+    // If either matcher1_ or matcher2_ doesn't match x, we only need
+    // to explain why one of them fails.
+    std::string all_match_result;
+
+    for (size_t i = 0; i < matchers_.size(); ++i) {
+      StringMatchResultListener slistener;
+      if (matchers_[i].MatchAndExplain(x, &slistener)) {
+        if (all_match_result.empty()) {
+          all_match_result = slistener.str();
+        } else {
+          std::string result = slistener.str();
+          if (!result.empty()) {
+            all_match_result += ", and ";
+            all_match_result += result;
+          }
+        }
+      } else {
+        *listener << slistener.str();
+        return false;
+      }
+    }
+
+    // Otherwise we need to explain why *both* of them match.
+    *listener << all_match_result;
+    return true;
+  }
+
+ private:
+  const std::vector<Matcher<T>> matchers_;
+};
+
+// VariadicMatcher is used for the variadic implementation of
+// AllOf(m_1, m_2, ...) and AnyOf(m_1, m_2, ...).
+// CombiningMatcher<T> is used to recursively combine the provided matchers
+// (of type Args...).
+template <template <typename T> class CombiningMatcher, typename... Args>
+class VariadicMatcher {
+ public:
+  VariadicMatcher(const Args&... matchers)  // NOLINT
+      : matchers_(matchers...) {
+    static_assert(sizeof...(Args) > 0, "Must have at least one matcher.");
+  }
+
+  VariadicMatcher(const VariadicMatcher&) = default;
+  VariadicMatcher& operator=(const VariadicMatcher&) = delete;
+
+  // This template type conversion operator allows an
+  // VariadicMatcher<Matcher1, Matcher2...> object to match any type that
+  // all of the provided matchers (Matcher1, Matcher2, ...) can match.
+  template <typename T>
+  operator Matcher<T>() const {
+    std::vector<Matcher<T>> values;
+    CreateVariadicMatcher<T>(&values, std::integral_constant<size_t, 0>());
+    return Matcher<T>(new CombiningMatcher<T>(std::move(values)));
+  }
+
+ private:
+  template <typename T, size_t I>
+  void CreateVariadicMatcher(std::vector<Matcher<T>>* values,
+                             std::integral_constant<size_t, I>) const {
+    values->push_back(SafeMatcherCast<T>(std::get<I>(matchers_)));
+    CreateVariadicMatcher<T>(values, std::integral_constant<size_t, I + 1>());
+  }
+
+  template <typename T>
+  void CreateVariadicMatcher(
+      std::vector<Matcher<T>>*,
+      std::integral_constant<size_t, sizeof...(Args)>) const {}
+
+  std::tuple<Args...> matchers_;
+};
+
+template <typename... Args>
+using AllOfMatcher = VariadicMatcher<AllOfMatcherImpl, Args...>;
+
+// Implements the AnyOf(m1, m2) matcher for a particular argument type
+// T.  We do not nest it inside the AnyOfMatcher class template, as
+// that will prevent different instantiations of AnyOfMatcher from
+// sharing the same EitherOfMatcherImpl<T> class.
+template <typename T>
+class AnyOfMatcherImpl : public MatcherInterface<const T&> {
+ public:
+  explicit AnyOfMatcherImpl(std::vector<Matcher<T>> matchers)
+      : matchers_(std::move(matchers)) {}
+
+  void DescribeTo(::std::ostream* os) const override {
+    *os << "(";
+    for (size_t i = 0; i < matchers_.size(); ++i) {
+      if (i != 0) *os << ") or (";
+      matchers_[i].DescribeTo(os);
+    }
+    *os << ")";
+  }
+
+  void DescribeNegationTo(::std::ostream* os) const override {
+    *os << "(";
+    for (size_t i = 0; i < matchers_.size(); ++i) {
+      if (i != 0) *os << ") and (";
+      matchers_[i].DescribeNegationTo(os);
+    }
+    *os << ")";
+  }
+
+  bool MatchAndExplain(const T& x,
+                       MatchResultListener* listener) const override {
+    std::string no_match_result;
+
+    // If either matcher1_ or matcher2_ matches x, we just need to
+    // explain why *one* of them matches.
+    for (size_t i = 0; i < matchers_.size(); ++i) {
+      StringMatchResultListener slistener;
+      if (matchers_[i].MatchAndExplain(x, &slistener)) {
+        *listener << slistener.str();
+        return true;
+      } else {
+        if (no_match_result.empty()) {
+          no_match_result = slistener.str();
+        } else {
+          std::string result = slistener.str();
+          if (!result.empty()) {
+            no_match_result += ", and ";
+            no_match_result += result;
+          }
+        }
+      }
+    }
+
+    // Otherwise we need to explain why *both* of them fail.
+    *listener << no_match_result;
+    return false;
+  }
+
+ private:
+  const std::vector<Matcher<T>> matchers_;
+};
+
+// AnyOfMatcher is used for the variadic implementation of AnyOf(m_1, m_2, ...).
+template <typename... Args>
+using AnyOfMatcher = VariadicMatcher<AnyOfMatcherImpl, Args...>;
+
+// ConditionalMatcher is the implementation of Conditional(cond, m1, m2)
+template <typename MatcherTrue, typename MatcherFalse>
+class ConditionalMatcher {
+ public:
+  ConditionalMatcher(bool condition, MatcherTrue matcher_true,
+                     MatcherFalse matcher_false)
+      : condition_(condition),
+        matcher_true_(std::move(matcher_true)),
+        matcher_false_(std::move(matcher_false)) {}
+
+  template <typename T>
+  operator Matcher<T>() const {  // NOLINT(runtime/explicit)
+    return condition_ ? SafeMatcherCast<T>(matcher_true_)
+                      : SafeMatcherCast<T>(matcher_false_);
+  }
+
+ private:
+  bool condition_;
+  MatcherTrue matcher_true_;
+  MatcherFalse matcher_false_;
+};
+
+// Wrapper for implementation of Any/AllOfArray().
+template <template <class> class MatcherImpl, typename T>
+class SomeOfArrayMatcher {
+ public:
+  // Constructs the matcher from a sequence of element values or
+  // element matchers.
+  template <typename Iter>
+  SomeOfArrayMatcher(Iter first, Iter last) : matchers_(first, last) {}
+
+  template <typename U>
+  operator Matcher<U>() const {  // NOLINT
+    using RawU = typename std::decay<U>::type;
+    std::vector<Matcher<RawU>> matchers;
+    matchers.reserve(matchers_.size());
+    for (const auto& matcher : matchers_) {
+      matchers.push_back(MatcherCast<RawU>(matcher));
+    }
+    return Matcher<U>(new MatcherImpl<RawU>(std::move(matchers)));
+  }
+
+ private:
+  const ::std::vector<T> matchers_;
+};
+
+template <typename T>
+using AllOfArrayMatcher = SomeOfArrayMatcher<AllOfMatcherImpl, T>;
+
+template <typename T>
+using AnyOfArrayMatcher = SomeOfArrayMatcher<AnyOfMatcherImpl, T>;
+
+// Used for implementing Truly(pred), which turns a predicate into a
+// matcher.
+template <typename Predicate>
+class TrulyMatcher {
+ public:
+  explicit TrulyMatcher(Predicate pred) : predicate_(pred) {}
+
+  // This method template allows Truly(pred) to be used as a matcher
+  // for type T where T is the argument type of predicate 'pred'.  The
+  // argument is passed by reference as the predicate may be
+  // interested in the address of the argument.
+  template <typename T>
+  bool MatchAndExplain(T& x,  // NOLINT
+                       MatchResultListener* listener) const {
+    // Without the if-statement, MSVC sometimes warns about converting
+    // a value to bool (warning 4800).
+    //
+    // We cannot write 'return !!predicate_(x);' as that doesn't work
+    // when predicate_(x) returns a class convertible to bool but
+    // having no operator!().
+    if (predicate_(x)) return true;
+    *listener << "didn't satisfy the given predicate";
+    return false;
+  }
+
+  void DescribeTo(::std::ostream* os) const {
+    *os << "satisfies the given predicate";
+  }
+
+  void DescribeNegationTo(::std::ostream* os) const {
+    *os << "doesn't satisfy the given predicate";
+  }
+
+ private:
+  Predicate predicate_;
+};
+
+// Used for implementing Matches(matcher), which turns a matcher into
+// a predicate.
+template <typename M>
+class MatcherAsPredicate {
+ public:
+  explicit MatcherAsPredicate(M matcher) : matcher_(matcher) {}
+
+  // This template operator() allows Matches(m) to be used as a
+  // predicate on type T where m is a matcher on type T.
+  //
+  // The argument x is passed by reference instead of by value, as
+  // some matcher may be interested in its address (e.g. as in
+  // Matches(Ref(n))(x)).
+  template <typename T>
+  bool operator()(const T& x) const {
+    // We let matcher_ commit to a particular type here instead of
+    // when the MatcherAsPredicate object was constructed.  This
+    // allows us to write Matches(m) where m is a polymorphic matcher
+    // (e.g. Eq(5)).
+    //
+    // If we write Matcher<T>(matcher_).Matches(x) here, it won't
+    // compile when matcher_ has type Matcher<const T&>; if we write
+    // Matcher<const T&>(matcher_).Matches(x) here, it won't compile
+    // when matcher_ has type Matcher<T>; if we just write
+    // matcher_.Matches(x), it won't compile when matcher_ is
+    // polymorphic, e.g. Eq(5).
+    //
+    // MatcherCast<const T&>() is necessary for making the code work
+    // in all of the above situations.
+    return MatcherCast<const T&>(matcher_).Matches(x);
+  }
+
+ private:
+  M matcher_;
+};
+
+// For implementing ASSERT_THAT() and EXPECT_THAT().  The template
+// argument M must be a type that can be converted to a matcher.
+template <typename M>
+class PredicateFormatterFromMatcher {
+ public:
+  explicit PredicateFormatterFromMatcher(M m) : matcher_(std::move(m)) {}
+
+  // This template () operator allows a PredicateFormatterFromMatcher
+  // object to act as a predicate-formatter suitable for using with
+  // Google Test's EXPECT_PRED_FORMAT1() macro.
+  template <typename T>
+  AssertionResult operator()(const char* value_text, const T& x) const {
+    // We convert matcher_ to a Matcher<const T&> *now* instead of
+    // when the PredicateFormatterFromMatcher object was constructed,
+    // as matcher_ may be polymorphic (e.g. NotNull()) and we won't
+    // know which type to instantiate it to until we actually see the
+    // type of x here.
+    //
+    // We write SafeMatcherCast<const T&>(matcher_) instead of
+    // Matcher<const T&>(matcher_), as the latter won't compile when
+    // matcher_ has type Matcher<T> (e.g. An<int>()).
+    // We don't write MatcherCast<const T&> either, as that allows
+    // potentially unsafe downcasting of the matcher argument.
+    const Matcher<const T&> matcher = SafeMatcherCast<const T&>(matcher_);
+
+    // The expected path here is that the matcher should match (i.e. that most
+    // tests pass) so optimize for this case.
+    if (matcher.Matches(x)) {
+      return AssertionSuccess();
+    }
+
+    ::std::stringstream ss;
+    ss << "Value of: " << value_text << "\n"
+       << "Expected: ";
+    matcher.DescribeTo(&ss);
+
+    // Rerun the matcher to "PrintAndExplain" the failure.
+    StringMatchResultListener listener;
+    if (MatchPrintAndExplain(x, matcher, &listener)) {
+      ss << "\n  The matcher failed on the initial attempt; but passed when "
+            "rerun to generate the explanation.";
+    }
+    ss << "\n  Actual: " << listener.str();
+    return AssertionFailure() << ss.str();
+  }
+
+ private:
+  const M matcher_;
+};
+
+// A helper function for converting a matcher to a predicate-formatter
+// without the user needing to explicitly write the type.  This is
+// used for implementing ASSERT_THAT() and EXPECT_THAT().
+// Implementation detail: 'matcher' is received by-value to force decaying.
+template <typename M>
+inline PredicateFormatterFromMatcher<M> MakePredicateFormatterFromMatcher(
+    M matcher) {
+  return PredicateFormatterFromMatcher<M>(std::move(matcher));
+}
+
+// Implements the polymorphic IsNan() matcher, which matches any floating type
+// value that is Nan.
+class IsNanMatcher {
+ public:
+  template <typename FloatType>
+  bool MatchAndExplain(const FloatType& f,
+                       MatchResultListener* /* listener */) const {
+    return (::std::isnan)(f);
+  }
+
+  void DescribeTo(::std::ostream* os) const { *os << "is NaN"; }
+  void DescribeNegationTo(::std::ostream* os) const { *os << "isn't NaN"; }
+};
+
+// Implements the polymorphic floating point equality matcher, which matches
+// two float values using ULP-based approximation or, optionally, a
+// user-specified epsilon.  The template is meant to be instantiated with
+// FloatType being either float or double.
+template <typename FloatType>
+class FloatingEqMatcher {
+ public:
+  // Constructor for FloatingEqMatcher.
+  // The matcher's input will be compared with expected.  The matcher treats two
+  // NANs as equal if nan_eq_nan is true.  Otherwise, under IEEE standards,
+  // equality comparisons between NANs will always return false.  We specify a
+  // negative max_abs_error_ term to indicate that ULP-based approximation will
+  // be used for comparison.
+  FloatingEqMatcher(FloatType expected, bool nan_eq_nan)
+      : expected_(expected), nan_eq_nan_(nan_eq_nan), max_abs_error_(-1) {}
+
+  // Constructor that supports a user-specified max_abs_error that will be used
+  // for comparison instead of ULP-based approximation.  The max absolute
+  // should be non-negative.
+  FloatingEqMatcher(FloatType expected, bool nan_eq_nan,
+                    FloatType max_abs_error)
+      : expected_(expected),
+        nan_eq_nan_(nan_eq_nan),
+        max_abs_error_(max_abs_error) {
+    GTEST_CHECK_(max_abs_error >= 0)
+        << ", where max_abs_error is" << max_abs_error;
+  }
+
+  // Implements floating point equality matcher as a Matcher<T>.
+  template <typename T>
+  class Impl : public MatcherInterface<T> {
+   public:
+    Impl(FloatType expected, bool nan_eq_nan, FloatType max_abs_error)
+        : expected_(expected),
+          nan_eq_nan_(nan_eq_nan),
+          max_abs_error_(max_abs_error) {}
+
+    bool MatchAndExplain(T value,
+                         MatchResultListener* listener) const override {
+      const FloatingPoint<FloatType> actual(value), expected(expected_);
+
+      // Compares NaNs first, if nan_eq_nan_ is true.
+      if (actual.is_nan() || expected.is_nan()) {
+        if (actual.is_nan() && expected.is_nan()) {
+          return nan_eq_nan_;
+        }
+        // One is nan; the other is not nan.
+        return false;
+      }
+      if (HasMaxAbsError()) {
+        // We perform an equality check so that inf will match inf, regardless
+        // of error bounds.  If the result of value - expected_ would result in
+        // overflow or if either value is inf, the default result is infinity,
+        // which should only match if max_abs_error_ is also infinity.
+        if (value == expected_) {
+          return true;
+        }
+
+        const FloatType diff = value - expected_;
+        if (::std::fabs(diff) <= max_abs_error_) {
+          return true;
+        }
+
+        if (listener->IsInterested()) {
+          *listener << "which is " << diff << " from " << expected_;
+        }
+        return false;
+      } else {
+        return actual.AlmostEquals(expected);
+      }
+    }
+
+    void DescribeTo(::std::ostream* os) const override {
+      // os->precision() returns the previously set precision, which we
+      // store to restore the ostream to its original configuration
+      // after outputting.
+      const ::std::streamsize old_precision =
+          os->precision(::std::numeric_limits<FloatType>::digits10 + 2);
+      if (FloatingPoint<FloatType>(expected_).is_nan()) {
+        if (nan_eq_nan_) {
+          *os << "is NaN";
+        } else {
+          *os << "never matches";
+        }
+      } else {
+        *os << "is approximately " << expected_;
+        if (HasMaxAbsError()) {
+          *os << " (absolute error <= " << max_abs_error_ << ")";
+        }
+      }
+      os->precision(old_precision);
+    }
+
+    void DescribeNegationTo(::std::ostream* os) const override {
+      // As before, get original precision.
+      const ::std::streamsize old_precision =
+          os->precision(::std::numeric_limits<FloatType>::digits10 + 2);
+      if (FloatingPoint<FloatType>(expected_).is_nan()) {
+        if (nan_eq_nan_) {
+          *os << "isn't NaN";
+        } else {
+          *os << "is anything";
+        }
+      } else {
+        *os << "isn't approximately " << expected_;
+        if (HasMaxAbsError()) {
+          *os << " (absolute error > " << max_abs_error_ << ")";
+        }
+      }
+      // Restore original precision.
+      os->precision(old_precision);
+    }
+
+   private:
+    bool HasMaxAbsError() const { return max_abs_error_ >= 0; }
+
+    const FloatType expected_;
+    const bool nan_eq_nan_;
+    // max_abs_error will be used for value comparison when >= 0.
+    const FloatType max_abs_error_;
+  };
+
+  // The following 3 type conversion operators allow FloatEq(expected) and
+  // NanSensitiveFloatEq(expected) to be used as a Matcher<float>, a
+  // Matcher<const float&>, or a Matcher<float&>, but nothing else.
+  operator Matcher<FloatType>() const {
+    return MakeMatcher(
+        new Impl<FloatType>(expected_, nan_eq_nan_, max_abs_error_));
+  }
+
+  operator Matcher<const FloatType&>() const {
+    return MakeMatcher(
+        new Impl<const FloatType&>(expected_, nan_eq_nan_, max_abs_error_));
+  }
+
+  operator Matcher<FloatType&>() const {
+    return MakeMatcher(
+        new Impl<FloatType&>(expected_, nan_eq_nan_, max_abs_error_));
+  }
+
+ private:
+  const FloatType expected_;
+  const bool nan_eq_nan_;
+  // max_abs_error will be used for value comparison when >= 0.
+  const FloatType max_abs_error_;
+};
+
+// A 2-tuple ("binary") wrapper around FloatingEqMatcher:
+// FloatingEq2Matcher() matches (x, y) by matching FloatingEqMatcher(x, false)
+// against y, and FloatingEq2Matcher(e) matches FloatingEqMatcher(x, false, e)
+// against y. The former implements "Eq", the latter "Near". At present, there
+// is no version that compares NaNs as equal.
+template <typename FloatType>
+class FloatingEq2Matcher {
+ public:
+  FloatingEq2Matcher() { Init(-1, false); }
+
+  explicit FloatingEq2Matcher(bool nan_eq_nan) { Init(-1, nan_eq_nan); }
+
+  explicit FloatingEq2Matcher(FloatType max_abs_error) {
+    Init(max_abs_error, false);
+  }
+
+  FloatingEq2Matcher(FloatType max_abs_error, bool nan_eq_nan) {
+    Init(max_abs_error, nan_eq_nan);
+  }
+
+  template <typename T1, typename T2>
+  operator Matcher<::std::tuple<T1, T2>>() const {
+    return MakeMatcher(
+        new Impl<::std::tuple<T1, T2>>(max_abs_error_, nan_eq_nan_));
+  }
+  template <typename T1, typename T2>
+  operator Matcher<const ::std::tuple<T1, T2>&>() const {
+    return MakeMatcher(
+        new Impl<const ::std::tuple<T1, T2>&>(max_abs_error_, nan_eq_nan_));
+  }
+
+ private:
+  static ::std::ostream& GetDesc(::std::ostream& os) {  // NOLINT
+    return os << "an almost-equal pair";
+  }
+
+  template <typename Tuple>
+  class Impl : public MatcherInterface<Tuple> {
+   public:
+    Impl(FloatType max_abs_error, bool nan_eq_nan)
+        : max_abs_error_(max_abs_error), nan_eq_nan_(nan_eq_nan) {}
+
+    bool MatchAndExplain(Tuple args,
+                         MatchResultListener* listener) const override {
+      if (max_abs_error_ == -1) {
+        FloatingEqMatcher<FloatType> fm(::std::get<0>(args), nan_eq_nan_);
+        return static_cast<Matcher<FloatType>>(fm).MatchAndExplain(
+            ::std::get<1>(args), listener);
+      } else {
+        FloatingEqMatcher<FloatType> fm(::std::get<0>(args), nan_eq_nan_,
+                                        max_abs_error_);
+        return static_cast<Matcher<FloatType>>(fm).MatchAndExplain(
+            ::std::get<1>(args), listener);
+      }
+    }
+    void DescribeTo(::std::ostream* os) const override {
+      *os << "are " << GetDesc;
+    }
+    void DescribeNegationTo(::std::ostream* os) const override {
+      *os << "aren't " << GetDesc;
+    }
+
+   private:
+    FloatType max_abs_error_;
+    const bool nan_eq_nan_;
+  };
+
+  void Init(FloatType max_abs_error_val, bool nan_eq_nan_val) {
+    max_abs_error_ = max_abs_error_val;
+    nan_eq_nan_ = nan_eq_nan_val;
+  }
+  FloatType max_abs_error_;
+  bool nan_eq_nan_;
+};
+
+// Implements the Pointee(m) matcher for matching a pointer whose
+// pointee matches matcher m.  The pointer can be either raw or smart.
+template <typename InnerMatcher>
+class PointeeMatcher {
+ public:
+  explicit PointeeMatcher(const InnerMatcher& matcher) : matcher_(matcher) {}
+
+  // This type conversion operator template allows Pointee(m) to be
+  // used as a matcher for any pointer type whose pointee type is
+  // compatible with the inner matcher, where type Pointer can be
+  // either a raw pointer or a smart pointer.
+  //
+  // The reason we do this instead of relying on
+  // MakePolymorphicMatcher() is that the latter is not flexible
+  // enough for implementing the DescribeTo() method of Pointee().
+  template <typename Pointer>
+  operator Matcher<Pointer>() const {
+    return Matcher<Pointer>(new Impl<const Pointer&>(matcher_));
+  }
+
+ private:
+  // The monomorphic implementation that works for a particular pointer type.
+  template <typename Pointer>
+  class Impl : public MatcherInterface<Pointer> {
+   public:
+    using Pointee =
+        typename std::pointer_traits<GTEST_REMOVE_REFERENCE_AND_CONST_(
+            Pointer)>::element_type;
+
+    explicit Impl(const InnerMatcher& matcher)
+        : matcher_(MatcherCast<const Pointee&>(matcher)) {}
+
+    void DescribeTo(::std::ostream* os) const override {
+      *os << "points to a value that ";
+      matcher_.DescribeTo(os);
+    }
+
+    void DescribeNegationTo(::std::ostream* os) const override {
+      *os << "does not point to a value that ";
+      matcher_.DescribeTo(os);
+    }
+
+    bool MatchAndExplain(Pointer pointer,
+                         MatchResultListener* listener) const override {
+      if (GetRawPointer(pointer) == nullptr) return false;
+
+      *listener << "which points to ";
+      return MatchPrintAndExplain(*pointer, matcher_, listener);
+    }
+
+   private:
+    const Matcher<const Pointee&> matcher_;
+  };
+
+  const InnerMatcher matcher_;
+};
+
+// Implements the Pointer(m) matcher
+// Implements the Pointer(m) matcher for matching a pointer that matches matcher
+// m.  The pointer can be either raw or smart, and will match `m` against the
+// raw pointer.
+template <typename InnerMatcher>
+class PointerMatcher {
+ public:
+  explicit PointerMatcher(const InnerMatcher& matcher) : matcher_(matcher) {}
+
+  // This type conversion operator template allows Pointer(m) to be
+  // used as a matcher for any pointer type whose pointer type is
+  // compatible with the inner matcher, where type PointerType can be
+  // either a raw pointer or a smart pointer.
+  //
+  // The reason we do this instead of relying on
+  // MakePolymorphicMatcher() is that the latter is not flexible
+  // enough for implementing the DescribeTo() method of Pointer().
+  template <typename PointerType>
+  operator Matcher<PointerType>() const {  // NOLINT
+    return Matcher<PointerType>(new Impl<const PointerType&>(matcher_));
+  }
+
+ private:
+  // The monomorphic implementation that works for a particular pointer type.
+  template <typename PointerType>
+  class Impl : public MatcherInterface<PointerType> {
+   public:
+    using Pointer =
+        const typename std::pointer_traits<GTEST_REMOVE_REFERENCE_AND_CONST_(
+            PointerType)>::element_type*;
+
+    explicit Impl(const InnerMatcher& matcher)
+        : matcher_(MatcherCast<Pointer>(matcher)) {}
+
+    void DescribeTo(::std::ostream* os) const override {
+      *os << "is a pointer that ";
+      matcher_.DescribeTo(os);
+    }
+
+    void DescribeNegationTo(::std::ostream* os) const override {
+      *os << "is not a pointer that ";
+      matcher_.DescribeTo(os);
+    }
+
+    bool MatchAndExplain(PointerType pointer,
+                         MatchResultListener* listener) const override {
+      *listener << "which is a pointer that ";
+      Pointer p = GetRawPointer(pointer);
+      return MatchPrintAndExplain(p, matcher_, listener);
+    }
+
+   private:
+    Matcher<Pointer> matcher_;
+  };
+
+  const InnerMatcher matcher_;
+};
+
+#if GTEST_HAS_RTTI
+// Implements the WhenDynamicCastTo<T>(m) matcher that matches a pointer or
+// reference that matches inner_matcher when dynamic_cast<T> is applied.
+// The result of dynamic_cast<To> is forwarded to the inner matcher.
+// If To is a pointer and the cast fails, the inner matcher will receive NULL.
+// If To is a reference and the cast fails, this matcher returns false
+// immediately.
+template <typename To>
+class WhenDynamicCastToMatcherBase {
+ public:
+  explicit WhenDynamicCastToMatcherBase(const Matcher<To>& matcher)
+      : matcher_(matcher) {}
+
+  void DescribeTo(::std::ostream* os) const {
+    GetCastTypeDescription(os);
+    matcher_.DescribeTo(os);
+  }
+
+  void DescribeNegationTo(::std::ostream* os) const {
+    GetCastTypeDescription(os);
+    matcher_.DescribeNegationTo(os);
+  }
+
+ protected:
+  const Matcher<To> matcher_;
+
+  static std::string GetToName() { return GetTypeName<To>(); }
+
+ private:
+  static void GetCastTypeDescription(::std::ostream* os) {
+    *os << "when dynamic_cast to " << GetToName() << ", ";
+  }
+};
+
+// Primary template.
+// To is a pointer. Cast and forward the result.
+template <typename To>
+class WhenDynamicCastToMatcher : public WhenDynamicCastToMatcherBase<To> {
+ public:
+  explicit WhenDynamicCastToMatcher(const Matcher<To>& matcher)
+      : WhenDynamicCastToMatcherBase<To>(matcher) {}
+
+  template <typename From>
+  bool MatchAndExplain(From from, MatchResultListener* listener) const {
+    To to = dynamic_cast<To>(from);
+    return MatchPrintAndExplain(to, this->matcher_, listener);
+  }
+};
+
+// Specialize for references.
+// In this case we return false if the dynamic_cast fails.
+template <typename To>
+class WhenDynamicCastToMatcher<To&> : public WhenDynamicCastToMatcherBase<To&> {
+ public:
+  explicit WhenDynamicCastToMatcher(const Matcher<To&>& matcher)
+      : WhenDynamicCastToMatcherBase<To&>(matcher) {}
+
+  template <typename From>
+  bool MatchAndExplain(From& from, MatchResultListener* listener) const {
+    // We don't want an std::bad_cast here, so do the cast with pointers.
+    To* to = dynamic_cast<To*>(&from);
+    if (to == nullptr) {
+      *listener << "which cannot be dynamic_cast to " << this->GetToName();
+      return false;
+    }
+    return MatchPrintAndExplain(*to, this->matcher_, listener);
+  }
+};
+#endif  // GTEST_HAS_RTTI
+
+// Implements the Field() matcher for matching a field (i.e. member
+// variable) of an object.
+template <typename Class, typename FieldType>
+class FieldMatcher {
+ public:
+  FieldMatcher(FieldType Class::*field,
+               const Matcher<const FieldType&>& matcher)
+      : field_(field), matcher_(matcher), whose_field_("whose given field ") {}
+
+  FieldMatcher(const std::string& field_name, FieldType Class::*field,
+               const Matcher<const FieldType&>& matcher)
+      : field_(field),
+        matcher_(matcher),
+        whose_field_("whose field `" + field_name + "` ") {}
+
+  void DescribeTo(::std::ostream* os) const {
+    *os << "is an object " << whose_field_;
+    matcher_.DescribeTo(os);
+  }
+
+  void DescribeNegationTo(::std::ostream* os) const {
+    *os << "is an object " << whose_field_;
+    matcher_.DescribeNegationTo(os);
+  }
+
+  template <typename T>
+  bool MatchAndExplain(const T& value, MatchResultListener* listener) const {
+    // FIXME: The dispatch on std::is_pointer was introduced as a workaround for
+    // a compiler bug, and can now be removed.
+    return MatchAndExplainImpl(
+        typename std::is_pointer<typename std::remove_const<T>::type>::type(),
+        value, listener);
+  }
+
+ private:
+  bool MatchAndExplainImpl(std::false_type /* is_not_pointer */,
+                           const Class& obj,
+                           MatchResultListener* listener) const {
+    *listener << whose_field_ << "is ";
+    return MatchPrintAndExplain(obj.*field_, matcher_, listener);
+  }
+
+  bool MatchAndExplainImpl(std::true_type /* is_pointer */, const Class* p,
+                           MatchResultListener* listener) const {
+    if (p == nullptr) return false;
+
+    *listener << "which points to an object ";
+    // Since *p has a field, it must be a class/struct/union type and
+    // thus cannot be a pointer.  Therefore we pass false_type() as
+    // the first argument.
+    return MatchAndExplainImpl(std::false_type(), *p, listener);
+  }
+
+  const FieldType Class::*field_;
+  const Matcher<const FieldType&> matcher_;
+
+  // Contains either "whose given field " if the name of the field is unknown
+  // or "whose field `name_of_field` " if the name is known.
+  const std::string whose_field_;
+};
+
+// Implements the Property() matcher for matching a property
+// (i.e. return value of a getter method) of an object.
+//
+// Property is a const-qualified member function of Class returning
+// PropertyType.
+template <typename Class, typename PropertyType, typename Property>
+class PropertyMatcher {
+ public:
+  typedef const PropertyType& RefToConstProperty;
+
+  PropertyMatcher(Property property, const Matcher<RefToConstProperty>& matcher)
+      : property_(property),
+        matcher_(matcher),
+        whose_property_("whose given property ") {}
+
+  PropertyMatcher(const std::string& property_name, Property property,
+                  const Matcher<RefToConstProperty>& matcher)
+      : property_(property),
+        matcher_(matcher),
+        whose_property_("whose property `" + property_name + "` ") {}
+
+  void DescribeTo(::std::ostream* os) const {
+    *os << "is an object " << whose_property_;
+    matcher_.DescribeTo(os);
+  }
+
+  void DescribeNegationTo(::std::ostream* os) const {
+    *os << "is an object " << whose_property_;
+    matcher_.DescribeNegationTo(os);
+  }
+
+  template <typename T>
+  bool MatchAndExplain(const T& value, MatchResultListener* listener) const {
+    return MatchAndExplainImpl(
+        typename std::is_pointer<typename std::remove_const<T>::type>::type(),
+        value, listener);
+  }
+
+ private:
+  bool MatchAndExplainImpl(std::false_type /* is_not_pointer */,
+                           const Class& obj,
+                           MatchResultListener* listener) const {
+    *listener << whose_property_ << "is ";
+    // Cannot pass the return value (for example, int) to MatchPrintAndExplain,
+    // which takes a non-const reference as argument.
+    RefToConstProperty result = (obj.*property_)();
+    return MatchPrintAndExplain(result, matcher_, listener);
+  }
+
+  bool MatchAndExplainImpl(std::true_type /* is_pointer */, const Class* p,
+                           MatchResultListener* listener) const {
+    if (p == nullptr) return false;
+
+    *listener << "which points to an object ";
+    // Since *p has a property method, it must be a class/struct/union
+    // type and thus cannot be a pointer.  Therefore we pass
+    // false_type() as the first argument.
+    return MatchAndExplainImpl(std::false_type(), *p, listener);
+  }
+
+  Property property_;
+  const Matcher<RefToConstProperty> matcher_;
+
+  // Contains either "whose given property " if the name of the property is
+  // unknown or "whose property `name_of_property` " if the name is known.
+  const std::string whose_property_;
+};
+
+// Type traits specifying various features of different functors for ResultOf.
+// The default template specifies features for functor objects.
+template <typename Functor>
+struct CallableTraits {
+  typedef Functor StorageType;
+
+  static void CheckIsValid(Functor /* functor */) {}
+
+  template <typename T>
+  static auto Invoke(Functor f, const T& arg) -> decltype(f(arg)) {
+    return f(arg);
+  }
+};
+
+// Specialization for function pointers.
+template <typename ArgType, typename ResType>
+struct CallableTraits<ResType (*)(ArgType)> {
+  typedef ResType ResultType;
+  typedef ResType (*StorageType)(ArgType);
+
+  static void CheckIsValid(ResType (*f)(ArgType)) {
+    GTEST_CHECK_(f != nullptr)
+        << "NULL function pointer is passed into ResultOf().";
+  }
+  template <typename T>
+  static ResType Invoke(ResType (*f)(ArgType), T arg) {
+    return (*f)(arg);
+  }
+};
+
+// Implements the ResultOf() matcher for matching a return value of a
+// unary function of an object.
+template <typename Callable, typename InnerMatcher>
+class ResultOfMatcher {
+ public:
+  ResultOfMatcher(Callable callable, InnerMatcher matcher)
+      : ResultOfMatcher(/*result_description=*/"", std::move(callable),
+                        std::move(matcher)) {}
+
+  ResultOfMatcher(const std::string& result_description, Callable callable,
+                  InnerMatcher matcher)
+      : result_description_(result_description),
+        callable_(std::move(callable)),
+        matcher_(std::move(matcher)) {
+    CallableTraits<Callable>::CheckIsValid(callable_);
+  }
+
+  template <typename T>
+  operator Matcher<T>() const {
+    return Matcher<T>(
+        new Impl<const T&>(result_description_, callable_, matcher_));
+  }
+
+ private:
+  typedef typename CallableTraits<Callable>::StorageType CallableStorageType;
+
+  template <typename T>
+  class Impl : public MatcherInterface<T> {
+    using ResultType = decltype(CallableTraits<Callable>::template Invoke<T>(
+        std::declval<CallableStorageType>(), std::declval<T>()));
+
+   public:
+    template <typename M>
+    Impl(const std::string& result_description,
+         const CallableStorageType& callable, const M& matcher)
+        : result_description_(result_description),
+          callable_(callable),
+          matcher_(MatcherCast<ResultType>(matcher)) {}
+
+    void DescribeTo(::std::ostream* os) const override {
+      if (result_description_.empty()) {
+        *os << "is mapped by the given callable to a value that ";
+      } else {
+        *os << "whose " << result_description_ << " ";
+      }
+      matcher_.DescribeTo(os);
+    }
+
+    void DescribeNegationTo(::std::ostream* os) const override {
+      if (result_description_.empty()) {
+        *os << "is mapped by the given callable to a value that ";
+      } else {
+        *os << "whose " << result_description_ << " ";
+      }
+      matcher_.DescribeNegationTo(os);
+    }
+
+    bool MatchAndExplain(T obj, MatchResultListener* listener) const override {
+      if (result_description_.empty()) {
+        *listener << "which is mapped by the given callable to ";
+      } else {
+        *listener << "whose " << result_description_ << " is ";
+      }
+      // Cannot pass the return value directly to MatchPrintAndExplain, which
+      // takes a non-const reference as argument.
+      // Also, specifying template argument explicitly is needed because T could
+      // be a non-const reference (e.g. Matcher<Uncopyable&>).
+      ResultType result =
+          CallableTraits<Callable>::template Invoke<T>(callable_, obj);
+      return MatchPrintAndExplain(result, matcher_, listener);
+    }
+
+   private:
+    const std::string result_description_;
+    // Functors often define operator() as non-const method even though
+    // they are actually stateless. But we need to use them even when
+    // 'this' is a const pointer. It's the user's responsibility not to
+    // use stateful callables with ResultOf(), which doesn't guarantee
+    // how many times the callable will be invoked.
+    mutable CallableStorageType callable_;
+    const Matcher<ResultType> matcher_;
+  };  // class Impl
+
+  const std::string result_description_;
+  const CallableStorageType callable_;
+  const InnerMatcher matcher_;
+};
+
+// Implements a matcher that checks the size of an STL-style container.
+template <typename SizeMatcher>
+class SizeIsMatcher {
+ public:
+  explicit SizeIsMatcher(const SizeMatcher& size_matcher)
+      : size_matcher_(size_matcher) {}
+
+  template <typename Container>
+  operator Matcher<Container>() const {
+    return Matcher<Container>(new Impl<const Container&>(size_matcher_));
+  }
+
+  template <typename Container>
+  class Impl : public MatcherInterface<Container> {
+   public:
+    using SizeType = decltype(std::declval<Container>().size());
+    explicit Impl(const SizeMatcher& size_matcher)
+        : size_matcher_(MatcherCast<SizeType>(size_matcher)) {}
+
+    void DescribeTo(::std::ostream* os) const override {
+      *os << "has a size that ";
+      size_matcher_.DescribeTo(os);
+    }
+    void DescribeNegationTo(::std::ostream* os) const override {
+      *os << "has a size that ";
+      size_matcher_.DescribeNegationTo(os);
+    }
+
+    bool MatchAndExplain(Container container,
+                         MatchResultListener* listener) const override {
+      SizeType size = container.size();
+      StringMatchResultListener size_listener;
+      const bool result = size_matcher_.MatchAndExplain(size, &size_listener);
+      *listener << "whose size " << size
+                << (result ? " matches" : " doesn't match");
+      PrintIfNotEmpty(size_listener.str(), listener->stream());
+      return result;
+    }
+
+   private:
+    const Matcher<SizeType> size_matcher_;
+  };
+
+ private:
+  const SizeMatcher size_matcher_;
+};
+
+// Implements a matcher that checks the begin()..end() distance of an STL-style
+// container.
+template <typename DistanceMatcher>
+class BeginEndDistanceIsMatcher {
+ public:
+  explicit BeginEndDistanceIsMatcher(const DistanceMatcher& distance_matcher)
+      : distance_matcher_(distance_matcher) {}
+
+  template <typename Container>
+  operator Matcher<Container>() const {
+    return Matcher<Container>(new Impl<const Container&>(distance_matcher_));
+  }
+
+  template <typename Container>
+  class Impl : public MatcherInterface<Container> {
+   public:
+    typedef internal::StlContainerView<GTEST_REMOVE_REFERENCE_AND_CONST_(
+        Container)>
+        ContainerView;
+    typedef typename std::iterator_traits<
+        typename ContainerView::type::const_iterator>::difference_type
+        DistanceType;
+    explicit Impl(const DistanceMatcher& distance_matcher)
+        : distance_matcher_(MatcherCast<DistanceType>(distance_matcher)) {}
+
+    void DescribeTo(::std::ostream* os) const override {
+      *os << "distance between begin() and end() ";
+      distance_matcher_.DescribeTo(os);
+    }
+    void DescribeNegationTo(::std::ostream* os) const override {
+      *os << "distance between begin() and end() ";
+      distance_matcher_.DescribeNegationTo(os);
+    }
+
+    bool MatchAndExplain(Container container,
+                         MatchResultListener* listener) const override {
+      using std::begin;
+      using std::end;
+      DistanceType distance = std::distance(begin(container), end(container));
+      StringMatchResultListener distance_listener;
+      const bool result =
+          distance_matcher_.MatchAndExplain(distance, &distance_listener);
+      *listener << "whose distance between begin() and end() " << distance
+                << (result ? " matches" : " doesn't match");
+      PrintIfNotEmpty(distance_listener.str(), listener->stream());
+      return result;
+    }
+
+   private:
+    const Matcher<DistanceType> distance_matcher_;
+  };
+
+ private:
+  const DistanceMatcher distance_matcher_;
+};
+
+// Implements an equality matcher for any STL-style container whose elements
+// support ==. This matcher is like Eq(), but its failure explanations provide
+// more detailed information that is useful when the container is used as a set.
+// The failure message reports elements that are in one of the operands but not
+// the other. The failure messages do not report duplicate or out-of-order
+// elements in the containers (which don't properly matter to sets, but can
+// occur if the containers are vectors or lists, for example).
+//
+// Uses the container's const_iterator, value_type, operator ==,
+// begin(), and end().
+template <typename Container>
+class ContainerEqMatcher {
+ public:
+  typedef internal::StlContainerView<Container> View;
+  typedef typename View::type StlContainer;
+  typedef typename View::const_reference StlContainerReference;
+
+  static_assert(!std::is_const<Container>::value,
+                "Container type must not be const");
+  static_assert(!std::is_reference<Container>::value,
+                "Container type must not be a reference");
+
+  // We make a copy of expected in case the elements in it are modified
+  // after this matcher is created.
+  explicit ContainerEqMatcher(const Container& expected)
+      : expected_(View::Copy(expected)) {}
+
+  void DescribeTo(::std::ostream* os) const {
+    *os << "equals ";
+    UniversalPrint(expected_, os);
+  }
+  void DescribeNegationTo(::std::ostream* os) const {
+    *os << "does not equal ";
+    UniversalPrint(expected_, os);
+  }
+
+  template <typename LhsContainer>
+  bool MatchAndExplain(const LhsContainer& lhs,
+                       MatchResultListener* listener) const {
+    typedef internal::StlContainerView<
+        typename std::remove_const<LhsContainer>::type>
+        LhsView;
+    StlContainerReference lhs_stl_container = LhsView::ConstReference(lhs);
+    if (lhs_stl_container == expected_) return true;
+
+    ::std::ostream* const os = listener->stream();
+    if (os != nullptr) {
+      // Something is different. Check for extra values first.
+      bool printed_header = false;
+      for (auto it = lhs_stl_container.begin(); it != lhs_stl_container.end();
+           ++it) {
+        if (internal::ArrayAwareFind(expected_.begin(), expected_.end(), *it) ==
+            expected_.end()) {
+          if (printed_header) {
+            *os << ", ";
+          } else {
+            *os << "which has these unexpected elements: ";
+            printed_header = true;
+          }
+          UniversalPrint(*it, os);
+        }
+      }
+
+      // Now check for missing values.
+      bool printed_header2 = false;
+      for (auto it = expected_.begin(); it != expected_.end(); ++it) {
+        if (internal::ArrayAwareFind(lhs_stl_container.begin(),
+                                     lhs_stl_container.end(),
+                                     *it) == lhs_stl_container.end()) {
+          if (printed_header2) {
+            *os << ", ";
+          } else {
+            *os << (printed_header ? ",\nand" : "which")
+                << " doesn't have these expected elements: ";
+            printed_header2 = true;
+          }
+          UniversalPrint(*it, os);
+        }
+      }
+    }
+
+    return false;
+  }
+
+ private:
+  const StlContainer expected_;
+};
+
+// A comparator functor that uses the < operator to compare two values.
+struct LessComparator {
+  template <typename T, typename U>
+  bool operator()(const T& lhs, const U& rhs) const {
+    return lhs < rhs;
+  }
+};
+
+// Implements WhenSortedBy(comparator, container_matcher).
+template <typename Comparator, typename ContainerMatcher>
+class WhenSortedByMatcher {
+ public:
+  WhenSortedByMatcher(const Comparator& comparator,
+                      const ContainerMatcher& matcher)
+      : comparator_(comparator), matcher_(matcher) {}
+
+  template <typename LhsContainer>
+  operator Matcher<LhsContainer>() const {
+    return MakeMatcher(new Impl<LhsContainer>(comparator_, matcher_));
+  }
+
+  template <typename LhsContainer>
+  class Impl : public MatcherInterface<LhsContainer> {
+   public:
+    typedef internal::StlContainerView<GTEST_REMOVE_REFERENCE_AND_CONST_(
+        LhsContainer)>
+        LhsView;
+    typedef typename LhsView::type LhsStlContainer;
+    typedef typename LhsView::const_reference LhsStlContainerReference;
+    // Transforms std::pair<const Key, Value> into std::pair<Key, Value>
+    // so that we can match associative containers.
+    typedef
+        typename RemoveConstFromKey<typename LhsStlContainer::value_type>::type
+            LhsValue;
+
+    Impl(const Comparator& comparator, const ContainerMatcher& matcher)
+        : comparator_(comparator), matcher_(matcher) {}
+
+    void DescribeTo(::std::ostream* os) const override {
+      *os << "(when sorted) ";
+      matcher_.DescribeTo(os);
+    }
+
+    void DescribeNegationTo(::std::ostream* os) const override {
+      *os << "(when sorted) ";
+      matcher_.DescribeNegationTo(os);
+    }
+
+    bool MatchAndExplain(LhsContainer lhs,
+                         MatchResultListener* listener) const override {
+      LhsStlContainerReference lhs_stl_container = LhsView::ConstReference(lhs);
+      ::std::vector<LhsValue> sorted_container(lhs_stl_container.begin(),
+                                               lhs_stl_container.end());
+      ::std::sort(sorted_container.begin(), sorted_container.end(),
+                  comparator_);
+
+      if (!listener->IsInterested()) {
+        // If the listener is not interested, we do not need to
+        // construct the inner explanation.
+        return matcher_.Matches(sorted_container);
+      }
+
+      *listener << "which is ";
+      UniversalPrint(sorted_container, listener->stream());
+      *listener << " when sorted";
+
+      StringMatchResultListener inner_listener;
+      const bool match =
+          matcher_.MatchAndExplain(sorted_container, &inner_listener);
+      PrintIfNotEmpty(inner_listener.str(), listener->stream());
+      return match;
+    }
+
+   private:
+    const Comparator comparator_;
+    const Matcher<const ::std::vector<LhsValue>&> matcher_;
+
+    Impl(const Impl&) = delete;
+    Impl& operator=(const Impl&) = delete;
+  };
+
+ private:
+  const Comparator comparator_;
+  const ContainerMatcher matcher_;
+};
+
+// Implements Pointwise(tuple_matcher, rhs_container).  tuple_matcher
+// must be able to be safely cast to Matcher<std::tuple<const T1&, const
+// T2&> >, where T1 and T2 are the types of elements in the LHS
+// container and the RHS container respectively.
+template <typename TupleMatcher, typename RhsContainer>
+class PointwiseMatcher {
+  static_assert(
+      !IsHashTable<GTEST_REMOVE_REFERENCE_AND_CONST_(RhsContainer)>::value,
+      "use UnorderedPointwise with hash tables");
+
+ public:
+  typedef internal::StlContainerView<RhsContainer> RhsView;
+  typedef typename RhsView::type RhsStlContainer;
+  typedef typename RhsStlContainer::value_type RhsValue;
+
+  static_assert(!std::is_const<RhsContainer>::value,
+                "RhsContainer type must not be const");
+  static_assert(!std::is_reference<RhsContainer>::value,
+                "RhsContainer type must not be a reference");
+
+  // Like ContainerEq, we make a copy of rhs in case the elements in
+  // it are modified after this matcher is created.
+  PointwiseMatcher(const TupleMatcher& tuple_matcher, const RhsContainer& rhs)
+      : tuple_matcher_(tuple_matcher), rhs_(RhsView::Copy(rhs)) {}
+
+  template <typename LhsContainer>
+  operator Matcher<LhsContainer>() const {
+    static_assert(
+        !IsHashTable<GTEST_REMOVE_REFERENCE_AND_CONST_(LhsContainer)>::value,
+        "use UnorderedPointwise with hash tables");
+
+    return Matcher<LhsContainer>(
+        new Impl<const LhsContainer&>(tuple_matcher_, rhs_));
+  }
+
+  template <typename LhsContainer>
+  class Impl : public MatcherInterface<LhsContainer> {
+   public:
+    typedef internal::StlContainerView<GTEST_REMOVE_REFERENCE_AND_CONST_(
+        LhsContainer)>
+        LhsView;
+    typedef typename LhsView::type LhsStlContainer;
+    typedef typename LhsView::const_reference LhsStlContainerReference;
+    typedef typename LhsStlContainer::value_type LhsValue;
+    // We pass the LHS value and the RHS value to the inner matcher by
+    // reference, as they may be expensive to copy.  We must use tuple
+    // instead of pair here, as a pair cannot hold references (C++ 98,
+    // 20.2.2 [lib.pairs]).
+    typedef ::std::tuple<const LhsValue&, const RhsValue&> InnerMatcherArg;
+
+    Impl(const TupleMatcher& tuple_matcher, const RhsStlContainer& rhs)
+        // mono_tuple_matcher_ holds a monomorphic version of the tuple matcher.
+        : mono_tuple_matcher_(SafeMatcherCast<InnerMatcherArg>(tuple_matcher)),
+          rhs_(rhs) {}
+
+    void DescribeTo(::std::ostream* os) const override {
+      *os << "contains " << rhs_.size()
+          << " values, where each value and its corresponding value in ";
+      UniversalPrinter<RhsStlContainer>::Print(rhs_, os);
+      *os << " ";
+      mono_tuple_matcher_.DescribeTo(os);
+    }
+    void DescribeNegationTo(::std::ostream* os) const override {
+      *os << "doesn't contain exactly " << rhs_.size()
+          << " values, or contains a value x at some index i"
+          << " where x and the i-th value of ";
+      UniversalPrint(rhs_, os);
+      *os << " ";
+      mono_tuple_matcher_.DescribeNegationTo(os);
+    }
+
+    bool MatchAndExplain(LhsContainer lhs,
+                         MatchResultListener* listener) const override {
+      LhsStlContainerReference lhs_stl_container = LhsView::ConstReference(lhs);
+      const size_t actual_size = lhs_stl_container.size();
+      if (actual_size != rhs_.size()) {
+        *listener << "which contains " << actual_size << " values";
+        return false;
+      }
+
+      auto left = lhs_stl_container.begin();
+      auto right = rhs_.begin();
+      for (size_t i = 0; i != actual_size; ++i, ++left, ++right) {
+        if (listener->IsInterested()) {
+          StringMatchResultListener inner_listener;
+          // Create InnerMatcherArg as a temporarily object to avoid it outlives
+          // *left and *right. Dereference or the conversion to `const T&` may
+          // return temp objects, e.g. for vector<bool>.
+          if (!mono_tuple_matcher_.MatchAndExplain(
+                  InnerMatcherArg(ImplicitCast_<const LhsValue&>(*left),
+                                  ImplicitCast_<const RhsValue&>(*right)),
+                  &inner_listener)) {
+            *listener << "where the value pair (";
+            UniversalPrint(*left, listener->stream());
+            *listener << ", ";
+            UniversalPrint(*right, listener->stream());
+            *listener << ") at index #" << i << " don't match";
+            PrintIfNotEmpty(inner_listener.str(), listener->stream());
+            return false;
+          }
+        } else {
+          if (!mono_tuple_matcher_.Matches(
+                  InnerMatcherArg(ImplicitCast_<const LhsValue&>(*left),
+                                  ImplicitCast_<const RhsValue&>(*right))))
+            return false;
+        }
+      }
+
+      return true;
+    }
+
+   private:
+    const Matcher<InnerMatcherArg> mono_tuple_matcher_;
+    const RhsStlContainer rhs_;
+  };
+
+ private:
+  const TupleMatcher tuple_matcher_;
+  const RhsStlContainer rhs_;
+};
+
+// Holds the logic common to ContainsMatcherImpl and EachMatcherImpl.
+template <typename Container>
+class QuantifierMatcherImpl : public MatcherInterface<Container> {
+ public:
+  typedef GTEST_REMOVE_REFERENCE_AND_CONST_(Container) RawContainer;
+  typedef StlContainerView<RawContainer> View;
+  typedef typename View::type StlContainer;
+  typedef typename View::const_reference StlContainerReference;
+  typedef typename StlContainer::value_type Element;
+
+  template <typename InnerMatcher>
+  explicit QuantifierMatcherImpl(InnerMatcher inner_matcher)
+      : inner_matcher_(
+            testing::SafeMatcherCast<const Element&>(inner_matcher)) {}
+
+  // Checks whether:
+  // * All elements in the container match, if all_elements_should_match.
+  // * Any element in the container matches, if !all_elements_should_match.
+  bool MatchAndExplainImpl(bool all_elements_should_match, Container container,
+                           MatchResultListener* listener) const {
+    StlContainerReference stl_container = View::ConstReference(container);
+    size_t i = 0;
+    for (auto it = stl_container.begin(); it != stl_container.end();
+         ++it, ++i) {
+      StringMatchResultListener inner_listener;
+      const bool matches = inner_matcher_.MatchAndExplain(*it, &inner_listener);
+
+      if (matches != all_elements_should_match) {
+        *listener << "whose element #" << i
+                  << (matches ? " matches" : " doesn't match");
+        PrintIfNotEmpty(inner_listener.str(), listener->stream());
+        return !all_elements_should_match;
+      }
+    }
+    return all_elements_should_match;
+  }
+
+  bool MatchAndExplainImpl(const Matcher<size_t>& count_matcher,
+                           Container container,
+                           MatchResultListener* listener) const {
+    StlContainerReference stl_container = View::ConstReference(container);
+    size_t i = 0;
+    std::vector<size_t> match_elements;
+    for (auto it = stl_container.begin(); it != stl_container.end();
+         ++it, ++i) {
+      StringMatchResultListener inner_listener;
+      const bool matches = inner_matcher_.MatchAndExplain(*it, &inner_listener);
+      if (matches) {
+        match_elements.push_back(i);
+      }
+    }
+    if (listener->IsInterested()) {
+      if (match_elements.empty()) {
+        *listener << "has no element that matches";
+      } else if (match_elements.size() == 1) {
+        *listener << "whose element #" << match_elements[0] << " matches";
+      } else {
+        *listener << "whose elements (";
+        std::string sep = "";
+        for (size_t e : match_elements) {
+          *listener << sep << e;
+          sep = ", ";
+        }
+        *listener << ") match";
+      }
+    }
+    StringMatchResultListener count_listener;
+    if (count_matcher.MatchAndExplain(match_elements.size(), &count_listener)) {
+      *listener << " and whose match quantity of " << match_elements.size()
+                << " matches";
+      PrintIfNotEmpty(count_listener.str(), listener->stream());
+      return true;
+    } else {
+      if (match_elements.empty()) {
+        *listener << " and";
+      } else {
+        *listener << " but";
+      }
+      *listener << " whose match quantity of " << match_elements.size()
+                << " does not match";
+      PrintIfNotEmpty(count_listener.str(), listener->stream());
+      return false;
+    }
+  }
+
+ protected:
+  const Matcher<const Element&> inner_matcher_;
+};
+
+// Implements Contains(element_matcher) for the given argument type Container.
+// Symmetric to EachMatcherImpl.
+template <typename Container>
+class ContainsMatcherImpl : public QuantifierMatcherImpl<Container> {
+ public:
+  template <typename InnerMatcher>
+  explicit ContainsMatcherImpl(InnerMatcher inner_matcher)
+      : QuantifierMatcherImpl<Container>(inner_matcher) {}
+
+  // Describes what this matcher does.
+  void DescribeTo(::std::ostream* os) const override {
+    *os << "contains at least one element that ";
+    this->inner_matcher_.DescribeTo(os);
+  }
+
+  void DescribeNegationTo(::std::ostream* os) const override {
+    *os << "doesn't contain any element that ";
+    this->inner_matcher_.DescribeTo(os);
+  }
+
+  bool MatchAndExplain(Container container,
+                       MatchResultListener* listener) const override {
+    return this->MatchAndExplainImpl(false, container, listener);
+  }
+};
+
+// Implements Each(element_matcher) for the given argument type Container.
+// Symmetric to ContainsMatcherImpl.
+template <typename Container>
+class EachMatcherImpl : public QuantifierMatcherImpl<Container> {
+ public:
+  template <typename InnerMatcher>
+  explicit EachMatcherImpl(InnerMatcher inner_matcher)
+      : QuantifierMatcherImpl<Container>(inner_matcher) {}
+
+  // Describes what this matcher does.
+  void DescribeTo(::std::ostream* os) const override {
+    *os << "only contains elements that ";
+    this->inner_matcher_.DescribeTo(os);
+  }
+
+  void DescribeNegationTo(::std::ostream* os) const override {
+    *os << "contains some element that ";
+    this->inner_matcher_.DescribeNegationTo(os);
+  }
+
+  bool MatchAndExplain(Container container,
+                       MatchResultListener* listener) const override {
+    return this->MatchAndExplainImpl(true, container, listener);
+  }
+};
+
+// Implements Contains(element_matcher).Times(n) for the given argument type
+// Container.
+template <typename Container>
+class ContainsTimesMatcherImpl : public QuantifierMatcherImpl<Container> {
+ public:
+  template <typename InnerMatcher>
+  explicit ContainsTimesMatcherImpl(InnerMatcher inner_matcher,
+                                    Matcher<size_t> count_matcher)
+      : QuantifierMatcherImpl<Container>(inner_matcher),
+        count_matcher_(std::move(count_matcher)) {}
+
+  void DescribeTo(::std::ostream* os) const override {
+    *os << "quantity of elements that match ";
+    this->inner_matcher_.DescribeTo(os);
+    *os << " ";
+    count_matcher_.DescribeTo(os);
+  }
+
+  void DescribeNegationTo(::std::ostream* os) const override {
+    *os << "quantity of elements that match ";
+    this->inner_matcher_.DescribeTo(os);
+    *os << " ";
+    count_matcher_.DescribeNegationTo(os);
+  }
+
+  bool MatchAndExplain(Container container,
+                       MatchResultListener* listener) const override {
+    return this->MatchAndExplainImpl(count_matcher_, container, listener);
+  }
+
+ private:
+  const Matcher<size_t> count_matcher_;
+};
+
+// Implements polymorphic Contains(element_matcher).Times(n).
+template <typename M>
+class ContainsTimesMatcher {
+ public:
+  explicit ContainsTimesMatcher(M m, Matcher<size_t> count_matcher)
+      : inner_matcher_(m), count_matcher_(std::move(count_matcher)) {}
+
+  template <typename Container>
+  operator Matcher<Container>() const {  // NOLINT
+    return Matcher<Container>(new ContainsTimesMatcherImpl<const Container&>(
+        inner_matcher_, count_matcher_));
+  }
+
+ private:
+  const M inner_matcher_;
+  const Matcher<size_t> count_matcher_;
+};
+
+// Implements polymorphic Contains(element_matcher).
+template <typename M>
+class ContainsMatcher {
+ public:
+  explicit ContainsMatcher(M m) : inner_matcher_(m) {}
+
+  template <typename Container>
+  operator Matcher<Container>() const {  // NOLINT
+    return Matcher<Container>(
+        new ContainsMatcherImpl<const Container&>(inner_matcher_));
+  }
+
+  ContainsTimesMatcher<M> Times(Matcher<size_t> count_matcher) const {
+    return ContainsTimesMatcher<M>(inner_matcher_, std::move(count_matcher));
+  }
+
+ private:
+  const M inner_matcher_;
+};
+
+// Implements polymorphic Each(element_matcher).
+template <typename M>
+class EachMatcher {
+ public:
+  explicit EachMatcher(M m) : inner_matcher_(m) {}
+
+  template <typename Container>
+  operator Matcher<Container>() const {  // NOLINT
+    return Matcher<Container>(
+        new EachMatcherImpl<const Container&>(inner_matcher_));
+  }
+
+ private:
+  const M inner_matcher_;
+};
+
+struct Rank1 {};
+struct Rank0 : Rank1 {};
+
+namespace pair_getters {
+using std::get;
+template <typename T>
+auto First(T& x, Rank1) -> decltype(get<0>(x)) {  // NOLINT
+  return get<0>(x);
+}
+template <typename T>
+auto First(T& x, Rank0) -> decltype((x.first)) {  // NOLINT
+  return x.first;
+}
+
+template <typename T>
+auto Second(T& x, Rank1) -> decltype(get<1>(x)) {  // NOLINT
+  return get<1>(x);
+}
+template <typename T>
+auto Second(T& x, Rank0) -> decltype((x.second)) {  // NOLINT
+  return x.second;
+}
+}  // namespace pair_getters
+
+// Implements Key(inner_matcher) for the given argument pair type.
+// Key(inner_matcher) matches an std::pair whose 'first' field matches
+// inner_matcher.  For example, Contains(Key(Ge(5))) can be used to match an
+// std::map that contains at least one element whose key is >= 5.
+template <typename PairType>
+class KeyMatcherImpl : public MatcherInterface<PairType> {
+ public:
+  typedef GTEST_REMOVE_REFERENCE_AND_CONST_(PairType) RawPairType;
+  typedef typename RawPairType::first_type KeyType;
+
+  template <typename InnerMatcher>
+  explicit KeyMatcherImpl(InnerMatcher inner_matcher)
+      : inner_matcher_(
+            testing::SafeMatcherCast<const KeyType&>(inner_matcher)) {}
+
+  // Returns true if and only if 'key_value.first' (the key) matches the inner
+  // matcher.
+  bool MatchAndExplain(PairType key_value,
+                       MatchResultListener* listener) const override {
+    StringMatchResultListener inner_listener;
+    const bool match = inner_matcher_.MatchAndExplain(
+        pair_getters::First(key_value, Rank0()), &inner_listener);
+    const std::string explanation = inner_listener.str();
+    if (!explanation.empty()) {
+      *listener << "whose first field is a value " << explanation;
+    }
+    return match;
+  }
+
+  // Describes what this matcher does.
+  void DescribeTo(::std::ostream* os) const override {
+    *os << "has a key that ";
+    inner_matcher_.DescribeTo(os);
+  }
+
+  // Describes what the negation of this matcher does.
+  void DescribeNegationTo(::std::ostream* os) const override {
+    *os << "doesn't have a key that ";
+    inner_matcher_.DescribeTo(os);
+  }
+
+ private:
+  const Matcher<const KeyType&> inner_matcher_;
+};
+
+// Implements polymorphic Key(matcher_for_key).
+template <typename M>
+class KeyMatcher {
+ public:
+  explicit KeyMatcher(M m) : matcher_for_key_(m) {}
+
+  template <typename PairType>
+  operator Matcher<PairType>() const {
+    return Matcher<PairType>(
+        new KeyMatcherImpl<const PairType&>(matcher_for_key_));
+  }
+
+ private:
+  const M matcher_for_key_;
+};
+
+// Implements polymorphic Address(matcher_for_address).
+template <typename InnerMatcher>
+class AddressMatcher {
+ public:
+  explicit AddressMatcher(InnerMatcher m) : matcher_(m) {}
+
+  template <typename Type>
+  operator Matcher<Type>() const {  // NOLINT
+    return Matcher<Type>(new Impl<const Type&>(matcher_));
+  }
+
+ private:
+  // The monomorphic implementation that works for a particular object type.
+  template <typename Type>
+  class Impl : public MatcherInterface<Type> {
+   public:
+    using Address = const GTEST_REMOVE_REFERENCE_AND_CONST_(Type) *;
+    explicit Impl(const InnerMatcher& matcher)
+        : matcher_(MatcherCast<Address>(matcher)) {}
+
+    void DescribeTo(::std::ostream* os) const override {
+      *os << "has address that ";
+      matcher_.DescribeTo(os);
+    }
+
+    void DescribeNegationTo(::std::ostream* os) const override {
+      *os << "does not have address that ";
+      matcher_.DescribeTo(os);
+    }
+
+    bool MatchAndExplain(Type object,
+                         MatchResultListener* listener) const override {
+      *listener << "which has address ";
+      Address address = std::addressof(object);
+      return MatchPrintAndExplain(address, matcher_, listener);
+    }
+
+   private:
+    const Matcher<Address> matcher_;
+  };
+  const InnerMatcher matcher_;
+};
+
+// Implements Pair(first_matcher, second_matcher) for the given argument pair
+// type with its two matchers. See Pair() function below.
+template <typename PairType>
+class PairMatcherImpl : public MatcherInterface<PairType> {
+ public:
+  typedef GTEST_REMOVE_REFERENCE_AND_CONST_(PairType) RawPairType;
+  typedef typename RawPairType::first_type FirstType;
+  typedef typename RawPairType::second_type SecondType;
+
+  template <typename FirstMatcher, typename SecondMatcher>
+  PairMatcherImpl(FirstMatcher first_matcher, SecondMatcher second_matcher)
+      : first_matcher_(
+            testing::SafeMatcherCast<const FirstType&>(first_matcher)),
+        second_matcher_(
+            testing::SafeMatcherCast<const SecondType&>(second_matcher)) {}
+
+  // Describes what this matcher does.
+  void DescribeTo(::std::ostream* os) const override {
+    *os << "has a first field that ";
+    first_matcher_.DescribeTo(os);
+    *os << ", and has a second field that ";
+    second_matcher_.DescribeTo(os);
+  }
+
+  // Describes what the negation of this matcher does.
+  void DescribeNegationTo(::std::ostream* os) const override {
+    *os << "has a first field that ";
+    first_matcher_.DescribeNegationTo(os);
+    *os << ", or has a second field that ";
+    second_matcher_.DescribeNegationTo(os);
+  }
+
+  // Returns true if and only if 'a_pair.first' matches first_matcher and
+  // 'a_pair.second' matches second_matcher.
+  bool MatchAndExplain(PairType a_pair,
+                       MatchResultListener* listener) const override {
+    if (!listener->IsInterested()) {
+      // If the listener is not interested, we don't need to construct the
+      // explanation.
+      return first_matcher_.Matches(pair_getters::First(a_pair, Rank0())) &&
+             second_matcher_.Matches(pair_getters::Second(a_pair, Rank0()));
+    }
+    StringMatchResultListener first_inner_listener;
+    if (!first_matcher_.MatchAndExplain(pair_getters::First(a_pair, Rank0()),
+                                        &first_inner_listener)) {
+      *listener << "whose first field does not match";
+      PrintIfNotEmpty(first_inner_listener.str(), listener->stream());
+      return false;
+    }
+    StringMatchResultListener second_inner_listener;
+    if (!second_matcher_.MatchAndExplain(pair_getters::Second(a_pair, Rank0()),
+                                         &second_inner_listener)) {
+      *listener << "whose second field does not match";
+      PrintIfNotEmpty(second_inner_listener.str(), listener->stream());
+      return false;
+    }
+    ExplainSuccess(first_inner_listener.str(), second_inner_listener.str(),
+                   listener);
+    return true;
+  }
+
+ private:
+  void ExplainSuccess(const std::string& first_explanation,
+                      const std::string& second_explanation,
+                      MatchResultListener* listener) const {
+    *listener << "whose both fields match";
+    if (!first_explanation.empty()) {
+      *listener << ", where the first field is a value " << first_explanation;
+    }
+    if (!second_explanation.empty()) {
+      *listener << ", ";
+      if (!first_explanation.empty()) {
+        *listener << "and ";
+      } else {
+        *listener << "where ";
+      }
+      *listener << "the second field is a value " << second_explanation;
+    }
+  }
+
+  const Matcher<const FirstType&> first_matcher_;
+  const Matcher<const SecondType&> second_matcher_;
+};
+
+// Implements polymorphic Pair(first_matcher, second_matcher).
+template <typename FirstMatcher, typename SecondMatcher>
+class PairMatcher {
+ public:
+  PairMatcher(FirstMatcher first_matcher, SecondMatcher second_matcher)
+      : first_matcher_(first_matcher), second_matcher_(second_matcher) {}
+
+  template <typename PairType>
+  operator Matcher<PairType>() const {
+    return Matcher<PairType>(
+        new PairMatcherImpl<const PairType&>(first_matcher_, second_matcher_));
+  }
+
+ private:
+  const FirstMatcher first_matcher_;
+  const SecondMatcher second_matcher_;
+};
+
+template <typename T, size_t... I>
+auto UnpackStructImpl(const T& t, IndexSequence<I...>, int)
+    -> decltype(std::tie(get<I>(t)...)) {
+  static_assert(std::tuple_size<T>::value == sizeof...(I),
+                "Number of arguments doesn't match the number of fields.");
+  return std::tie(get<I>(t)...);
+}
+
+#if defined(__cpp_structured_bindings) && __cpp_structured_bindings >= 201606
+template <typename T>
+auto UnpackStructImpl(const T& t, MakeIndexSequence<1>, char) {
+  const auto& [a] = t;
+  return std::tie(a);
+}
+template <typename T>
+auto UnpackStructImpl(const T& t, MakeIndexSequence<2>, char) {
+  const auto& [a, b] = t;
+  return std::tie(a, b);
+}
+template <typename T>
+auto UnpackStructImpl(const T& t, MakeIndexSequence<3>, char) {
+  const auto& [a, b, c] = t;
+  return std::tie(a, b, c);
+}
+template <typename T>
+auto UnpackStructImpl(const T& t, MakeIndexSequence<4>, char) {
+  const auto& [a, b, c, d] = t;
+  return std::tie(a, b, c, d);
+}
+template <typename T>
+auto UnpackStructImpl(const T& t, MakeIndexSequence<5>, char) {
+  const auto& [a, b, c, d, e] = t;
+  return std::tie(a, b, c, d, e);
+}
+template <typename T>
+auto UnpackStructImpl(const T& t, MakeIndexSequence<6>, char) {
+  const auto& [a, b, c, d, e, f] = t;
+  return std::tie(a, b, c, d, e, f);
+}
+template <typename T>
+auto UnpackStructImpl(const T& t, MakeIndexSequence<7>, char) {
+  const auto& [a, b, c, d, e, f, g] = t;
+  return std::tie(a, b, c, d, e, f, g);
+}
+template <typename T>
+auto UnpackStructImpl(const T& t, MakeIndexSequence<8>, char) {
+  const auto& [a, b, c, d, e, f, g, h] = t;
+  return std::tie(a, b, c, d, e, f, g, h);
+}
+template <typename T>
+auto UnpackStructImpl(const T& t, MakeIndexSequence<9>, char) {
+  const auto& [a, b, c, d, e, f, g, h, i] = t;
+  return std::tie(a, b, c, d, e, f, g, h, i);
+}
+template <typename T>
+auto UnpackStructImpl(const T& t, MakeIndexSequence<10>, char) {
+  const auto& [a, b, c, d, e, f, g, h, i, j] = t;
+  return std::tie(a, b, c, d, e, f, g, h, i, j);
+}
+template <typename T>
+auto UnpackStructImpl(const T& t, MakeIndexSequence<11>, char) {
+  const auto& [a, b, c, d, e, f, g, h, i, j, k] = t;
+  return std::tie(a, b, c, d, e, f, g, h, i, j, k);
+}
+template <typename T>
+auto UnpackStructImpl(const T& t, MakeIndexSequence<12>, char) {
+  const auto& [a, b, c, d, e, f, g, h, i, j, k, l] = t;
+  return std::tie(a, b, c, d, e, f, g, h, i, j, k, l);
+}
+template <typename T>
+auto UnpackStructImpl(const T& t, MakeIndexSequence<13>, char) {
+  const auto& [a, b, c, d, e, f, g, h, i, j, k, l, m] = t;
+  return std::tie(a, b, c, d, e, f, g, h, i, j, k, l, m);
+}
+template <typename T>
+auto UnpackStructImpl(const T& t, MakeIndexSequence<14>, char) {
+  const auto& [a, b, c, d, e, f, g, h, i, j, k, l, m, n] = t;
+  return std::tie(a, b, c, d, e, f, g, h, i, j, k, l, m, n);
+}
+template <typename T>
+auto UnpackStructImpl(const T& t, MakeIndexSequence<15>, char) {
+  const auto& [a, b, c, d, e, f, g, h, i, j, k, l, m, n, o] = t;
+  return std::tie(a, b, c, d, e, f, g, h, i, j, k, l, m, n, o);
+}
+template <typename T>
+auto UnpackStructImpl(const T& t, MakeIndexSequence<16>, char) {
+  const auto& [a, b, c, d, e, f, g, h, i, j, k, l, m, n, o, p] = t;
+  return std::tie(a, b, c, d, e, f, g, h, i, j, k, l, m, n, o, p);
+}
+template <typename T>
+auto UnpackStructImpl(const T& t, MakeIndexSequence<17>, char) {
+  const auto& [a, b, c, d, e, f, g, h, i, j, k, l, m, n, o, p, q] = t;
+  return std::tie(a, b, c, d, e, f, g, h, i, j, k, l, m, n, o, p, q);
+}
+template <typename T>
+auto UnpackStructImpl(const T& t, MakeIndexSequence<18>, char) {
+  const auto& [a, b, c, d, e, f, g, h, i, j, k, l, m, n, o, p, q, r] = t;
+  return std::tie(a, b, c, d, e, f, g, h, i, j, k, l, m, n, o, p, q, r);
+}
+template <typename T>
+auto UnpackStructImpl(const T& t, MakeIndexSequence<19>, char) {
+  const auto& [a, b, c, d, e, f, g, h, i, j, k, l, m, n, o, p, q, r, s] = t;
+  return std::tie(a, b, c, d, e, f, g, h, i, j, k, l, m, n, o, p, q, r, s);
+}
+#endif  // defined(__cpp_structured_bindings)
+
+template <size_t I, typename T>
+auto UnpackStruct(const T& t)
+    -> decltype((UnpackStructImpl)(t, MakeIndexSequence<I>{}, 0)) {
+  return (UnpackStructImpl)(t, MakeIndexSequence<I>{}, 0);
+}
+
+// Helper function to do comma folding in C++11.
+// The array ensures left-to-right order of evaluation.
+// Usage: VariadicExpand({expr...});
+template <typename T, size_t N>
+void VariadicExpand(const T (&)[N]) {}
+
+template <typename Struct, typename StructSize>
+class FieldsAreMatcherImpl;
+
+template <typename Struct, size_t... I>
+class FieldsAreMatcherImpl<Struct, IndexSequence<I...>>
+    : public MatcherInterface<Struct> {
+  using UnpackedType =
+      decltype(UnpackStruct<sizeof...(I)>(std::declval<const Struct&>()));
+  using MatchersType = std::tuple<
+      Matcher<const typename std::tuple_element<I, UnpackedType>::type&>...>;
+
+ public:
+  template <typename Inner>
+  explicit FieldsAreMatcherImpl(const Inner& matchers)
+      : matchers_(testing::SafeMatcherCast<
+                  const typename std::tuple_element<I, UnpackedType>::type&>(
+            std::get<I>(matchers))...) {}
+
+  void DescribeTo(::std::ostream* os) const override {
+    const char* separator = "";
+    VariadicExpand(
+        {(*os << separator << "has field #" << I << " that ",
+          std::get<I>(matchers_).DescribeTo(os), separator = ", and ")...});
+  }
+
+  void DescribeNegationTo(::std::ostream* os) const override {
+    const char* separator = "";
+    VariadicExpand({(*os << separator << "has field #" << I << " that ",
+                     std::get<I>(matchers_).DescribeNegationTo(os),
+                     separator = ", or ")...});
+  }
+
+  bool MatchAndExplain(Struct t, MatchResultListener* listener) const override {
+    return MatchInternal((UnpackStruct<sizeof...(I)>)(t), listener);
+  }
+
+ private:
+  bool MatchInternal(UnpackedType tuple, MatchResultListener* listener) const {
+    if (!listener->IsInterested()) {
+      // If the listener is not interested, we don't need to construct the
+      // explanation.
+      bool good = true;
+      VariadicExpand({good = good && std::get<I>(matchers_).Matches(
+                                         std::get<I>(tuple))...});
+      return good;
+    }
+
+    size_t failed_pos = ~size_t{};
+
+    std::vector<StringMatchResultListener> inner_listener(sizeof...(I));
+
+    VariadicExpand(
+        {failed_pos == ~size_t{} && !std::get<I>(matchers_).MatchAndExplain(
+                                        std::get<I>(tuple), &inner_listener[I])
+             ? failed_pos = I
+             : 0 ...});
+    if (failed_pos != ~size_t{}) {
+      *listener << "whose field #" << failed_pos << " does not match";
+      PrintIfNotEmpty(inner_listener[failed_pos].str(), listener->stream());
+      return false;
+    }
+
+    *listener << "whose all elements match";
+    const char* separator = ", where";
+    for (size_t index = 0; index < sizeof...(I); ++index) {
+      const std::string str = inner_listener[index].str();
+      if (!str.empty()) {
+        *listener << separator << " field #" << index << " is a value " << str;
+        separator = ", and";
+      }
+    }
+
+    return true;
+  }
+
+  MatchersType matchers_;
+};
+
+template <typename... Inner>
+class FieldsAreMatcher {
+ public:
+  explicit FieldsAreMatcher(Inner... inner) : matchers_(std::move(inner)...) {}
+
+  template <typename Struct>
+  operator Matcher<Struct>() const {  // NOLINT
+    return Matcher<Struct>(
+        new FieldsAreMatcherImpl<const Struct&, IndexSequenceFor<Inner...>>(
+            matchers_));
+  }
+
+ private:
+  std::tuple<Inner...> matchers_;
+};
+
+// Implements ElementsAre() and ElementsAreArray().
+template <typename Container>
+class ElementsAreMatcherImpl : public MatcherInterface<Container> {
+ public:
+  typedef GTEST_REMOVE_REFERENCE_AND_CONST_(Container) RawContainer;
+  typedef internal::StlContainerView<RawContainer> View;
+  typedef typename View::type StlContainer;
+  typedef typename View::const_reference StlContainerReference;
+  typedef typename StlContainer::value_type Element;
+
+  // Constructs the matcher from a sequence of element values or
+  // element matchers.
+  template <typename InputIter>
+  ElementsAreMatcherImpl(InputIter first, InputIter last) {
+    while (first != last) {
+      matchers_.push_back(MatcherCast<const Element&>(*first++));
+    }
+  }
+
+  // Describes what this matcher does.
+  void DescribeTo(::std::ostream* os) const override {
+    if (count() == 0) {
+      *os << "is empty";
+    } else if (count() == 1) {
+      *os << "has 1 element that ";
+      matchers_[0].DescribeTo(os);
+    } else {
+      *os << "has " << Elements(count()) << " where\n";
+      for (size_t i = 0; i != count(); ++i) {
+        *os << "element #" << i << " ";
+        matchers_[i].DescribeTo(os);
+        if (i + 1 < count()) {
+          *os << ",\n";
+        }
+      }
+    }
+  }
+
+  // Describes what the negation of this matcher does.
+  void DescribeNegationTo(::std::ostream* os) const override {
+    if (count() == 0) {
+      *os << "isn't empty";
+      return;
+    }
+
+    *os << "doesn't have " << Elements(count()) << ", or\n";
+    for (size_t i = 0; i != count(); ++i) {
+      *os << "element #" << i << " ";
+      matchers_[i].DescribeNegationTo(os);
+      if (i + 1 < count()) {
+        *os << ", or\n";
+      }
+    }
+  }
+
+  bool MatchAndExplain(Container container,
+                       MatchResultListener* listener) const override {
+    // To work with stream-like "containers", we must only walk
+    // through the elements in one pass.
+
+    const bool listener_interested = listener->IsInterested();
+
+    // explanations[i] is the explanation of the element at index i.
+    ::std::vector<std::string> explanations(count());
+    StlContainerReference stl_container = View::ConstReference(container);
+    auto it = stl_container.begin();
+    size_t exam_pos = 0;
+    bool mismatch_found = false;  // Have we found a mismatched element yet?
+
+    // Go through the elements and matchers in pairs, until we reach
+    // the end of either the elements or the matchers, or until we find a
+    // mismatch.
+    for (; it != stl_container.end() && exam_pos != count(); ++it, ++exam_pos) {
+      bool match;  // Does the current element match the current matcher?
+      if (listener_interested) {
+        StringMatchResultListener s;
+        match = matchers_[exam_pos].MatchAndExplain(*it, &s);
+        explanations[exam_pos] = s.str();
+      } else {
+        match = matchers_[exam_pos].Matches(*it);
+      }
+
+      if (!match) {
+        mismatch_found = true;
+        break;
+      }
+    }
+    // If mismatch_found is true, 'exam_pos' is the index of the mismatch.
+
+    // Find how many elements the actual container has.  We avoid
+    // calling size() s.t. this code works for stream-like "containers"
+    // that don't define size().
+    size_t actual_count = exam_pos;
+    for (; it != stl_container.end(); ++it) {
+      ++actual_count;
+    }
+
+    if (actual_count != count()) {
+      // The element count doesn't match.  If the container is empty,
+      // there's no need to explain anything as Google Mock already
+      // prints the empty container.  Otherwise we just need to show
+      // how many elements there actually are.
+      if (listener_interested && (actual_count != 0)) {
+        *listener << "which has " << Elements(actual_count);
+      }
+      return false;
+    }
+
+    if (mismatch_found) {
+      // The element count matches, but the exam_pos-th element doesn't match.
+      if (listener_interested) {
+        *listener << "whose element #" << exam_pos << " doesn't match";
+        PrintIfNotEmpty(explanations[exam_pos], listener->stream());
+      }
+      return false;
+    }
+
+    // Every element matches its expectation.  We need to explain why
+    // (the obvious ones can be skipped).
+    if (listener_interested) {
+      bool reason_printed = false;
+      for (size_t i = 0; i != count(); ++i) {
+        const std::string& s = explanations[i];
+        if (!s.empty()) {
+          if (reason_printed) {
+            *listener << ",\nand ";
+          }
+          *listener << "whose element #" << i << " matches, " << s;
+          reason_printed = true;
+        }
+      }
+    }
+    return true;
+  }
+
+ private:
+  static Message Elements(size_t count) {
+    return Message() << count << (count == 1 ? " element" : " elements");
+  }
+
+  size_t count() const { return matchers_.size(); }
+
+  ::std::vector<Matcher<const Element&>> matchers_;
+};
+
+// Connectivity matrix of (elements X matchers), in element-major order.
+// Initially, there are no edges.
+// Use NextGraph() to iterate over all possible edge configurations.
+// Use Randomize() to generate a random edge configuration.
+class GTEST_API_ MatchMatrix {
+ public:
+  MatchMatrix(size_t num_elements, size_t num_matchers)
+      : num_elements_(num_elements),
+        num_matchers_(num_matchers),
+        matched_(num_elements_ * num_matchers_, 0) {}
+
+  size_t LhsSize() const { return num_elements_; }
+  size_t RhsSize() const { return num_matchers_; }
+  bool HasEdge(size_t ilhs, size_t irhs) const {
+    return matched_[SpaceIndex(ilhs, irhs)] == 1;
+  }
+  void SetEdge(size_t ilhs, size_t irhs, bool b) {
+    matched_[SpaceIndex(ilhs, irhs)] = b ? 1 : 0;
+  }
+
+  // Treating the connectivity matrix as a (LhsSize()*RhsSize())-bit number,
+  // adds 1 to that number; returns false if incrementing the graph left it
+  // empty.
+  bool NextGraph();
+
+  void Randomize();
+
+  std::string DebugString() const;
+
+ private:
+  size_t SpaceIndex(size_t ilhs, size_t irhs) const {
+    return ilhs * num_matchers_ + irhs;
+  }
+
+  size_t num_elements_;
+  size_t num_matchers_;
+
+  // Each element is a char interpreted as bool. They are stored as a
+  // flattened array in lhs-major order, use 'SpaceIndex()' to translate
+  // a (ilhs, irhs) matrix coordinate into an offset.
+  ::std::vector<char> matched_;
+};
+
+typedef ::std::pair<size_t, size_t> ElementMatcherPair;
+typedef ::std::vector<ElementMatcherPair> ElementMatcherPairs;
+
+// Returns a maximum bipartite matching for the specified graph 'g'.
+// The matching is represented as a vector of {element, matcher} pairs.
+GTEST_API_ ElementMatcherPairs FindMaxBipartiteMatching(const MatchMatrix& g);
+
+struct UnorderedMatcherRequire {
+  enum Flags {
+    Superset = 1 << 0,
+    Subset = 1 << 1,
+    ExactMatch = Superset | Subset,
+  };
+};
+
+// Untyped base class for implementing UnorderedElementsAre.  By
+// putting logic that's not specific to the element type here, we
+// reduce binary bloat and increase compilation speed.
+class GTEST_API_ UnorderedElementsAreMatcherImplBase {
+ protected:
+  explicit UnorderedElementsAreMatcherImplBase(
+      UnorderedMatcherRequire::Flags matcher_flags)
+      : match_flags_(matcher_flags) {}
+
+  // A vector of matcher describers, one for each element matcher.
+  // Does not own the describers (and thus can be used only when the
+  // element matchers are alive).
+  typedef ::std::vector<const MatcherDescriberInterface*> MatcherDescriberVec;
+
+  // Describes this UnorderedElementsAre matcher.
+  void DescribeToImpl(::std::ostream* os) const;
+
+  // Describes the negation of this UnorderedElementsAre matcher.
+  void DescribeNegationToImpl(::std::ostream* os) const;
+
+  bool VerifyMatchMatrix(const ::std::vector<std::string>& element_printouts,
+                         const MatchMatrix& matrix,
+                         MatchResultListener* listener) const;
+
+  bool FindPairing(const MatchMatrix& matrix,
+                   MatchResultListener* listener) const;
+
+  MatcherDescriberVec& matcher_describers() { return matcher_describers_; }
+
+  static Message Elements(size_t n) {
+    return Message() << n << " element" << (n == 1 ? "" : "s");
+  }
+
+  UnorderedMatcherRequire::Flags match_flags() const { return match_flags_; }
+
+ private:
+  UnorderedMatcherRequire::Flags match_flags_;
+  MatcherDescriberVec matcher_describers_;
+};
+
+// Implements UnorderedElementsAre, UnorderedElementsAreArray, IsSubsetOf, and
+// IsSupersetOf.
+template <typename Container>
+class UnorderedElementsAreMatcherImpl
+    : public MatcherInterface<Container>,
+      public UnorderedElementsAreMatcherImplBase {
+ public:
+  typedef GTEST_REMOVE_REFERENCE_AND_CONST_(Container) RawContainer;
+  typedef internal::StlContainerView<RawContainer> View;
+  typedef typename View::type StlContainer;
+  typedef typename View::const_reference StlContainerReference;
+  typedef typename StlContainer::value_type Element;
+
+  template <typename InputIter>
+  UnorderedElementsAreMatcherImpl(UnorderedMatcherRequire::Flags matcher_flags,
+                                  InputIter first, InputIter last)
+      : UnorderedElementsAreMatcherImplBase(matcher_flags) {
+    for (; first != last; ++first) {
+      matchers_.push_back(MatcherCast<const Element&>(*first));
+    }
+    for (const auto& m : matchers_) {
+      matcher_describers().push_back(m.GetDescriber());
+    }
+  }
+
+  // Describes what this matcher does.
+  void DescribeTo(::std::ostream* os) const override {
+    return UnorderedElementsAreMatcherImplBase::DescribeToImpl(os);
+  }
+
+  // Describes what the negation of this matcher does.
+  void DescribeNegationTo(::std::ostream* os) const override {
+    return UnorderedElementsAreMatcherImplBase::DescribeNegationToImpl(os);
+  }
+
+  bool MatchAndExplain(Container container,
+                       MatchResultListener* listener) const override {
+    StlContainerReference stl_container = View::ConstReference(container);
+    ::std::vector<std::string> element_printouts;
+    MatchMatrix matrix =
+        AnalyzeElements(stl_container.begin(), stl_container.end(),
+                        &element_printouts, listener);
+
+    return VerifyMatchMatrix(element_printouts, matrix, listener) &&
+           FindPairing(matrix, listener);
+  }
+
+ private:
+  template <typename ElementIter>
+  MatchMatrix AnalyzeElements(ElementIter elem_first, ElementIter elem_last,
+                              ::std::vector<std::string>* element_printouts,
+                              MatchResultListener* listener) const {
+    element_printouts->clear();
+    ::std::vector<char> did_match;
+    size_t num_elements = 0;
+    DummyMatchResultListener dummy;
+    for (; elem_first != elem_last; ++num_elements, ++elem_first) {
+      if (listener->IsInterested()) {
+        element_printouts->push_back(PrintToString(*elem_first));
+      }
+      for (size_t irhs = 0; irhs != matchers_.size(); ++irhs) {
+        did_match.push_back(
+            matchers_[irhs].MatchAndExplain(*elem_first, &dummy));
+      }
+    }
+
+    MatchMatrix matrix(num_elements, matchers_.size());
+    ::std::vector<char>::const_iterator did_match_iter = did_match.begin();
+    for (size_t ilhs = 0; ilhs != num_elements; ++ilhs) {
+      for (size_t irhs = 0; irhs != matchers_.size(); ++irhs) {
+        matrix.SetEdge(ilhs, irhs, *did_match_iter++ != 0);
+      }
+    }
+    return matrix;
+  }
+
+  ::std::vector<Matcher<const Element&>> matchers_;
+};
+
+// Functor for use in TransformTuple.
+// Performs MatcherCast<Target> on an input argument of any type.
+template <typename Target>
+struct CastAndAppendTransform {
+  template <typename Arg>
+  Matcher<Target> operator()(const Arg& a) const {
+    return MatcherCast<Target>(a);
+  }
+};
+
+// Implements UnorderedElementsAre.
+template <typename MatcherTuple>
+class UnorderedElementsAreMatcher {
+ public:
+  explicit UnorderedElementsAreMatcher(const MatcherTuple& args)
+      : matchers_(args) {}
+
+  template <typename Container>
+  operator Matcher<Container>() const {
+    typedef GTEST_REMOVE_REFERENCE_AND_CONST_(Container) RawContainer;
+    typedef typename internal::StlContainerView<RawContainer>::type View;
+    typedef typename View::value_type Element;
+    typedef ::std::vector<Matcher<const Element&>> MatcherVec;
+    MatcherVec matchers;
+    matchers.reserve(::std::tuple_size<MatcherTuple>::value);
+    TransformTupleValues(CastAndAppendTransform<const Element&>(), matchers_,
+                         ::std::back_inserter(matchers));
+    return Matcher<Container>(
+        new UnorderedElementsAreMatcherImpl<const Container&>(
+            UnorderedMatcherRequire::ExactMatch, matchers.begin(),
+            matchers.end()));
+  }
+
+ private:
+  const MatcherTuple matchers_;
+};
+
+// Implements ElementsAre.
+template <typename MatcherTuple>
+class ElementsAreMatcher {
+ public:
+  explicit ElementsAreMatcher(const MatcherTuple& args) : matchers_(args) {}
+
+  template <typename Container>
+  operator Matcher<Container>() const {
+    static_assert(
+        !IsHashTable<GTEST_REMOVE_REFERENCE_AND_CONST_(Container)>::value ||
+            ::std::tuple_size<MatcherTuple>::value < 2,
+        "use UnorderedElementsAre with hash tables");
+
+    typedef GTEST_REMOVE_REFERENCE_AND_CONST_(Container) RawContainer;
+    typedef typename internal::StlContainerView<RawContainer>::type View;
+    typedef typename View::value_type Element;
+    typedef ::std::vector<Matcher<const Element&>> MatcherVec;
+    MatcherVec matchers;
+    matchers.reserve(::std::tuple_size<MatcherTuple>::value);
+    TransformTupleValues(CastAndAppendTransform<const Element&>(), matchers_,
+                         ::std::back_inserter(matchers));
+    return Matcher<Container>(new ElementsAreMatcherImpl<const Container&>(
+        matchers.begin(), matchers.end()));
+  }
+
+ private:
+  const MatcherTuple matchers_;
+};
+
+// Implements UnorderedElementsAreArray(), IsSubsetOf(), and IsSupersetOf().
+template <typename T>
+class UnorderedElementsAreArrayMatcher {
+ public:
+  template <typename Iter>
+  UnorderedElementsAreArrayMatcher(UnorderedMatcherRequire::Flags match_flags,
+                                   Iter first, Iter last)
+      : match_flags_(match_flags), matchers_(first, last) {}
+
+  template <typename Container>
+  operator Matcher<Container>() const {
+    return Matcher<Container>(
+        new UnorderedElementsAreMatcherImpl<const Container&>(
+            match_flags_, matchers_.begin(), matchers_.end()));
+  }
+
+ private:
+  UnorderedMatcherRequire::Flags match_flags_;
+  ::std::vector<T> matchers_;
+};
+
+// Implements ElementsAreArray().
+template <typename T>
+class ElementsAreArrayMatcher {
+ public:
+  template <typename Iter>
+  ElementsAreArrayMatcher(Iter first, Iter last) : matchers_(first, last) {}
+
+  template <typename Container>
+  operator Matcher<Container>() const {
+    static_assert(
+        !IsHashTable<GTEST_REMOVE_REFERENCE_AND_CONST_(Container)>::value,
+        "use UnorderedElementsAreArray with hash tables");
+
+    return Matcher<Container>(new ElementsAreMatcherImpl<const Container&>(
+        matchers_.begin(), matchers_.end()));
+  }
+
+ private:
+  const ::std::vector<T> matchers_;
+};
+
+// Given a 2-tuple matcher tm of type Tuple2Matcher and a value second
+// of type Second, BoundSecondMatcher<Tuple2Matcher, Second>(tm,
+// second) is a polymorphic matcher that matches a value x if and only if
+// tm matches tuple (x, second).  Useful for implementing
+// UnorderedPointwise() in terms of UnorderedElementsAreArray().
+//
+// BoundSecondMatcher is copyable and assignable, as we need to put
+// instances of this class in a vector when implementing
+// UnorderedPointwise().
+template <typename Tuple2Matcher, typename Second>
+class BoundSecondMatcher {
+ public:
+  BoundSecondMatcher(const Tuple2Matcher& tm, const Second& second)
+      : tuple2_matcher_(tm), second_value_(second) {}
+
+  BoundSecondMatcher(const BoundSecondMatcher& other) = default;
+
+  template <typename T>
+  operator Matcher<T>() const {
+    return MakeMatcher(new Impl<T>(tuple2_matcher_, second_value_));
+  }
+
+  // We have to define this for UnorderedPointwise() to compile in
+  // C++98 mode, as it puts BoundSecondMatcher instances in a vector,
+  // which requires the elements to be assignable in C++98.  The
+  // compiler cannot generate the operator= for us, as Tuple2Matcher
+  // and Second may not be assignable.
+  //
+  // However, this should never be called, so the implementation just
+  // need to assert.
+  void operator=(const BoundSecondMatcher& /*rhs*/) {
+    GTEST_LOG_(FATAL) << "BoundSecondMatcher should never be assigned.";
+  }
+
+ private:
+  template <typename T>
+  class Impl : public MatcherInterface<T> {
+   public:
+    typedef ::std::tuple<T, Second> ArgTuple;
+
+    Impl(const Tuple2Matcher& tm, const Second& second)
+        : mono_tuple2_matcher_(SafeMatcherCast<const ArgTuple&>(tm)),
+          second_value_(second) {}
+
+    void DescribeTo(::std::ostream* os) const override {
+      *os << "and ";
+      UniversalPrint(second_value_, os);
+      *os << " ";
+      mono_tuple2_matcher_.DescribeTo(os);
+    }
+
+    bool MatchAndExplain(T x, MatchResultListener* listener) const override {
+      return mono_tuple2_matcher_.MatchAndExplain(ArgTuple(x, second_value_),
+                                                  listener);
+    }
+
+   private:
+    const Matcher<const ArgTuple&> mono_tuple2_matcher_;
+    const Second second_value_;
+  };
+
+  const Tuple2Matcher tuple2_matcher_;
+  const Second second_value_;
+};
+
+// Given a 2-tuple matcher tm and a value second,
+// MatcherBindSecond(tm, second) returns a matcher that matches a
+// value x if and only if tm matches tuple (x, second).  Useful for
+// implementing UnorderedPointwise() in terms of UnorderedElementsAreArray().
+template <typename Tuple2Matcher, typename Second>
+BoundSecondMatcher<Tuple2Matcher, Second> MatcherBindSecond(
+    const Tuple2Matcher& tm, const Second& second) {
+  return BoundSecondMatcher<Tuple2Matcher, Second>(tm, second);
+}
+
+// Returns the description for a matcher defined using the MATCHER*()
+// macro where the user-supplied description string is "", if
+// 'negation' is false; otherwise returns the description of the
+// negation of the matcher.  'param_values' contains a list of strings
+// that are the print-out of the matcher's parameters.
+GTEST_API_ std::string FormatMatcherDescription(
+    bool negation, const char* matcher_name,
+    const std::vector<const char*>& param_names, const Strings& param_values);
+
+// Implements a matcher that checks the value of a optional<> type variable.
+template <typename ValueMatcher>
+class OptionalMatcher {
+ public:
+  explicit OptionalMatcher(const ValueMatcher& value_matcher)
+      : value_matcher_(value_matcher) {}
+
+  template <typename Optional>
+  operator Matcher<Optional>() const {
+    return Matcher<Optional>(new Impl<const Optional&>(value_matcher_));
+  }
+
+  template <typename Optional>
+  class Impl : public MatcherInterface<Optional> {
+   public:
+    typedef GTEST_REMOVE_REFERENCE_AND_CONST_(Optional) OptionalView;
+    typedef typename OptionalView::value_type ValueType;
+    explicit Impl(const ValueMatcher& value_matcher)
+        : value_matcher_(MatcherCast<ValueType>(value_matcher)) {}
+
+    void DescribeTo(::std::ostream* os) const override {
+      *os << "value ";
+      value_matcher_.DescribeTo(os);
+    }
+
+    void DescribeNegationTo(::std::ostream* os) const override {
+      *os << "value ";
+      value_matcher_.DescribeNegationTo(os);
+    }
+
+    bool MatchAndExplain(Optional optional,
+                         MatchResultListener* listener) const override {
+      if (!optional) {
+        *listener << "which is not engaged";
+        return false;
+      }
+      const ValueType& value = *optional;
+      StringMatchResultListener value_listener;
+      const bool match = value_matcher_.MatchAndExplain(value, &value_listener);
+      *listener << "whose value " << PrintToString(value)
+                << (match ? " matches" : " doesn't match");
+      PrintIfNotEmpty(value_listener.str(), listener->stream());
+      return match;
+    }
+
+   private:
+    const Matcher<ValueType> value_matcher_;
+  };
+
+ private:
+  const ValueMatcher value_matcher_;
+};
+
+namespace variant_matcher {
+// Overloads to allow VariantMatcher to do proper ADL lookup.
+template <typename T>
+void holds_alternative() {}
+template <typename T>
+void get() {}
+
+// Implements a matcher that checks the value of a variant<> type variable.
+template <typename T>
+class VariantMatcher {
+ public:
+  explicit VariantMatcher(::testing::Matcher<const T&> matcher)
+      : matcher_(std::move(matcher)) {}
+
+  template <typename Variant>
+  bool MatchAndExplain(const Variant& value,
+                       ::testing::MatchResultListener* listener) const {
+    using std::get;
+    if (!listener->IsInterested()) {
+      return holds_alternative<T>(value) && matcher_.Matches(get<T>(value));
+    }
+
+    if (!holds_alternative<T>(value)) {
+      *listener << "whose value is not of type '" << GetTypeName() << "'";
+      return false;
+    }
+
+    const T& elem = get<T>(value);
+    StringMatchResultListener elem_listener;
+    const bool match = matcher_.MatchAndExplain(elem, &elem_listener);
+    *listener << "whose value " << PrintToString(elem)
+              << (match ? " matches" : " doesn't match");
+    PrintIfNotEmpty(elem_listener.str(), listener->stream());
+    return match;
+  }
+
+  void DescribeTo(std::ostream* os) const {
+    *os << "is a variant<> with value of type '" << GetTypeName()
+        << "' and the value ";
+    matcher_.DescribeTo(os);
+  }
+
+  void DescribeNegationTo(std::ostream* os) const {
+    *os << "is a variant<> with value of type other than '" << GetTypeName()
+        << "' or the value ";
+    matcher_.DescribeNegationTo(os);
+  }
+
+ private:
+  static std::string GetTypeName() {
+#if GTEST_HAS_RTTI
+    GTEST_SUPPRESS_UNREACHABLE_CODE_WARNING_BELOW_(
+        return internal::GetTypeName<T>());
+#endif
+    return "the element type";
+  }
+
+  const ::testing::Matcher<const T&> matcher_;
+};
+
+}  // namespace variant_matcher
+
+namespace any_cast_matcher {
+
+// Overloads to allow AnyCastMatcher to do proper ADL lookup.
+template <typename T>
+void any_cast() {}
+
+// Implements a matcher that any_casts the value.
+template <typename T>
+class AnyCastMatcher {
+ public:
+  explicit AnyCastMatcher(const ::testing::Matcher<const T&>& matcher)
+      : matcher_(matcher) {}
+
+  template <typename AnyType>
+  bool MatchAndExplain(const AnyType& value,
+                       ::testing::MatchResultListener* listener) const {
+    if (!listener->IsInterested()) {
+      const T* ptr = any_cast<T>(&value);
+      return ptr != nullptr && matcher_.Matches(*ptr);
+    }
+
+    const T* elem = any_cast<T>(&value);
+    if (elem == nullptr) {
+      *listener << "whose value is not of type '" << GetTypeName() << "'";
+      return false;
+    }
+
+    StringMatchResultListener elem_listener;
+    const bool match = matcher_.MatchAndExplain(*elem, &elem_listener);
+    *listener << "whose value " << PrintToString(*elem)
+              << (match ? " matches" : " doesn't match");
+    PrintIfNotEmpty(elem_listener.str(), listener->stream());
+    return match;
+  }
+
+  void DescribeTo(std::ostream* os) const {
+    *os << "is an 'any' type with value of type '" << GetTypeName()
+        << "' and the value ";
+    matcher_.DescribeTo(os);
+  }
+
+  void DescribeNegationTo(std::ostream* os) const {
+    *os << "is an 'any' type with value of type other than '" << GetTypeName()
+        << "' or the value ";
+    matcher_.DescribeNegationTo(os);
+  }
+
+ private:
+  static std::string GetTypeName() {
+#if GTEST_HAS_RTTI
+    GTEST_SUPPRESS_UNREACHABLE_CODE_WARNING_BELOW_(
+        return internal::GetTypeName<T>());
+#endif
+    return "the element type";
+  }
+
+  const ::testing::Matcher<const T&> matcher_;
+};
+
+}  // namespace any_cast_matcher
+
+// Implements the Args() matcher.
+template <class ArgsTuple, size_t... k>
+class ArgsMatcherImpl : public MatcherInterface<ArgsTuple> {
+ public:
+  using RawArgsTuple = typename std::decay<ArgsTuple>::type;
+  using SelectedArgs =
+      std::tuple<typename std::tuple_element<k, RawArgsTuple>::type...>;
+  using MonomorphicInnerMatcher = Matcher<const SelectedArgs&>;
+
+  template <typename InnerMatcher>
+  explicit ArgsMatcherImpl(const InnerMatcher& inner_matcher)
+      : inner_matcher_(SafeMatcherCast<const SelectedArgs&>(inner_matcher)) {}
+
+  bool MatchAndExplain(ArgsTuple args,
+                       MatchResultListener* listener) const override {
+    // Workaround spurious C4100 on MSVC<=15.7 when k is empty.
+    (void)args;
+    const SelectedArgs& selected_args =
+        std::forward_as_tuple(std::get<k>(args)...);
+    if (!listener->IsInterested()) return inner_matcher_.Matches(selected_args);
+
+    PrintIndices(listener->stream());
+    *listener << "are " << PrintToString(selected_args);
+
+    StringMatchResultListener inner_listener;
+    const bool match =
+        inner_matcher_.MatchAndExplain(selected_args, &inner_listener);
+    PrintIfNotEmpty(inner_listener.str(), listener->stream());
+    return match;
+  }
+
+  void DescribeTo(::std::ostream* os) const override {
+    *os << "are a tuple ";
+    PrintIndices(os);
+    inner_matcher_.DescribeTo(os);
+  }
+
+  void DescribeNegationTo(::std::ostream* os) const override {
+    *os << "are a tuple ";
+    PrintIndices(os);
+    inner_matcher_.DescribeNegationTo(os);
+  }
+
+ private:
+  // Prints the indices of the selected fields.
+  static void PrintIndices(::std::ostream* os) {
+    *os << "whose fields (";
+    const char* sep = "";
+    // Workaround spurious C4189 on MSVC<=15.7 when k is empty.
+    (void)sep;
+    // The static_cast to void is needed to silence Clang's -Wcomma warning.
+    // This pattern looks suspiciously like we may have mismatched parentheses
+    // and may have been trying to use the first operation of the comma operator
+    // as a member of the array, so Clang warns that we may have made a mistake.
+    const char* dummy[] = {
+        "", (static_cast<void>(*os << sep << "#" << k), sep = ", ")...};
+    (void)dummy;
+    *os << ") ";
+  }
+
+  MonomorphicInnerMatcher inner_matcher_;
+};
+
+template <class InnerMatcher, size_t... k>
+class ArgsMatcher {
+ public:
+  explicit ArgsMatcher(InnerMatcher inner_matcher)
+      : inner_matcher_(std::move(inner_matcher)) {}
+
+  template <typename ArgsTuple>
+  operator Matcher<ArgsTuple>() const {  // NOLINT
+    return MakeMatcher(new ArgsMatcherImpl<ArgsTuple, k...>(inner_matcher_));
+  }
+
+ private:
+  InnerMatcher inner_matcher_;
+};
+
+}  // namespace internal
+
+// ElementsAreArray(iterator_first, iterator_last)
+// ElementsAreArray(pointer, count)
+// ElementsAreArray(array)
+// ElementsAreArray(container)
+// ElementsAreArray({ e1, e2, ..., en })
+//
+// The ElementsAreArray() functions are like ElementsAre(...), except
+// that they are given a homogeneous sequence rather than taking each
+// element as a function argument. The sequence can be specified as an
+// array, a pointer and count, a vector, an initializer list, or an
+// STL iterator range. In each of these cases, the underlying sequence
+// can be either a sequence of values or a sequence of matchers.
+//
+// All forms of ElementsAreArray() make a copy of the input matcher sequence.
+
+template <typename Iter>
+inline internal::ElementsAreArrayMatcher<
+    typename ::std::iterator_traits<Iter>::value_type>
+ElementsAreArray(Iter first, Iter last) {
+  typedef typename ::std::iterator_traits<Iter>::value_type T;
+  return internal::ElementsAreArrayMatcher<T>(first, last);
+}
+
+template <typename T>
+inline auto ElementsAreArray(const T* pointer, size_t count)
+    -> decltype(ElementsAreArray(pointer, pointer + count)) {
+  return ElementsAreArray(pointer, pointer + count);
+}
+
+template <typename T, size_t N>
+inline auto ElementsAreArray(const T (&array)[N])
+    -> decltype(ElementsAreArray(array, N)) {
+  return ElementsAreArray(array, N);
+}
+
+template <typename Container>
+inline auto ElementsAreArray(const Container& container)
+    -> decltype(ElementsAreArray(container.begin(), container.end())) {
+  return ElementsAreArray(container.begin(), container.end());
+}
+
+template <typename T>
+inline auto ElementsAreArray(::std::initializer_list<T> xs)
+    -> decltype(ElementsAreArray(xs.begin(), xs.end())) {
+  return ElementsAreArray(xs.begin(), xs.end());
+}
+
+// UnorderedElementsAreArray(iterator_first, iterator_last)
+// UnorderedElementsAreArray(pointer, count)
+// UnorderedElementsAreArray(array)
+// UnorderedElementsAreArray(container)
+// UnorderedElementsAreArray({ e1, e2, ..., en })
+//
+// UnorderedElementsAreArray() verifies that a bijective mapping onto a
+// collection of matchers exists.
+//
+// The matchers can be specified as an array, a pointer and count, a container,
+// an initializer list, or an STL iterator range. In each of these cases, the
+// underlying matchers can be either values or matchers.
+
+template <typename Iter>
+inline internal::UnorderedElementsAreArrayMatcher<
+    typename ::std::iterator_traits<Iter>::value_type>
+UnorderedElementsAreArray(Iter first, Iter last) {
+  typedef typename ::std::iterator_traits<Iter>::value_type T;
+  return internal::UnorderedElementsAreArrayMatcher<T>(
+      internal::UnorderedMatcherRequire::ExactMatch, first, last);
+}
+
+template <typename T>
+inline internal::UnorderedElementsAreArrayMatcher<T> UnorderedElementsAreArray(
+    const T* pointer, size_t count) {
+  return UnorderedElementsAreArray(pointer, pointer + count);
+}
+
+template <typename T, size_t N>
+inline internal::UnorderedElementsAreArrayMatcher<T> UnorderedElementsAreArray(
+    const T (&array)[N]) {
+  return UnorderedElementsAreArray(array, N);
+}
+
+template <typename Container>
+inline internal::UnorderedElementsAreArrayMatcher<
+    typename Container::value_type>
+UnorderedElementsAreArray(const Container& container) {
+  return UnorderedElementsAreArray(container.begin(), container.end());
+}
+
+template <typename T>
+inline internal::UnorderedElementsAreArrayMatcher<T> UnorderedElementsAreArray(
+    ::std::initializer_list<T> xs) {
+  return UnorderedElementsAreArray(xs.begin(), xs.end());
+}
+
+// _ is a matcher that matches anything of any type.
+//
+// This definition is fine as:
+//
+//   1. The C++ standard permits using the name _ in a namespace that
+//      is not the global namespace or ::std.
+//   2. The AnythingMatcher class has no data member or constructor,
+//      so it's OK to create global variables of this type.
+//   3. c-style has approved of using _ in this case.
+const internal::AnythingMatcher _ = {};
+// Creates a matcher that matches any value of the given type T.
+template <typename T>
+inline Matcher<T> A() {
+  return _;
+}
+
+// Creates a matcher that matches any value of the given type T.
+template <typename T>
+inline Matcher<T> An() {
+  return _;
+}
+
+template <typename T, typename M>
+Matcher<T> internal::MatcherCastImpl<T, M>::CastImpl(
+    const M& value, std::false_type /* convertible_to_matcher */,
+    std::false_type /* convertible_to_T */) {
+  return Eq(value);
+}
+
+// Creates a polymorphic matcher that matches any NULL pointer.
+inline PolymorphicMatcher<internal::IsNullMatcher> IsNull() {
+  return MakePolymorphicMatcher(internal::IsNullMatcher());
+}
+
+// Creates a polymorphic matcher that matches any non-NULL pointer.
+// This is convenient as Not(NULL) doesn't compile (the compiler
+// thinks that that expression is comparing a pointer with an integer).
+inline PolymorphicMatcher<internal::NotNullMatcher> NotNull() {
+  return MakePolymorphicMatcher(internal::NotNullMatcher());
+}
+
+// Creates a polymorphic matcher that matches any argument that
+// references variable x.
+template <typename T>
+inline internal::RefMatcher<T&> Ref(T& x) {  // NOLINT
+  return internal::RefMatcher<T&>(x);
+}
+
+// Creates a polymorphic matcher that matches any NaN floating point.
+inline PolymorphicMatcher<internal::IsNanMatcher> IsNan() {
+  return MakePolymorphicMatcher(internal::IsNanMatcher());
+}
+
+// Creates a matcher that matches any double argument approximately
+// equal to rhs, where two NANs are considered unequal.
+inline internal::FloatingEqMatcher<double> DoubleEq(double rhs) {
+  return internal::FloatingEqMatcher<double>(rhs, false);
+}
+
+// Creates a matcher that matches any double argument approximately
+// equal to rhs, including NaN values when rhs is NaN.
+inline internal::FloatingEqMatcher<double> NanSensitiveDoubleEq(double rhs) {
+  return internal::FloatingEqMatcher<double>(rhs, true);
+}
+
+// Creates a matcher that matches any double argument approximately equal to
+// rhs, up to the specified max absolute error bound, where two NANs are
+// considered unequal.  The max absolute error bound must be non-negative.
+inline internal::FloatingEqMatcher<double> DoubleNear(double rhs,
+                                                      double max_abs_error) {
+  return internal::FloatingEqMatcher<double>(rhs, false, max_abs_error);
+}
+
+// Creates a matcher that matches any double argument approximately equal to
+// rhs, up to the specified max absolute error bound, including NaN values when
+// rhs is NaN.  The max absolute error bound must be non-negative.
+inline internal::FloatingEqMatcher<double> NanSensitiveDoubleNear(
+    double rhs, double max_abs_error) {
+  return internal::FloatingEqMatcher<double>(rhs, true, max_abs_error);
+}
+
+// Creates a matcher that matches any float argument approximately
+// equal to rhs, where two NANs are considered unequal.
+inline internal::FloatingEqMatcher<float> FloatEq(float rhs) {
+  return internal::FloatingEqMatcher<float>(rhs, false);
+}
+
+// Creates a matcher that matches any float argument approximately
+// equal to rhs, including NaN values when rhs is NaN.
+inline internal::FloatingEqMatcher<float> NanSensitiveFloatEq(float rhs) {
+  return internal::FloatingEqMatcher<float>(rhs, true);
+}
+
+// Creates a matcher that matches any float argument approximately equal to
+// rhs, up to the specified max absolute error bound, where two NANs are
+// considered unequal.  The max absolute error bound must be non-negative.
+inline internal::FloatingEqMatcher<float> FloatNear(float rhs,
+                                                    float max_abs_error) {
+  return internal::FloatingEqMatcher<float>(rhs, false, max_abs_error);
+}
+
+// Creates a matcher that matches any float argument approximately equal to
+// rhs, up to the specified max absolute error bound, including NaN values when
+// rhs is NaN.  The max absolute error bound must be non-negative.
+inline internal::FloatingEqMatcher<float> NanSensitiveFloatNear(
+    float rhs, float max_abs_error) {
+  return internal::FloatingEqMatcher<float>(rhs, true, max_abs_error);
+}
+
+// Creates a matcher that matches a pointer (raw or smart) that points
+// to a value that matches inner_matcher.
+template <typename InnerMatcher>
+inline internal::PointeeMatcher<InnerMatcher> Pointee(
+    const InnerMatcher& inner_matcher) {
+  return internal::PointeeMatcher<InnerMatcher>(inner_matcher);
+}
+
+#if GTEST_HAS_RTTI
+// Creates a matcher that matches a pointer or reference that matches
+// inner_matcher when dynamic_cast<To> is applied.
+// The result of dynamic_cast<To> is forwarded to the inner matcher.
+// If To is a pointer and the cast fails, the inner matcher will receive NULL.
+// If To is a reference and the cast fails, this matcher returns false
+// immediately.
+template <typename To>
+inline PolymorphicMatcher<internal::WhenDynamicCastToMatcher<To>>
+WhenDynamicCastTo(const Matcher<To>& inner_matcher) {
+  return MakePolymorphicMatcher(
+      internal::WhenDynamicCastToMatcher<To>(inner_matcher));
+}
+#endif  // GTEST_HAS_RTTI
+
+// Creates a matcher that matches an object whose given field matches
+// 'matcher'.  For example,
+//   Field(&Foo::number, Ge(5))
+// matches a Foo object x if and only if x.number >= 5.
+template <typename Class, typename FieldType, typename FieldMatcher>
+inline PolymorphicMatcher<internal::FieldMatcher<Class, FieldType>> Field(
+    FieldType Class::*field, const FieldMatcher& matcher) {
+  return MakePolymorphicMatcher(internal::FieldMatcher<Class, FieldType>(
+      field, MatcherCast<const FieldType&>(matcher)));
+  // The call to MatcherCast() is required for supporting inner
+  // matchers of compatible types.  For example, it allows
+  //   Field(&Foo::bar, m)
+  // to compile where bar is an int32 and m is a matcher for int64.
+}
+
+// Same as Field() but also takes the name of the field to provide better error
+// messages.
+template <typename Class, typename FieldType, typename FieldMatcher>
+inline PolymorphicMatcher<internal::FieldMatcher<Class, FieldType>> Field(
+    const std::string& field_name, FieldType Class::*field,
+    const FieldMatcher& matcher) {
+  return MakePolymorphicMatcher(internal::FieldMatcher<Class, FieldType>(
+      field_name, field, MatcherCast<const FieldType&>(matcher)));
+}
+
+// Creates a matcher that matches an object whose given property
+// matches 'matcher'.  For example,
+//   Property(&Foo::str, StartsWith("hi"))
+// matches a Foo object x if and only if x.str() starts with "hi".
+template <typename Class, typename PropertyType, typename PropertyMatcher>
+inline PolymorphicMatcher<internal::PropertyMatcher<
+    Class, PropertyType, PropertyType (Class::*)() const>>
+Property(PropertyType (Class::*property)() const,
+         const PropertyMatcher& matcher) {
+  return MakePolymorphicMatcher(
+      internal::PropertyMatcher<Class, PropertyType,
+                                PropertyType (Class::*)() const>(
+          property, MatcherCast<const PropertyType&>(matcher)));
+  // The call to MatcherCast() is required for supporting inner
+  // matchers of compatible types.  For example, it allows
+  //   Property(&Foo::bar, m)
+  // to compile where bar() returns an int32 and m is a matcher for int64.
+}
+
+// Same as Property() above, but also takes the name of the property to provide
+// better error messages.
+template <typename Class, typename PropertyType, typename PropertyMatcher>
+inline PolymorphicMatcher<internal::PropertyMatcher<
+    Class, PropertyType, PropertyType (Class::*)() const>>
+Property(const std::string& property_name,
+         PropertyType (Class::*property)() const,
+         const PropertyMatcher& matcher) {
+  return MakePolymorphicMatcher(
+      internal::PropertyMatcher<Class, PropertyType,
+                                PropertyType (Class::*)() const>(
+          property_name, property, MatcherCast<const PropertyType&>(matcher)));
+}
+
+// The same as above but for reference-qualified member functions.
+template <typename Class, typename PropertyType, typename PropertyMatcher>
+inline PolymorphicMatcher<internal::PropertyMatcher<
+    Class, PropertyType, PropertyType (Class::*)() const&>>
+Property(PropertyType (Class::*property)() const&,
+         const PropertyMatcher& matcher) {
+  return MakePolymorphicMatcher(
+      internal::PropertyMatcher<Class, PropertyType,
+                                PropertyType (Class::*)() const&>(
+          property, MatcherCast<const PropertyType&>(matcher)));
+}
+
+// Three-argument form for reference-qualified member functions.
+template <typename Class, typename PropertyType, typename PropertyMatcher>
+inline PolymorphicMatcher<internal::PropertyMatcher<
+    Class, PropertyType, PropertyType (Class::*)() const&>>
+Property(const std::string& property_name,
+         PropertyType (Class::*property)() const&,
+         const PropertyMatcher& matcher) {
+  return MakePolymorphicMatcher(
+      internal::PropertyMatcher<Class, PropertyType,
+                                PropertyType (Class::*)() const&>(
+          property_name, property, MatcherCast<const PropertyType&>(matcher)));
+}
+
+// Creates a matcher that matches an object if and only if the result of
+// applying a callable to x matches 'matcher'. For example,
+//   ResultOf(f, StartsWith("hi"))
+// matches a Foo object x if and only if f(x) starts with "hi".
+// `callable` parameter can be a function, function pointer, or a functor. It is
+// required to keep no state affecting the results of the calls on it and make
+// no assumptions about how many calls will be made. Any state it keeps must be
+// protected from the concurrent access.
+template <typename Callable, typename InnerMatcher>
+internal::ResultOfMatcher<Callable, InnerMatcher> ResultOf(
+    Callable callable, InnerMatcher matcher) {
+  return internal::ResultOfMatcher<Callable, InnerMatcher>(std::move(callable),
+                                                           std::move(matcher));
+}
+
+// Same as ResultOf() above, but also takes a description of the `callable`
+// result to provide better error messages.
+template <typename Callable, typename InnerMatcher>
+internal::ResultOfMatcher<Callable, InnerMatcher> ResultOf(
+    const std::string& result_description, Callable callable,
+    InnerMatcher matcher) {
+  return internal::ResultOfMatcher<Callable, InnerMatcher>(
+      result_description, std::move(callable), std::move(matcher));
+}
+
+// String matchers.
+
+// Matches a string equal to str.
+template <typename T = std::string>
+PolymorphicMatcher<internal::StrEqualityMatcher<std::string>> StrEq(
+    const internal::StringLike<T>& str) {
+  return MakePolymorphicMatcher(
+      internal::StrEqualityMatcher<std::string>(std::string(str), true, true));
+}
+
+// Matches a string not equal to str.
+template <typename T = std::string>
+PolymorphicMatcher<internal::StrEqualityMatcher<std::string>> StrNe(
+    const internal::StringLike<T>& str) {
+  return MakePolymorphicMatcher(
+      internal::StrEqualityMatcher<std::string>(std::string(str), false, true));
+}
+
+// Matches a string equal to str, ignoring case.
+template <typename T = std::string>
+PolymorphicMatcher<internal::StrEqualityMatcher<std::string>> StrCaseEq(
+    const internal::StringLike<T>& str) {
+  return MakePolymorphicMatcher(
+      internal::StrEqualityMatcher<std::string>(std::string(str), true, false));
+}
+
+// Matches a string not equal to str, ignoring case.
+template <typename T = std::string>
+PolymorphicMatcher<internal::StrEqualityMatcher<std::string>> StrCaseNe(
+    const internal::StringLike<T>& str) {
+  return MakePolymorphicMatcher(internal::StrEqualityMatcher<std::string>(
+      std::string(str), false, false));
+}
+
+// Creates a matcher that matches any string, std::string, or C string
+// that contains the given substring.
+template <typename T = std::string>
+PolymorphicMatcher<internal::HasSubstrMatcher<std::string>> HasSubstr(
+    const internal::StringLike<T>& substring) {
+  return MakePolymorphicMatcher(
+      internal::HasSubstrMatcher<std::string>(std::string(substring)));
+}
+
+// Matches a string that starts with 'prefix' (case-sensitive).
+template <typename T = std::string>
+PolymorphicMatcher<internal::StartsWithMatcher<std::string>> StartsWith(
+    const internal::StringLike<T>& prefix) {
+  return MakePolymorphicMatcher(
+      internal::StartsWithMatcher<std::string>(std::string(prefix)));
+}
+
+// Matches a string that ends with 'suffix' (case-sensitive).
+template <typename T = std::string>
+PolymorphicMatcher<internal::EndsWithMatcher<std::string>> EndsWith(
+    const internal::StringLike<T>& suffix) {
+  return MakePolymorphicMatcher(
+      internal::EndsWithMatcher<std::string>(std::string(suffix)));
+}
+
+#if GTEST_HAS_STD_WSTRING
+// Wide string matchers.
+
+// Matches a string equal to str.
+inline PolymorphicMatcher<internal::StrEqualityMatcher<std::wstring>> StrEq(
+    const std::wstring& str) {
+  return MakePolymorphicMatcher(
+      internal::StrEqualityMatcher<std::wstring>(str, true, true));
+}
+
+// Matches a string not equal to str.
+inline PolymorphicMatcher<internal::StrEqualityMatcher<std::wstring>> StrNe(
+    const std::wstring& str) {
+  return MakePolymorphicMatcher(
+      internal::StrEqualityMatcher<std::wstring>(str, false, true));
+}
+
+// Matches a string equal to str, ignoring case.
+inline PolymorphicMatcher<internal::StrEqualityMatcher<std::wstring>> StrCaseEq(
+    const std::wstring& str) {
+  return MakePolymorphicMatcher(
+      internal::StrEqualityMatcher<std::wstring>(str, true, false));
+}
+
+// Matches a string not equal to str, ignoring case.
+inline PolymorphicMatcher<internal::StrEqualityMatcher<std::wstring>> StrCaseNe(
+    const std::wstring& str) {
+  return MakePolymorphicMatcher(
+      internal::StrEqualityMatcher<std::wstring>(str, false, false));
+}
+
+// Creates a matcher that matches any ::wstring, std::wstring, or C wide string
+// that contains the given substring.
+inline PolymorphicMatcher<internal::HasSubstrMatcher<std::wstring>> HasSubstr(
+    const std::wstring& substring) {
+  return MakePolymorphicMatcher(
+      internal::HasSubstrMatcher<std::wstring>(substring));
+}
+
+// Matches a string that starts with 'prefix' (case-sensitive).
+inline PolymorphicMatcher<internal::StartsWithMatcher<std::wstring>> StartsWith(
+    const std::wstring& prefix) {
+  return MakePolymorphicMatcher(
+      internal::StartsWithMatcher<std::wstring>(prefix));
+}
+
+// Matches a string that ends with 'suffix' (case-sensitive).
+inline PolymorphicMatcher<internal::EndsWithMatcher<std::wstring>> EndsWith(
+    const std::wstring& suffix) {
+  return MakePolymorphicMatcher(
+      internal::EndsWithMatcher<std::wstring>(suffix));
+}
+
+#endif  // GTEST_HAS_STD_WSTRING
+
+// Creates a polymorphic matcher that matches a 2-tuple where the
+// first field == the second field.
+inline internal::Eq2Matcher Eq() { return internal::Eq2Matcher(); }
+
+// Creates a polymorphic matcher that matches a 2-tuple where the
+// first field >= the second field.
+inline internal::Ge2Matcher Ge() { return internal::Ge2Matcher(); }
+
+// Creates a polymorphic matcher that matches a 2-tuple where the
+// first field > the second field.
+inline internal::Gt2Matcher Gt() { return internal::Gt2Matcher(); }
+
+// Creates a polymorphic matcher that matches a 2-tuple where the
+// first field <= the second field.
+inline internal::Le2Matcher Le() { return internal::Le2Matcher(); }
+
+// Creates a polymorphic matcher that matches a 2-tuple where the
+// first field < the second field.
+inline internal::Lt2Matcher Lt() { return internal::Lt2Matcher(); }
+
+// Creates a polymorphic matcher that matches a 2-tuple where the
+// first field != the second field.
+inline internal::Ne2Matcher Ne() { return internal::Ne2Matcher(); }
+
+// Creates a polymorphic matcher that matches a 2-tuple where
+// FloatEq(first field) matches the second field.
+inline internal::FloatingEq2Matcher<float> FloatEq() {
+  return internal::FloatingEq2Matcher<float>();
+}
+
+// Creates a polymorphic matcher that matches a 2-tuple where
+// DoubleEq(first field) matches the second field.
+inline internal::FloatingEq2Matcher<double> DoubleEq() {
+  return internal::FloatingEq2Matcher<double>();
+}
+
+// Creates a polymorphic matcher that matches a 2-tuple where
+// FloatEq(first field) matches the second field with NaN equality.
+inline internal::FloatingEq2Matcher<float> NanSensitiveFloatEq() {
+  return internal::FloatingEq2Matcher<float>(true);
+}
+
+// Creates a polymorphic matcher that matches a 2-tuple where
+// DoubleEq(first field) matches the second field with NaN equality.
+inline internal::FloatingEq2Matcher<double> NanSensitiveDoubleEq() {
+  return internal::FloatingEq2Matcher<double>(true);
+}
+
+// Creates a polymorphic matcher that matches a 2-tuple where
+// FloatNear(first field, max_abs_error) matches the second field.
+inline internal::FloatingEq2Matcher<float> FloatNear(float max_abs_error) {
+  return internal::FloatingEq2Matcher<float>(max_abs_error);
+}
+
+// Creates a polymorphic matcher that matches a 2-tuple where
+// DoubleNear(first field, max_abs_error) matches the second field.
+inline internal::FloatingEq2Matcher<double> DoubleNear(double max_abs_error) {
+  return internal::FloatingEq2Matcher<double>(max_abs_error);
+}
+
+// Creates a polymorphic matcher that matches a 2-tuple where
+// FloatNear(first field, max_abs_error) matches the second field with NaN
+// equality.
+inline internal::FloatingEq2Matcher<float> NanSensitiveFloatNear(
+    float max_abs_error) {
+  return internal::FloatingEq2Matcher<float>(max_abs_error, true);
+}
+
+// Creates a polymorphic matcher that matches a 2-tuple where
+// DoubleNear(first field, max_abs_error) matches the second field with NaN
+// equality.
+inline internal::FloatingEq2Matcher<double> NanSensitiveDoubleNear(
+    double max_abs_error) {
+  return internal::FloatingEq2Matcher<double>(max_abs_error, true);
+}
+
+// Creates a matcher that matches any value of type T that m doesn't
+// match.
+template <typename InnerMatcher>
+inline internal::NotMatcher<InnerMatcher> Not(InnerMatcher m) {
+  return internal::NotMatcher<InnerMatcher>(m);
+}
+
+// Returns a matcher that matches anything that satisfies the given
+// predicate.  The predicate can be any unary function or functor
+// whose return type can be implicitly converted to bool.
+template <typename Predicate>
+inline PolymorphicMatcher<internal::TrulyMatcher<Predicate>> Truly(
+    Predicate pred) {
+  return MakePolymorphicMatcher(internal::TrulyMatcher<Predicate>(pred));
+}
+
+// Returns a matcher that matches the container size. The container must
+// support both size() and size_type which all STL-like containers provide.
+// Note that the parameter 'size' can be a value of type size_type as well as
+// matcher. For instance:
+//   EXPECT_THAT(container, SizeIs(2));     // Checks container has 2 elements.
+//   EXPECT_THAT(container, SizeIs(Le(2));  // Checks container has at most 2.
+template <typename SizeMatcher>
+inline internal::SizeIsMatcher<SizeMatcher> SizeIs(
+    const SizeMatcher& size_matcher) {
+  return internal::SizeIsMatcher<SizeMatcher>(size_matcher);
+}
+
+// Returns a matcher that matches the distance between the container's begin()
+// iterator and its end() iterator, i.e. the size of the container. This matcher
+// can be used instead of SizeIs with containers such as std::forward_list which
+// do not implement size(). The container must provide const_iterator (with
+// valid iterator_traits), begin() and end().
+template <typename DistanceMatcher>
+inline internal::BeginEndDistanceIsMatcher<DistanceMatcher> BeginEndDistanceIs(
+    const DistanceMatcher& distance_matcher) {
+  return internal::BeginEndDistanceIsMatcher<DistanceMatcher>(distance_matcher);
+}
+
+// Returns a matcher that matches an equal container.
+// This matcher behaves like Eq(), but in the event of mismatch lists the
+// values that are included in one container but not the other. (Duplicate
+// values and order differences are not explained.)
+template <typename Container>
+inline PolymorphicMatcher<
+    internal::ContainerEqMatcher<typename std::remove_const<Container>::type>>
+ContainerEq(const Container& rhs) {
+  return MakePolymorphicMatcher(internal::ContainerEqMatcher<Container>(rhs));
+}
+
+// Returns a matcher that matches a container that, when sorted using
+// the given comparator, matches container_matcher.
+template <typename Comparator, typename ContainerMatcher>
+inline internal::WhenSortedByMatcher<Comparator, ContainerMatcher> WhenSortedBy(
+    const Comparator& comparator, const ContainerMatcher& container_matcher) {
+  return internal::WhenSortedByMatcher<Comparator, ContainerMatcher>(
+      comparator, container_matcher);
+}
+
+// Returns a matcher that matches a container that, when sorted using
+// the < operator, matches container_matcher.
+template <typename ContainerMatcher>
+inline internal::WhenSortedByMatcher<internal::LessComparator, ContainerMatcher>
+WhenSorted(const ContainerMatcher& container_matcher) {
+  return internal::WhenSortedByMatcher<internal::LessComparator,
+                                       ContainerMatcher>(
+      internal::LessComparator(), container_matcher);
+}
+
+// Matches an STL-style container or a native array that contains the
+// same number of elements as in rhs, where its i-th element and rhs's
+// i-th element (as a pair) satisfy the given pair matcher, for all i.
+// TupleMatcher must be able to be safely cast to Matcher<std::tuple<const
+// T1&, const T2&> >, where T1 and T2 are the types of elements in the
+// LHS container and the RHS container respectively.
+template <typename TupleMatcher, typename Container>
+inline internal::PointwiseMatcher<TupleMatcher,
+                                  typename std::remove_const<Container>::type>
+Pointwise(const TupleMatcher& tuple_matcher, const Container& rhs) {
+  return internal::PointwiseMatcher<TupleMatcher, Container>(tuple_matcher,
+                                                             rhs);
+}
+
+// Supports the Pointwise(m, {a, b, c}) syntax.
+template <typename TupleMatcher, typename T>
+inline internal::PointwiseMatcher<TupleMatcher, std::vector<T>> Pointwise(
+    const TupleMatcher& tuple_matcher, std::initializer_list<T> rhs) {
+  return Pointwise(tuple_matcher, std::vector<T>(rhs));
+}
+
+// UnorderedPointwise(pair_matcher, rhs) matches an STL-style
+// container or a native array that contains the same number of
+// elements as in rhs, where in some permutation of the container, its
+// i-th element and rhs's i-th element (as a pair) satisfy the given
+// pair matcher, for all i.  Tuple2Matcher must be able to be safely
+// cast to Matcher<std::tuple<const T1&, const T2&> >, where T1 and T2 are
+// the types of elements in the LHS container and the RHS container
+// respectively.
+//
+// This is like Pointwise(pair_matcher, rhs), except that the element
+// order doesn't matter.
+template <typename Tuple2Matcher, typename RhsContainer>
+inline internal::UnorderedElementsAreArrayMatcher<
+    typename internal::BoundSecondMatcher<
+        Tuple2Matcher,
+        typename internal::StlContainerView<
+            typename std::remove_const<RhsContainer>::type>::type::value_type>>
+UnorderedPointwise(const Tuple2Matcher& tuple2_matcher,
+                   const RhsContainer& rhs_container) {
+  // RhsView allows the same code to handle RhsContainer being a
+  // STL-style container and it being a native C-style array.
+  typedef typename internal::StlContainerView<RhsContainer> RhsView;
+  typedef typename RhsView::type RhsStlContainer;
+  typedef typename RhsStlContainer::value_type Second;
+  const RhsStlContainer& rhs_stl_container =
+      RhsView::ConstReference(rhs_container);
+
+  // Create a matcher for each element in rhs_container.
+  ::std::vector<internal::BoundSecondMatcher<Tuple2Matcher, Second>> matchers;
+  for (auto it = rhs_stl_container.begin(); it != rhs_stl_container.end();
+       ++it) {
+    matchers.push_back(internal::MatcherBindSecond(tuple2_matcher, *it));
+  }
+
+  // Delegate the work to UnorderedElementsAreArray().
+  return UnorderedElementsAreArray(matchers);
+}
+
+// Supports the UnorderedPointwise(m, {a, b, c}) syntax.
+template <typename Tuple2Matcher, typename T>
+inline internal::UnorderedElementsAreArrayMatcher<
+    typename internal::BoundSecondMatcher<Tuple2Matcher, T>>
+UnorderedPointwise(const Tuple2Matcher& tuple2_matcher,
+                   std::initializer_list<T> rhs) {
+  return UnorderedPointwise(tuple2_matcher, std::vector<T>(rhs));
+}
+
+// Matches an STL-style container or a native array that contains at
+// least one element matching the given value or matcher.
+//
+// Examples:
+//   ::std::set<int> page_ids;
+//   page_ids.insert(3);
+//   page_ids.insert(1);
+//   EXPECT_THAT(page_ids, Contains(1));
+//   EXPECT_THAT(page_ids, Contains(Gt(2)));
+//   EXPECT_THAT(page_ids, Not(Contains(4)));  // See below for Times(0)
+//
+//   ::std::map<int, size_t> page_lengths;
+//   page_lengths[1] = 100;
+//   EXPECT_THAT(page_lengths,
+//               Contains(::std::pair<const int, size_t>(1, 100)));
+//
+//   const char* user_ids[] = { "joe", "mike", "tom" };
+//   EXPECT_THAT(user_ids, Contains(Eq(::std::string("tom"))));
+//
+// The matcher supports a modifier `Times` that allows to check for arbitrary
+// occurrences including testing for absence with Times(0).
+//
+// Examples:
+//   ::std::vector<int> ids;
+//   ids.insert(1);
+//   ids.insert(1);
+//   ids.insert(3);
+//   EXPECT_THAT(ids, Contains(1).Times(2));      // 1 occurs 2 times
+//   EXPECT_THAT(ids, Contains(2).Times(0));      // 2 is not present
+//   EXPECT_THAT(ids, Contains(3).Times(Ge(1)));  // 3 occurs at least once
+
+template <typename M>
+inline internal::ContainsMatcher<M> Contains(M matcher) {
+  return internal::ContainsMatcher<M>(matcher);
+}
+
+// IsSupersetOf(iterator_first, iterator_last)
+// IsSupersetOf(pointer, count)
+// IsSupersetOf(array)
+// IsSupersetOf(container)
+// IsSupersetOf({e1, e2, ..., en})
+//
+// IsSupersetOf() verifies that a surjective partial mapping onto a collection
+// of matchers exists. In other words, a container matches
+// IsSupersetOf({e1, ..., en}) if and only if there is a permutation
+// {y1, ..., yn} of some of the container's elements where y1 matches e1,
+// ..., and yn matches en. Obviously, the size of the container must be >= n
+// in order to have a match. Examples:
+//
+// - {1, 2, 3} matches IsSupersetOf({Ge(3), Ne(0)}), as 3 matches Ge(3) and
+//   1 matches Ne(0).
+// - {1, 2} doesn't match IsSupersetOf({Eq(1), Lt(2)}), even though 1 matches
+//   both Eq(1) and Lt(2). The reason is that different matchers must be used
+//   for elements in different slots of the container.
+// - {1, 1, 2} matches IsSupersetOf({Eq(1), Lt(2)}), as (the first) 1 matches
+//   Eq(1) and (the second) 1 matches Lt(2).
+// - {1, 2, 3} matches IsSupersetOf(Gt(1), Gt(1)), as 2 matches (the first)
+//   Gt(1) and 3 matches (the second) Gt(1).
+//
+// The matchers can be specified as an array, a pointer and count, a container,
+// an initializer list, or an STL iterator range. In each of these cases, the
+// underlying matchers can be either values or matchers.
+
+template <typename Iter>
+inline internal::UnorderedElementsAreArrayMatcher<
+    typename ::std::iterator_traits<Iter>::value_type>
+IsSupersetOf(Iter first, Iter last) {
+  typedef typename ::std::iterator_traits<Iter>::value_type T;
+  return internal::UnorderedElementsAreArrayMatcher<T>(
+      internal::UnorderedMatcherRequire::Superset, first, last);
+}
+
+template <typename T>
+inline internal::UnorderedElementsAreArrayMatcher<T> IsSupersetOf(
+    const T* pointer, size_t count) {
+  return IsSupersetOf(pointer, pointer + count);
+}
+
+template <typename T, size_t N>
+inline internal::UnorderedElementsAreArrayMatcher<T> IsSupersetOf(
+    const T (&array)[N]) {
+  return IsSupersetOf(array, N);
+}
+
+template <typename Container>
+inline internal::UnorderedElementsAreArrayMatcher<
+    typename Container::value_type>
+IsSupersetOf(const Container& container) {
+  return IsSupersetOf(container.begin(), container.end());
+}
+
+template <typename T>
+inline internal::UnorderedElementsAreArrayMatcher<T> IsSupersetOf(
+    ::std::initializer_list<T> xs) {
+  return IsSupersetOf(xs.begin(), xs.end());
+}
+
+// IsSubsetOf(iterator_first, iterator_last)
+// IsSubsetOf(pointer, count)
+// IsSubsetOf(array)
+// IsSubsetOf(container)
+// IsSubsetOf({e1, e2, ..., en})
+//
+// IsSubsetOf() verifies that an injective mapping onto a collection of matchers
+// exists.  In other words, a container matches IsSubsetOf({e1, ..., en}) if and
+// only if there is a subset of matchers {m1, ..., mk} which would match the
+// container using UnorderedElementsAre.  Obviously, the size of the container
+// must be <= n in order to have a match. Examples:
+//
+// - {1} matches IsSubsetOf({Gt(0), Lt(0)}), as 1 matches Gt(0).
+// - {1, -1} matches IsSubsetOf({Lt(0), Gt(0)}), as 1 matches Gt(0) and -1
+//   matches Lt(0).
+// - {1, 2} doesn't matches IsSubsetOf({Gt(0), Lt(0)}), even though 1 and 2 both
+//   match Gt(0). The reason is that different matchers must be used for
+//   elements in different slots of the container.
+//
+// The matchers can be specified as an array, a pointer and count, a container,
+// an initializer list, or an STL iterator range. In each of these cases, the
+// underlying matchers can be either values or matchers.
+
+template <typename Iter>
+inline internal::UnorderedElementsAreArrayMatcher<
+    typename ::std::iterator_traits<Iter>::value_type>
+IsSubsetOf(Iter first, Iter last) {
+  typedef typename ::std::iterator_traits<Iter>::value_type T;
+  return internal::UnorderedElementsAreArrayMatcher<T>(
+      internal::UnorderedMatcherRequire::Subset, first, last);
+}
+
+template <typename T>
+inline internal::UnorderedElementsAreArrayMatcher<T> IsSubsetOf(
+    const T* pointer, size_t count) {
+  return IsSubsetOf(pointer, pointer + count);
+}
+
+template <typename T, size_t N>
+inline internal::UnorderedElementsAreArrayMatcher<T> IsSubsetOf(
+    const T (&array)[N]) {
+  return IsSubsetOf(array, N);
+}
+
+template <typename Container>
+inline internal::UnorderedElementsAreArrayMatcher<
+    typename Container::value_type>
+IsSubsetOf(const Container& container) {
+  return IsSubsetOf(container.begin(), container.end());
+}
+
+template <typename T>
+inline internal::UnorderedElementsAreArrayMatcher<T> IsSubsetOf(
+    ::std::initializer_list<T> xs) {
+  return IsSubsetOf(xs.begin(), xs.end());
+}
+
+// Matches an STL-style container or a native array that contains only
+// elements matching the given value or matcher.
+//
+// Each(m) is semantically equivalent to `Not(Contains(Not(m)))`. Only
+// the messages are different.
+//
+// Examples:
+//   ::std::set<int> page_ids;
+//   // Each(m) matches an empty container, regardless of what m is.
+//   EXPECT_THAT(page_ids, Each(Eq(1)));
+//   EXPECT_THAT(page_ids, Each(Eq(77)));
+//
+//   page_ids.insert(3);
+//   EXPECT_THAT(page_ids, Each(Gt(0)));
+//   EXPECT_THAT(page_ids, Not(Each(Gt(4))));
+//   page_ids.insert(1);
+//   EXPECT_THAT(page_ids, Not(Each(Lt(2))));
+//
+//   ::std::map<int, size_t> page_lengths;
+//   page_lengths[1] = 100;
+//   page_lengths[2] = 200;
+//   page_lengths[3] = 300;
+//   EXPECT_THAT(page_lengths, Not(Each(Pair(1, 100))));
+//   EXPECT_THAT(page_lengths, Each(Key(Le(3))));
+//
+//   const char* user_ids[] = { "joe", "mike", "tom" };
+//   EXPECT_THAT(user_ids, Not(Each(Eq(::std::string("tom")))));
+template <typename M>
+inline internal::EachMatcher<M> Each(M matcher) {
+  return internal::EachMatcher<M>(matcher);
+}
+
+// Key(inner_matcher) matches an std::pair whose 'first' field matches
+// inner_matcher.  For example, Contains(Key(Ge(5))) can be used to match an
+// std::map that contains at least one element whose key is >= 5.
+template <typename M>
+inline internal::KeyMatcher<M> Key(M inner_matcher) {
+  return internal::KeyMatcher<M>(inner_matcher);
+}
+
+// Pair(first_matcher, second_matcher) matches a std::pair whose 'first' field
+// matches first_matcher and whose 'second' field matches second_matcher.  For
+// example, EXPECT_THAT(map_type, ElementsAre(Pair(Ge(5), "foo"))) can be used
+// to match a std::map<int, string> that contains exactly one element whose key
+// is >= 5 and whose value equals "foo".
+template <typename FirstMatcher, typename SecondMatcher>
+inline internal::PairMatcher<FirstMatcher, SecondMatcher> Pair(
+    FirstMatcher first_matcher, SecondMatcher second_matcher) {
+  return internal::PairMatcher<FirstMatcher, SecondMatcher>(first_matcher,
+                                                            second_matcher);
+}
+
+namespace no_adl {
+// Conditional() creates a matcher that conditionally uses either the first or
+// second matcher provided. For example, we could create an `equal if, and only
+// if' matcher using the Conditional wrapper as follows:
+//
+//   EXPECT_THAT(result, Conditional(condition, Eq(expected), Ne(expected)));
+template <typename MatcherTrue, typename MatcherFalse>
+internal::ConditionalMatcher<MatcherTrue, MatcherFalse> Conditional(
+    bool condition, MatcherTrue matcher_true, MatcherFalse matcher_false) {
+  return internal::ConditionalMatcher<MatcherTrue, MatcherFalse>(
+      condition, std::move(matcher_true), std::move(matcher_false));
+}
+
+// FieldsAre(matchers...) matches piecewise the fields of compatible structs.
+// These include those that support `get<I>(obj)`, and when structured bindings
+// are enabled any class that supports them.
+// In particular, `std::tuple`, `std::pair`, `std::array` and aggregate types.
+template <typename... M>
+internal::FieldsAreMatcher<typename std::decay<M>::type...> FieldsAre(
+    M&&... matchers) {
+  return internal::FieldsAreMatcher<typename std::decay<M>::type...>(
+      std::forward<M>(matchers)...);
+}
+
+// Creates a matcher that matches a pointer (raw or smart) that matches
+// inner_matcher.
+template <typename InnerMatcher>
+inline internal::PointerMatcher<InnerMatcher> Pointer(
+    const InnerMatcher& inner_matcher) {
+  return internal::PointerMatcher<InnerMatcher>(inner_matcher);
+}
+
+// Creates a matcher that matches an object that has an address that matches
+// inner_matcher.
+template <typename InnerMatcher>
+inline internal::AddressMatcher<InnerMatcher> Address(
+    const InnerMatcher& inner_matcher) {
+  return internal::AddressMatcher<InnerMatcher>(inner_matcher);
+}
+
+// Matches a base64 escaped string, when the unescaped string matches the
+// internal matcher.
+template <typename MatcherType>
+internal::WhenBase64UnescapedMatcher WhenBase64Unescaped(
+    const MatcherType& internal_matcher) {
+  return internal::WhenBase64UnescapedMatcher(internal_matcher);
+}
+}  // namespace no_adl
+
+// Returns a predicate that is satisfied by anything that matches the
+// given matcher.
+template <typename M>
+inline internal::MatcherAsPredicate<M> Matches(M matcher) {
+  return internal::MatcherAsPredicate<M>(matcher);
+}
+
+// Returns true if and only if the value matches the matcher.
+template <typename T, typename M>
+inline bool Value(const T& value, M matcher) {
+  return testing::Matches(matcher)(value);
+}
+
+// Matches the value against the given matcher and explains the match
+// result to listener.
+template <typename T, typename M>
+inline bool ExplainMatchResult(M matcher, const T& value,
+                               MatchResultListener* listener) {
+  return SafeMatcherCast<const T&>(matcher).MatchAndExplain(value, listener);
+}
+
+// Returns a string representation of the given matcher.  Useful for description
+// strings of matchers defined using MATCHER_P* macros that accept matchers as
+// their arguments.  For example:
+//
+// MATCHER_P(XAndYThat, matcher,
+//           "X that " + DescribeMatcher<int>(matcher, negation) +
+//               (negation ? " or" : " and") + " Y that " +
+//               DescribeMatcher<double>(matcher, negation)) {
+//   return ExplainMatchResult(matcher, arg.x(), result_listener) &&
+//          ExplainMatchResult(matcher, arg.y(), result_listener);
+// }
+template <typename T, typename M>
+std::string DescribeMatcher(const M& matcher, bool negation = false) {
+  ::std::stringstream ss;
+  Matcher<T> monomorphic_matcher = SafeMatcherCast<T>(matcher);
+  if (negation) {
+    monomorphic_matcher.DescribeNegationTo(&ss);
+  } else {
+    monomorphic_matcher.DescribeTo(&ss);
+  }
+  return ss.str();
+}
+
+template <typename... Args>
+internal::ElementsAreMatcher<
+    std::tuple<typename std::decay<const Args&>::type...>>
+ElementsAre(const Args&... matchers) {
+  return internal::ElementsAreMatcher<
+      std::tuple<typename std::decay<const Args&>::type...>>(
+      std::make_tuple(matchers...));
+}
+
+template <typename... Args>
+internal::UnorderedElementsAreMatcher<
+    std::tuple<typename std::decay<const Args&>::type...>>
+UnorderedElementsAre(const Args&... matchers) {
+  return internal::UnorderedElementsAreMatcher<
+      std::tuple<typename std::decay<const Args&>::type...>>(
+      std::make_tuple(matchers...));
+}
+
+// Define variadic matcher versions.
+template <typename... Args>
+internal::AllOfMatcher<typename std::decay<const Args&>::type...> AllOf(
+    const Args&... matchers) {
+  return internal::AllOfMatcher<typename std::decay<const Args&>::type...>(
+      matchers...);
+}
+
+template <typename... Args>
+internal::AnyOfMatcher<typename std::decay<const Args&>::type...> AnyOf(
+    const Args&... matchers) {
+  return internal::AnyOfMatcher<typename std::decay<const Args&>::type...>(
+      matchers...);
+}
+
+// AnyOfArray(array)
+// AnyOfArray(pointer, count)
+// AnyOfArray(container)
+// AnyOfArray({ e1, e2, ..., en })
+// AnyOfArray(iterator_first, iterator_last)
+//
+// AnyOfArray() verifies whether a given value matches any member of a
+// collection of matchers.
+//
+// AllOfArray(array)
+// AllOfArray(pointer, count)
+// AllOfArray(container)
+// AllOfArray({ e1, e2, ..., en })
+// AllOfArray(iterator_first, iterator_last)
+//
+// AllOfArray() verifies whether a given value matches all members of a
+// collection of matchers.
+//
+// The matchers can be specified as an array, a pointer and count, a container,
+// an initializer list, or an STL iterator range. In each of these cases, the
+// underlying matchers can be either values or matchers.
+
+template <typename Iter>
+inline internal::AnyOfArrayMatcher<
+    typename ::std::iterator_traits<Iter>::value_type>
+AnyOfArray(Iter first, Iter last) {
+  return internal::AnyOfArrayMatcher<
+      typename ::std::iterator_traits<Iter>::value_type>(first, last);
+}
+
+template <typename Iter>
+inline internal::AllOfArrayMatcher<
+    typename ::std::iterator_traits<Iter>::value_type>
+AllOfArray(Iter first, Iter last) {
+  return internal::AllOfArrayMatcher<
+      typename ::std::iterator_traits<Iter>::value_type>(first, last);
+}
+
+template <typename T>
+inline internal::AnyOfArrayMatcher<T> AnyOfArray(const T* ptr, size_t count) {
+  return AnyOfArray(ptr, ptr + count);
+}
+
+template <typename T>
+inline internal::AllOfArrayMatcher<T> AllOfArray(const T* ptr, size_t count) {
+  return AllOfArray(ptr, ptr + count);
+}
+
+template <typename T, size_t N>
+inline internal::AnyOfArrayMatcher<T> AnyOfArray(const T (&array)[N]) {
+  return AnyOfArray(array, N);
+}
+
+template <typename T, size_t N>
+inline internal::AllOfArrayMatcher<T> AllOfArray(const T (&array)[N]) {
+  return AllOfArray(array, N);
+}
+
+template <typename Container>
+inline internal::AnyOfArrayMatcher<typename Container::value_type> AnyOfArray(
+    const Container& container) {
+  return AnyOfArray(container.begin(), container.end());
+}
+
+template <typename Container>
+inline internal::AllOfArrayMatcher<typename Container::value_type> AllOfArray(
+    const Container& container) {
+  return AllOfArray(container.begin(), container.end());
+}
+
+template <typename T>
+inline internal::AnyOfArrayMatcher<T> AnyOfArray(
+    ::std::initializer_list<T> xs) {
+  return AnyOfArray(xs.begin(), xs.end());
+}
+
+template <typename T>
+inline internal::AllOfArrayMatcher<T> AllOfArray(
+    ::std::initializer_list<T> xs) {
+  return AllOfArray(xs.begin(), xs.end());
+}
+
+// Args<N1, N2, ..., Nk>(a_matcher) matches a tuple if the selected
+// fields of it matches a_matcher.  C++ doesn't support default
+// arguments for function templates, so we have to overload it.
+template <size_t... k, typename InnerMatcher>
+internal::ArgsMatcher<typename std::decay<InnerMatcher>::type, k...> Args(
+    InnerMatcher&& matcher) {
+  return internal::ArgsMatcher<typename std::decay<InnerMatcher>::type, k...>(
+      std::forward<InnerMatcher>(matcher));
+}
+
+// AllArgs(m) is a synonym of m.  This is useful in
+//
+//   EXPECT_CALL(foo, Bar(_, _)).With(AllArgs(Eq()));
+//
+// which is easier to read than
+//
+//   EXPECT_CALL(foo, Bar(_, _)).With(Eq());
+template <typename InnerMatcher>
+inline InnerMatcher AllArgs(const InnerMatcher& matcher) {
+  return matcher;
+}
+
+// Returns a matcher that matches the value of an optional<> type variable.
+// The matcher implementation only uses '!arg' and requires that the optional<>
+// type has a 'value_type' member type and that '*arg' is of type 'value_type'
+// and is printable using 'PrintToString'. It is compatible with
+// std::optional/std::experimental::optional.
+// Note that to compare an optional type variable against nullopt you should
+// use Eq(nullopt) and not Eq(Optional(nullopt)). The latter implies that the
+// optional value contains an optional itself.
+template <typename ValueMatcher>
+inline internal::OptionalMatcher<ValueMatcher> Optional(
+    const ValueMatcher& value_matcher) {
+  return internal::OptionalMatcher<ValueMatcher>(value_matcher);
+}
+
+// Returns a matcher that matches the value of a absl::any type variable.
+template <typename T>
+PolymorphicMatcher<internal::any_cast_matcher::AnyCastMatcher<T>> AnyWith(
+    const Matcher<const T&>& matcher) {
+  return MakePolymorphicMatcher(
+      internal::any_cast_matcher::AnyCastMatcher<T>(matcher));
+}
+
+// Returns a matcher that matches the value of a variant<> type variable.
+// The matcher implementation uses ADL to find the holds_alternative and get
+// functions.
+// It is compatible with std::variant.
+template <typename T>
+PolymorphicMatcher<internal::variant_matcher::VariantMatcher<T>> VariantWith(
+    const Matcher<const T&>& matcher) {
+  return MakePolymorphicMatcher(
+      internal::variant_matcher::VariantMatcher<T>(matcher));
+}
+
+#if GTEST_HAS_EXCEPTIONS
+
+// Anything inside the `internal` namespace is internal to the implementation
+// and must not be used in user code!
+namespace internal {
+
+class WithWhatMatcherImpl {
+ public:
+  WithWhatMatcherImpl(Matcher<std::string> matcher)
+      : matcher_(std::move(matcher)) {}
+
+  void DescribeTo(std::ostream* os) const {
+    *os << "contains .what() that ";
+    matcher_.DescribeTo(os);
+  }
+
+  void DescribeNegationTo(std::ostream* os) const {
+    *os << "contains .what() that does not ";
+    matcher_.DescribeTo(os);
+  }
+
+  template <typename Err>
+  bool MatchAndExplain(const Err& err, MatchResultListener* listener) const {
+    *listener << "which contains .what() (of value = " << err.what()
+              << ") that ";
+    return matcher_.MatchAndExplain(err.what(), listener);
+  }
+
+ private:
+  const Matcher<std::string> matcher_;
+};
+
+inline PolymorphicMatcher<WithWhatMatcherImpl> WithWhat(
+    Matcher<std::string> m) {
+  return MakePolymorphicMatcher(WithWhatMatcherImpl(std::move(m)));
+}
+
+template <typename Err>
+class ExceptionMatcherImpl {
+  class NeverThrown {
+   public:
+    const char* what() const noexcept {
+      return "this exception should never be thrown";
+    }
+  };
+
+  // If the matchee raises an exception of a wrong type, we'd like to
+  // catch it and print its message and type. To do that, we add an additional
+  // catch clause:
+  //
+  //     try { ... }
+  //     catch (const Err&) { /* an expected exception */ }
+  //     catch (const std::exception&) { /* exception of a wrong type */ }
+  //
+  // However, if the `Err` itself is `std::exception`, we'd end up with two
+  // identical `catch` clauses:
+  //
+  //     try { ... }
+  //     catch (const std::exception&) { /* an expected exception */ }
+  //     catch (const std::exception&) { /* exception of a wrong type */ }
+  //
+  // This can cause a warning or an error in some compilers. To resolve
+  // the issue, we use a fake error type whenever `Err` is `std::exception`:
+  //
+  //     try { ... }
+  //     catch (const std::exception&) { /* an expected exception */ }
+  //     catch (const NeverThrown&) { /* exception of a wrong type */ }
+  using DefaultExceptionType = typename std::conditional<
+      std::is_same<typename std::remove_cv<
+                       typename std::remove_reference<Err>::type>::type,
+                   std::exception>::value,
+      const NeverThrown&, const std::exception&>::type;
+
+ public:
+  ExceptionMatcherImpl(Matcher<const Err&> matcher)
+      : matcher_(std::move(matcher)) {}
+
+  void DescribeTo(std::ostream* os) const {
+    *os << "throws an exception which is a " << GetTypeName<Err>();
+    *os << " which ";
+    matcher_.DescribeTo(os);
+  }
+
+  void DescribeNegationTo(std::ostream* os) const {
+    *os << "throws an exception which is not a " << GetTypeName<Err>();
+    *os << " which ";
+    matcher_.DescribeNegationTo(os);
+  }
+
+  template <typename T>
+  bool MatchAndExplain(T&& x, MatchResultListener* listener) const {
+    try {
+      (void)(std::forward<T>(x)());
+    } catch (const Err& err) {
+      *listener << "throws an exception which is a " << GetTypeName<Err>();
+      *listener << " ";
+      return matcher_.MatchAndExplain(err, listener);
+    } catch (DefaultExceptionType err) {
+#if GTEST_HAS_RTTI
+      *listener << "throws an exception of type " << GetTypeName(typeid(err));
+      *listener << " ";
+#else
+      *listener << "throws an std::exception-derived type ";
+#endif
+      *listener << "with description \"" << err.what() << "\"";
+      return false;
+    } catch (...) {
+      *listener << "throws an exception of an unknown type";
+      return false;
+    }
+
+    *listener << "does not throw any exception";
+    return false;
+  }
+
+ private:
+  const Matcher<const Err&> matcher_;
+};
+
+}  // namespace internal
+
+// Throws()
+// Throws(exceptionMatcher)
+// ThrowsMessage(messageMatcher)
+//
+// This matcher accepts a callable and verifies that when invoked, it throws
+// an exception with the given type and properties.
+//
+// Examples:
+//
+//   EXPECT_THAT(
+//       []() { throw std::runtime_error("message"); },
+//       Throws<std::runtime_error>());
+//
+//   EXPECT_THAT(
+//       []() { throw std::runtime_error("message"); },
+//       ThrowsMessage<std::runtime_error>(HasSubstr("message")));
+//
+//   EXPECT_THAT(
+//       []() { throw std::runtime_error("message"); },
+//       Throws<std::runtime_error>(
+//           Property(&std::runtime_error::what, HasSubstr("message"))));
+
+template <typename Err>
+PolymorphicMatcher<internal::ExceptionMatcherImpl<Err>> Throws() {
+  return MakePolymorphicMatcher(
+      internal::ExceptionMatcherImpl<Err>(A<const Err&>()));
+}
+
+template <typename Err, typename ExceptionMatcher>
+PolymorphicMatcher<internal::ExceptionMatcherImpl<Err>> Throws(
+    const ExceptionMatcher& exception_matcher) {
+  // Using matcher cast allows users to pass a matcher of a more broad type.
+  // For example user may want to pass Matcher<std::exception>
+  // to Throws<std::runtime_error>, or Matcher<int64> to Throws<int32>.
+  return MakePolymorphicMatcher(internal::ExceptionMatcherImpl<Err>(
+      SafeMatcherCast<const Err&>(exception_matcher)));
+}
+
+template <typename Err, typename MessageMatcher>
+PolymorphicMatcher<internal::ExceptionMatcherImpl<Err>> ThrowsMessage(
+    MessageMatcher&& message_matcher) {
+  static_assert(std::is_base_of<std::exception, Err>::value,
+                "expected an std::exception-derived type");
+  return Throws<Err>(internal::WithWhat(
+      MatcherCast<std::string>(std::forward<MessageMatcher>(message_matcher))));
+}
+
+#endif  // GTEST_HAS_EXCEPTIONS
+
+// These macros allow using matchers to check values in Google Test
+// tests.  ASSERT_THAT(value, matcher) and EXPECT_THAT(value, matcher)
+// succeed if and only if the value matches the matcher.  If the assertion
+// fails, the value and the description of the matcher will be printed.
+#define ASSERT_THAT(value, matcher) \
+  ASSERT_PRED_FORMAT1(              \
+      ::testing::internal::MakePredicateFormatterFromMatcher(matcher), value)
+#define EXPECT_THAT(value, matcher) \
+  EXPECT_PRED_FORMAT1(              \
+      ::testing::internal::MakePredicateFormatterFromMatcher(matcher), value)
+
+// MATCHER* macros itself are listed below.
+#define MATCHER(name, description)                                             \
+  class name##Matcher                                                          \
+      : public ::testing::internal::MatcherBaseImpl<name##Matcher> {           \
+   public:                                                                     \
+    template <typename arg_type>                                               \
+    class gmock_Impl : public ::testing::MatcherInterface<const arg_type&> {   \
+     public:                                                                   \
+      gmock_Impl() {}                                                          \
+      bool MatchAndExplain(                                                    \
+          const arg_type& arg,                                                 \
+          ::testing::MatchResultListener* result_listener) const override;     \
+      void DescribeTo(::std::ostream* gmock_os) const override {               \
+        *gmock_os << FormatDescription(false);                                 \
+      }                                                                        \
+      void DescribeNegationTo(::std::ostream* gmock_os) const override {       \
+        *gmock_os << FormatDescription(true);                                  \
+      }                                                                        \
+                                                                               \
+     private:                                                                  \
+      ::std::string FormatDescription(bool negation) const {                   \
+        /* NOLINTNEXTLINE readability-redundant-string-init */                 \
+        ::std::string gmock_description = (description);                       \
+        if (!gmock_description.empty()) {                                      \
+          return gmock_description;                                            \
+        }                                                                      \
+        return ::testing::internal::FormatMatcherDescription(negation, #name,  \
+                                                             {}, {});          \
+      }                                                                        \
+    };                                                                         \
+  };                                                                           \
+  inline name##Matcher GMOCK_INTERNAL_WARNING_PUSH()                           \
+      GMOCK_INTERNAL_WARNING_CLANG(ignored, "-Wunused-function")               \
+          GMOCK_INTERNAL_WARNING_CLANG(ignored, "-Wunused-member-function")    \
+              name GMOCK_INTERNAL_WARNING_POP()() {                            \
+    return {};                                                                 \
+  }                                                                            \
+  template <typename arg_type>                                                 \
+  bool name##Matcher::gmock_Impl<arg_type>::MatchAndExplain(                   \
+      const arg_type& arg,                                                     \
+      ::testing::MatchResultListener* result_listener GTEST_ATTRIBUTE_UNUSED_) \
+      const
+
+#define MATCHER_P(name, p0, description) \
+  GMOCK_INTERNAL_MATCHER(name, name##MatcherP, description, (#p0), (p0))
+#define MATCHER_P2(name, p0, p1, description)                            \
+  GMOCK_INTERNAL_MATCHER(name, name##MatcherP2, description, (#p0, #p1), \
+                         (p0, p1))
+#define MATCHER_P3(name, p0, p1, p2, description)                             \
+  GMOCK_INTERNAL_MATCHER(name, name##MatcherP3, description, (#p0, #p1, #p2), \
+                         (p0, p1, p2))
+#define MATCHER_P4(name, p0, p1, p2, p3, description)        \
+  GMOCK_INTERNAL_MATCHER(name, name##MatcherP4, description, \
+                         (#p0, #p1, #p2, #p3), (p0, p1, p2, p3))
+#define MATCHER_P5(name, p0, p1, p2, p3, p4, description)    \
+  GMOCK_INTERNAL_MATCHER(name, name##MatcherP5, description, \
+                         (#p0, #p1, #p2, #p3, #p4), (p0, p1, p2, p3, p4))
+#define MATCHER_P6(name, p0, p1, p2, p3, p4, p5, description) \
+  GMOCK_INTERNAL_MATCHER(name, name##MatcherP6, description,  \
+                         (#p0, #p1, #p2, #p3, #p4, #p5),      \
+                         (p0, p1, p2, p3, p4, p5))
+#define MATCHER_P7(name, p0, p1, p2, p3, p4, p5, p6, description) \
+  GMOCK_INTERNAL_MATCHER(name, name##MatcherP7, description,      \
+                         (#p0, #p1, #p2, #p3, #p4, #p5, #p6),     \
+                         (p0, p1, p2, p3, p4, p5, p6))
+#define MATCHER_P8(name, p0, p1, p2, p3, p4, p5, p6, p7, description) \
+  GMOCK_INTERNAL_MATCHER(name, name##MatcherP8, description,          \
+                         (#p0, #p1, #p2, #p3, #p4, #p5, #p6, #p7),    \
+                         (p0, p1, p2, p3, p4, p5, p6, p7))
+#define MATCHER_P9(name, p0, p1, p2, p3, p4, p5, p6, p7, p8, description) \
+  GMOCK_INTERNAL_MATCHER(name, name##MatcherP9, description,              \
+                         (#p0, #p1, #p2, #p3, #p4, #p5, #p6, #p7, #p8),   \
+                         (p0, p1, p2, p3, p4, p5, p6, p7, p8))
+#define MATCHER_P10(name, p0, p1, p2, p3, p4, p5, p6, p7, p8, p9, description) \
+  GMOCK_INTERNAL_MATCHER(name, name##MatcherP10, description,                  \
+                         (#p0, #p1, #p2, #p3, #p4, #p5, #p6, #p7, #p8, #p9),   \
+                         (p0, p1, p2, p3, p4, p5, p6, p7, p8, p9))
+
+#define GMOCK_INTERNAL_MATCHER(name, full_name, description, arg_names, args)  \
+  template <GMOCK_INTERNAL_MATCHER_TEMPLATE_PARAMS(args)>                      \
+  class full_name : public ::testing::internal::MatcherBaseImpl<               \
+                        full_name<GMOCK_INTERNAL_MATCHER_TYPE_PARAMS(args)>> { \
+   public:                                                                     \
+    using full_name::MatcherBaseImpl::MatcherBaseImpl;                         \
+    template <typename arg_type>                                               \
+    class gmock_Impl : public ::testing::MatcherInterface<const arg_type&> {   \
+     public:                                                                   \
+      explicit gmock_Impl(GMOCK_INTERNAL_MATCHER_FUNCTION_ARGS(args))          \
+          : GMOCK_INTERNAL_MATCHER_FORWARD_ARGS(args) {}                       \
+      bool MatchAndExplain(                                                    \
+          const arg_type& arg,                                                 \
+          ::testing::MatchResultListener* result_listener) const override;     \
+      void DescribeTo(::std::ostream* gmock_os) const override {               \
+        *gmock_os << FormatDescription(false);                                 \
+      }                                                                        \
+      void DescribeNegationTo(::std::ostream* gmock_os) const override {       \
+        *gmock_os << FormatDescription(true);                                  \
+      }                                                                        \
+      GMOCK_INTERNAL_MATCHER_MEMBERS(args)                                     \
+                                                                               \
+     private:                                                                  \
+      ::std::string FormatDescription(bool negation) const {                   \
+        ::std::string gmock_description;                                       \
+        gmock_description = (description);                                     \
+        if (!gmock_description.empty()) {                                      \
+          return gmock_description;                                            \
+        }                                                                      \
+        return ::testing::internal::FormatMatcherDescription(                  \
+            negation, #name, {GMOCK_PP_REMOVE_PARENS(arg_names)},              \
+            ::testing::internal::UniversalTersePrintTupleFieldsToStrings(      \
+                ::std::tuple<GMOCK_INTERNAL_MATCHER_TYPE_PARAMS(args)>(        \
+                    GMOCK_INTERNAL_MATCHER_MEMBERS_USAGE(args))));             \
+      }                                                                        \
+    };                                                                         \
+  };                                                                           \
+  template <GMOCK_INTERNAL_MATCHER_TEMPLATE_PARAMS(args)>                      \
+  inline full_name<GMOCK_INTERNAL_MATCHER_TYPE_PARAMS(args)> name(             \
+      GMOCK_INTERNAL_MATCHER_FUNCTION_ARGS(args)) {                            \
+    return full_name<GMOCK_INTERNAL_MATCHER_TYPE_PARAMS(args)>(                \
+        GMOCK_INTERNAL_MATCHER_ARGS_USAGE(args));                              \
+  }                                                                            \
+  template <GMOCK_INTERNAL_MATCHER_TEMPLATE_PARAMS(args)>                      \
+  template <typename arg_type>                                                 \
+  bool full_name<GMOCK_INTERNAL_MATCHER_TYPE_PARAMS(args)>::gmock_Impl<        \
+      arg_type>::MatchAndExplain(const arg_type& arg,                          \
+                                 ::testing::MatchResultListener*               \
+                                     result_listener GTEST_ATTRIBUTE_UNUSED_)  \
+      const
+
+#define GMOCK_INTERNAL_MATCHER_TEMPLATE_PARAMS(args) \
+  GMOCK_PP_TAIL(                                     \
+      GMOCK_PP_FOR_EACH(GMOCK_INTERNAL_MATCHER_TEMPLATE_PARAM, , args))
+#define GMOCK_INTERNAL_MATCHER_TEMPLATE_PARAM(i_unused, data_unused, arg) \
+  , typename arg##_type
+
+#define GMOCK_INTERNAL_MATCHER_TYPE_PARAMS(args) \
+  GMOCK_PP_TAIL(GMOCK_PP_FOR_EACH(GMOCK_INTERNAL_MATCHER_TYPE_PARAM, , args))
+#define GMOCK_INTERNAL_MATCHER_TYPE_PARAM(i_unused, data_unused, arg) \
+  , arg##_type
+
+#define GMOCK_INTERNAL_MATCHER_FUNCTION_ARGS(args) \
+  GMOCK_PP_TAIL(dummy_first GMOCK_PP_FOR_EACH(     \
+      GMOCK_INTERNAL_MATCHER_FUNCTION_ARG, , args))
+#define GMOCK_INTERNAL_MATCHER_FUNCTION_ARG(i, data_unused, arg) \
+  , arg##_type gmock_p##i
+
+#define GMOCK_INTERNAL_MATCHER_FORWARD_ARGS(args) \
+  GMOCK_PP_TAIL(GMOCK_PP_FOR_EACH(GMOCK_INTERNAL_MATCHER_FORWARD_ARG, , args))
+#define GMOCK_INTERNAL_MATCHER_FORWARD_ARG(i, data_unused, arg) \
+  , arg(::std::forward<arg##_type>(gmock_p##i))
+
+#define GMOCK_INTERNAL_MATCHER_MEMBERS(args) \
+  GMOCK_PP_FOR_EACH(GMOCK_INTERNAL_MATCHER_MEMBER, , args)
+#define GMOCK_INTERNAL_MATCHER_MEMBER(i_unused, data_unused, arg) \
+  const arg##_type arg;
+
+#define GMOCK_INTERNAL_MATCHER_MEMBERS_USAGE(args) \
+  GMOCK_PP_TAIL(GMOCK_PP_FOR_EACH(GMOCK_INTERNAL_MATCHER_MEMBER_USAGE, , args))
+#define GMOCK_INTERNAL_MATCHER_MEMBER_USAGE(i_unused, data_unused, arg) , arg
+
+#define GMOCK_INTERNAL_MATCHER_ARGS_USAGE(args) \
+  GMOCK_PP_TAIL(GMOCK_PP_FOR_EACH(GMOCK_INTERNAL_MATCHER_ARG_USAGE, , args))
+#define GMOCK_INTERNAL_MATCHER_ARG_USAGE(i, data_unused, arg_unused) \
+  , gmock_p##i
+
+// To prevent ADL on certain functions we put them on a separate namespace.
+using namespace no_adl;  // NOLINT
+
+}  // namespace testing
+
+GTEST_DISABLE_MSC_WARNINGS_POP_()  //  4251 5046
+
+// Include any custom callback matchers added by the local installation.
+// We must include this header at the end to make sure it can use the
+// declarations from this file.
+#include "gmock/internal/custom/gmock-matchers.h"
+
+#endif  // GOOGLEMOCK_INCLUDE_GMOCK_GMOCK_MATCHERS_H_

contrib/googletest/googlemock/include/gmock/gmock-more-actions.h

@@ -0,0 +1,658 @@
+// Copyright 2007, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+// Google Mock - a framework for writing C++ mock classes.
+//
+// This file implements some commonly used variadic actions.
+
+// IWYU pragma: private, include "gmock/gmock.h"
+// IWYU pragma: friend gmock/.*
+
+#ifndef GOOGLEMOCK_INCLUDE_GMOCK_GMOCK_MORE_ACTIONS_H_
+#define GOOGLEMOCK_INCLUDE_GMOCK_GMOCK_MORE_ACTIONS_H_
+
+#include <memory>
+#include <utility>
+
+#include "gmock/gmock-actions.h"
+#include "gmock/internal/gmock-port.h"
+
+// Include any custom callback actions added by the local installation.
+#include "gmock/internal/custom/gmock-generated-actions.h"
+
+// Sometimes you want to give an action explicit template parameters
+// that cannot be inferred from its value parameters.  ACTION() and
+// ACTION_P*() don't support that.  ACTION_TEMPLATE() remedies that
+// and can be viewed as an extension to ACTION() and ACTION_P*().
+//
+// The syntax:
+//
+//   ACTION_TEMPLATE(ActionName,
+//                   HAS_m_TEMPLATE_PARAMS(kind1, name1, ..., kind_m, name_m),
+//                   AND_n_VALUE_PARAMS(p1, ..., p_n)) { statements; }
+//
+// defines an action template that takes m explicit template
+// parameters and n value parameters.  name_i is the name of the i-th
+// template parameter, and kind_i specifies whether it's a typename,
+// an integral constant, or a template.  p_i is the name of the i-th
+// value parameter.
+//
+// Example:
+//
+//   // DuplicateArg<k, T>(output) converts the k-th argument of the mock
+//   // function to type T and copies it to *output.
+//   ACTION_TEMPLATE(DuplicateArg,
+//                   HAS_2_TEMPLATE_PARAMS(int, k, typename, T),
+//                   AND_1_VALUE_PARAMS(output)) {
+//     *output = T(::std::get<k>(args));
+//   }
+//   ...
+//     int n;
+//     EXPECT_CALL(mock, Foo(_, _))
+//         .WillOnce(DuplicateArg<1, unsigned char>(&n));
+//
+// To create an instance of an action template, write:
+//
+//   ActionName<t1, ..., t_m>(v1, ..., v_n)
+//
+// where the ts are the template arguments and the vs are the value
+// arguments.  The value argument types are inferred by the compiler.
+// If you want to explicitly specify the value argument types, you can
+// provide additional template arguments:
+//
+//   ActionName<t1, ..., t_m, u1, ..., u_k>(v1, ..., v_n)
+//
+// where u_i is the desired type of v_i.
+//
+// ACTION_TEMPLATE and ACTION/ACTION_P* can be overloaded on the
+// number of value parameters, but not on the number of template
+// parameters.  Without the restriction, the meaning of the following
+// is unclear:
+//
+//   OverloadedAction<int, bool>(x);
+//
+// Are we using a single-template-parameter action where 'bool' refers
+// to the type of x, or are we using a two-template-parameter action
+// where the compiler is asked to infer the type of x?
+//
+// Implementation notes:
+//
+// GMOCK_INTERNAL_*_HAS_m_TEMPLATE_PARAMS and
+// GMOCK_INTERNAL_*_AND_n_VALUE_PARAMS are internal macros for
+// implementing ACTION_TEMPLATE.  The main trick we use is to create
+// new macro invocations when expanding a macro.  For example, we have
+//
+//   #define ACTION_TEMPLATE(name, template_params, value_params)
+//       ... GMOCK_INTERNAL_DECL_##template_params ...
+//
+// which causes ACTION_TEMPLATE(..., HAS_1_TEMPLATE_PARAMS(typename, T), ...)
+// to expand to
+//
+//       ... GMOCK_INTERNAL_DECL_HAS_1_TEMPLATE_PARAMS(typename, T) ...
+//
+// Since GMOCK_INTERNAL_DECL_HAS_1_TEMPLATE_PARAMS is a macro, the
+// preprocessor will continue to expand it to
+//
+//       ... typename T ...
+//
+// This technique conforms to the C++ standard and is portable.  It
+// allows us to implement action templates using O(N) code, where N is
+// the maximum number of template/value parameters supported.  Without
+// using it, we'd have to devote O(N^2) amount of code to implement all
+// combinations of m and n.
+
+// Declares the template parameters.
+#define GMOCK_INTERNAL_DECL_HAS_1_TEMPLATE_PARAMS(kind0, name0) kind0 name0
+#define GMOCK_INTERNAL_DECL_HAS_2_TEMPLATE_PARAMS(kind0, name0, kind1, name1) \
+  kind0 name0, kind1 name1
+#define GMOCK_INTERNAL_DECL_HAS_3_TEMPLATE_PARAMS(kind0, name0, kind1, name1, \
+                                                  kind2, name2)               \
+  kind0 name0, kind1 name1, kind2 name2
+#define GMOCK_INTERNAL_DECL_HAS_4_TEMPLATE_PARAMS(kind0, name0, kind1, name1, \
+                                                  kind2, name2, kind3, name3) \
+  kind0 name0, kind1 name1, kind2 name2, kind3 name3
+#define GMOCK_INTERNAL_DECL_HAS_5_TEMPLATE_PARAMS(                        \
+    kind0, name0, kind1, name1, kind2, name2, kind3, name3, kind4, name4) \
+  kind0 name0, kind1 name1, kind2 name2, kind3 name3, kind4 name4
+#define GMOCK_INTERNAL_DECL_HAS_6_TEMPLATE_PARAMS(kind0, name0, kind1, name1, \
+                                                  kind2, name2, kind3, name3, \
+                                                  kind4, name4, kind5, name5) \
+  kind0 name0, kind1 name1, kind2 name2, kind3 name3, kind4 name4, kind5 name5
+#define GMOCK_INTERNAL_DECL_HAS_7_TEMPLATE_PARAMS(                        \
+    kind0, name0, kind1, name1, kind2, name2, kind3, name3, kind4, name4, \
+    kind5, name5, kind6, name6)                                           \
+  kind0 name0, kind1 name1, kind2 name2, kind3 name3, kind4 name4,        \
+      kind5 name5, kind6 name6
+#define GMOCK_INTERNAL_DECL_HAS_8_TEMPLATE_PARAMS(                        \
+    kind0, name0, kind1, name1, kind2, name2, kind3, name3, kind4, name4, \
+    kind5, name5, kind6, name6, kind7, name7)                             \
+  kind0 name0, kind1 name1, kind2 name2, kind3 name3, kind4 name4,        \
+      kind5 name5, kind6 name6, kind7 name7
+#define GMOCK_INTERNAL_DECL_HAS_9_TEMPLATE_PARAMS(                        \
+    kind0, name0, kind1, name1, kind2, name2, kind3, name3, kind4, name4, \
+    kind5, name5, kind6, name6, kind7, name7, kind8, name8)               \
+  kind0 name0, kind1 name1, kind2 name2, kind3 name3, kind4 name4,        \
+      kind5 name5, kind6 name6, kind7 name7, kind8 name8
+#define GMOCK_INTERNAL_DECL_HAS_10_TEMPLATE_PARAMS(                       \
+    kind0, name0, kind1, name1, kind2, name2, kind3, name3, kind4, name4, \
+    kind5, name5, kind6, name6, kind7, name7, kind8, name8, kind9, name9) \
+  kind0 name0, kind1 name1, kind2 name2, kind3 name3, kind4 name4,        \
+      kind5 name5, kind6 name6, kind7 name7, kind8 name8, kind9 name9
+
+// Lists the template parameters.
+#define GMOCK_INTERNAL_LIST_HAS_1_TEMPLATE_PARAMS(kind0, name0) name0
+#define GMOCK_INTERNAL_LIST_HAS_2_TEMPLATE_PARAMS(kind0, name0, kind1, name1) \
+  name0, name1
+#define GMOCK_INTERNAL_LIST_HAS_3_TEMPLATE_PARAMS(kind0, name0, kind1, name1, \
+                                                  kind2, name2)               \
+  name0, name1, name2
+#define GMOCK_INTERNAL_LIST_HAS_4_TEMPLATE_PARAMS(kind0, name0, kind1, name1, \
+                                                  kind2, name2, kind3, name3) \
+  name0, name1, name2, name3
+#define GMOCK_INTERNAL_LIST_HAS_5_TEMPLATE_PARAMS(                        \
+    kind0, name0, kind1, name1, kind2, name2, kind3, name3, kind4, name4) \
+  name0, name1, name2, name3, name4
+#define GMOCK_INTERNAL_LIST_HAS_6_TEMPLATE_PARAMS(kind0, name0, kind1, name1, \
+                                                  kind2, name2, kind3, name3, \
+                                                  kind4, name4, kind5, name5) \
+  name0, name1, name2, name3, name4, name5
+#define GMOCK_INTERNAL_LIST_HAS_7_TEMPLATE_PARAMS(                        \
+    kind0, name0, kind1, name1, kind2, name2, kind3, name3, kind4, name4, \
+    kind5, name5, kind6, name6)                                           \
+  name0, name1, name2, name3, name4, name5, name6
+#define GMOCK_INTERNAL_LIST_HAS_8_TEMPLATE_PARAMS(                        \
+    kind0, name0, kind1, name1, kind2, name2, kind3, name3, kind4, name4, \
+    kind5, name5, kind6, name6, kind7, name7)                             \
+  name0, name1, name2, name3, name4, name5, name6, name7
+#define GMOCK_INTERNAL_LIST_HAS_9_TEMPLATE_PARAMS(                        \
+    kind0, name0, kind1, name1, kind2, name2, kind3, name3, kind4, name4, \
+    kind5, name5, kind6, name6, kind7, name7, kind8, name8)               \
+  name0, name1, name2, name3, name4, name5, name6, name7, name8
+#define GMOCK_INTERNAL_LIST_HAS_10_TEMPLATE_PARAMS(                       \
+    kind0, name0, kind1, name1, kind2, name2, kind3, name3, kind4, name4, \
+    kind5, name5, kind6, name6, kind7, name7, kind8, name8, kind9, name9) \
+  name0, name1, name2, name3, name4, name5, name6, name7, name8, name9
+
+// Declares the types of value parameters.
+#define GMOCK_INTERNAL_DECL_TYPE_AND_0_VALUE_PARAMS()
+#define GMOCK_INTERNAL_DECL_TYPE_AND_1_VALUE_PARAMS(p0) , typename p0##_type
+#define GMOCK_INTERNAL_DECL_TYPE_AND_2_VALUE_PARAMS(p0, p1) \
+  , typename p0##_type, typename p1##_type
+#define GMOCK_INTERNAL_DECL_TYPE_AND_3_VALUE_PARAMS(p0, p1, p2) \
+  , typename p0##_type, typename p1##_type, typename p2##_type
+#define GMOCK_INTERNAL_DECL_TYPE_AND_4_VALUE_PARAMS(p0, p1, p2, p3) \
+  , typename p0##_type, typename p1##_type, typename p2##_type,     \
+      typename p3##_type
+#define GMOCK_INTERNAL_DECL_TYPE_AND_5_VALUE_PARAMS(p0, p1, p2, p3, p4) \
+  , typename p0##_type, typename p1##_type, typename p2##_type,         \
+      typename p3##_type, typename p4##_type
+#define GMOCK_INTERNAL_DECL_TYPE_AND_6_VALUE_PARAMS(p0, p1, p2, p3, p4, p5) \
+  , typename p0##_type, typename p1##_type, typename p2##_type,             \
+      typename p3##_type, typename p4##_type, typename p5##_type
+#define GMOCK_INTERNAL_DECL_TYPE_AND_7_VALUE_PARAMS(p0, p1, p2, p3, p4, p5, \
+                                                    p6)                     \
+  , typename p0##_type, typename p1##_type, typename p2##_type,             \
+      typename p3##_type, typename p4##_type, typename p5##_type,           \
+      typename p6##_type
+#define GMOCK_INTERNAL_DECL_TYPE_AND_8_VALUE_PARAMS(p0, p1, p2, p3, p4, p5, \
+                                                    p6, p7)                 \
+  , typename p0##_type, typename p1##_type, typename p2##_type,             \
+      typename p3##_type, typename p4##_type, typename p5##_type,           \
+      typename p6##_type, typename p7##_type
+#define GMOCK_INTERNAL_DECL_TYPE_AND_9_VALUE_PARAMS(p0, p1, p2, p3, p4, p5, \
+                                                    p6, p7, p8)             \
+  , typename p0##_type, typename p1##_type, typename p2##_type,             \
+      typename p3##_type, typename p4##_type, typename p5##_type,           \
+      typename p6##_type, typename p7##_type, typename p8##_type
+#define GMOCK_INTERNAL_DECL_TYPE_AND_10_VALUE_PARAMS(p0, p1, p2, p3, p4, p5, \
+                                                     p6, p7, p8, p9)         \
+  , typename p0##_type, typename p1##_type, typename p2##_type,              \
+      typename p3##_type, typename p4##_type, typename p5##_type,            \
+      typename p6##_type, typename p7##_type, typename p8##_type,            \
+      typename p9##_type
+
+// Initializes the value parameters.
+#define GMOCK_INTERNAL_INIT_AND_0_VALUE_PARAMS() ()
+#define GMOCK_INTERNAL_INIT_AND_1_VALUE_PARAMS(p0) \
+  (p0##_type gmock_p0) : p0(::std::move(gmock_p0))
+#define GMOCK_INTERNAL_INIT_AND_2_VALUE_PARAMS(p0, p1) \
+  (p0##_type gmock_p0, p1##_type gmock_p1)             \
+      : p0(::std::move(gmock_p0)), p1(::std::move(gmock_p1))
+#define GMOCK_INTERNAL_INIT_AND_3_VALUE_PARAMS(p0, p1, p2)     \
+  (p0##_type gmock_p0, p1##_type gmock_p1, p2##_type gmock_p2) \
+      : p0(::std::move(gmock_p0)),                             \
+        p1(::std::move(gmock_p1)),                             \
+        p2(::std::move(gmock_p2))
+#define GMOCK_INTERNAL_INIT_AND_4_VALUE_PARAMS(p0, p1, p2, p3) \
+  (p0##_type gmock_p0, p1##_type gmock_p1, p2##_type gmock_p2, \
+   p3##_type gmock_p3)                                         \
+      : p0(::std::move(gmock_p0)),                             \
+        p1(::std::move(gmock_p1)),                             \
+        p2(::std::move(gmock_p2)),                             \
+        p3(::std::move(gmock_p3))
+#define GMOCK_INTERNAL_INIT_AND_5_VALUE_PARAMS(p0, p1, p2, p3, p4) \
+  (p0##_type gmock_p0, p1##_type gmock_p1, p2##_type gmock_p2,     \
+   p3##_type gmock_p3, p4##_type gmock_p4)                         \
+      : p0(::std::move(gmock_p0)),                                 \
+        p1(::std::move(gmock_p1)),                                 \
+        p2(::std::move(gmock_p2)),                                 \
+        p3(::std::move(gmock_p3)),                                 \
+        p4(::std::move(gmock_p4))
+#define GMOCK_INTERNAL_INIT_AND_6_VALUE_PARAMS(p0, p1, p2, p3, p4, p5) \
+  (p0##_type gmock_p0, p1##_type gmock_p1, p2##_type gmock_p2,         \
+   p3##_type gmock_p3, p4##_type gmock_p4, p5##_type gmock_p5)         \
+      : p0(::std::move(gmock_p0)),                                     \
+        p1(::std::move(gmock_p1)),                                     \
+        p2(::std::move(gmock_p2)),                                     \
+        p3(::std::move(gmock_p3)),                                     \
+        p4(::std::move(gmock_p4)),                                     \
+        p5(::std::move(gmock_p5))
+#define GMOCK_INTERNAL_INIT_AND_7_VALUE_PARAMS(p0, p1, p2, p3, p4, p5, p6) \
+  (p0##_type gmock_p0, p1##_type gmock_p1, p2##_type gmock_p2,             \
+   p3##_type gmock_p3, p4##_type gmock_p4, p5##_type gmock_p5,             \
+   p6##_type gmock_p6)                                                     \
+      : p0(::std::move(gmock_p0)),                                         \
+        p1(::std::move(gmock_p1)),                                         \
+        p2(::std::move(gmock_p2)),                                         \
+        p3(::std::move(gmock_p3)),                                         \
+        p4(::std::move(gmock_p4)),                                         \
+        p5(::std::move(gmock_p5)),                                         \
+        p6(::std::move(gmock_p6))
+#define GMOCK_INTERNAL_INIT_AND_8_VALUE_PARAMS(p0, p1, p2, p3, p4, p5, p6, p7) \
+  (p0##_type gmock_p0, p1##_type gmock_p1, p2##_type gmock_p2,                 \
+   p3##_type gmock_p3, p4##_type gmock_p4, p5##_type gmock_p5,                 \
+   p6##_type gmock_p6, p7##_type gmock_p7)                                     \
+      : p0(::std::move(gmock_p0)),                                             \
+        p1(::std::move(gmock_p1)),                                             \
+        p2(::std::move(gmock_p2)),                                             \
+        p3(::std::move(gmock_p3)),                                             \
+        p4(::std::move(gmock_p4)),                                             \
+        p5(::std::move(gmock_p5)),                                             \
+        p6(::std::move(gmock_p6)),                                             \
+        p7(::std::move(gmock_p7))
+#define GMOCK_INTERNAL_INIT_AND_9_VALUE_PARAMS(p0, p1, p2, p3, p4, p5, p6, p7, \
+                                               p8)                             \
+  (p0##_type gmock_p0, p1##_type gmock_p1, p2##_type gmock_p2,                 \
+   p3##_type gmock_p3, p4##_type gmock_p4, p5##_type gmock_p5,                 \
+   p6##_type gmock_p6, p7##_type gmock_p7, p8##_type gmock_p8)                 \
+      : p0(::std::move(gmock_p0)),                                             \
+        p1(::std::move(gmock_p1)),                                             \
+        p2(::std::move(gmock_p2)),                                             \
+        p3(::std::move(gmock_p3)),                                             \
+        p4(::std::move(gmock_p4)),                                             \
+        p5(::std::move(gmock_p5)),                                             \
+        p6(::std::move(gmock_p6)),                                             \
+        p7(::std::move(gmock_p7)),                                             \
+        p8(::std::move(gmock_p8))
+#define GMOCK_INTERNAL_INIT_AND_10_VALUE_PARAMS(p0, p1, p2, p3, p4, p5, p6, \
+                                                p7, p8, p9)                 \
+  (p0##_type gmock_p0, p1##_type gmock_p1, p2##_type gmock_p2,              \
+   p3##_type gmock_p3, p4##_type gmock_p4, p5##_type gmock_p5,              \
+   p6##_type gmock_p6, p7##_type gmock_p7, p8##_type gmock_p8,              \
+   p9##_type gmock_p9)                                                      \
+      : p0(::std::move(gmock_p0)),                                          \
+        p1(::std::move(gmock_p1)),                                          \
+        p2(::std::move(gmock_p2)),                                          \
+        p3(::std::move(gmock_p3)),                                          \
+        p4(::std::move(gmock_p4)),                                          \
+        p5(::std::move(gmock_p5)),                                          \
+        p6(::std::move(gmock_p6)),                                          \
+        p7(::std::move(gmock_p7)),                                          \
+        p8(::std::move(gmock_p8)),                                          \
+        p9(::std::move(gmock_p9))
+
+// Defines the copy constructor
+#define GMOCK_INTERNAL_DEFN_COPY_AND_0_VALUE_PARAMS() \
+  {}  // Avoid https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82134
+#define GMOCK_INTERNAL_DEFN_COPY_AND_1_VALUE_PARAMS(...) = default;
+#define GMOCK_INTERNAL_DEFN_COPY_AND_2_VALUE_PARAMS(...) = default;
+#define GMOCK_INTERNAL_DEFN_COPY_AND_3_VALUE_PARAMS(...) = default;
+#define GMOCK_INTERNAL_DEFN_COPY_AND_4_VALUE_PARAMS(...) = default;
+#define GMOCK_INTERNAL_DEFN_COPY_AND_5_VALUE_PARAMS(...) = default;
+#define GMOCK_INTERNAL_DEFN_COPY_AND_6_VALUE_PARAMS(...) = default;
+#define GMOCK_INTERNAL_DEFN_COPY_AND_7_VALUE_PARAMS(...) = default;
+#define GMOCK_INTERNAL_DEFN_COPY_AND_8_VALUE_PARAMS(...) = default;
+#define GMOCK_INTERNAL_DEFN_COPY_AND_9_VALUE_PARAMS(...) = default;
+#define GMOCK_INTERNAL_DEFN_COPY_AND_10_VALUE_PARAMS(...) = default;
+
+// Declares the fields for storing the value parameters.
+#define GMOCK_INTERNAL_DEFN_AND_0_VALUE_PARAMS()
+#define GMOCK_INTERNAL_DEFN_AND_1_VALUE_PARAMS(p0) p0##_type p0;
+#define GMOCK_INTERNAL_DEFN_AND_2_VALUE_PARAMS(p0, p1) \
+  p0##_type p0;                                        \
+  p1##_type p1;
+#define GMOCK_INTERNAL_DEFN_AND_3_VALUE_PARAMS(p0, p1, p2) \
+  p0##_type p0;                                            \
+  p1##_type p1;                                            \
+  p2##_type p2;
+#define GMOCK_INTERNAL_DEFN_AND_4_VALUE_PARAMS(p0, p1, p2, p3) \
+  p0##_type p0;                                                \
+  p1##_type p1;                                                \
+  p2##_type p2;                                                \
+  p3##_type p3;
+#define GMOCK_INTERNAL_DEFN_AND_5_VALUE_PARAMS(p0, p1, p2, p3, p4) \
+  p0##_type p0;                                                    \
+  p1##_type p1;                                                    \
+  p2##_type p2;                                                    \
+  p3##_type p3;                                                    \
+  p4##_type p4;
+#define GMOCK_INTERNAL_DEFN_AND_6_VALUE_PARAMS(p0, p1, p2, p3, p4, p5) \
+  p0##_type p0;                                                        \
+  p1##_type p1;                                                        \
+  p2##_type p2;                                                        \
+  p3##_type p3;                                                        \
+  p4##_type p4;                                                        \
+  p5##_type p5;
+#define GMOCK_INTERNAL_DEFN_AND_7_VALUE_PARAMS(p0, p1, p2, p3, p4, p5, p6) \
+  p0##_type p0;                                                            \
+  p1##_type p1;                                                            \
+  p2##_type p2;                                                            \
+  p3##_type p3;                                                            \
+  p4##_type p4;                                                            \
+  p5##_type p5;                                                            \
+  p6##_type p6;
+#define GMOCK_INTERNAL_DEFN_AND_8_VALUE_PARAMS(p0, p1, p2, p3, p4, p5, p6, p7) \
+  p0##_type p0;                                                                \
+  p1##_type p1;                                                                \
+  p2##_type p2;                                                                \
+  p3##_type p3;                                                                \
+  p4##_type p4;                                                                \
+  p5##_type p5;                                                                \
+  p6##_type p6;                                                                \
+  p7##_type p7;
+#define GMOCK_INTERNAL_DEFN_AND_9_VALUE_PARAMS(p0, p1, p2, p3, p4, p5, p6, p7, \
+                                               p8)                             \
+  p0##_type p0;                                                                \
+  p1##_type p1;                                                                \
+  p2##_type p2;                                                                \
+  p3##_type p3;                                                                \
+  p4##_type p4;                                                                \
+  p5##_type p5;                                                                \
+  p6##_type p6;                                                                \
+  p7##_type p7;                                                                \
+  p8##_type p8;
+#define GMOCK_INTERNAL_DEFN_AND_10_VALUE_PARAMS(p0, p1, p2, p3, p4, p5, p6, \
+                                                p7, p8, p9)                 \
+  p0##_type p0;                                                             \
+  p1##_type p1;                                                             \
+  p2##_type p2;                                                             \
+  p3##_type p3;                                                             \
+  p4##_type p4;                                                             \
+  p5##_type p5;                                                             \
+  p6##_type p6;                                                             \
+  p7##_type p7;                                                             \
+  p8##_type p8;                                                             \
+  p9##_type p9;
+
+// Lists the value parameters.
+#define GMOCK_INTERNAL_LIST_AND_0_VALUE_PARAMS()
+#define GMOCK_INTERNAL_LIST_AND_1_VALUE_PARAMS(p0) p0
+#define GMOCK_INTERNAL_LIST_AND_2_VALUE_PARAMS(p0, p1) p0, p1
+#define GMOCK_INTERNAL_LIST_AND_3_VALUE_PARAMS(p0, p1, p2) p0, p1, p2
+#define GMOCK_INTERNAL_LIST_AND_4_VALUE_PARAMS(p0, p1, p2, p3) p0, p1, p2, p3
+#define GMOCK_INTERNAL_LIST_AND_5_VALUE_PARAMS(p0, p1, p2, p3, p4) \
+  p0, p1, p2, p3, p4
+#define GMOCK_INTERNAL_LIST_AND_6_VALUE_PARAMS(p0, p1, p2, p3, p4, p5) \
+  p0, p1, p2, p3, p4, p5
+#define GMOCK_INTERNAL_LIST_AND_7_VALUE_PARAMS(p0, p1, p2, p3, p4, p5, p6) \
+  p0, p1, p2, p3, p4, p5, p6
+#define GMOCK_INTERNAL_LIST_AND_8_VALUE_PARAMS(p0, p1, p2, p3, p4, p5, p6, p7) \
+  p0, p1, p2, p3, p4, p5, p6, p7
+#define GMOCK_INTERNAL_LIST_AND_9_VALUE_PARAMS(p0, p1, p2, p3, p4, p5, p6, p7, \
+                                               p8)                             \
+  p0, p1, p2, p3, p4, p5, p6, p7, p8
+#define GMOCK_INTERNAL_LIST_AND_10_VALUE_PARAMS(p0, p1, p2, p3, p4, p5, p6, \
+                                                p7, p8, p9)                 \
+  p0, p1, p2, p3, p4, p5, p6, p7, p8, p9
+
+// Lists the value parameter types.
+#define GMOCK_INTERNAL_LIST_TYPE_AND_0_VALUE_PARAMS()
+#define GMOCK_INTERNAL_LIST_TYPE_AND_1_VALUE_PARAMS(p0) , p0##_type
+#define GMOCK_INTERNAL_LIST_TYPE_AND_2_VALUE_PARAMS(p0, p1) \
+  , p0##_type, p1##_type
+#define GMOCK_INTERNAL_LIST_TYPE_AND_3_VALUE_PARAMS(p0, p1, p2) \
+  , p0##_type, p1##_type, p2##_type
+#define GMOCK_INTERNAL_LIST_TYPE_AND_4_VALUE_PARAMS(p0, p1, p2, p3) \
+  , p0##_type, p1##_type, p2##_type, p3##_type
+#define GMOCK_INTERNAL_LIST_TYPE_AND_5_VALUE_PARAMS(p0, p1, p2, p3, p4) \
+  , p0##_type, p1##_type, p2##_type, p3##_type, p4##_type
+#define GMOCK_INTERNAL_LIST_TYPE_AND_6_VALUE_PARAMS(p0, p1, p2, p3, p4, p5) \
+  , p0##_type, p1##_type, p2##_type, p3##_type, p4##_type, p5##_type
+#define GMOCK_INTERNAL_LIST_TYPE_AND_7_VALUE_PARAMS(p0, p1, p2, p3, p4, p5, \
+                                                    p6)                     \
+  , p0##_type, p1##_type, p2##_type, p3##_type, p4##_type, p5##_type, p6##_type
+#define GMOCK_INTERNAL_LIST_TYPE_AND_8_VALUE_PARAMS(p0, p1, p2, p3, p4, p5, \
+                                                    p6, p7)                 \
+  , p0##_type, p1##_type, p2##_type, p3##_type, p4##_type, p5##_type,       \
+      p6##_type, p7##_type
+#define GMOCK_INTERNAL_LIST_TYPE_AND_9_VALUE_PARAMS(p0, p1, p2, p3, p4, p5, \
+                                                    p6, p7, p8)             \
+  , p0##_type, p1##_type, p2##_type, p3##_type, p4##_type, p5##_type,       \
+      p6##_type, p7##_type, p8##_type
+#define GMOCK_INTERNAL_LIST_TYPE_AND_10_VALUE_PARAMS(p0, p1, p2, p3, p4, p5, \
+                                                     p6, p7, p8, p9)         \
+  , p0##_type, p1##_type, p2##_type, p3##_type, p4##_type, p5##_type,        \
+      p6##_type, p7##_type, p8##_type, p9##_type
+
+// Declares the value parameters.
+#define GMOCK_INTERNAL_DECL_AND_0_VALUE_PARAMS()
+#define GMOCK_INTERNAL_DECL_AND_1_VALUE_PARAMS(p0) p0##_type p0
+#define GMOCK_INTERNAL_DECL_AND_2_VALUE_PARAMS(p0, p1) \
+  p0##_type p0, p1##_type p1
+#define GMOCK_INTERNAL_DECL_AND_3_VALUE_PARAMS(p0, p1, p2) \
+  p0##_type p0, p1##_type p1, p2##_type p2
+#define GMOCK_INTERNAL_DECL_AND_4_VALUE_PARAMS(p0, p1, p2, p3) \
+  p0##_type p0, p1##_type p1, p2##_type p2, p3##_type p3
+#define GMOCK_INTERNAL_DECL_AND_5_VALUE_PARAMS(p0, p1, p2, p3, p4) \
+  p0##_type p0, p1##_type p1, p2##_type p2, p3##_type p3, p4##_type p4
+#define GMOCK_INTERNAL_DECL_AND_6_VALUE_PARAMS(p0, p1, p2, p3, p4, p5)  \
+  p0##_type p0, p1##_type p1, p2##_type p2, p3##_type p3, p4##_type p4, \
+      p5##_type p5
+#define GMOCK_INTERNAL_DECL_AND_7_VALUE_PARAMS(p0, p1, p2, p3, p4, p5, p6) \
+  p0##_type p0, p1##_type p1, p2##_type p2, p3##_type p3, p4##_type p4,    \
+      p5##_type p5, p6##_type p6
+#define GMOCK_INTERNAL_DECL_AND_8_VALUE_PARAMS(p0, p1, p2, p3, p4, p5, p6, p7) \
+  p0##_type p0, p1##_type p1, p2##_type p2, p3##_type p3, p4##_type p4,        \
+      p5##_type p5, p6##_type p6, p7##_type p7
+#define GMOCK_INTERNAL_DECL_AND_9_VALUE_PARAMS(p0, p1, p2, p3, p4, p5, p6, p7, \
+                                               p8)                             \
+  p0##_type p0, p1##_type p1, p2##_type p2, p3##_type p3, p4##_type p4,        \
+      p5##_type p5, p6##_type p6, p7##_type p7, p8##_type p8
+#define GMOCK_INTERNAL_DECL_AND_10_VALUE_PARAMS(p0, p1, p2, p3, p4, p5, p6, \
+                                                p7, p8, p9)                 \
+  p0##_type p0, p1##_type p1, p2##_type p2, p3##_type p3, p4##_type p4,     \
+      p5##_type p5, p6##_type p6, p7##_type p7, p8##_type p8, p9##_type p9
+
+// The suffix of the class template implementing the action template.
+#define GMOCK_INTERNAL_COUNT_AND_0_VALUE_PARAMS()
+#define GMOCK_INTERNAL_COUNT_AND_1_VALUE_PARAMS(p0) P
+#define GMOCK_INTERNAL_COUNT_AND_2_VALUE_PARAMS(p0, p1) P2
+#define GMOCK_INTERNAL_COUNT_AND_3_VALUE_PARAMS(p0, p1, p2) P3
+#define GMOCK_INTERNAL_COUNT_AND_4_VALUE_PARAMS(p0, p1, p2, p3) P4
+#define GMOCK_INTERNAL_COUNT_AND_5_VALUE_PARAMS(p0, p1, p2, p3, p4) P5
+#define GMOCK_INTERNAL_COUNT_AND_6_VALUE_PARAMS(p0, p1, p2, p3, p4, p5) P6
+#define GMOCK_INTERNAL_COUNT_AND_7_VALUE_PARAMS(p0, p1, p2, p3, p4, p5, p6) P7
+#define GMOCK_INTERNAL_COUNT_AND_8_VALUE_PARAMS(p0, p1, p2, p3, p4, p5, p6, \
+                                                p7)                         \
+  P8
+#define GMOCK_INTERNAL_COUNT_AND_9_VALUE_PARAMS(p0, p1, p2, p3, p4, p5, p6, \
+                                                p7, p8)                     \
+  P9
+#define GMOCK_INTERNAL_COUNT_AND_10_VALUE_PARAMS(p0, p1, p2, p3, p4, p5, p6, \
+                                                 p7, p8, p9)                 \
+  P10
+
+// The name of the class template implementing the action template.
+#define GMOCK_ACTION_CLASS_(name, value_params) \
+  GTEST_CONCAT_TOKEN_(name##Action, GMOCK_INTERNAL_COUNT_##value_params)
+
+#define ACTION_TEMPLATE(name, template_params, value_params)                   \
+  template <GMOCK_INTERNAL_DECL_##template_params                              \
+                GMOCK_INTERNAL_DECL_TYPE_##value_params>                       \
+  class GMOCK_ACTION_CLASS_(name, value_params) {                              \
+   public:                                                                     \
+    explicit GMOCK_ACTION_CLASS_(name, value_params)(                          \
+        GMOCK_INTERNAL_DECL_##value_params)                                    \
+        GMOCK_PP_IF(GMOCK_PP_IS_EMPTY(GMOCK_INTERNAL_COUNT_##value_params),    \
+                    = default;                                                 \
+                    ,                                                          \
+                    : impl_(std::make_shared<gmock_Impl>(                      \
+                        GMOCK_INTERNAL_LIST_##value_params)){})                \
+            GMOCK_ACTION_CLASS_(name, value_params)(const GMOCK_ACTION_CLASS_( \
+                name, value_params) &) noexcept GMOCK_INTERNAL_DEFN_COPY_      \
+        ##value_params                                                         \
+        GMOCK_ACTION_CLASS_(name, value_params)(GMOCK_ACTION_CLASS_(           \
+            name, value_params) &&) noexcept GMOCK_INTERNAL_DEFN_COPY_         \
+        ##value_params template <typename F>                                   \
+        operator ::testing::Action<F>() const {                                \
+      return GMOCK_PP_IF(                                                      \
+          GMOCK_PP_IS_EMPTY(GMOCK_INTERNAL_COUNT_##value_params),              \
+          (::testing::internal::MakeAction<F, gmock_Impl>()),                  \
+          (::testing::internal::MakeAction<F>(impl_)));                        \
+    }                                                                          \
+                                                                               \
+   private:                                                                    \
+    class gmock_Impl {                                                         \
+     public:                                                                   \
+      explicit gmock_Impl GMOCK_INTERNAL_INIT_##value_params {}                \
+      template <typename function_type, typename return_type,                  \
+                typename args_type, GMOCK_ACTION_TEMPLATE_ARGS_NAMES_>         \
+      return_type gmock_PerformImpl(GMOCK_ACTION_ARG_TYPES_AND_NAMES_) const;  \
+      GMOCK_INTERNAL_DEFN_##value_params                                       \
+    };                                                                         \
+    GMOCK_PP_IF(GMOCK_PP_IS_EMPTY(GMOCK_INTERNAL_COUNT_##value_params), ,      \
+                std::shared_ptr<const gmock_Impl> impl_;)                      \
+  };                                                                           \
+  template <GMOCK_INTERNAL_DECL_##template_params                              \
+                GMOCK_INTERNAL_DECL_TYPE_##value_params>                       \
+  GMOCK_ACTION_CLASS_(                                                         \
+      name, value_params)<GMOCK_INTERNAL_LIST_##template_params                \
+                              GMOCK_INTERNAL_LIST_TYPE_##value_params>         \
+      name(GMOCK_INTERNAL_DECL_##value_params) GTEST_MUST_USE_RESULT_;         \
+  template <GMOCK_INTERNAL_DECL_##template_params                              \
+                GMOCK_INTERNAL_DECL_TYPE_##value_params>                       \
+  inline GMOCK_ACTION_CLASS_(                                                  \
+      name, value_params)<GMOCK_INTERNAL_LIST_##template_params                \
+                              GMOCK_INTERNAL_LIST_TYPE_##value_params>         \
+  name(GMOCK_INTERNAL_DECL_##value_params) {                                   \
+    return GMOCK_ACTION_CLASS_(                                                \
+        name, value_params)<GMOCK_INTERNAL_LIST_##template_params              \
+                                GMOCK_INTERNAL_LIST_TYPE_##value_params>(      \
+        GMOCK_INTERNAL_LIST_##value_params);                                   \
+  }                                                                            \
+  template <GMOCK_INTERNAL_DECL_##template_params                              \
+                GMOCK_INTERNAL_DECL_TYPE_##value_params>                       \
+  template <typename function_type, typename return_type, typename args_type,  \
+            GMOCK_ACTION_TEMPLATE_ARGS_NAMES_>                                 \
+  return_type GMOCK_ACTION_CLASS_(                                             \
+      name, value_params)<GMOCK_INTERNAL_LIST_##template_params                \
+                              GMOCK_INTERNAL_LIST_TYPE_##value_params>::       \
+      gmock_Impl::gmock_PerformImpl(GMOCK_ACTION_ARG_TYPES_AND_NAMES_UNUSED_)  \
+          const
+
+namespace testing {
+
+// The ACTION*() macros trigger warning C4100 (unreferenced formal
+// parameter) in MSVC with -W4.  Unfortunately they cannot be fixed in
+// the macro definition, as the warnings are generated when the macro
+// is expanded and macro expansion cannot contain #pragma.  Therefore
+// we suppress them here.
+GTEST_DISABLE_MSC_WARNINGS_PUSH_(4100)
+
+namespace internal {
+
+// internal::InvokeArgument - a helper for InvokeArgument action.
+// The basic overloads are provided here for generic functors.
+// Overloads for other custom-callables are provided in the
+// internal/custom/gmock-generated-actions.h header.
+template <typename F, typename... Args>
+auto InvokeArgument(F f, Args... args) -> decltype(f(args...)) {
+  return f(args...);
+}
+
+template <std::size_t index, typename... Params>
+struct InvokeArgumentAction {
+  template <typename... Args,
+            typename = typename std::enable_if<(index < sizeof...(Args))>::type>
+  auto operator()(Args &&...args) const -> decltype(internal::InvokeArgument(
+      std::get<index>(std::forward_as_tuple(std::forward<Args>(args)...)),
+      std::declval<const Params &>()...)) {
+    internal::FlatTuple<Args &&...> args_tuple(FlatTupleConstructTag{},
+                                               std::forward<Args>(args)...);
+    return params.Apply([&](const Params &...unpacked_params) {
+      auto &&callable = args_tuple.template Get<index>();
+      return internal::InvokeArgument(
+          std::forward<decltype(callable)>(callable), unpacked_params...);
+    });
+  }
+
+  internal::FlatTuple<Params...> params;
+};
+
+}  // namespace internal
+
+// The InvokeArgument<N>(a1, a2, ..., a_k) action invokes the N-th
+// (0-based) argument, which must be a k-ary callable, of the mock
+// function, with arguments a1, a2, ..., a_k.
+//
+// Notes:
+//
+//   1. The arguments are passed by value by default.  If you need to
+//   pass an argument by reference, wrap it inside std::ref().  For
+//   example,
+//
+//     InvokeArgument<1>(5, string("Hello"), std::ref(foo))
+//
+//   passes 5 and string("Hello") by value, and passes foo by
+//   reference.
+//
+//   2. If the callable takes an argument by reference but std::ref() is
+//   not used, it will receive the reference to a copy of the value,
+//   instead of the original value.  For example, when the 0-th
+//   argument of the mock function takes a const string&, the action
+//
+//     InvokeArgument<0>(string("Hello"))
+//
+//   makes a copy of the temporary string("Hello") object and passes a
+//   reference of the copy, instead of the original temporary object,
+//   to the callable.  This makes it easy for a user to define an
+//   InvokeArgument action from temporary values and have it performed
+//   later.
+template <std::size_t index, typename... Params>
+internal::InvokeArgumentAction<index, typename std::decay<Params>::type...>
+InvokeArgument(Params &&...params) {
+  return {internal::FlatTuple<typename std::decay<Params>::type...>(
+      internal::FlatTupleConstructTag{}, std::forward<Params>(params)...)};
+}
+
+GTEST_DISABLE_MSC_WARNINGS_POP_()  // 4100
+
+}  // namespace testing
+
+#endif  // GOOGLEMOCK_INCLUDE_GMOCK_GMOCK_MORE_ACTIONS_H_

contrib/googletest/googlemock/include/gmock/gmock-more-matchers.h

@@ -0,0 +1,120 @@
+// Copyright 2013, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+// Google Mock - a framework for writing C++ mock classes.
+//
+// This file implements some matchers that depend on gmock-matchers.h.
+//
+// Note that tests are implemented in gmock-matchers_test.cc rather than
+// gmock-more-matchers-test.cc.
+
+// IWYU pragma: private, include "gmock/gmock.h"
+// IWYU pragma: friend gmock/.*
+
+#ifndef GOOGLEMOCK_INCLUDE_GMOCK_GMOCK_MORE_MATCHERS_H_
+#define GOOGLEMOCK_INCLUDE_GMOCK_GMOCK_MORE_MATCHERS_H_
+
+#include <ostream>
+#include <string>
+
+#include "gmock/gmock-matchers.h"
+
+namespace testing {
+
+// Silence C4100 (unreferenced formal
+// parameter) for MSVC
+GTEST_DISABLE_MSC_WARNINGS_PUSH_(4100)
+#if defined(_MSC_VER) && (_MSC_VER == 1900)
+// and silence C4800 (C4800: 'int *const ': forcing value
+// to bool 'true' or 'false') for MSVC 14
+GTEST_DISABLE_MSC_WARNINGS_PUSH_(4800)
+#endif
+
+namespace internal {
+
+// Implements the polymorphic IsEmpty matcher, which
+// can be used as a Matcher<T> as long as T is either a container that defines
+// empty() and size() (e.g. std::vector or std::string), or a C-style string.
+class IsEmptyMatcher {
+ public:
+  // Matches anything that defines empty() and size().
+  template <typename MatcheeContainerType>
+  bool MatchAndExplain(const MatcheeContainerType& c,
+                       MatchResultListener* listener) const {
+    if (c.empty()) {
+      return true;
+    }
+    *listener << "whose size is " << c.size();
+    return false;
+  }
+
+  // Matches C-style strings.
+  bool MatchAndExplain(const char* s, MatchResultListener* listener) const {
+    return MatchAndExplain(std::string(s), listener);
+  }
+
+  // Describes what this matcher matches.
+  void DescribeTo(std::ostream* os) const { *os << "is empty"; }
+
+  void DescribeNegationTo(std::ostream* os) const { *os << "isn't empty"; }
+};
+
+}  // namespace internal
+
+// Creates a polymorphic matcher that matches an empty container or C-style
+// string. The container must support both size() and empty(), which all
+// STL-like containers provide.
+inline PolymorphicMatcher<internal::IsEmptyMatcher> IsEmpty() {
+  return MakePolymorphicMatcher(internal::IsEmptyMatcher());
+}
+
+// Define a matcher that matches a value that evaluates in boolean
+// context to true.  Useful for types that define "explicit operator
+// bool" operators and so can't be compared for equality with true
+// and false.
+MATCHER(IsTrue, negation ? "is false" : "is true") {
+  return static_cast<bool>(arg);
+}
+
+// Define a matcher that matches a value that evaluates in boolean
+// context to false.  Useful for types that define "explicit operator
+// bool" operators and so can't be compared for equality with true
+// and false.
+MATCHER(IsFalse, negation ? "is true" : "is false") {
+  return !static_cast<bool>(arg);
+}
+
+#if defined(_MSC_VER) && (_MSC_VER == 1900)
+GTEST_DISABLE_MSC_WARNINGS_POP_()  // 4800
+#endif
+GTEST_DISABLE_MSC_WARNINGS_POP_()  // 4100
+
+}  // namespace testing
+
+#endif  // GOOGLEMOCK_INCLUDE_GMOCK_GMOCK_MORE_MATCHERS_H_

contrib/googletest/googlemock/include/gmock/gmock-nice-strict.h

@@ -0,0 +1,277 @@
+// Copyright 2008, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+// Implements class templates NiceMock, NaggyMock, and StrictMock.
+//
+// Given a mock class MockFoo that is created using Google Mock,
+// NiceMock<MockFoo> is a subclass of MockFoo that allows
+// uninteresting calls (i.e. calls to mock methods that have no
+// EXPECT_CALL specs), NaggyMock<MockFoo> is a subclass of MockFoo
+// that prints a warning when an uninteresting call occurs, and
+// StrictMock<MockFoo> is a subclass of MockFoo that treats all
+// uninteresting calls as errors.
+//
+// Currently a mock is naggy by default, so MockFoo and
+// NaggyMock<MockFoo> behave like the same.  However, we will soon
+// switch the default behavior of mocks to be nice, as that in general
+// leads to more maintainable tests.  When that happens, MockFoo will
+// stop behaving like NaggyMock<MockFoo> and start behaving like
+// NiceMock<MockFoo>.
+//
+// NiceMock, NaggyMock, and StrictMock "inherit" the constructors of
+// their respective base class.  Therefore you can write
+// NiceMock<MockFoo>(5, "a") to construct a nice mock where MockFoo
+// has a constructor that accepts (int, const char*), for example.
+//
+// A known limitation is that NiceMock<MockFoo>, NaggyMock<MockFoo>,
+// and StrictMock<MockFoo> only works for mock methods defined using
+// the MOCK_METHOD* family of macros DIRECTLY in the MockFoo class.
+// If a mock method is defined in a base class of MockFoo, the "nice"
+// or "strict" modifier may not affect it, depending on the compiler.
+// In particular, nesting NiceMock, NaggyMock, and StrictMock is NOT
+// supported.
+
+// IWYU pragma: private, include "gmock/gmock.h"
+// IWYU pragma: friend gmock/.*
+
+#ifndef GOOGLEMOCK_INCLUDE_GMOCK_GMOCK_NICE_STRICT_H_
+#define GOOGLEMOCK_INCLUDE_GMOCK_GMOCK_NICE_STRICT_H_
+
+#include <cstdint>
+#include <type_traits>
+
+#include "gmock/gmock-spec-builders.h"
+#include "gmock/internal/gmock-port.h"
+
+namespace testing {
+template <class MockClass>
+class NiceMock;
+template <class MockClass>
+class NaggyMock;
+template <class MockClass>
+class StrictMock;
+
+namespace internal {
+template <typename T>
+std::true_type StrictnessModifierProbe(const NiceMock<T>&);
+template <typename T>
+std::true_type StrictnessModifierProbe(const NaggyMock<T>&);
+template <typename T>
+std::true_type StrictnessModifierProbe(const StrictMock<T>&);
+std::false_type StrictnessModifierProbe(...);
+
+template <typename T>
+constexpr bool HasStrictnessModifier() {
+  return decltype(StrictnessModifierProbe(std::declval<const T&>()))::value;
+}
+
+// Base classes that register and deregister with testing::Mock to alter the
+// default behavior around uninteresting calls. Inheriting from one of these
+// classes first and then MockClass ensures the MockClass constructor is run
+// after registration, and that the MockClass destructor runs before
+// deregistration. This guarantees that MockClass's constructor and destructor
+// run with the same level of strictness as its instance methods.
+
+#if defined(GTEST_OS_WINDOWS) && !defined(GTEST_OS_WINDOWS_MINGW) && \
+    (defined(_MSC_VER) || defined(__clang__))
+// We need to mark these classes with this declspec to ensure that
+// the empty base class optimization is performed.
+#define GTEST_INTERNAL_EMPTY_BASE_CLASS __declspec(empty_bases)
+#else
+#define GTEST_INTERNAL_EMPTY_BASE_CLASS
+#endif
+
+template <typename Base>
+class NiceMockImpl {
+ public:
+  NiceMockImpl() {
+    ::testing::Mock::AllowUninterestingCalls(reinterpret_cast<uintptr_t>(this));
+  }
+
+  ~NiceMockImpl() {
+    ::testing::Mock::UnregisterCallReaction(reinterpret_cast<uintptr_t>(this));
+  }
+};
+
+template <typename Base>
+class NaggyMockImpl {
+ public:
+  NaggyMockImpl() {
+    ::testing::Mock::WarnUninterestingCalls(reinterpret_cast<uintptr_t>(this));
+  }
+
+  ~NaggyMockImpl() {
+    ::testing::Mock::UnregisterCallReaction(reinterpret_cast<uintptr_t>(this));
+  }
+};
+
+template <typename Base>
+class StrictMockImpl {
+ public:
+  StrictMockImpl() {
+    ::testing::Mock::FailUninterestingCalls(reinterpret_cast<uintptr_t>(this));
+  }
+
+  ~StrictMockImpl() {
+    ::testing::Mock::UnregisterCallReaction(reinterpret_cast<uintptr_t>(this));
+  }
+};
+
+}  // namespace internal
+
+template <class MockClass>
+class GTEST_INTERNAL_EMPTY_BASE_CLASS NiceMock
+    : private internal::NiceMockImpl<MockClass>,
+      public MockClass {
+ public:
+  static_assert(!internal::HasStrictnessModifier<MockClass>(),
+                "Can't apply NiceMock to a class hierarchy that already has a "
+                "strictness modifier. See "
+                "https://google.github.io/googletest/"
+                "gmock_cook_book.html#NiceStrictNaggy");
+  NiceMock() : MockClass() {
+    static_assert(sizeof(*this) == sizeof(MockClass),
+                  "The impl subclass shouldn't introduce any padding");
+  }
+
+  // Ideally, we would inherit base class's constructors through a using
+  // declaration, which would preserve their visibility. However, many existing
+  // tests rely on the fact that current implementation reexports protected
+  // constructors as public. These tests would need to be cleaned up first.
+
+  // Single argument constructor is special-cased so that it can be
+  // made explicit.
+  template <typename A>
+  explicit NiceMock(A&& arg) : MockClass(std::forward<A>(arg)) {
+    static_assert(sizeof(*this) == sizeof(MockClass),
+                  "The impl subclass shouldn't introduce any padding");
+  }
+
+  template <typename TArg1, typename TArg2, typename... An>
+  NiceMock(TArg1&& arg1, TArg2&& arg2, An&&... args)
+      : MockClass(std::forward<TArg1>(arg1), std::forward<TArg2>(arg2),
+                  std::forward<An>(args)...) {
+    static_assert(sizeof(*this) == sizeof(MockClass),
+                  "The impl subclass shouldn't introduce any padding");
+  }
+
+ private:
+  NiceMock(const NiceMock&) = delete;
+  NiceMock& operator=(const NiceMock&) = delete;
+};
+
+template <class MockClass>
+class GTEST_INTERNAL_EMPTY_BASE_CLASS NaggyMock
+    : private internal::NaggyMockImpl<MockClass>,
+      public MockClass {
+  static_assert(!internal::HasStrictnessModifier<MockClass>(),
+                "Can't apply NaggyMock to a class hierarchy that already has a "
+                "strictness modifier. See "
+                "https://google.github.io/googletest/"
+                "gmock_cook_book.html#NiceStrictNaggy");
+
+ public:
+  NaggyMock() : MockClass() {
+    static_assert(sizeof(*this) == sizeof(MockClass),
+                  "The impl subclass shouldn't introduce any padding");
+  }
+
+  // Ideally, we would inherit base class's constructors through a using
+  // declaration, which would preserve their visibility. However, many existing
+  // tests rely on the fact that current implementation reexports protected
+  // constructors as public. These tests would need to be cleaned up first.
+
+  // Single argument constructor is special-cased so that it can be
+  // made explicit.
+  template <typename A>
+  explicit NaggyMock(A&& arg) : MockClass(std::forward<A>(arg)) {
+    static_assert(sizeof(*this) == sizeof(MockClass),
+                  "The impl subclass shouldn't introduce any padding");
+  }
+
+  template <typename TArg1, typename TArg2, typename... An>
+  NaggyMock(TArg1&& arg1, TArg2&& arg2, An&&... args)
+      : MockClass(std::forward<TArg1>(arg1), std::forward<TArg2>(arg2),
+                  std::forward<An>(args)...) {
+    static_assert(sizeof(*this) == sizeof(MockClass),
+                  "The impl subclass shouldn't introduce any padding");
+  }
+
+ private:
+  NaggyMock(const NaggyMock&) = delete;
+  NaggyMock& operator=(const NaggyMock&) = delete;
+};
+
+template <class MockClass>
+class GTEST_INTERNAL_EMPTY_BASE_CLASS StrictMock
+    : private internal::StrictMockImpl<MockClass>,
+      public MockClass {
+ public:
+  static_assert(
+      !internal::HasStrictnessModifier<MockClass>(),
+      "Can't apply StrictMock to a class hierarchy that already has a "
+      "strictness modifier. See "
+      "https://google.github.io/googletest/"
+      "gmock_cook_book.html#NiceStrictNaggy");
+  StrictMock() : MockClass() {
+    static_assert(sizeof(*this) == sizeof(MockClass),
+                  "The impl subclass shouldn't introduce any padding");
+  }
+
+  // Ideally, we would inherit base class's constructors through a using
+  // declaration, which would preserve their visibility. However, many existing
+  // tests rely on the fact that current implementation reexports protected
+  // constructors as public. These tests would need to be cleaned up first.
+
+  // Single argument constructor is special-cased so that it can be
+  // made explicit.
+  template <typename A>
+  explicit StrictMock(A&& arg) : MockClass(std::forward<A>(arg)) {
+    static_assert(sizeof(*this) == sizeof(MockClass),
+                  "The impl subclass shouldn't introduce any padding");
+  }
+
+  template <typename TArg1, typename TArg2, typename... An>
+  StrictMock(TArg1&& arg1, TArg2&& arg2, An&&... args)
+      : MockClass(std::forward<TArg1>(arg1), std::forward<TArg2>(arg2),
+                  std::forward<An>(args)...) {
+    static_assert(sizeof(*this) == sizeof(MockClass),
+                  "The impl subclass shouldn't introduce any padding");
+  }
+
+ private:
+  StrictMock(const StrictMock&) = delete;
+  StrictMock& operator=(const StrictMock&) = delete;
+};
+
+#undef GTEST_INTERNAL_EMPTY_BASE_CLASS
+
+}  // namespace testing
+
+#endif  // GOOGLEMOCK_INCLUDE_GMOCK_GMOCK_NICE_STRICT_H_

contrib/googletest/googlemock/include/gmock/gmock-spec-builders.h

@@ -0,0 +1,2148 @@
+// Copyright 2007, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+// Google Mock - a framework for writing C++ mock classes.
+//
+// This file implements the ON_CALL() and EXPECT_CALL() macros.
+//
+// A user can use the ON_CALL() macro to specify the default action of
+// a mock method.  The syntax is:
+//
+//   ON_CALL(mock_object, Method(argument-matchers))
+//       .With(multi-argument-matcher)
+//       .WillByDefault(action);
+//
+//  where the .With() clause is optional.
+//
+// A user can use the EXPECT_CALL() macro to specify an expectation on
+// a mock method.  The syntax is:
+//
+//   EXPECT_CALL(mock_object, Method(argument-matchers))
+//       .With(multi-argument-matchers)
+//       .Times(cardinality)
+//       .InSequence(sequences)
+//       .After(expectations)
+//       .WillOnce(action)
+//       .WillRepeatedly(action)
+//       .RetiresOnSaturation();
+//
+// where all clauses are optional, and .InSequence()/.After()/
+// .WillOnce() can appear any number of times.
+
+// IWYU pragma: private, include "gmock/gmock.h"
+// IWYU pragma: friend gmock/.*
+
+#ifndef GOOGLEMOCK_INCLUDE_GMOCK_GMOCK_SPEC_BUILDERS_H_
+#define GOOGLEMOCK_INCLUDE_GMOCK_GMOCK_SPEC_BUILDERS_H_
+
+#include <cstdint>
+#include <functional>
+#include <map>
+#include <memory>
+#include <ostream>
+#include <set>
+#include <sstream>
+#include <string>
+#include <type_traits>
+#include <utility>
+#include <vector>
+
+#include "gmock/gmock-actions.h"
+#include "gmock/gmock-cardinalities.h"
+#include "gmock/gmock-matchers.h"
+#include "gmock/internal/gmock-internal-utils.h"
+#include "gmock/internal/gmock-port.h"
+#include "gtest/gtest.h"
+
+#if GTEST_HAS_EXCEPTIONS
+#include <stdexcept>  // NOLINT
+#endif
+
+GTEST_DISABLE_MSC_WARNINGS_PUSH_(4251 \
+/* class A needs to have dll-interface to be used by clients of class B */)
+
+namespace testing {
+
+// An abstract handle of an expectation.
+class Expectation;
+
+// A set of expectation handles.
+class ExpectationSet;
+
+// Anything inside the 'internal' namespace IS INTERNAL IMPLEMENTATION
+// and MUST NOT BE USED IN USER CODE!!!
+namespace internal {
+
+// Implements a mock function.
+template <typename F>
+class FunctionMocker;
+
+// Base class for expectations.
+class ExpectationBase;
+
+// Implements an expectation.
+template <typename F>
+class TypedExpectation;
+
+// Helper class for testing the Expectation class template.
+class ExpectationTester;
+
+// Helper classes for implementing NiceMock, StrictMock, and NaggyMock.
+template <typename MockClass>
+class NiceMockImpl;
+template <typename MockClass>
+class StrictMockImpl;
+template <typename MockClass>
+class NaggyMockImpl;
+
+// Protects the mock object registry (in class Mock), all function
+// mockers, and all expectations.
+//
+// The reason we don't use more fine-grained protection is: when a
+// mock function Foo() is called, it needs to consult its expectations
+// to see which one should be picked.  If another thread is allowed to
+// call a mock function (either Foo() or a different one) at the same
+// time, it could affect the "retired" attributes of Foo()'s
+// expectations when InSequence() is used, and thus affect which
+// expectation gets picked.  Therefore, we sequence all mock function
+// calls to ensure the integrity of the mock objects' states.
+GTEST_API_ GTEST_DECLARE_STATIC_MUTEX_(g_gmock_mutex);
+
+// Abstract base class of FunctionMocker.  This is the
+// type-agnostic part of the function mocker interface.  Its pure
+// virtual methods are implemented by FunctionMocker.
+class GTEST_API_ UntypedFunctionMockerBase {
+ public:
+  UntypedFunctionMockerBase();
+  virtual ~UntypedFunctionMockerBase();
+
+  // Verifies that all expectations on this mock function have been
+  // satisfied.  Reports one or more Google Test non-fatal failures
+  // and returns false if not.
+  bool VerifyAndClearExpectationsLocked()
+      GTEST_EXCLUSIVE_LOCK_REQUIRED_(g_gmock_mutex);
+
+  // Clears the ON_CALL()s set on this mock function.
+  virtual void ClearDefaultActionsLocked()
+      GTEST_EXCLUSIVE_LOCK_REQUIRED_(g_gmock_mutex) = 0;
+
+  // In all of the following Untyped* functions, it's the caller's
+  // responsibility to guarantee the correctness of the arguments'
+  // types.
+
+  // Writes a message that the call is uninteresting (i.e. neither
+  // explicitly expected nor explicitly unexpected) to the given
+  // ostream.
+  virtual void UntypedDescribeUninterestingCall(const void* untyped_args,
+                                                ::std::ostream* os) const
+      GTEST_LOCK_EXCLUDED_(g_gmock_mutex) = 0;
+
+  // Returns the expectation that matches the given function arguments
+  // (or NULL is there's no match); when a match is found,
+  // untyped_action is set to point to the action that should be
+  // performed (or NULL if the action is "do default"), and
+  // is_excessive is modified to indicate whether the call exceeds the
+  // expected number.
+  virtual const ExpectationBase* UntypedFindMatchingExpectation(
+      const void* untyped_args, const void** untyped_action, bool* is_excessive,
+      ::std::ostream* what, ::std::ostream* why)
+      GTEST_LOCK_EXCLUDED_(g_gmock_mutex) = 0;
+
+  // Prints the given function arguments to the ostream.
+  virtual void UntypedPrintArgs(const void* untyped_args,
+                                ::std::ostream* os) const = 0;
+
+  // Sets the mock object this mock method belongs to, and registers
+  // this information in the global mock registry.  Will be called
+  // whenever an EXPECT_CALL() or ON_CALL() is executed on this mock
+  // method.
+  void RegisterOwner(const void* mock_obj) GTEST_LOCK_EXCLUDED_(g_gmock_mutex);
+
+  // Sets the mock object this mock method belongs to, and sets the
+  // name of the mock function.  Will be called upon each invocation
+  // of this mock function.
+  void SetOwnerAndName(const void* mock_obj, const char* name)
+      GTEST_LOCK_EXCLUDED_(g_gmock_mutex);
+
+  // Returns the mock object this mock method belongs to.  Must be
+  // called after RegisterOwner() or SetOwnerAndName() has been
+  // called.
+  const void* MockObject() const GTEST_LOCK_EXCLUDED_(g_gmock_mutex);
+
+  // Returns the name of this mock method.  Must be called after
+  // SetOwnerAndName() has been called.
+  const char* Name() const GTEST_LOCK_EXCLUDED_(g_gmock_mutex);
+
+ protected:
+  typedef std::vector<const void*> UntypedOnCallSpecs;
+
+  using UntypedExpectations = std::vector<std::shared_ptr<ExpectationBase>>;
+
+  struct UninterestingCallCleanupHandler;
+  struct FailureCleanupHandler;
+
+  // Returns an Expectation object that references and co-owns exp,
+  // which must be an expectation on this mock function.
+  Expectation GetHandleOf(ExpectationBase* exp);
+
+  // Address of the mock object this mock method belongs to.  Only
+  // valid after this mock method has been called or
+  // ON_CALL/EXPECT_CALL has been invoked on it.
+  const void* mock_obj_;  // Protected by g_gmock_mutex.
+
+  // Name of the function being mocked.  Only valid after this mock
+  // method has been called.
+  const char* name_;  // Protected by g_gmock_mutex.
+
+  // All default action specs for this function mocker.
+  UntypedOnCallSpecs untyped_on_call_specs_;
+
+  // All expectations for this function mocker.
+  //
+  // It's undefined behavior to interleave expectations (EXPECT_CALLs
+  // or ON_CALLs) and mock function calls.  Also, the order of
+  // expectations is important.  Therefore it's a logic race condition
+  // to read/write untyped_expectations_ concurrently.  In order for
+  // tools like tsan to catch concurrent read/write accesses to
+  // untyped_expectations, we deliberately leave accesses to it
+  // unprotected.
+  UntypedExpectations untyped_expectations_;
+};  // class UntypedFunctionMockerBase
+
+// Untyped base class for OnCallSpec<F>.
+class UntypedOnCallSpecBase {
+ public:
+  // The arguments are the location of the ON_CALL() statement.
+  UntypedOnCallSpecBase(const char* a_file, int a_line)
+      : file_(a_file), line_(a_line), last_clause_(kNone) {}
+
+  // Where in the source file was the default action spec defined?
+  const char* file() const { return file_; }
+  int line() const { return line_; }
+
+ protected:
+  // Gives each clause in the ON_CALL() statement a name.
+  enum Clause {
+    // Do not change the order of the enum members!  The run-time
+    // syntax checking relies on it.
+    kNone,
+    kWith,
+    kWillByDefault
+  };
+
+  // Asserts that the ON_CALL() statement has a certain property.
+  void AssertSpecProperty(bool property,
+                          const std::string& failure_message) const {
+    Assert(property, file_, line_, failure_message);
+  }
+
+  // Expects that the ON_CALL() statement has a certain property.
+  void ExpectSpecProperty(bool property,
+                          const std::string& failure_message) const {
+    Expect(property, file_, line_, failure_message);
+  }
+
+  const char* file_;
+  int line_;
+
+  // The last clause in the ON_CALL() statement as seen so far.
+  // Initially kNone and changes as the statement is parsed.
+  Clause last_clause_;
+};  // class UntypedOnCallSpecBase
+
+// This template class implements an ON_CALL spec.
+template <typename F>
+class OnCallSpec : public UntypedOnCallSpecBase {
+ public:
+  typedef typename Function<F>::ArgumentTuple ArgumentTuple;
+  typedef typename Function<F>::ArgumentMatcherTuple ArgumentMatcherTuple;
+
+  // Constructs an OnCallSpec object from the information inside
+  // the parenthesis of an ON_CALL() statement.
+  OnCallSpec(const char* a_file, int a_line,
+             const ArgumentMatcherTuple& matchers)
+      : UntypedOnCallSpecBase(a_file, a_line),
+        matchers_(matchers),
+        // By default, extra_matcher_ should match anything.  However,
+        // we cannot initialize it with _ as that causes ambiguity between
+        // Matcher's copy and move constructor for some argument types.
+        extra_matcher_(A<const ArgumentTuple&>()) {}
+
+  // Implements the .With() clause.
+  OnCallSpec& With(const Matcher<const ArgumentTuple&>& m) {
+    // Makes sure this is called at most once.
+    ExpectSpecProperty(last_clause_ < kWith,
+                       ".With() cannot appear "
+                       "more than once in an ON_CALL().");
+    last_clause_ = kWith;
+
+    extra_matcher_ = m;
+    return *this;
+  }
+
+  // Implements the .WillByDefault() clause.
+  OnCallSpec& WillByDefault(const Action<F>& action) {
+    ExpectSpecProperty(last_clause_ < kWillByDefault,
+                       ".WillByDefault() must appear "
+                       "exactly once in an ON_CALL().");
+    last_clause_ = kWillByDefault;
+
+    ExpectSpecProperty(!action.IsDoDefault(),
+                       "DoDefault() cannot be used in ON_CALL().");
+    action_ = action;
+    return *this;
+  }
+
+  // Returns true if and only if the given arguments match the matchers.
+  bool Matches(const ArgumentTuple& args) const {
+    return TupleMatches(matchers_, args) && extra_matcher_.Matches(args);
+  }
+
+  // Returns the action specified by the user.
+  const Action<F>& GetAction() const {
+    AssertSpecProperty(last_clause_ == kWillByDefault,
+                       ".WillByDefault() must appear exactly "
+                       "once in an ON_CALL().");
+    return action_;
+  }
+
+ private:
+  // The information in statement
+  //
+  //   ON_CALL(mock_object, Method(matchers))
+  //       .With(multi-argument-matcher)
+  //       .WillByDefault(action);
+  //
+  // is recorded in the data members like this:
+  //
+  //   source file that contains the statement => file_
+  //   line number of the statement            => line_
+  //   matchers                                => matchers_
+  //   multi-argument-matcher                  => extra_matcher_
+  //   action                                  => action_
+  ArgumentMatcherTuple matchers_;
+  Matcher<const ArgumentTuple&> extra_matcher_;
+  Action<F> action_;
+};  // class OnCallSpec
+
+// Possible reactions on uninteresting calls.
+enum CallReaction {
+  kAllow,
+  kWarn,
+  kFail,
+};
+
+}  // namespace internal
+
+// Utilities for manipulating mock objects.
+class GTEST_API_ Mock {
+ public:
+  // The following public methods can be called concurrently.
+
+  // Tells Google Mock to ignore mock_obj when checking for leaked
+  // mock objects.
+  static void AllowLeak(const void* mock_obj)
+      GTEST_LOCK_EXCLUDED_(internal::g_gmock_mutex);
+
+  // Verifies and clears all expectations on the given mock object.
+  // If the expectations aren't satisfied, generates one or more
+  // Google Test non-fatal failures and returns false.
+  static bool VerifyAndClearExpectations(void* mock_obj)
+      GTEST_LOCK_EXCLUDED_(internal::g_gmock_mutex);
+
+  // Verifies all expectations on the given mock object and clears its
+  // default actions and expectations.  Returns true if and only if the
+  // verification was successful.
+  static bool VerifyAndClear(void* mock_obj)
+      GTEST_LOCK_EXCLUDED_(internal::g_gmock_mutex);
+
+  // Returns whether the mock was created as a naggy mock (default)
+  static bool IsNaggy(void* mock_obj)
+      GTEST_LOCK_EXCLUDED_(internal::g_gmock_mutex);
+  // Returns whether the mock was created as a nice mock
+  static bool IsNice(void* mock_obj)
+      GTEST_LOCK_EXCLUDED_(internal::g_gmock_mutex);
+  // Returns whether the mock was created as a strict mock
+  static bool IsStrict(void* mock_obj)
+      GTEST_LOCK_EXCLUDED_(internal::g_gmock_mutex);
+
+ private:
+  friend class internal::UntypedFunctionMockerBase;
+
+  // Needed for a function mocker to register itself (so that we know
+  // how to clear a mock object).
+  template <typename F>
+  friend class internal::FunctionMocker;
+
+  template <typename MockClass>
+  friend class internal::NiceMockImpl;
+  template <typename MockClass>
+  friend class internal::NaggyMockImpl;
+  template <typename MockClass>
+  friend class internal::StrictMockImpl;
+
+  // Tells Google Mock to allow uninteresting calls on the given mock
+  // object.
+  static void AllowUninterestingCalls(uintptr_t mock_obj)
+      GTEST_LOCK_EXCLUDED_(internal::g_gmock_mutex);
+
+  // Tells Google Mock to warn the user about uninteresting calls on
+  // the given mock object.
+  static void WarnUninterestingCalls(uintptr_t mock_obj)
+      GTEST_LOCK_EXCLUDED_(internal::g_gmock_mutex);
+
+  // Tells Google Mock to fail uninteresting calls on the given mock
+  // object.
+  static void FailUninterestingCalls(uintptr_t mock_obj)
+      GTEST_LOCK_EXCLUDED_(internal::g_gmock_mutex);
+
+  // Tells Google Mock the given mock object is being destroyed and
+  // its entry in the call-reaction table should be removed.
+  static void UnregisterCallReaction(uintptr_t mock_obj)
+      GTEST_LOCK_EXCLUDED_(internal::g_gmock_mutex);
+
+  // Returns the reaction Google Mock will have on uninteresting calls
+  // made on the given mock object.
+  static internal::CallReaction GetReactionOnUninterestingCalls(
+      const void* mock_obj) GTEST_LOCK_EXCLUDED_(internal::g_gmock_mutex);
+
+  // Verifies that all expectations on the given mock object have been
+  // satisfied.  Reports one or more Google Test non-fatal failures
+  // and returns false if not.
+  static bool VerifyAndClearExpectationsLocked(void* mock_obj)
+      GTEST_EXCLUSIVE_LOCK_REQUIRED_(internal::g_gmock_mutex);
+
+  // Clears all ON_CALL()s set on the given mock object.
+  static void ClearDefaultActionsLocked(void* mock_obj)
+      GTEST_EXCLUSIVE_LOCK_REQUIRED_(internal::g_gmock_mutex);
+
+  // Registers a mock object and a mock method it owns.
+  static void Register(const void* mock_obj,
+                       internal::UntypedFunctionMockerBase* mocker)
+      GTEST_LOCK_EXCLUDED_(internal::g_gmock_mutex);
+
+  // Tells Google Mock where in the source code mock_obj is used in an
+  // ON_CALL or EXPECT_CALL.  In case mock_obj is leaked, this
+  // information helps the user identify which object it is.
+  static void RegisterUseByOnCallOrExpectCall(const void* mock_obj,
+                                              const char* file, int line)
+      GTEST_LOCK_EXCLUDED_(internal::g_gmock_mutex);
+
+  // Unregisters a mock method; removes the owning mock object from
+  // the registry when the last mock method associated with it has
+  // been unregistered.  This is called only in the destructor of
+  // FunctionMocker.
+  static void UnregisterLocked(internal::UntypedFunctionMockerBase* mocker)
+      GTEST_EXCLUSIVE_LOCK_REQUIRED_(internal::g_gmock_mutex);
+};  // class Mock
+
+// An abstract handle of an expectation.  Useful in the .After()
+// clause of EXPECT_CALL() for setting the (partial) order of
+// expectations.  The syntax:
+//
+//   Expectation e1 = EXPECT_CALL(...)...;
+//   EXPECT_CALL(...).After(e1)...;
+//
+// sets two expectations where the latter can only be matched after
+// the former has been satisfied.
+//
+// Notes:
+//   - This class is copyable and has value semantics.
+//   - Constness is shallow: a const Expectation object itself cannot
+//     be modified, but the mutable methods of the ExpectationBase
+//     object it references can be called via expectation_base().
+
+class GTEST_API_ Expectation {
+ public:
+  // Constructs a null object that doesn't reference any expectation.
+  Expectation();
+  Expectation(Expectation&&) = default;
+  Expectation(const Expectation&) = default;
+  Expectation& operator=(Expectation&&) = default;
+  Expectation& operator=(const Expectation&) = default;
+  ~Expectation();
+
+  // This single-argument ctor must not be explicit, in order to support the
+  //   Expectation e = EXPECT_CALL(...);
+  // syntax.
+  //
+  // A TypedExpectation object stores its pre-requisites as
+  // Expectation objects, and needs to call the non-const Retire()
+  // method on the ExpectationBase objects they reference.  Therefore
+  // Expectation must receive a *non-const* reference to the
+  // ExpectationBase object.
+  Expectation(internal::ExpectationBase& exp);  // NOLINT
+
+  // The compiler-generated copy ctor and operator= work exactly as
+  // intended, so we don't need to define our own.
+
+  // Returns true if and only if rhs references the same expectation as this
+  // object does.
+  bool operator==(const Expectation& rhs) const {
+    return expectation_base_ == rhs.expectation_base_;
+  }
+
+  bool operator!=(const Expectation& rhs) const { return !(*this == rhs); }
+
+ private:
+  friend class ExpectationSet;
+  friend class Sequence;
+  friend class ::testing::internal::ExpectationBase;
+  friend class ::testing::internal::UntypedFunctionMockerBase;
+
+  template <typename F>
+  friend class ::testing::internal::FunctionMocker;
+
+  template <typename F>
+  friend class ::testing::internal::TypedExpectation;
+
+  // This comparator is needed for putting Expectation objects into a set.
+  class Less {
+   public:
+    bool operator()(const Expectation& lhs, const Expectation& rhs) const {
+      return lhs.expectation_base_.get() < rhs.expectation_base_.get();
+    }
+  };
+
+  typedef ::std::set<Expectation, Less> Set;
+
+  Expectation(
+      const std::shared_ptr<internal::ExpectationBase>& expectation_base);
+
+  // Returns the expectation this object references.
+  const std::shared_ptr<internal::ExpectationBase>& expectation_base() const {
+    return expectation_base_;
+  }
+
+  // A shared_ptr that co-owns the expectation this handle references.
+  std::shared_ptr<internal::ExpectationBase> expectation_base_;
+};
+
+// A set of expectation handles.  Useful in the .After() clause of
+// EXPECT_CALL() for setting the (partial) order of expectations.  The
+// syntax:
+//
+//   ExpectationSet es;
+//   es += EXPECT_CALL(...)...;
+//   es += EXPECT_CALL(...)...;
+//   EXPECT_CALL(...).After(es)...;
+//
+// sets three expectations where the last one can only be matched
+// after the first two have both been satisfied.
+//
+// This class is copyable and has value semantics.
+class ExpectationSet {
+ public:
+  // A bidirectional iterator that can read a const element in the set.
+  typedef Expectation::Set::const_iterator const_iterator;
+
+  // An object stored in the set.  This is an alias of Expectation.
+  typedef Expectation::Set::value_type value_type;
+
+  // Constructs an empty set.
+  ExpectationSet() = default;
+
+  // This single-argument ctor must not be explicit, in order to support the
+  //   ExpectationSet es = EXPECT_CALL(...);
+  // syntax.
+  ExpectationSet(internal::ExpectationBase& exp) {  // NOLINT
+    *this += Expectation(exp);
+  }
+
+  // This single-argument ctor implements implicit conversion from
+  // Expectation and thus must not be explicit.  This allows either an
+  // Expectation or an ExpectationSet to be used in .After().
+  ExpectationSet(const Expectation& e) {  // NOLINT
+    *this += e;
+  }
+
+  // The compiler-generator ctor and operator= works exactly as
+  // intended, so we don't need to define our own.
+
+  // Returns true if and only if rhs contains the same set of Expectation
+  // objects as this does.
+  bool operator==(const ExpectationSet& rhs) const {
+    return expectations_ == rhs.expectations_;
+  }
+
+  bool operator!=(const ExpectationSet& rhs) const { return !(*this == rhs); }
+
+  // Implements the syntax
+  //   expectation_set += EXPECT_CALL(...);
+  ExpectationSet& operator+=(const Expectation& e) {
+    expectations_.insert(e);
+    return *this;
+  }
+
+  int size() const { return static_cast<int>(expectations_.size()); }
+
+  const_iterator begin() const { return expectations_.begin(); }
+  const_iterator end() const { return expectations_.end(); }
+
+ private:
+  Expectation::Set expectations_;
+};
+
+// Sequence objects are used by a user to specify the relative order
+// in which the expectations should match.  They are copyable (we rely
+// on the compiler-defined copy constructor and assignment operator).
+class GTEST_API_ Sequence {
+ public:
+  // Constructs an empty sequence.
+  Sequence() : last_expectation_(new Expectation) {}
+
+  // Adds an expectation to this sequence.  The caller must ensure
+  // that no other thread is accessing this Sequence object.
+  void AddExpectation(const Expectation& expectation) const;
+
+ private:
+  // The last expectation in this sequence.
+  std::shared_ptr<Expectation> last_expectation_;
+};  // class Sequence
+
+// An object of this type causes all EXPECT_CALL() statements
+// encountered in its scope to be put in an anonymous sequence.  The
+// work is done in the constructor and destructor.  You should only
+// create an InSequence object on the stack.
+//
+// The sole purpose for this class is to support easy definition of
+// sequential expectations, e.g.
+//
+//   {
+//     InSequence dummy;  // The name of the object doesn't matter.
+//
+//     // The following expectations must match in the order they appear.
+//     EXPECT_CALL(a, Bar())...;
+//     EXPECT_CALL(a, Baz())...;
+//     ...
+//     EXPECT_CALL(b, Xyz())...;
+//   }
+//
+// You can create InSequence objects in multiple threads, as long as
+// they are used to affect different mock objects.  The idea is that
+// each thread can create and set up its own mocks as if it's the only
+// thread.  However, for clarity of your tests we recommend you to set
+// up mocks in the main thread unless you have a good reason not to do
+// so.
+class GTEST_API_ InSequence {
+ public:
+  InSequence();
+  ~InSequence();
+
+ private:
+  bool sequence_created_;
+
+  InSequence(const InSequence&) = delete;
+  InSequence& operator=(const InSequence&) = delete;
+};
+
+namespace internal {
+
+// Points to the implicit sequence introduced by a living InSequence
+// object (if any) in the current thread or NULL.
+GTEST_API_ extern ThreadLocal<Sequence*> g_gmock_implicit_sequence;
+
+// Base class for implementing expectations.
+//
+// There are two reasons for having a type-agnostic base class for
+// Expectation:
+//
+//   1. We need to store collections of expectations of different
+//   types (e.g. all pre-requisites of a particular expectation, all
+//   expectations in a sequence).  Therefore these expectation objects
+//   must share a common base class.
+//
+//   2. We can avoid binary code bloat by moving methods not depending
+//   on the template argument of Expectation to the base class.
+//
+// This class is internal and mustn't be used by user code directly.
+class GTEST_API_ ExpectationBase {
+ public:
+  // source_text is the EXPECT_CALL(...) source that created this Expectation.
+  ExpectationBase(const char* file, int line, const std::string& source_text);
+
+  virtual ~ExpectationBase();
+
+  // Where in the source file was the expectation spec defined?
+  const char* file() const { return file_; }
+  int line() const { return line_; }
+  const char* source_text() const { return source_text_.c_str(); }
+  // Returns the cardinality specified in the expectation spec.
+  const Cardinality& cardinality() const { return cardinality_; }
+
+  // Describes the source file location of this expectation.
+  void DescribeLocationTo(::std::ostream* os) const {
+    *os << FormatFileLocation(file(), line()) << " ";
+  }
+
+  // Describes how many times a function call matching this
+  // expectation has occurred.
+  void DescribeCallCountTo(::std::ostream* os) const
+      GTEST_EXCLUSIVE_LOCK_REQUIRED_(g_gmock_mutex);
+
+  // If this mock method has an extra matcher (i.e. .With(matcher)),
+  // describes it to the ostream.
+  virtual void MaybeDescribeExtraMatcherTo(::std::ostream* os) = 0;
+
+  // Do not rely on this for correctness.
+  // This is only for making human-readable test output easier to understand.
+  void UntypedDescription(std::string description) {
+    description_ = std::move(description);
+  }
+
+ protected:
+  friend class ::testing::Expectation;
+  friend class UntypedFunctionMockerBase;
+
+  enum Clause {
+    // Don't change the order of the enum members!
+    kNone,
+    kWith,
+    kTimes,
+    kInSequence,
+    kAfter,
+    kWillOnce,
+    kWillRepeatedly,
+    kRetiresOnSaturation
+  };
+
+  typedef std::vector<const void*> UntypedActions;
+
+  // Returns an Expectation object that references and co-owns this
+  // expectation.
+  virtual Expectation GetHandle() = 0;
+
+  // Asserts that the EXPECT_CALL() statement has the given property.
+  void AssertSpecProperty(bool property,
+                          const std::string& failure_message) const {
+    Assert(property, file_, line_, failure_message);
+  }
+
+  // Expects that the EXPECT_CALL() statement has the given property.
+  void ExpectSpecProperty(bool property,
+                          const std::string& failure_message) const {
+    Expect(property, file_, line_, failure_message);
+  }
+
+  // Explicitly specifies the cardinality of this expectation.  Used
+  // by the subclasses to implement the .Times() clause.
+  void SpecifyCardinality(const Cardinality& cardinality);
+
+  // Returns true if and only if the user specified the cardinality
+  // explicitly using a .Times().
+  bool cardinality_specified() const { return cardinality_specified_; }
+
+  // Sets the cardinality of this expectation spec.
+  void set_cardinality(const Cardinality& a_cardinality) {
+    cardinality_ = a_cardinality;
+  }
+
+  // The following group of methods should only be called after the
+  // EXPECT_CALL() statement, and only when g_gmock_mutex is held by
+  // the current thread.
+
+  // Retires all pre-requisites of this expectation.
+  void RetireAllPreRequisites() GTEST_EXCLUSIVE_LOCK_REQUIRED_(g_gmock_mutex);
+
+  // Returns true if and only if this expectation is retired.
+  bool is_retired() const GTEST_EXCLUSIVE_LOCK_REQUIRED_(g_gmock_mutex) {
+    g_gmock_mutex.AssertHeld();
+    return retired_;
+  }
+
+  // Retires this expectation.
+  void Retire() GTEST_EXCLUSIVE_LOCK_REQUIRED_(g_gmock_mutex) {
+    g_gmock_mutex.AssertHeld();
+    retired_ = true;
+  }
+
+  // Returns a human-readable description of this expectation.
+  // Do not rely on this for correctness. It is only for human readability.
+  const std::string& GetDescription() const { return description_; }
+
+  // Returns true if and only if this expectation is satisfied.
+  bool IsSatisfied() const GTEST_EXCLUSIVE_LOCK_REQUIRED_(g_gmock_mutex) {
+    g_gmock_mutex.AssertHeld();
+    return cardinality().IsSatisfiedByCallCount(call_count_);
+  }
+
+  // Returns true if and only if this expectation is saturated.
+  bool IsSaturated() const GTEST_EXCLUSIVE_LOCK_REQUIRED_(g_gmock_mutex) {
+    g_gmock_mutex.AssertHeld();
+    return cardinality().IsSaturatedByCallCount(call_count_);
+  }
+
+  // Returns true if and only if this expectation is over-saturated.
+  bool IsOverSaturated() const GTEST_EXCLUSIVE_LOCK_REQUIRED_(g_gmock_mutex) {
+    g_gmock_mutex.AssertHeld();
+    return cardinality().IsOverSaturatedByCallCount(call_count_);
+  }
+
+  // Returns true if and only if all pre-requisites of this expectation are
+  // satisfied.
+  bool AllPrerequisitesAreSatisfied() const
+      GTEST_EXCLUSIVE_LOCK_REQUIRED_(g_gmock_mutex);
+
+  // Adds unsatisfied pre-requisites of this expectation to 'result'.
+  void FindUnsatisfiedPrerequisites(ExpectationSet* result) const
+      GTEST_EXCLUSIVE_LOCK_REQUIRED_(g_gmock_mutex);
+
+  // Returns the number this expectation has been invoked.
+  int call_count() const GTEST_EXCLUSIVE_LOCK_REQUIRED_(g_gmock_mutex) {
+    g_gmock_mutex.AssertHeld();
+    return call_count_;
+  }
+
+  // Increments the number this expectation has been invoked.
+  void IncrementCallCount() GTEST_EXCLUSIVE_LOCK_REQUIRED_(g_gmock_mutex) {
+    g_gmock_mutex.AssertHeld();
+    call_count_++;
+  }
+
+  // Checks the action count (i.e. the number of WillOnce() and
+  // WillRepeatedly() clauses) against the cardinality if this hasn't
+  // been done before.  Prints a warning if there are too many or too
+  // few actions.
+  void CheckActionCountIfNotDone() const GTEST_LOCK_EXCLUDED_(mutex_);
+
+  friend class ::testing::Sequence;
+  friend class ::testing::internal::ExpectationTester;
+
+  template <typename Function>
+  friend class TypedExpectation;
+
+  // Implements the .Times() clause.
+  void UntypedTimes(const Cardinality& a_cardinality);
+
+  // This group of fields are part of the spec and won't change after
+  // an EXPECT_CALL() statement finishes.
+  const char* file_;               // The file that contains the expectation.
+  int line_;                       // The line number of the expectation.
+  const std::string source_text_;  // The EXPECT_CALL(...) source text.
+  std::string description_;        // User-readable name for the expectation.
+  // True if and only if the cardinality is specified explicitly.
+  bool cardinality_specified_;
+  Cardinality cardinality_;  // The cardinality of the expectation.
+  // The immediate pre-requisites (i.e. expectations that must be
+  // satisfied before this expectation can be matched) of this
+  // expectation.  We use std::shared_ptr in the set because we want an
+  // Expectation object to be co-owned by its FunctionMocker and its
+  // successors.  This allows multiple mock objects to be deleted at
+  // different times.
+  ExpectationSet immediate_prerequisites_;
+
+  // This group of fields are the current state of the expectation,
+  // and can change as the mock function is called.
+  int call_count_;  // How many times this expectation has been invoked.
+  bool retired_;    // True if and only if this expectation has retired.
+  UntypedActions untyped_actions_;
+  bool extra_matcher_specified_;
+  bool repeated_action_specified_;  // True if a WillRepeatedly() was specified.
+  bool retires_on_saturation_;
+  Clause last_clause_;
+  mutable bool action_count_checked_;  // Under mutex_.
+  mutable Mutex mutex_;                // Protects action_count_checked_.
+};                                     // class ExpectationBase
+
+template <typename F>
+class TypedExpectation;
+
+// Implements an expectation for the given function type.
+template <typename R, typename... Args>
+class TypedExpectation<R(Args...)> : public ExpectationBase {
+ private:
+  using F = R(Args...);
+
+ public:
+  typedef typename Function<F>::ArgumentTuple ArgumentTuple;
+  typedef typename Function<F>::ArgumentMatcherTuple ArgumentMatcherTuple;
+  typedef typename Function<F>::Result Result;
+
+  TypedExpectation(FunctionMocker<F>* owner, const char* a_file, int a_line,
+                   const std::string& a_source_text,
+                   const ArgumentMatcherTuple& m)
+      : ExpectationBase(a_file, a_line, a_source_text),
+        owner_(owner),
+        matchers_(m),
+        // By default, extra_matcher_ should match anything.  However,
+        // we cannot initialize it with _ as that causes ambiguity between
+        // Matcher's copy and move constructor for some argument types.
+        extra_matcher_(A<const ArgumentTuple&>()),
+        repeated_action_(DoDefault()) {}
+
+  ~TypedExpectation() override {
+    // Check the validity of the action count if it hasn't been done
+    // yet (for example, if the expectation was never used).
+    CheckActionCountIfNotDone();
+    for (UntypedActions::const_iterator it = untyped_actions_.begin();
+         it != untyped_actions_.end(); ++it) {
+      delete static_cast<const Action<F>*>(*it);
+    }
+  }
+
+  // Implements the .With() clause.
+  TypedExpectation& With(const Matcher<const ArgumentTuple&>& m) {
+    if (last_clause_ == kWith) {
+      ExpectSpecProperty(false,
+                         ".With() cannot appear "
+                         "more than once in an EXPECT_CALL().");
+    } else {
+      ExpectSpecProperty(last_clause_ < kWith,
+                         ".With() must be the first "
+                         "clause in an EXPECT_CALL().");
+    }
+    last_clause_ = kWith;
+
+    extra_matcher_ = m;
+    extra_matcher_specified_ = true;
+    return *this;
+  }
+
+  // Do not rely on this for correctness.
+  // This is only for making human-readable test output easier to understand.
+  TypedExpectation& Description(std::string name) {
+    ExpectationBase::UntypedDescription(std::move(name));
+    return *this;
+  }
+
+  // Implements the .Times() clause.
+  TypedExpectation& Times(const Cardinality& a_cardinality) {
+    ExpectationBase::UntypedTimes(a_cardinality);
+    return *this;
+  }
+
+  // Implements the .Times() clause.
+  TypedExpectation& Times(int n) { return Times(Exactly(n)); }
+
+  // Implements the .InSequence() clause.
+  TypedExpectation& InSequence(const Sequence& s) {
+    ExpectSpecProperty(last_clause_ <= kInSequence,
+                       ".InSequence() cannot appear after .After(),"
+                       " .WillOnce(), .WillRepeatedly(), or "
+                       ".RetiresOnSaturation().");
+    last_clause_ = kInSequence;
+
+    s.AddExpectation(GetHandle());
+    return *this;
+  }
+  TypedExpectation& InSequence(const Sequence& s1, const Sequence& s2) {
+    return InSequence(s1).InSequence(s2);
+  }
+  TypedExpectation& InSequence(const Sequence& s1, const Sequence& s2,
+                               const Sequence& s3) {
+    return InSequence(s1, s2).InSequence(s3);
+  }
+  TypedExpectation& InSequence(const Sequence& s1, const Sequence& s2,
+                               const Sequence& s3, const Sequence& s4) {
+    return InSequence(s1, s2, s3).InSequence(s4);
+  }
+  TypedExpectation& InSequence(const Sequence& s1, const Sequence& s2,
+                               const Sequence& s3, const Sequence& s4,
+                               const Sequence& s5) {
+    return InSequence(s1, s2, s3, s4).InSequence(s5);
+  }
+
+  // Implements that .After() clause.
+  TypedExpectation& After(const ExpectationSet& s) {
+    ExpectSpecProperty(last_clause_ <= kAfter,
+                       ".After() cannot appear after .WillOnce(),"
+                       " .WillRepeatedly(), or "
+                       ".RetiresOnSaturation().");
+    last_clause_ = kAfter;
+
+    for (ExpectationSet::const_iterator it = s.begin(); it != s.end(); ++it) {
+      immediate_prerequisites_ += *it;
+    }
+    return *this;
+  }
+  TypedExpectation& After(const ExpectationSet& s1, const ExpectationSet& s2) {
+    return After(s1).After(s2);
+  }
+  TypedExpectation& After(const ExpectationSet& s1, const ExpectationSet& s2,
+                          const ExpectationSet& s3) {
+    return After(s1, s2).After(s3);
+  }
+  TypedExpectation& After(const ExpectationSet& s1, const ExpectationSet& s2,
+                          const ExpectationSet& s3, const ExpectationSet& s4) {
+    return After(s1, s2, s3).After(s4);
+  }
+  TypedExpectation& After(const ExpectationSet& s1, const ExpectationSet& s2,
+                          const ExpectationSet& s3, const ExpectationSet& s4,
+                          const ExpectationSet& s5) {
+    return After(s1, s2, s3, s4).After(s5);
+  }
+
+  // Preferred, type-safe overload: consume anything that can be directly
+  // converted to a OnceAction, except for Action<F> objects themselves.
+  TypedExpectation& WillOnce(OnceAction<F> once_action) {
+    // Call the overload below, smuggling the OnceAction as a copyable callable.
+    // We know this is safe because a WillOnce action will not be called more
+    // than once.
+    return WillOnce(Action<F>(ActionAdaptor{
+        std::make_shared<OnceAction<F>>(std::move(once_action)),
+    }));
+  }
+
+  // Fallback overload: accept Action<F> objects and those actions that define
+  // `operator Action<F>` but not `operator OnceAction<F>`.
+  //
+  // This is templated in order to cause the overload above to be preferred
+  // when the input is convertible to either type.
+  template <int&... ExplicitArgumentBarrier, typename = void>
+  TypedExpectation& WillOnce(Action<F> action) {
+    ExpectSpecProperty(last_clause_ <= kWillOnce,
+                       ".WillOnce() cannot appear after "
+                       ".WillRepeatedly() or .RetiresOnSaturation().");
+    last_clause_ = kWillOnce;
+
+    untyped_actions_.push_back(new Action<F>(std::move(action)));
+
+    if (!cardinality_specified()) {
+      set_cardinality(Exactly(static_cast<int>(untyped_actions_.size())));
+    }
+    return *this;
+  }
+
+  // Implements the .WillRepeatedly() clause.
+  TypedExpectation& WillRepeatedly(const Action<F>& action) {
+    if (last_clause_ == kWillRepeatedly) {
+      ExpectSpecProperty(false,
+                         ".WillRepeatedly() cannot appear "
+                         "more than once in an EXPECT_CALL().");
+    } else {
+      ExpectSpecProperty(last_clause_ < kWillRepeatedly,
+                         ".WillRepeatedly() cannot appear "
+                         "after .RetiresOnSaturation().");
+    }
+    last_clause_ = kWillRepeatedly;
+    repeated_action_specified_ = true;
+
+    repeated_action_ = action;
+    if (!cardinality_specified()) {
+      set_cardinality(AtLeast(static_cast<int>(untyped_actions_.size())));
+    }
+
+    // Now that no more action clauses can be specified, we check
+    // whether their count makes sense.
+    CheckActionCountIfNotDone();
+    return *this;
+  }
+
+  // Implements the .RetiresOnSaturation() clause.
+  TypedExpectation& RetiresOnSaturation() {
+    ExpectSpecProperty(last_clause_ < kRetiresOnSaturation,
+                       ".RetiresOnSaturation() cannot appear "
+                       "more than once.");
+    last_clause_ = kRetiresOnSaturation;
+    retires_on_saturation_ = true;
+
+    // Now that no more action clauses can be specified, we check
+    // whether their count makes sense.
+    CheckActionCountIfNotDone();
+    return *this;
+  }
+
+  // Returns the matchers for the arguments as specified inside the
+  // EXPECT_CALL() macro.
+  const ArgumentMatcherTuple& matchers() const { return matchers_; }
+
+  // Returns the matcher specified by the .With() clause.
+  const Matcher<const ArgumentTuple&>& extra_matcher() const {
+    return extra_matcher_;
+  }
+
+  // Returns the action specified by the .WillRepeatedly() clause.
+  const Action<F>& repeated_action() const { return repeated_action_; }
+
+  // If this mock method has an extra matcher (i.e. .With(matcher)),
+  // describes it to the ostream.
+  void MaybeDescribeExtraMatcherTo(::std::ostream* os) override {
+    if (extra_matcher_specified_) {
+      *os << "    Expected args: ";
+      extra_matcher_.DescribeTo(os);
+      *os << "\n";
+    }
+  }
+
+ private:
+  template <typename Function>
+  friend class FunctionMocker;
+
+  // An adaptor that turns a OneAction<F> into something compatible with
+  // Action<F>. Must be called at most once.
+  struct ActionAdaptor {
+    std::shared_ptr<OnceAction<R(Args...)>> once_action;
+
+    R operator()(Args&&... args) const {
+      return std::move(*once_action).Call(std::forward<Args>(args)...);
+    }
+  };
+
+  // Returns an Expectation object that references and co-owns this
+  // expectation.
+  Expectation GetHandle() override { return owner_->GetHandleOf(this); }
+
+  // The following methods will be called only after the EXPECT_CALL()
+  // statement finishes and when the current thread holds
+  // g_gmock_mutex.
+
+  // Returns true if and only if this expectation matches the given arguments.
+  bool Matches(const ArgumentTuple& args) const
+      GTEST_EXCLUSIVE_LOCK_REQUIRED_(g_gmock_mutex) {
+    g_gmock_mutex.AssertHeld();
+    return TupleMatches(matchers_, args) && extra_matcher_.Matches(args);
+  }
+
+  // Returns true if and only if this expectation should handle the given
+  // arguments.
+  bool ShouldHandleArguments(const ArgumentTuple& args) const
+      GTEST_EXCLUSIVE_LOCK_REQUIRED_(g_gmock_mutex) {
+    g_gmock_mutex.AssertHeld();
+
+    // In case the action count wasn't checked when the expectation
+    // was defined (e.g. if this expectation has no WillRepeatedly()
+    // or RetiresOnSaturation() clause), we check it when the
+    // expectation is used for the first time.
+    CheckActionCountIfNotDone();
+    return !is_retired() && AllPrerequisitesAreSatisfied() && Matches(args);
+  }
+
+  // Describes the result of matching the arguments against this
+  // expectation to the given ostream.
+  void ExplainMatchResultTo(const ArgumentTuple& args, ::std::ostream* os) const
+      GTEST_EXCLUSIVE_LOCK_REQUIRED_(g_gmock_mutex) {
+    g_gmock_mutex.AssertHeld();
+
+    if (is_retired()) {
+      *os << "         Expected: the expectation is active\n"
+          << "           Actual: it is retired\n";
+    } else if (!Matches(args)) {
+      if (!TupleMatches(matchers_, args)) {
+        ExplainMatchFailureTupleTo(matchers_, args, os);
+      }
+      StringMatchResultListener listener;
+      if (!extra_matcher_.MatchAndExplain(args, &listener)) {
+        *os << "    Expected args: ";
+        extra_matcher_.DescribeTo(os);
+        *os << "\n           Actual: don't match";
+
+        internal::PrintIfNotEmpty(listener.str(), os);
+        *os << "\n";
+      }
+    } else if (!AllPrerequisitesAreSatisfied()) {
+      *os << "         Expected: all pre-requisites are satisfied\n"
+          << "           Actual: the following immediate pre-requisites "
+          << "are not satisfied:\n";
+      ExpectationSet unsatisfied_prereqs;
+      FindUnsatisfiedPrerequisites(&unsatisfied_prereqs);
+      int i = 0;
+      for (ExpectationSet::const_iterator it = unsatisfied_prereqs.begin();
+           it != unsatisfied_prereqs.end(); ++it) {
+        it->expectation_base()->DescribeLocationTo(os);
+        *os << "pre-requisite #" << i++ << "\n";
+      }
+      *os << "                   (end of pre-requisites)\n";
+    } else {
+      // This line is here just for completeness' sake.  It will never
+      // be executed as currently the ExplainMatchResultTo() function
+      // is called only when the mock function call does NOT match the
+      // expectation.
+      *os << "The call matches the expectation.\n";
+    }
+  }
+
+  // Returns the action that should be taken for the current invocation.
+  const Action<F>& GetCurrentAction(const FunctionMocker<F>* mocker,
+                                    const ArgumentTuple& args) const
+      GTEST_EXCLUSIVE_LOCK_REQUIRED_(g_gmock_mutex) {
+    g_gmock_mutex.AssertHeld();
+    const int count = call_count();
+    Assert(count >= 1, __FILE__, __LINE__,
+           "call_count() is <= 0 when GetCurrentAction() is "
+           "called - this should never happen.");
+
+    const int action_count = static_cast<int>(untyped_actions_.size());
+    if (action_count > 0 && !repeated_action_specified_ &&
+        count > action_count) {
+      // If there is at least one WillOnce() and no WillRepeatedly(),
+      // we warn the user when the WillOnce() clauses ran out.
+      ::std::stringstream ss;
+      DescribeLocationTo(&ss);
+      ss << "Actions ran out in " << source_text() << "...\n"
+         << "Called " << count << " times, but only " << action_count
+         << " WillOnce()" << (action_count == 1 ? " is" : "s are")
+         << " specified - ";
+      mocker->DescribeDefaultActionTo(args, &ss);
+      Log(kWarning, ss.str(), 1);
+    }
+
+    return count <= action_count
+               ? *static_cast<const Action<F>*>(
+                     untyped_actions_[static_cast<size_t>(count - 1)])
+               : repeated_action();
+  }
+
+  // Given the arguments of a mock function call, if the call will
+  // over-saturate this expectation, returns the default action;
+  // otherwise, returns the next action in this expectation.  Also
+  // describes *what* happened to 'what', and explains *why* Google
+  // Mock does it to 'why'.  This method is not const as it calls
+  // IncrementCallCount().  A return value of NULL means the default
+  // action.
+  const Action<F>* GetActionForArguments(const FunctionMocker<F>* mocker,
+                                         const ArgumentTuple& args,
+                                         ::std::ostream* what,
+                                         ::std::ostream* why)
+      GTEST_EXCLUSIVE_LOCK_REQUIRED_(g_gmock_mutex) {
+    g_gmock_mutex.AssertHeld();
+    const ::std::string& expectation_description = GetDescription();
+    if (IsSaturated()) {
+      // We have an excessive call.
+      IncrementCallCount();
+      *what << "Mock function ";
+      if (!expectation_description.empty()) {
+        *what << "\"" << expectation_description << "\" ";
+      }
+      *what << "called more times than expected - ";
+      mocker->DescribeDefaultActionTo(args, what);
+      DescribeCallCountTo(why);
+
+      return nullptr;
+    }
+
+    IncrementCallCount();
+    RetireAllPreRequisites();
+
+    if (retires_on_saturation_ && IsSaturated()) {
+      Retire();
+    }
+
+    // Must be done after IncrementCount()!
+    *what << "Mock function ";
+    if (!expectation_description.empty()) {
+      *what << "\"" << expectation_description << "\" ";
+    }
+    *what << "call matches " << source_text() << "...\n";
+    return &(GetCurrentAction(mocker, args));
+  }
+
+  // All the fields below won't change once the EXPECT_CALL()
+  // statement finishes.
+  FunctionMocker<F>* const owner_;
+  ArgumentMatcherTuple matchers_;
+  Matcher<const ArgumentTuple&> extra_matcher_;
+  Action<F> repeated_action_;
+
+  TypedExpectation(const TypedExpectation&) = delete;
+  TypedExpectation& operator=(const TypedExpectation&) = delete;
+};  // class TypedExpectation
+
+// A MockSpec object is used by ON_CALL() or EXPECT_CALL() for
+// specifying the default behavior of, or expectation on, a mock
+// function.
+
+// Note: class MockSpec really belongs to the ::testing namespace.
+// However if we define it in ::testing, MSVC will complain when
+// classes in ::testing::internal declare it as a friend class
+// template.  To workaround this compiler bug, we define MockSpec in
+// ::testing::internal and import it into ::testing.
+
+// Logs a message including file and line number information.
+GTEST_API_ void LogWithLocation(testing::internal::LogSeverity severity,
+                                const char* file, int line,
+                                const std::string& message);
+
+template <typename F>
+class MockSpec {
+ public:
+  typedef typename internal::Function<F>::ArgumentTuple ArgumentTuple;
+  typedef
+      typename internal::Function<F>::ArgumentMatcherTuple ArgumentMatcherTuple;
+
+  // Constructs a MockSpec object, given the function mocker object
+  // that the spec is associated with.
+  MockSpec(internal::FunctionMocker<F>* function_mocker,
+           const ArgumentMatcherTuple& matchers)
+      : function_mocker_(function_mocker), matchers_(matchers) {}
+
+  // Adds a new default action spec to the function mocker and returns
+  // the newly created spec.
+  internal::OnCallSpec<F>& InternalDefaultActionSetAt(const char* file,
+                                                      int line, const char* obj,
+                                                      const char* call) {
+    LogWithLocation(internal::kInfo, file, line,
+                    std::string("ON_CALL(") + obj + ", " + call + ") invoked");
+    return function_mocker_->AddNewOnCallSpec(file, line, matchers_);
+  }
+
+  // Adds a new expectation spec to the function mocker and returns
+  // the newly created spec.
+  internal::TypedExpectation<F>& InternalExpectedAt(const char* file, int line,
+                                                    const char* obj,
+                                                    const char* call) {
+    const std::string source_text(std::string("EXPECT_CALL(") + obj + ", " +
+                                  call + ")");
+    LogWithLocation(internal::kInfo, file, line, source_text + " invoked");
+    return function_mocker_->AddNewExpectation(file, line, source_text,
+                                               matchers_);
+  }
+
+  // This operator overload is used to swallow the superfluous parameter list
+  // introduced by the ON/EXPECT_CALL macros. See the macro comments for more
+  // explanation.
+  MockSpec<F>& operator()(const internal::WithoutMatchers&, void* const) {
+    return *this;
+  }
+
+ private:
+  template <typename Function>
+  friend class internal::FunctionMocker;
+
+  // The function mocker that owns this spec.
+  internal::FunctionMocker<F>* const function_mocker_;
+  // The argument matchers specified in the spec.
+  ArgumentMatcherTuple matchers_;
+};  // class MockSpec
+
+// Wrapper type for generically holding an ordinary value or lvalue reference.
+// If T is not a reference type, it must be copyable or movable.
+// ReferenceOrValueWrapper<T> is movable, and will also be copyable unless
+// T is a move-only value type (which means that it will always be copyable
+// if the current platform does not support move semantics).
+//
+// The primary template defines handling for values, but function header
+// comments describe the contract for the whole template (including
+// specializations).
+template <typename T>
+class ReferenceOrValueWrapper {
+ public:
+  // Constructs a wrapper from the given value/reference.
+  explicit ReferenceOrValueWrapper(T value) : value_(std::move(value)) {}
+
+  // Unwraps and returns the underlying value/reference, exactly as
+  // originally passed. The behavior of calling this more than once on
+  // the same object is unspecified.
+  T Unwrap() { return std::move(value_); }
+
+  // Provides nondestructive access to the underlying value/reference.
+  // Always returns a const reference (more precisely,
+  // const std::add_lvalue_reference<T>::type). The behavior of calling this
+  // after calling Unwrap on the same object is unspecified.
+  const T& Peek() const { return value_; }
+
+ private:
+  T value_;
+};
+
+// Specialization for lvalue reference types. See primary template
+// for documentation.
+template <typename T>
+class ReferenceOrValueWrapper<T&> {
+ public:
+  // Workaround for debatable pass-by-reference lint warning (c-library-team
+  // policy precludes NOLINT in this context)
+  typedef T& reference;
+  explicit ReferenceOrValueWrapper(reference ref) : value_ptr_(&ref) {}
+  T& Unwrap() { return *value_ptr_; }
+  const T& Peek() const { return *value_ptr_; }
+
+ private:
+  T* value_ptr_;
+};
+
+// Prints the held value as an action's result to os.
+template <typename T>
+void PrintAsActionResult(const T& result, std::ostream& os) {
+  os << "\n          Returns: ";
+  // T may be a reference type, so we don't use UniversalPrint().
+  UniversalPrinter<T>::Print(result, &os);
+}
+
+// Reports an uninteresting call (whose description is in msg) in the
+// manner specified by 'reaction'.
+GTEST_API_ void ReportUninterestingCall(CallReaction reaction,
+                                        const std::string& msg);
+
+// A generic RAII type that runs a user-provided function in its destructor.
+class Cleanup final {
+ public:
+  explicit Cleanup(std::function<void()> f) : f_(std::move(f)) {}
+  ~Cleanup() { f_(); }
+
+ private:
+  std::function<void()> f_;
+};
+
+struct UntypedFunctionMockerBase::UninterestingCallCleanupHandler {
+  CallReaction reaction;
+  std::stringstream& ss;
+
+  ~UninterestingCallCleanupHandler() {
+    ReportUninterestingCall(reaction, ss.str());
+  }
+};
+
+struct UntypedFunctionMockerBase::FailureCleanupHandler {
+  std::stringstream& ss;
+  std::stringstream& why;
+  std::stringstream& loc;
+  const ExpectationBase* untyped_expectation;
+  bool found;
+  bool is_excessive;
+
+  ~FailureCleanupHandler() {
+    ss << "\n" << why.str();
+
+    if (!found) {
+      // No expectation matches this call - reports a failure.
+      Expect(false, nullptr, -1, ss.str());
+    } else if (is_excessive) {
+      // We had an upper-bound violation and the failure message is in ss.
+      Expect(false, untyped_expectation->file(), untyped_expectation->line(),
+             ss.str());
+    } else {
+      // We had an expected call and the matching expectation is
+      // described in ss.
+      Log(kInfo, loc.str() + ss.str(), 2);
+    }
+  }
+};
+
+template <typename F>
+class FunctionMocker;
+
+template <typename R, typename... Args>
+class FunctionMocker<R(Args...)> final : public UntypedFunctionMockerBase {
+  using F = R(Args...);
+
+ public:
+  using Result = R;
+  using ArgumentTuple = std::tuple<Args...>;
+  using ArgumentMatcherTuple = std::tuple<Matcher<Args>...>;
+
+  FunctionMocker() = default;
+
+  // There is no generally useful and implementable semantics of
+  // copying a mock object, so copying a mock is usually a user error.
+  // Thus we disallow copying function mockers.  If the user really
+  // wants to copy a mock object, they should implement their own copy
+  // operation, for example:
+  //
+  //   class MockFoo : public Foo {
+  //    public:
+  //     // Defines a copy constructor explicitly.
+  //     MockFoo(const MockFoo& src) {}
+  //     ...
+  //   };
+  FunctionMocker(const FunctionMocker&) = delete;
+  FunctionMocker& operator=(const FunctionMocker&) = delete;
+
+  // The destructor verifies that all expectations on this mock
+  // function have been satisfied.  If not, it will report Google Test
+  // non-fatal failures for the violations.
+  ~FunctionMocker() override GTEST_LOCK_EXCLUDED_(g_gmock_mutex) {
+    MutexLock l(&g_gmock_mutex);
+    VerifyAndClearExpectationsLocked();
+    Mock::UnregisterLocked(this);
+    ClearDefaultActionsLocked();
+  }
+
+  // Returns the ON_CALL spec that matches this mock function with the
+  // given arguments; returns NULL if no matching ON_CALL is found.
+  // L = *
+  const OnCallSpec<F>* FindOnCallSpec(const ArgumentTuple& args) const {
+    for (UntypedOnCallSpecs::const_reverse_iterator it =
+             untyped_on_call_specs_.rbegin();
+         it != untyped_on_call_specs_.rend(); ++it) {
+      const OnCallSpec<F>* spec = static_cast<const OnCallSpec<F>*>(*it);
+      if (spec->Matches(args)) return spec;
+    }
+
+    return nullptr;
+  }
+
+  // Performs the default action of this mock function on the given
+  // arguments and returns the result. Asserts (or throws if
+  // exceptions are enabled) with a helpful call description if there
+  // is no valid return value. This method doesn't depend on the
+  // mutable state of this object, and thus can be called concurrently
+  // without locking.
+  // L = *
+  Result PerformDefaultAction(ArgumentTuple&& args,
+                              const std::string& call_description) const {
+    const OnCallSpec<F>* const spec = this->FindOnCallSpec(args);
+    if (spec != nullptr) {
+      return spec->GetAction().Perform(std::move(args));
+    }
+    const std::string message =
+        call_description +
+        "\n    The mock function has no default action "
+        "set, and its return type has no default value set.";
+#if GTEST_HAS_EXCEPTIONS
+    if (!DefaultValue<Result>::Exists()) {
+      throw std::runtime_error(message);
+    }
+#else
+    Assert(DefaultValue<Result>::Exists(), "", -1, message);
+#endif
+    return DefaultValue<Result>::Get();
+  }
+
+  // Implements UntypedFunctionMockerBase::ClearDefaultActionsLocked():
+  // clears the ON_CALL()s set on this mock function.
+  void ClearDefaultActionsLocked() override
+      GTEST_EXCLUSIVE_LOCK_REQUIRED_(g_gmock_mutex) {
+    g_gmock_mutex.AssertHeld();
+
+    // Deleting our default actions may trigger other mock objects to be
+    // deleted, for example if an action contains a reference counted smart
+    // pointer to that mock object, and that is the last reference. So if we
+    // delete our actions within the context of the global mutex we may deadlock
+    // when this method is called again. Instead, make a copy of the set of
+    // actions to delete, clear our set within the mutex, and then delete the
+    // actions outside of the mutex.
+    UntypedOnCallSpecs specs_to_delete;
+    untyped_on_call_specs_.swap(specs_to_delete);
+
+    g_gmock_mutex.Unlock();
+    for (UntypedOnCallSpecs::const_iterator it = specs_to_delete.begin();
+         it != specs_to_delete.end(); ++it) {
+      delete static_cast<const OnCallSpec<F>*>(*it);
+    }
+
+    // Lock the mutex again, since the caller expects it to be locked when we
+    // return.
+    g_gmock_mutex.Lock();
+  }
+
+  // Returns the result of invoking this mock function with the given
+  // arguments.  This function can be safely called from multiple
+  // threads concurrently.
+  Result Invoke(Args... args) GTEST_LOCK_EXCLUDED_(g_gmock_mutex) {
+    return InvokeWith(ArgumentTuple(std::forward<Args>(args)...));
+  }
+
+  MockSpec<F> With(Matcher<Args>... m) {
+    return MockSpec<F>(this, ::std::make_tuple(std::move(m)...));
+  }
+
+ protected:
+  template <typename Function>
+  friend class MockSpec;
+
+  // Adds and returns a default action spec for this mock function.
+  OnCallSpec<F>& AddNewOnCallSpec(const char* file, int line,
+                                  const ArgumentMatcherTuple& m)
+      GTEST_LOCK_EXCLUDED_(g_gmock_mutex) {
+    Mock::RegisterUseByOnCallOrExpectCall(MockObject(), file, line);
+    OnCallSpec<F>* const on_call_spec = new OnCallSpec<F>(file, line, m);
+    untyped_on_call_specs_.push_back(on_call_spec);
+    return *on_call_spec;
+  }
+
+  // Adds and returns an expectation spec for this mock function.
+  TypedExpectation<F>& AddNewExpectation(const char* file, int line,
+                                         const std::string& source_text,
+                                         const ArgumentMatcherTuple& m)
+      GTEST_LOCK_EXCLUDED_(g_gmock_mutex) {
+    Mock::RegisterUseByOnCallOrExpectCall(MockObject(), file, line);
+    TypedExpectation<F>* const expectation =
+        new TypedExpectation<F>(this, file, line, source_text, m);
+    const std::shared_ptr<ExpectationBase> untyped_expectation(expectation);
+    // See the definition of untyped_expectations_ for why access to
+    // it is unprotected here.
+    untyped_expectations_.push_back(untyped_expectation);
+
+    // Adds this expectation into the implicit sequence if there is one.
+    Sequence* const implicit_sequence = g_gmock_implicit_sequence.get();
+    if (implicit_sequence != nullptr) {
+      implicit_sequence->AddExpectation(Expectation(untyped_expectation));
+    }
+
+    return *expectation;
+  }
+
+ private:
+  template <typename Func>
+  friend class TypedExpectation;
+
+  // Some utilities needed for implementing UntypedInvokeWith().
+
+  // Describes what default action will be performed for the given
+  // arguments.
+  // L = *
+  void DescribeDefaultActionTo(const ArgumentTuple& args,
+                               ::std::ostream* os) const {
+    const OnCallSpec<F>* const spec = FindOnCallSpec(args);
+
+    if (spec == nullptr) {
+      *os << (std::is_void<Result>::value ? "returning directly.\n"
+                                          : "returning default value.\n");
+    } else {
+      *os << "taking default action specified at:\n"
+          << FormatFileLocation(spec->file(), spec->line()) << "\n";
+    }
+  }
+
+  // Writes a message that the call is uninteresting (i.e. neither
+  // explicitly expected nor explicitly unexpected) to the given
+  // ostream.
+  void UntypedDescribeUninterestingCall(const void* untyped_args,
+                                        ::std::ostream* os) const override
+      GTEST_LOCK_EXCLUDED_(g_gmock_mutex) {
+    const ArgumentTuple& args =
+        *static_cast<const ArgumentTuple*>(untyped_args);
+    *os << "Uninteresting mock function call - ";
+    DescribeDefaultActionTo(args, os);
+    *os << "    Function call: " << Name();
+    UniversalPrint(args, os);
+  }
+
+  // Returns the expectation that matches the given function arguments
+  // (or NULL is there's no match); when a match is found,
+  // untyped_action is set to point to the action that should be
+  // performed (or NULL if the action is "do default"), and
+  // is_excessive is modified to indicate whether the call exceeds the
+  // expected number.
+  //
+  // Critical section: We must find the matching expectation and the
+  // corresponding action that needs to be taken in an ATOMIC
+  // transaction.  Otherwise another thread may call this mock
+  // method in the middle and mess up the state.
+  //
+  // However, performing the action has to be left out of the critical
+  // section.  The reason is that we have no control on what the
+  // action does (it can invoke an arbitrary user function or even a
+  // mock function) and excessive locking could cause a dead lock.
+  const ExpectationBase* UntypedFindMatchingExpectation(
+      const void* untyped_args, const void** untyped_action, bool* is_excessive,
+      ::std::ostream* what, ::std::ostream* why) override
+      GTEST_LOCK_EXCLUDED_(g_gmock_mutex) {
+    const ArgumentTuple& args =
+        *static_cast<const ArgumentTuple*>(untyped_args);
+    MutexLock l(&g_gmock_mutex);
+    TypedExpectation<F>* exp = this->FindMatchingExpectationLocked(args);
+    if (exp == nullptr) {  // A match wasn't found.
+      this->FormatUnexpectedCallMessageLocked(args, what, why);
+      return nullptr;
+    }
+
+    // This line must be done before calling GetActionForArguments(),
+    // which will increment the call count for *exp and thus affect
+    // its saturation status.
+    *is_excessive = exp->IsSaturated();
+    const Action<F>* action = exp->GetActionForArguments(this, args, what, why);
+    if (action != nullptr && action->IsDoDefault())
+      action = nullptr;  // Normalize "do default" to NULL.
+    *untyped_action = action;
+    return exp;
+  }
+
+  // Prints the given function arguments to the ostream.
+  void UntypedPrintArgs(const void* untyped_args,
+                        ::std::ostream* os) const override {
+    const ArgumentTuple& args =
+        *static_cast<const ArgumentTuple*>(untyped_args);
+    UniversalPrint(args, os);
+  }
+
+  // Returns the expectation that matches the arguments, or NULL if no
+  // expectation matches them.
+  TypedExpectation<F>* FindMatchingExpectationLocked(const ArgumentTuple& args)
+      const GTEST_EXCLUSIVE_LOCK_REQUIRED_(g_gmock_mutex) {
+    g_gmock_mutex.AssertHeld();
+    // See the definition of untyped_expectations_ for why access to
+    // it is unprotected here.
+    for (typename UntypedExpectations::const_reverse_iterator it =
+             untyped_expectations_.rbegin();
+         it != untyped_expectations_.rend(); ++it) {
+      TypedExpectation<F>* const exp =
+          static_cast<TypedExpectation<F>*>(it->get());
+      if (exp->ShouldHandleArguments(args)) {
+        return exp;
+      }
+    }
+    return nullptr;
+  }
+
+  // Returns a message that the arguments don't match any expectation.
+  void FormatUnexpectedCallMessageLocked(const ArgumentTuple& args,
+                                         ::std::ostream* os,
+                                         ::std::ostream* why) const
+      GTEST_EXCLUSIVE_LOCK_REQUIRED_(g_gmock_mutex) {
+    g_gmock_mutex.AssertHeld();
+    *os << "\nUnexpected mock function call - ";
+    DescribeDefaultActionTo(args, os);
+    PrintTriedExpectationsLocked(args, why);
+  }
+
+  // Prints a list of expectations that have been tried against the
+  // current mock function call.
+  void PrintTriedExpectationsLocked(const ArgumentTuple& args,
+                                    ::std::ostream* why) const
+      GTEST_EXCLUSIVE_LOCK_REQUIRED_(g_gmock_mutex) {
+    g_gmock_mutex.AssertHeld();
+    const size_t count = untyped_expectations_.size();
+    *why << "Google Mock tried the following " << count << " "
+         << (count == 1 ? "expectation, but it didn't match"
+                        : "expectations, but none matched")
+         << ":\n";
+    for (size_t i = 0; i < count; i++) {
+      TypedExpectation<F>* const expectation =
+          static_cast<TypedExpectation<F>*>(untyped_expectations_[i].get());
+      *why << "\n";
+      expectation->DescribeLocationTo(why);
+      if (count > 1) {
+        *why << "tried expectation #" << i << ": ";
+      }
+      *why << expectation->source_text() << "...\n";
+      expectation->ExplainMatchResultTo(args, why);
+      expectation->DescribeCallCountTo(why);
+    }
+  }
+
+  // Performs the given action (or the default if it's null) with the given
+  // arguments and returns the action's result.
+  // L = *
+  R PerformAction(const void* untyped_action, ArgumentTuple&& args,
+                  const std::string& call_description) const {
+    if (untyped_action == nullptr) {
+      return PerformDefaultAction(std::move(args), call_description);
+    }
+
+    // Make a copy of the action before performing it, in case the
+    // action deletes the mock object (and thus deletes itself).
+    const Action<F> action = *static_cast<const Action<F>*>(untyped_action);
+    return action.Perform(std::move(args));
+  }
+
+  // Is it possible to store an object of the supplied type in a local variable
+  // for the sake of printing it, then return it on to the caller?
+  template <typename T>
+  using can_print_result = internal::conjunction<
+      // void can't be stored as an object (and we also don't need to print it).
+      internal::negation<std::is_void<T>>,
+      // Non-moveable types can't be returned on to the user, so there's no way
+      // for us to intercept and print them.
+      std::is_move_constructible<T>>;
+
+  // Perform the supplied action, printing the result to os.
+  template <typename T = R,
+            typename std::enable_if<can_print_result<T>::value, int>::type = 0>
+  R PerformActionAndPrintResult(const void* const untyped_action,
+                                ArgumentTuple&& args,
+                                const std::string& call_description,
+                                std::ostream& os) {
+    R result = PerformAction(untyped_action, std::move(args), call_description);
+
+    PrintAsActionResult(result, os);
+    return std::forward<R>(result);
+  }
+
+  // An overload for when it's not possible to print the result. In this case we
+  // simply perform the action.
+  template <typename T = R,
+            typename std::enable_if<
+                internal::negation<can_print_result<T>>::value, int>::type = 0>
+  R PerformActionAndPrintResult(const void* const untyped_action,
+                                ArgumentTuple&& args,
+                                const std::string& call_description,
+                                std::ostream&) {
+    return PerformAction(untyped_action, std::move(args), call_description);
+  }
+
+  // Returns the result of invoking this mock function with the given
+  // arguments. This function can be safely called from multiple
+  // threads concurrently.
+  R InvokeWith(ArgumentTuple&& args) GTEST_LOCK_EXCLUDED_(g_gmock_mutex);
+};  // class FunctionMocker
+
+// Calculates the result of invoking this mock function with the given
+// arguments, prints it, and returns it.
+template <typename R, typename... Args>
+R FunctionMocker<R(Args...)>::InvokeWith(ArgumentTuple&& args)
+    GTEST_LOCK_EXCLUDED_(g_gmock_mutex) {
+  // See the definition of untyped_expectations_ for why access to it
+  // is unprotected here.
+  if (untyped_expectations_.size() == 0) {
+    // No expectation is set on this mock method - we have an
+    // uninteresting call.
+
+    // We must get Google Mock's reaction on uninteresting calls
+    // made on this mock object BEFORE performing the action,
+    // because the action may DELETE the mock object and make the
+    // following expression meaningless.
+    const CallReaction reaction =
+        Mock::GetReactionOnUninterestingCalls(MockObject());
+
+    // True if and only if we need to print this call's arguments and return
+    // value.  This definition must be kept in sync with
+    // the behavior of ReportUninterestingCall().
+    const bool need_to_report_uninteresting_call =
+        // If the user allows this uninteresting call, we print it
+        // only when they want informational messages.
+        reaction == kAllow ? LogIsVisible(kInfo) :
+                           // If the user wants this to be a warning, we print
+                           // it only when they want to see warnings.
+            reaction == kWarn
+            ? LogIsVisible(kWarning)
+            :
+            // Otherwise, the user wants this to be an error, and we
+            // should always print detailed information in the error.
+            true;
+
+    if (!need_to_report_uninteresting_call) {
+      // Perform the action without printing the call information.
+      return this->PerformDefaultAction(
+          std::move(args), "Function call: " + std::string(Name()));
+    }
+
+    // Warns about the uninteresting call.
+    ::std::stringstream ss;
+    this->UntypedDescribeUninterestingCall(&args, &ss);
+
+    // Perform the action, print the result, and then report the uninteresting
+    // call.
+    //
+    // We use RAII to do the latter in case R is void or a non-moveable type. In
+    // either case we can't assign it to a local variable.
+    //
+    // Note that std::bind() is essential here.
+    // We *don't* use any local callback types (like lambdas).
+    // Doing so slows down compilation dramatically because the *constructor* of
+    // std::function<T> is re-instantiated with different template
+    // parameters each time.
+    const UninterestingCallCleanupHandler report_uninteresting_call = {
+        reaction, ss
+    };
+
+    return PerformActionAndPrintResult(nullptr, std::move(args), ss.str(), ss);
+  }
+
+  bool is_excessive = false;
+  ::std::stringstream ss;
+  ::std::stringstream why;
+  ::std::stringstream loc;
+  const void* untyped_action = nullptr;
+
+  // The UntypedFindMatchingExpectation() function acquires and
+  // releases g_gmock_mutex.
+
+  const ExpectationBase* const untyped_expectation =
+      this->UntypedFindMatchingExpectation(&args, &untyped_action,
+                                           &is_excessive, &ss, &why);
+  const bool found = untyped_expectation != nullptr;
+
+  // True if and only if we need to print the call's arguments
+  // and return value.
+  // This definition must be kept in sync with the uses of Expect()
+  // and Log() in this function.
+  const bool need_to_report_call =
+      !found || is_excessive || LogIsVisible(kInfo);
+  if (!need_to_report_call) {
+    // Perform the action without printing the call information.
+    return PerformAction(untyped_action, std::move(args), "");
+  }
+
+  ss << "    Function call: " << Name();
+  this->UntypedPrintArgs(&args, &ss);
+
+  // In case the action deletes a piece of the expectation, we
+  // generate the message beforehand.
+  if (found && !is_excessive) {
+    untyped_expectation->DescribeLocationTo(&loc);
+  }
+
+  // Perform the action, print the result, and then fail or log in whatever way
+  // is appropriate.
+  //
+  // We use RAII to do the latter in case R is void or a non-moveable type. In
+  // either case we can't assign it to a local variable.
+  //
+  // Note that we *don't* use any local callback types (like lambdas) here.
+  // Doing so slows down compilation dramatically because the *constructor* of
+  // std::function<T> is re-instantiated with different template
+  // parameters each time.
+  const FailureCleanupHandler handle_failures = {
+      ss, why, loc, untyped_expectation, found, is_excessive
+  };
+
+  return PerformActionAndPrintResult(untyped_action, std::move(args), ss.str(),
+                                     ss);
+}
+
+}  // namespace internal
+
+namespace internal {
+
+template <typename F>
+class MockFunction;
+
+template <typename R, typename... Args>
+class MockFunction<R(Args...)> {
+ public:
+  MockFunction(const MockFunction&) = delete;
+  MockFunction& operator=(const MockFunction&) = delete;
+
+  std::function<R(Args...)> AsStdFunction() {
+    return [this](Args... args) -> R {
+      return this->Call(std::forward<Args>(args)...);
+    };
+  }
+
+  // Implementation detail: the expansion of the MOCK_METHOD macro.
+  R Call(Args... args) {
+    mock_.SetOwnerAndName(this, "Call");
+    return mock_.Invoke(std::forward<Args>(args)...);
+  }
+
+  MockSpec<R(Args...)> gmock_Call(Matcher<Args>... m) {
+    mock_.RegisterOwner(this);
+    return mock_.With(std::move(m)...);
+  }
+
+  MockSpec<R(Args...)> gmock_Call(const WithoutMatchers&, R (*)(Args...)) {
+    return this->gmock_Call(::testing::A<Args>()...);
+  }
+
+ protected:
+  MockFunction() = default;
+  ~MockFunction() = default;
+
+ private:
+  FunctionMocker<R(Args...)> mock_;
+};
+
+/*
+The SignatureOf<F> struct is a meta-function returning function signature
+corresponding to the provided F argument.
+
+It makes use of MockFunction easier by allowing it to accept more F arguments
+than just function signatures.
+
+Specializations provided here cover a signature type itself and any template
+that can be parameterized with a signature, including std::function and
+boost::function.
+*/
+
+template <typename F, typename = void>
+struct SignatureOf;
+
+template <typename R, typename... Args>
+struct SignatureOf<R(Args...)> {
+  using type = R(Args...);
+};
+
+template <template <typename> class C, typename F>
+struct SignatureOf<C<F>,
+                   typename std::enable_if<std::is_function<F>::value>::type>
+    : SignatureOf<F> {};
+
+template <typename F>
+using SignatureOfT = typename SignatureOf<F>::type;
+
+}  // namespace internal
+
+// A MockFunction<F> type has one mock method whose type is
+// internal::SignatureOfT<F>.  It is useful when you just want your
+// test code to emit some messages and have Google Mock verify the
+// right messages are sent (and perhaps at the right times).  For
+// example, if you are exercising code:
+//
+//   Foo(1);
+//   Foo(2);
+//   Foo(3);
+//
+// and want to verify that Foo(1) and Foo(3) both invoke
+// mock.Bar("a"), but Foo(2) doesn't invoke anything, you can write:
+//
+// TEST(FooTest, InvokesBarCorrectly) {
+//   MyMock mock;
+//   MockFunction<void(string check_point_name)> check;
+//   {
+//     InSequence s;
+//
+//     EXPECT_CALL(mock, Bar("a"));
+//     EXPECT_CALL(check, Call("1"));
+//     EXPECT_CALL(check, Call("2"));
+//     EXPECT_CALL(mock, Bar("a"));
+//   }
+//   Foo(1);
+//   check.Call("1");
+//   Foo(2);
+//   check.Call("2");
+//   Foo(3);
+// }
+//
+// The expectation spec says that the first Bar("a") must happen
+// before check point "1", the second Bar("a") must happen after check
+// point "2", and nothing should happen between the two check
+// points. The explicit check points make it easy to tell which
+// Bar("a") is called by which call to Foo().
+//
+// MockFunction<F> can also be used to exercise code that accepts
+// std::function<internal::SignatureOfT<F>> callbacks. To do so, use
+// AsStdFunction() method to create std::function proxy forwarding to
+// original object's Call. Example:
+//
+// TEST(FooTest, RunsCallbackWithBarArgument) {
+//   MockFunction<int(string)> callback;
+//   EXPECT_CALL(callback, Call("bar")).WillOnce(Return(1));
+//   Foo(callback.AsStdFunction());
+// }
+//
+// The internal::SignatureOfT<F> indirection allows to use other types
+// than just function signature type. This is typically useful when
+// providing a mock for a predefined std::function type. Example:
+//
+// using FilterPredicate = std::function<bool(string)>;
+// void MyFilterAlgorithm(FilterPredicate predicate);
+//
+// TEST(FooTest, FilterPredicateAlwaysAccepts) {
+//   MockFunction<FilterPredicate> predicateMock;
+//   EXPECT_CALL(predicateMock, Call(_)).WillRepeatedly(Return(true));
+//   MyFilterAlgorithm(predicateMock.AsStdFunction());
+// }
+template <typename F>
+class MockFunction : public internal::MockFunction<internal::SignatureOfT<F>> {
+  using Base = internal::MockFunction<internal::SignatureOfT<F>>;
+
+ public:
+  using Base::Base;
+};
+
+// The style guide prohibits "using" statements in a namespace scope
+// inside a header file.  However, the MockSpec class template is
+// meant to be defined in the ::testing namespace.  The following line
+// is just a trick for working around a bug in MSVC 8.0, which cannot
+// handle it if we define MockSpec in ::testing.
+using internal::MockSpec;
+
+// Const(x) is a convenient function for obtaining a const reference
+// to x.  This is useful for setting expectations on an overloaded
+// const mock method, e.g.
+//
+//   class MockFoo : public FooInterface {
+//    public:
+//     MOCK_METHOD0(Bar, int());
+//     MOCK_CONST_METHOD0(Bar, int&());
+//   };
+//
+//   MockFoo foo;
+//   // Expects a call to non-const MockFoo::Bar().
+//   EXPECT_CALL(foo, Bar());
+//   // Expects a call to const MockFoo::Bar().
+//   EXPECT_CALL(Const(foo), Bar());
+template <typename T>
+inline const T& Const(const T& x) {
+  return x;
+}
+
+// Constructs an Expectation object that references and co-owns exp.
+inline Expectation::Expectation(internal::ExpectationBase& exp)  // NOLINT
+    : expectation_base_(exp.GetHandle().expectation_base()) {}
+
+}  // namespace testing
+
+GTEST_DISABLE_MSC_WARNINGS_POP_()  //  4251
+
+// Implementation for ON_CALL and EXPECT_CALL macros. A separate macro is
+// required to avoid compile errors when the name of the method used in call is
+// a result of macro expansion. See CompilesWithMethodNameExpandedFromMacro
+// tests in internal/gmock-spec-builders_test.cc for more details.
+//
+// This macro supports statements both with and without parameter matchers. If
+// the parameter list is omitted, gMock will accept any parameters, which allows
+// tests to be written that don't need to encode the number of method
+// parameter. This technique may only be used for non-overloaded methods.
+//
+//   // These are the same:
+//   ON_CALL(mock, NoArgsMethod()).WillByDefault(...);
+//   ON_CALL(mock, NoArgsMethod).WillByDefault(...);
+//
+//   // As are these:
+//   ON_CALL(mock, TwoArgsMethod(_, _)).WillByDefault(...);
+//   ON_CALL(mock, TwoArgsMethod).WillByDefault(...);
+//
+//   // Can also specify args if you want, of course:
+//   ON_CALL(mock, TwoArgsMethod(_, 45)).WillByDefault(...);
+//
+//   // Overloads work as long as you specify parameters:
+//   ON_CALL(mock, OverloadedMethod(_)).WillByDefault(...);
+//   ON_CALL(mock, OverloadedMethod(_, _)).WillByDefault(...);
+//
+//   // Oops! Which overload did you want?
+//   ON_CALL(mock, OverloadedMethod).WillByDefault(...);
+//     => ERROR: call to member function 'gmock_OverloadedMethod' is ambiguous
+//
+// How this works: The mock class uses two overloads of the gmock_Method
+// expectation setter method plus an operator() overload on the MockSpec object.
+// In the matcher list form, the macro expands to:
+//
+//   // This statement:
+//   ON_CALL(mock, TwoArgsMethod(_, 45))...
+//
+//   // ...expands to:
+//   mock.gmock_TwoArgsMethod(_, 45)(WithoutMatchers(), nullptr)...
+//   |-------------v---------------||------------v-------------|
+//       invokes first overload        swallowed by operator()
+//
+//   // ...which is essentially:
+//   mock.gmock_TwoArgsMethod(_, 45)...
+//
+// Whereas the form without a matcher list:
+//
+//   // This statement:
+//   ON_CALL(mock, TwoArgsMethod)...
+//
+//   // ...expands to:
+//   mock.gmock_TwoArgsMethod(WithoutMatchers(), nullptr)...
+//   |-----------------------v--------------------------|
+//                 invokes second overload
+//
+//   // ...which is essentially:
+//   mock.gmock_TwoArgsMethod(_, _)...
+//
+// The WithoutMatchers() argument is used to disambiguate overloads and to
+// block the caller from accidentally invoking the second overload directly. The
+// second argument is an internal type derived from the method signature. The
+// failure to disambiguate two overloads of this method in the ON_CALL statement
+// is how we block callers from setting expectations on overloaded methods.
+#define GMOCK_ON_CALL_IMPL_(mock_expr, Setter, call)                    \
+  ((mock_expr).gmock_##call)(::testing::internal::GetWithoutMatchers(), \
+                             nullptr)                                   \
+      .Setter(__FILE__, __LINE__, #mock_expr, #call)
+
+#define ON_CALL(obj, call) \
+  GMOCK_ON_CALL_IMPL_(obj, InternalDefaultActionSetAt, call)
+
+#define EXPECT_CALL(obj, call) \
+  GMOCK_ON_CALL_IMPL_(obj, InternalExpectedAt, call)
+
+#endif  // GOOGLEMOCK_INCLUDE_GMOCK_GMOCK_SPEC_BUILDERS_H_

contrib/googletest/googlemock/include/gmock/gmock.h

@@ -0,0 +1,96 @@
+// Copyright 2007, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+// Google Mock - a framework for writing C++ mock classes.
+//
+// This is the main header file a user should include.
+
+#ifndef GOOGLEMOCK_INCLUDE_GMOCK_GMOCK_H_
+#define GOOGLEMOCK_INCLUDE_GMOCK_GMOCK_H_
+
+// This file implements the following syntax:
+//
+//   ON_CALL(mock_object, Method(...))
+//     .With(...) ?
+//     .WillByDefault(...);
+//
+// where With() is optional and WillByDefault() must appear exactly
+// once.
+//
+//   EXPECT_CALL(mock_object, Method(...))
+//     .With(...) ?
+//     .Times(...) ?
+//     .InSequence(...) *
+//     .WillOnce(...) *
+//     .WillRepeatedly(...) ?
+//     .RetiresOnSaturation() ? ;
+//
+// where all clauses are optional and WillOnce() can be repeated.
+
+#include "gmock/gmock-actions.h"
+#include "gmock/gmock-cardinalities.h"
+#include "gmock/gmock-function-mocker.h"
+#include "gmock/gmock-matchers.h"
+#include "gmock/gmock-more-actions.h"
+#include "gmock/gmock-more-matchers.h"
+#include "gmock/gmock-nice-strict.h"
+#include "gmock/internal/gmock-internal-utils.h"
+#include "gmock/internal/gmock-port.h"
+
+// Declares Google Mock flags that we want a user to use programmatically.
+GMOCK_DECLARE_bool_(catch_leaked_mocks);
+GMOCK_DECLARE_string_(verbose);
+GMOCK_DECLARE_int32_(default_mock_behavior);
+
+namespace testing {
+
+// Initializes Google Mock.  This must be called before running the
+// tests.  In particular, it parses the command line for the flags
+// that Google Mock recognizes.  Whenever a Google Mock flag is seen,
+// it is removed from argv, and *argc is decremented.
+//
+// No value is returned.  Instead, the Google Mock flag variables are
+// updated.
+//
+// Since Google Test is needed for Google Mock to work, this function
+// also initializes Google Test and parses its flags, if that hasn't
+// been done.
+GTEST_API_ void InitGoogleMock(int* argc, char** argv);
+
+// This overloaded version can be used in Windows programs compiled in
+// UNICODE mode.
+GTEST_API_ void InitGoogleMock(int* argc, wchar_t** argv);
+
+// This overloaded version can be used on Arduino/embedded platforms where
+// there is no argc/argv.
+GTEST_API_ void InitGoogleMock();
+
+}  // namespace testing
+
+#endif  // GOOGLEMOCK_INCLUDE_GMOCK_GMOCK_H_

contrib/googletest/googlemock/include/gmock/internal/custom/README.md

@@ -0,0 +1,18 @@
+# Customization Points
+
+The custom directory is an injection point for custom user configurations.
+
+## Header `gmock-port.h`
+
+The following macros can be defined:
+
+### Flag related macros:
+
+*   `GMOCK_DECLARE_bool_(name)`
+*   `GMOCK_DECLARE_int32_(name)`
+*   `GMOCK_DECLARE_string_(name)`
+*   `GMOCK_DEFINE_bool_(name, default_val, doc)`
+*   `GMOCK_DEFINE_int32_(name, default_val, doc)`
+*   `GMOCK_DEFINE_string_(name, default_val, doc)`
+*   `GMOCK_FLAG_GET(flag_name)`
+*   `GMOCK_FLAG_SET(flag_name, value)`

contrib/googletest/googlemock/include/gmock/internal/custom/gmock-generated-actions.h

@@ -0,0 +1,7 @@
+// IWYU pragma: private, include "gmock/gmock.h"
+// IWYU pragma: friend gmock/.*
+
+#ifndef GOOGLEMOCK_INCLUDE_GMOCK_INTERNAL_CUSTOM_GMOCK_GENERATED_ACTIONS_H_
+#define GOOGLEMOCK_INCLUDE_GMOCK_INTERNAL_CUSTOM_GMOCK_GENERATED_ACTIONS_H_
+
+#endif  // GOOGLEMOCK_INCLUDE_GMOCK_INTERNAL_CUSTOM_GMOCK_GENERATED_ACTIONS_H_

contrib/googletest/googlemock/include/gmock/internal/custom/gmock-matchers.h

@@ -0,0 +1,37 @@
+// Copyright 2015, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+// Injection point for custom user configurations. See README for details
+
+// IWYU pragma: private, include "gmock/gmock.h"
+// IWYU pragma: friend gmock/.*
+
+#ifndef GOOGLEMOCK_INCLUDE_GMOCK_INTERNAL_CUSTOM_GMOCK_MATCHERS_H_
+#define GOOGLEMOCK_INCLUDE_GMOCK_INTERNAL_CUSTOM_GMOCK_MATCHERS_H_
+#endif  // GOOGLEMOCK_INCLUDE_GMOCK_INTERNAL_CUSTOM_GMOCK_MATCHERS_H_

contrib/gtest/codegear/gtest_link.cc → contrib/googletest/googlemock/include/gmock/internal/custom/gmock-port.h

@@ -1,4 +1,4 @@
-// Copyright 2009, Google Inc.
+// Copyright 2015, Google Inc.
 // All rights reserved.
 //
 // Redistribution and use in source and binary forms, with or without
@@ -26,15 +26,15 @@
 // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+// Injection point for custom user configurations. See README for details
 //
-// Author: Josh Kelley ([email protected])
-//
-// Google C++ Testing Framework (Google Test)
-//
-// Links gtest.lib and gtest_main.lib into the current project in C++Builder.
-// This means that these libraries can't be renamed, but it's the only way to
-// ensure that Debug versus Release test builds are linked against the
-// appropriate Debug or Release build of the libraries.
+// ** Custom implementation starts here **
+
+// IWYU pragma: private, include "gmock/gmock.h"
+// IWYU pragma: friend gmock/.*
+
+#ifndef GOOGLEMOCK_INCLUDE_GMOCK_INTERNAL_CUSTOM_GMOCK_PORT_H_
+#define GOOGLEMOCK_INCLUDE_GMOCK_INTERNAL_CUSTOM_GMOCK_PORT_H_
 
-#pragma link "gtest.lib"
-#pragma link "gtest_main.lib"
+#endif  // GOOGLEMOCK_INCLUDE_GMOCK_INTERNAL_CUSTOM_GMOCK_PORT_H_

contrib/googletest/googlemock/include/gmock/internal/gmock-internal-utils.h

@@ -0,0 +1,487 @@
+// Copyright 2007, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+// Google Mock - a framework for writing C++ mock classes.
+//
+// This file defines some utilities useful for implementing Google
+// Mock.  They are subject to change without notice, so please DO NOT
+// USE THEM IN USER CODE.
+
+// IWYU pragma: private, include "gmock/gmock.h"
+// IWYU pragma: friend gmock/.*
+
+#ifndef GOOGLEMOCK_INCLUDE_GMOCK_INTERNAL_GMOCK_INTERNAL_UTILS_H_
+#define GOOGLEMOCK_INCLUDE_GMOCK_INTERNAL_GMOCK_INTERNAL_UTILS_H_
+
+#include <stdio.h>
+
+#include <ostream>  // NOLINT
+#include <string>
+#include <type_traits>
+#include <vector>
+
+#include "gmock/internal/gmock-port.h"
+#include "gtest/gtest.h"
+
+namespace testing {
+
+template <typename>
+class Matcher;
+
+namespace internal {
+
+// Silence MSVC C4100 (unreferenced formal parameter) and
+// C4805('==': unsafe mix of type 'const int' and type 'const bool')
+GTEST_DISABLE_MSC_WARNINGS_PUSH_(4100 4805)
+
+// Joins a vector of strings as if they are fields of a tuple; returns
+// the joined string.
+GTEST_API_ std::string JoinAsKeyValueTuple(
+    const std::vector<const char*>& names, const Strings& values);
+
+// Converts an identifier name to a space-separated list of lower-case
+// words.  Each maximum substring of the form [A-Za-z][a-z]*|\d+ is
+// treated as one word.  For example, both "FooBar123" and
+// "foo_bar_123" are converted to "foo bar 123".
+GTEST_API_ std::string ConvertIdentifierNameToWords(const char* id_name);
+
+// GetRawPointer(p) returns the raw pointer underlying p when p is a
+// smart pointer, or returns p itself when p is already a raw pointer.
+// The following default implementation is for the smart pointer case.
+template <typename Pointer>
+inline const typename Pointer::element_type* GetRawPointer(const Pointer& p) {
+  return p.get();
+}
+// This overload version is for std::reference_wrapper, which does not work with
+// the overload above, as it does not have an `element_type`.
+template <typename Element>
+inline const Element* GetRawPointer(const std::reference_wrapper<Element>& r) {
+  return &r.get();
+}
+
+// This overloaded version is for the raw pointer case.
+template <typename Element>
+inline Element* GetRawPointer(Element* p) {
+  return p;
+}
+
+// Default definitions for all compilers.
+// NOTE: If you implement support for other compilers, make sure to avoid
+// unexpected overlaps.
+// (e.g., Clang also processes #pragma GCC, and clang-cl also handles _MSC_VER.)
+#define GMOCK_INTERNAL_WARNING_PUSH()
+#define GMOCK_INTERNAL_WARNING_CLANG(Level, Name)
+#define GMOCK_INTERNAL_WARNING_POP()
+
+#if defined(__clang__)
+#undef GMOCK_INTERNAL_WARNING_PUSH
+#define GMOCK_INTERNAL_WARNING_PUSH() _Pragma("clang diagnostic push")
+#undef GMOCK_INTERNAL_WARNING_CLANG
+#define GMOCK_INTERNAL_WARNING_CLANG(Level, Warning) \
+  _Pragma(GMOCK_PP_INTERNAL_STRINGIZE(clang diagnostic Level Warning))
+#undef GMOCK_INTERNAL_WARNING_POP
+#define GMOCK_INTERNAL_WARNING_POP() _Pragma("clang diagnostic pop")
+#endif
+
+// MSVC treats wchar_t as a native type usually, but treats it as the
+// same as unsigned short when the compiler option /Zc:wchar_t- is
+// specified.  It defines _NATIVE_WCHAR_T_DEFINED symbol when wchar_t
+// is a native type.
+#if defined(_MSC_VER) && !defined(_NATIVE_WCHAR_T_DEFINED)
+// wchar_t is a typedef.
+#else
+#define GMOCK_WCHAR_T_IS_NATIVE_ 1
+#endif
+
+// In what follows, we use the term "kind" to indicate whether a type
+// is bool, an integer type (excluding bool), a floating-point type,
+// or none of them.  This categorization is useful for determining
+// when a matcher argument type can be safely converted to another
+// type in the implementation of SafeMatcherCast.
+enum TypeKind { kBool, kInteger, kFloatingPoint, kOther };
+
+// KindOf<T>::value is the kind of type T.
+template <typename T>
+struct KindOf {
+  enum { value = kOther };  // The default kind.
+};
+
+// This macro declares that the kind of 'type' is 'kind'.
+#define GMOCK_DECLARE_KIND_(type, kind) \
+  template <>                           \
+  struct KindOf<type> {                 \
+    enum { value = kind };              \
+  }
+
+GMOCK_DECLARE_KIND_(bool, kBool);
+
+// All standard integer types.
+GMOCK_DECLARE_KIND_(char, kInteger);
+GMOCK_DECLARE_KIND_(signed char, kInteger);
+GMOCK_DECLARE_KIND_(unsigned char, kInteger);
+GMOCK_DECLARE_KIND_(short, kInteger);           // NOLINT
+GMOCK_DECLARE_KIND_(unsigned short, kInteger);  // NOLINT
+GMOCK_DECLARE_KIND_(int, kInteger);
+GMOCK_DECLARE_KIND_(unsigned int, kInteger);
+GMOCK_DECLARE_KIND_(long, kInteger);                // NOLINT
+GMOCK_DECLARE_KIND_(unsigned long, kInteger);       // NOLINT
+GMOCK_DECLARE_KIND_(long long, kInteger);           // NOLINT
+GMOCK_DECLARE_KIND_(unsigned long long, kInteger);  // NOLINT
+
+#if GMOCK_WCHAR_T_IS_NATIVE_
+GMOCK_DECLARE_KIND_(wchar_t, kInteger);
+#endif
+
+// All standard floating-point types.
+GMOCK_DECLARE_KIND_(float, kFloatingPoint);
+GMOCK_DECLARE_KIND_(double, kFloatingPoint);
+GMOCK_DECLARE_KIND_(long double, kFloatingPoint);
+
+#undef GMOCK_DECLARE_KIND_
+
+// Evaluates to the kind of 'type'.
+#define GMOCK_KIND_OF_(type)                   \
+  static_cast< ::testing::internal::TypeKind>( \
+      ::testing::internal::KindOf<type>::value)
+
+// LosslessArithmeticConvertibleImpl<kFromKind, From, kToKind, To>::value
+// is true if and only if arithmetic type From can be losslessly converted to
+// arithmetic type To.
+//
+// It's the user's responsibility to ensure that both From and To are
+// raw (i.e. has no CV modifier, is not a pointer, and is not a
+// reference) built-in arithmetic types, kFromKind is the kind of
+// From, and kToKind is the kind of To; the value is
+// implementation-defined when the above pre-condition is violated.
+template <TypeKind kFromKind, typename From, TypeKind kToKind, typename To>
+using LosslessArithmeticConvertibleImpl = std::integral_constant<
+    bool,
+    // clang-format off
+      // Converting from bool is always lossless
+      (kFromKind == kBool) ? true
+      // Converting between any other type kinds will be lossy if the type
+      // kinds are not the same.
+    : (kFromKind != kToKind) ? false
+    : (kFromKind == kInteger &&
+       // Converting between integers of different widths is allowed so long
+       // as the conversion does not go from signed to unsigned.
+      (((sizeof(From) < sizeof(To)) &&
+        !(std::is_signed<From>::value && !std::is_signed<To>::value)) ||
+       // Converting between integers of the same width only requires the
+       // two types to have the same signedness.
+       ((sizeof(From) == sizeof(To)) &&
+        (std::is_signed<From>::value == std::is_signed<To>::value)))
+       ) ? true
+      // Floating point conversions are lossless if and only if `To` is at least
+      // as wide as `From`.
+    : (kFromKind == kFloatingPoint && (sizeof(From) <= sizeof(To))) ? true
+    : false
+    // clang-format on
+    >;
+
+// LosslessArithmeticConvertible<From, To>::value is true if and only if
+// arithmetic type From can be losslessly converted to arithmetic type To.
+//
+// It's the user's responsibility to ensure that both From and To are
+// raw (i.e. has no CV modifier, is not a pointer, and is not a
+// reference) built-in arithmetic types; the value is
+// implementation-defined when the above pre-condition is violated.
+template <typename From, typename To>
+using LosslessArithmeticConvertible =
+    LosslessArithmeticConvertibleImpl<GMOCK_KIND_OF_(From), From,
+                                      GMOCK_KIND_OF_(To), To>;
+
+// This interface knows how to report a Google Mock failure (either
+// non-fatal or fatal).
+class FailureReporterInterface {
+ public:
+  // The type of a failure (either non-fatal or fatal).
+  enum FailureType { kNonfatal, kFatal };
+
+  virtual ~FailureReporterInterface() = default;
+
+  // Reports a failure that occurred at the given source file location.
+  virtual void ReportFailure(FailureType type, const char* file, int line,
+                             const std::string& message) = 0;
+};
+
+// Returns the failure reporter used by Google Mock.
+GTEST_API_ FailureReporterInterface* GetFailureReporter();
+
+// Asserts that condition is true; aborts the process with the given
+// message if condition is false.  We cannot use LOG(FATAL) or CHECK()
+// as Google Mock might be used to mock the log sink itself.  We
+// inline this function to prevent it from showing up in the stack
+// trace.
+inline void Assert(bool condition, const char* file, int line,
+                   const std::string& msg) {
+  if (!condition) {
+    GetFailureReporter()->ReportFailure(FailureReporterInterface::kFatal, file,
+                                        line, msg);
+  }
+}
+inline void Assert(bool condition, const char* file, int line) {
+  Assert(condition, file, line, "Assertion failed.");
+}
+
+// Verifies that condition is true; generates a non-fatal failure if
+// condition is false.
+inline void Expect(bool condition, const char* file, int line,
+                   const std::string& msg) {
+  if (!condition) {
+    GetFailureReporter()->ReportFailure(FailureReporterInterface::kNonfatal,
+                                        file, line, msg);
+  }
+}
+inline void Expect(bool condition, const char* file, int line) {
+  Expect(condition, file, line, "Expectation failed.");
+}
+
+// Severity level of a log.
+enum LogSeverity { kInfo = 0, kWarning = 1 };
+
+// Valid values for the --gmock_verbose flag.
+
+// All logs (informational and warnings) are printed.
+const char kInfoVerbosity[] = "info";
+// Only warnings are printed.
+const char kWarningVerbosity[] = "warning";
+// No logs are printed.
+const char kErrorVerbosity[] = "error";
+
+// Returns true if and only if a log with the given severity is visible
+// according to the --gmock_verbose flag.
+GTEST_API_ bool LogIsVisible(LogSeverity severity);
+
+// Prints the given message to stdout if and only if 'severity' >= the level
+// specified by the --gmock_verbose flag.  If stack_frames_to_skip >=
+// 0, also prints the stack trace excluding the top
+// stack_frames_to_skip frames.  In opt mode, any positive
+// stack_frames_to_skip is treated as 0, since we don't know which
+// function calls will be inlined by the compiler and need to be
+// conservative.
+GTEST_API_ void Log(LogSeverity severity, const std::string& message,
+                    int stack_frames_to_skip);
+
+// A marker class that is used to resolve parameterless expectations to the
+// correct overload. This must not be instantiable, to prevent client code from
+// accidentally resolving to the overload; for example:
+//
+//    ON_CALL(mock, Method({}, nullptr))...
+//
+class WithoutMatchers {
+ private:
+  WithoutMatchers() {}
+  friend GTEST_API_ WithoutMatchers GetWithoutMatchers();
+};
+
+// Internal use only: access the singleton instance of WithoutMatchers.
+GTEST_API_ WithoutMatchers GetWithoutMatchers();
+
+// Invalid<T>() is usable as an expression of type T, but will terminate
+// the program with an assertion failure if actually run.  This is useful
+// when a value of type T is needed for compilation, but the statement
+// will not really be executed (or we don't care if the statement
+// crashes).
+template <typename T>
+inline T Invalid() {
+  Assert(/*condition=*/false, /*file=*/"", /*line=*/-1,
+         "Internal error: attempt to return invalid value");
+#if defined(__GNUC__) || defined(__clang__)
+  __builtin_unreachable();
+#elif defined(_MSC_VER)
+  __assume(0);
+#else
+  return Invalid<T>();
+#endif
+}
+
+// Given a raw type (i.e. having no top-level reference or const
+// modifier) RawContainer that's either an STL-style container or a
+// native array, class StlContainerView<RawContainer> has the
+// following members:
+//
+//   - type is a type that provides an STL-style container view to
+//     (i.e. implements the STL container concept for) RawContainer;
+//   - const_reference is a type that provides a reference to a const
+//     RawContainer;
+//   - ConstReference(raw_container) returns a const reference to an STL-style
+//     container view to raw_container, which is a RawContainer.
+//   - Copy(raw_container) returns an STL-style container view of a
+//     copy of raw_container, which is a RawContainer.
+//
+// This generic version is used when RawContainer itself is already an
+// STL-style container.
+template <class RawContainer>
+class StlContainerView {
+ public:
+  typedef RawContainer type;
+  typedef const type& const_reference;
+
+  static const_reference ConstReference(const RawContainer& container) {
+    static_assert(!std::is_const<RawContainer>::value,
+                  "RawContainer type must not be const");
+    return container;
+  }
+  static type Copy(const RawContainer& container) { return container; }
+};
+
+// This specialization is used when RawContainer is a native array type.
+template <typename Element, size_t N>
+class StlContainerView<Element[N]> {
+ public:
+  typedef typename std::remove_const<Element>::type RawElement;
+  typedef internal::NativeArray<RawElement> type;
+  // NativeArray<T> can represent a native array either by value or by
+  // reference (selected by a constructor argument), so 'const type'
+  // can be used to reference a const native array.  We cannot
+  // 'typedef const type& const_reference' here, as that would mean
+  // ConstReference() has to return a reference to a local variable.
+  typedef const type const_reference;
+
+  static const_reference ConstReference(const Element (&array)[N]) {
+    static_assert(std::is_same<Element, RawElement>::value,
+                  "Element type must not be const");
+    return type(array, N, RelationToSourceReference());
+  }
+  static type Copy(const Element (&array)[N]) {
+    return type(array, N, RelationToSourceCopy());
+  }
+};
+
+// This specialization is used when RawContainer is a native array
+// represented as a (pointer, size) tuple.
+template <typename ElementPointer, typename Size>
+class StlContainerView< ::std::tuple<ElementPointer, Size> > {
+ public:
+  typedef typename std::remove_const<
+      typename std::pointer_traits<ElementPointer>::element_type>::type
+      RawElement;
+  typedef internal::NativeArray<RawElement> type;
+  typedef const type const_reference;
+
+  static const_reference ConstReference(
+      const ::std::tuple<ElementPointer, Size>& array) {
+    return type(std::get<0>(array), std::get<1>(array),
+                RelationToSourceReference());
+  }
+  static type Copy(const ::std::tuple<ElementPointer, Size>& array) {
+    return type(std::get<0>(array), std::get<1>(array), RelationToSourceCopy());
+  }
+};
+
+// The following specialization prevents the user from instantiating
+// StlContainer with a reference type.
+template <typename T>
+class StlContainerView<T&>;
+
+// A type transform to remove constness from the first part of a pair.
+// Pairs like that are used as the value_type of associative containers,
+// and this transform produces a similar but assignable pair.
+template <typename T>
+struct RemoveConstFromKey {
+  typedef T type;
+};
+
+// Partially specialized to remove constness from std::pair<const K, V>.
+template <typename K, typename V>
+struct RemoveConstFromKey<std::pair<const K, V> > {
+  typedef std::pair<K, V> type;
+};
+
+// Emit an assertion failure due to incorrect DoDefault() usage. Out-of-lined to
+// reduce code size.
+GTEST_API_ void IllegalDoDefault(const char* file, int line);
+
+template <typename F, typename Tuple, size_t... Idx>
+auto ApplyImpl(F&& f, Tuple&& args, IndexSequence<Idx...>)
+    -> decltype(std::forward<F>(f)(
+        std::get<Idx>(std::forward<Tuple>(args))...)) {
+  return std::forward<F>(f)(std::get<Idx>(std::forward<Tuple>(args))...);
+}
+
+// Apply the function to a tuple of arguments.
+template <typename F, typename Tuple>
+auto Apply(F&& f, Tuple&& args) -> decltype(ApplyImpl(
+    std::forward<F>(f), std::forward<Tuple>(args),
+    MakeIndexSequence<std::tuple_size<
+        typename std::remove_reference<Tuple>::type>::value>())) {
+  return ApplyImpl(std::forward<F>(f), std::forward<Tuple>(args),
+                   MakeIndexSequence<std::tuple_size<
+                       typename std::remove_reference<Tuple>::type>::value>());
+}
+
+// Template struct Function<F>, where F must be a function type, contains
+// the following typedefs:
+//
+//   Result:               the function's return type.
+//   Arg<N>:               the type of the N-th argument, where N starts with 0.
+//   ArgumentTuple:        the tuple type consisting of all parameters of F.
+//   ArgumentMatcherTuple: the tuple type consisting of Matchers for all
+//                         parameters of F.
+//   MakeResultVoid:       the function type obtained by substituting void
+//                         for the return type of F.
+//   MakeResultIgnoredValue:
+//                         the function type obtained by substituting Something
+//                         for the return type of F.
+template <typename T>
+struct Function;
+
+template <typename R, typename... Args>
+struct Function<R(Args...)> {
+  using Result = R;
+  static constexpr size_t ArgumentCount = sizeof...(Args);
+  template <size_t I>
+  using Arg = ElemFromList<I, Args...>;
+  using ArgumentTuple = std::tuple<Args...>;
+  using ArgumentMatcherTuple = std::tuple<Matcher<Args>...>;
+  using MakeResultVoid = void(Args...);
+  using MakeResultIgnoredValue = IgnoredValue(Args...);
+};
+
+#ifdef GTEST_INTERNAL_NEED_REDUNDANT_CONSTEXPR_DECL
+template <typename R, typename... Args>
+constexpr size_t Function<R(Args...)>::ArgumentCount;
+#endif
+
+// Workaround for MSVC error C2039: 'type': is not a member of 'std'
+// when std::tuple_element is used.
+// See: https://github.com/google/googletest/issues/3931
+// Can be replaced with std::tuple_element_t in C++14.
+template <size_t I, typename T>
+using TupleElement = typename std::tuple_element<I, T>::type;
+
+bool Base64Unescape(const std::string& encoded, std::string* decoded);
+
+GTEST_DISABLE_MSC_WARNINGS_POP_()  // 4100 4805
+
+}  // namespace internal
+}  // namespace testing
+
+#endif  // GOOGLEMOCK_INCLUDE_GMOCK_INTERNAL_GMOCK_INTERNAL_UTILS_H_

contrib/googletest/googlemock/include/gmock/internal/gmock-port.h

@@ -0,0 +1,139 @@
+// Copyright 2008, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+// Low-level types and utilities for porting Google Mock to various
+// platforms.  All macros ending with _ and symbols defined in an
+// internal namespace are subject to change without notice.  Code
+// outside Google Mock MUST NOT USE THEM DIRECTLY.  Macros that don't
+// end with _ are part of Google Mock's public API and can be used by
+// code outside Google Mock.
+
+// IWYU pragma: private, include "gmock/gmock.h"
+// IWYU pragma: friend gmock/.*
+
+#ifndef GOOGLEMOCK_INCLUDE_GMOCK_INTERNAL_GMOCK_PORT_H_
+#define GOOGLEMOCK_INCLUDE_GMOCK_INTERNAL_GMOCK_PORT_H_
+
+#include <assert.h>
+#include <stdlib.h>
+#include <cstdint>
+#include <iostream>
+
+// Most of the utilities needed for porting Google Mock are also
+// required for Google Test and are defined in gtest-port.h.
+//
+// Note to maintainers: to reduce code duplication, prefer adding
+// portability utilities to Google Test's gtest-port.h instead of
+// here, as Google Mock depends on Google Test.  Only add a utility
+// here if it's truly specific to Google Mock.
+
+#include "gmock/internal/custom/gmock-port.h"
+#include "gtest/internal/gtest-port.h"
+
+#ifdef GTEST_HAS_ABSL
+#include "absl/flags/declare.h"
+#include "absl/flags/flag.h"
+#endif
+
+// For MS Visual C++, check the compiler version. At least VS 2015 is
+// required to compile Google Mock.
+#if defined(_MSC_VER) && _MSC_VER < 1900
+#error "At least Visual C++ 2015 (14.0) is required to compile Google Mock."
+#endif
+
+// Macro for referencing flags.  This is public as we want the user to
+// use this syntax to reference Google Mock flags.
+#define GMOCK_FLAG_NAME_(name) gmock_##name
+#define GMOCK_FLAG(name) FLAGS_gmock_##name
+
+// Pick a command line flags implementation.
+#ifdef GTEST_HAS_ABSL
+
+// Macros for defining flags.
+#define GMOCK_DEFINE_bool_(name, default_val, doc) \
+  ABSL_FLAG(bool, GMOCK_FLAG_NAME_(name), default_val, doc)
+#define GMOCK_DEFINE_int32_(name, default_val, doc) \
+  ABSL_FLAG(int32_t, GMOCK_FLAG_NAME_(name), default_val, doc)
+#define GMOCK_DEFINE_string_(name, default_val, doc) \
+  ABSL_FLAG(std::string, GMOCK_FLAG_NAME_(name), default_val, doc)
+
+// Macros for declaring flags.
+#define GMOCK_DECLARE_bool_(name) \
+  ABSL_DECLARE_FLAG(bool, GMOCK_FLAG_NAME_(name))
+#define GMOCK_DECLARE_int32_(name) \
+  ABSL_DECLARE_FLAG(int32_t, GMOCK_FLAG_NAME_(name))
+#define GMOCK_DECLARE_string_(name) \
+  ABSL_DECLARE_FLAG(std::string, GMOCK_FLAG_NAME_(name))
+
+#define GMOCK_FLAG_GET(name) ::absl::GetFlag(GMOCK_FLAG(name))
+#define GMOCK_FLAG_SET(name, value) \
+  (void)(::absl::SetFlag(&GMOCK_FLAG(name), value))
+
+#else  // GTEST_HAS_ABSL
+
+// Macros for defining flags.
+#define GMOCK_DEFINE_bool_(name, default_val, doc)  \
+  namespace testing {                               \
+  GTEST_API_ bool GMOCK_FLAG(name) = (default_val); \
+  }                                                 \
+  static_assert(true, "no-op to require trailing semicolon")
+#define GMOCK_DEFINE_int32_(name, default_val, doc)    \
+  namespace testing {                                  \
+  GTEST_API_ int32_t GMOCK_FLAG(name) = (default_val); \
+  }                                                    \
+  static_assert(true, "no-op to require trailing semicolon")
+#define GMOCK_DEFINE_string_(name, default_val, doc)         \
+  namespace testing {                                        \
+  GTEST_API_ ::std::string GMOCK_FLAG(name) = (default_val); \
+  }                                                          \
+  static_assert(true, "no-op to require trailing semicolon")
+
+// Macros for declaring flags.
+#define GMOCK_DECLARE_bool_(name)          \
+  namespace testing {                      \
+  GTEST_API_ extern bool GMOCK_FLAG(name); \
+  }                                        \
+  static_assert(true, "no-op to require trailing semicolon")
+#define GMOCK_DECLARE_int32_(name)            \
+  namespace testing {                         \
+  GTEST_API_ extern int32_t GMOCK_FLAG(name); \
+  }                                           \
+  static_assert(true, "no-op to require trailing semicolon")
+#define GMOCK_DECLARE_string_(name)                 \
+  namespace testing {                               \
+  GTEST_API_ extern ::std::string GMOCK_FLAG(name); \
+  }                                                 \
+  static_assert(true, "no-op to require trailing semicolon")
+
+#define GMOCK_FLAG_GET(name) ::testing::GMOCK_FLAG(name)
+#define GMOCK_FLAG_SET(name, value) (void)(::testing::GMOCK_FLAG(name) = value)
+
+#endif  // GTEST_HAS_ABSL
+
+#endif  // GOOGLEMOCK_INCLUDE_GMOCK_INTERNAL_GMOCK_PORT_H_

contrib/googletest/googlemock/include/gmock/internal/gmock-pp.h

@@ -0,0 +1,279 @@
+#ifndef GOOGLEMOCK_INCLUDE_GMOCK_INTERNAL_GMOCK_PP_H_
+#define GOOGLEMOCK_INCLUDE_GMOCK_INTERNAL_GMOCK_PP_H_
+
+// Expands and concatenates the arguments. Constructed macros reevaluate.
+#define GMOCK_PP_CAT(_1, _2) GMOCK_PP_INTERNAL_CAT(_1, _2)
+
+// Expands and stringifies the only argument.
+#define GMOCK_PP_STRINGIZE(...) GMOCK_PP_INTERNAL_STRINGIZE(__VA_ARGS__)
+
+// Returns empty. Given a variadic number of arguments.
+#define GMOCK_PP_EMPTY(...)
+
+// Returns a comma. Given a variadic number of arguments.
+#define GMOCK_PP_COMMA(...) ,
+
+// Returns the only argument.
+#define GMOCK_PP_IDENTITY(_1) _1
+
+// Evaluates to the number of arguments after expansion.
+//
+//   #define PAIR x, y
+//
+//   GMOCK_PP_NARG() => 1
+//   GMOCK_PP_NARG(x) => 1
+//   GMOCK_PP_NARG(x, y) => 2
+//   GMOCK_PP_NARG(PAIR) => 2
+//
+// Requires: the number of arguments after expansion is at most 15.
+#define GMOCK_PP_NARG(...) \
+  GMOCK_PP_INTERNAL_16TH(  \
+      (__VA_ARGS__, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, 1, 0))
+
+// Returns 1 if the expansion of arguments has an unprotected comma. Otherwise
+// returns 0. Requires no more than 15 unprotected commas.
+#define GMOCK_PP_HAS_COMMA(...) \
+  GMOCK_PP_INTERNAL_16TH(       \
+      (__VA_ARGS__, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0))
+
+// Returns the first argument.
+#define GMOCK_PP_HEAD(...) GMOCK_PP_INTERNAL_HEAD((__VA_ARGS__, unusedArg))
+
+// Returns the tail. A variadic list of all arguments minus the first. Requires
+// at least one argument.
+#define GMOCK_PP_TAIL(...) GMOCK_PP_INTERNAL_TAIL((__VA_ARGS__))
+
+// Calls CAT(_Macro, NARG(__VA_ARGS__))(__VA_ARGS__)
+#define GMOCK_PP_VARIADIC_CALL(_Macro, ...) \
+  GMOCK_PP_IDENTITY(                        \
+      GMOCK_PP_CAT(_Macro, GMOCK_PP_NARG(__VA_ARGS__))(__VA_ARGS__))
+
+// If the arguments after expansion have no tokens, evaluates to `1`. Otherwise
+// evaluates to `0`.
+//
+// Requires: * the number of arguments after expansion is at most 15.
+//           * If the argument is a macro, it must be able to be called with one
+//             argument.
+//
+// Implementation details:
+//
+// There is one case when it generates a compile error: if the argument is macro
+// that cannot be called with one argument.
+//
+//   #define M(a, b)  // it doesn't matter what it expands to
+//
+//   // Expected: expands to `0`.
+//   // Actual: compile error.
+//   GMOCK_PP_IS_EMPTY(M)
+//
+// There are 4 cases tested:
+//
+// * __VA_ARGS__ possible expansion has no unparen'd commas. Expected 0.
+// * __VA_ARGS__ possible expansion is not enclosed in parenthesis. Expected 0.
+// * __VA_ARGS__ possible expansion is not a macro that ()-evaluates to a comma.
+//   Expected 0
+// * __VA_ARGS__ is empty, or has unparen'd commas, or is enclosed in
+//   parenthesis, or is a macro that ()-evaluates to comma. Expected 1.
+//
+// We trigger detection on '0001', i.e. on empty.
+#define GMOCK_PP_IS_EMPTY(...)                                               \
+  GMOCK_PP_INTERNAL_IS_EMPTY(GMOCK_PP_HAS_COMMA(__VA_ARGS__),                \
+                             GMOCK_PP_HAS_COMMA(GMOCK_PP_COMMA __VA_ARGS__), \
+                             GMOCK_PP_HAS_COMMA(__VA_ARGS__()),              \
+                             GMOCK_PP_HAS_COMMA(GMOCK_PP_COMMA __VA_ARGS__()))
+
+// Evaluates to _Then if _Cond is 1 and _Else if _Cond is 0.
+#define GMOCK_PP_IF(_Cond, _Then, _Else) \
+  GMOCK_PP_CAT(GMOCK_PP_INTERNAL_IF_, _Cond)(_Then, _Else)
+
+// Similar to GMOCK_PP_IF but takes _Then and _Else in parentheses.
+//
+// GMOCK_PP_GENERIC_IF(1, (a, b, c), (d, e, f)) => a, b, c
+// GMOCK_PP_GENERIC_IF(0, (a, b, c), (d, e, f)) => d, e, f
+//
+#define GMOCK_PP_GENERIC_IF(_Cond, _Then, _Else) \
+  GMOCK_PP_REMOVE_PARENS(GMOCK_PP_IF(_Cond, _Then, _Else))
+
+// Evaluates to the number of arguments after expansion. Identifies 'empty' as
+// 0.
+//
+//   #define PAIR x, y
+//
+//   GMOCK_PP_NARG0() => 0
+//   GMOCK_PP_NARG0(x) => 1
+//   GMOCK_PP_NARG0(x, y) => 2
+//   GMOCK_PP_NARG0(PAIR) => 2
+//
+// Requires: * the number of arguments after expansion is at most 15.
+//           * If the argument is a macro, it must be able to be called with one
+//             argument.
+#define GMOCK_PP_NARG0(...) \
+  GMOCK_PP_IF(GMOCK_PP_IS_EMPTY(__VA_ARGS__), 0, GMOCK_PP_NARG(__VA_ARGS__))
+
+// Expands to 1 if the first argument starts with something in parentheses,
+// otherwise to 0.
+#define GMOCK_PP_IS_BEGIN_PARENS(...)                              \
+  GMOCK_PP_HEAD(GMOCK_PP_CAT(GMOCK_PP_INTERNAL_IBP_IS_VARIADIC_R_, \
+                             GMOCK_PP_INTERNAL_IBP_IS_VARIADIC_C __VA_ARGS__))
+
+// Expands to 1 is there is only one argument and it is enclosed in parentheses.
+#define GMOCK_PP_IS_ENCLOSED_PARENS(...)             \
+  GMOCK_PP_IF(GMOCK_PP_IS_BEGIN_PARENS(__VA_ARGS__), \
+              GMOCK_PP_IS_EMPTY(GMOCK_PP_EMPTY __VA_ARGS__), 0)
+
+// Remove the parens, requires GMOCK_PP_IS_ENCLOSED_PARENS(args) => 1.
+#define GMOCK_PP_REMOVE_PARENS(...) GMOCK_PP_INTERNAL_REMOVE_PARENS __VA_ARGS__
+
+// Expands to _Macro(0, _Data, e1) _Macro(1, _Data, e2) ... _Macro(K -1, _Data,
+// eK) as many of GMOCK_INTERNAL_NARG0 _Tuple.
+// Requires: * |_Macro| can be called with 3 arguments.
+//           * |_Tuple| expansion has no more than 15 elements.
+#define GMOCK_PP_FOR_EACH(_Macro, _Data, _Tuple)                        \
+  GMOCK_PP_CAT(GMOCK_PP_INTERNAL_FOR_EACH_IMPL_, GMOCK_PP_NARG0 _Tuple) \
+  (0, _Macro, _Data, _Tuple)
+
+// Expands to _Macro(0, _Data, ) _Macro(1, _Data, ) ... _Macro(K - 1, _Data, )
+// Empty if _K = 0.
+// Requires: * |_Macro| can be called with 3 arguments.
+//           * |_K| literal between 0 and 15
+#define GMOCK_PP_REPEAT(_Macro, _Data, _N)           \
+  GMOCK_PP_CAT(GMOCK_PP_INTERNAL_FOR_EACH_IMPL_, _N) \
+  (0, _Macro, _Data, GMOCK_PP_INTENRAL_EMPTY_TUPLE)
+
+// Increments the argument, requires the argument to be between 0 and 15.
+#define GMOCK_PP_INC(_i) GMOCK_PP_CAT(GMOCK_PP_INTERNAL_INC_, _i)
+
+// Returns comma if _i != 0. Requires _i to be between 0 and 15.
+#define GMOCK_PP_COMMA_IF(_i) GMOCK_PP_CAT(GMOCK_PP_INTERNAL_COMMA_IF_, _i)
+
+// Internal details follow. Do not use any of these symbols outside of this
+// file or we will break your code.
+#define GMOCK_PP_INTENRAL_EMPTY_TUPLE (, , , , , , , , , , , , , , , )
+#define GMOCK_PP_INTERNAL_CAT(_1, _2) _1##_2
+#define GMOCK_PP_INTERNAL_STRINGIZE(...) #__VA_ARGS__
+#define GMOCK_PP_INTERNAL_CAT_5(_1, _2, _3, _4, _5) _1##_2##_3##_4##_5
+#define GMOCK_PP_INTERNAL_IS_EMPTY(_1, _2, _3, _4)                             \
+  GMOCK_PP_HAS_COMMA(GMOCK_PP_INTERNAL_CAT_5(GMOCK_PP_INTERNAL_IS_EMPTY_CASE_, \
+                                             _1, _2, _3, _4))
+#define GMOCK_PP_INTERNAL_IS_EMPTY_CASE_0001 ,
+#define GMOCK_PP_INTERNAL_IF_1(_Then, _Else) _Then
+#define GMOCK_PP_INTERNAL_IF_0(_Then, _Else) _Else
+
+// Because of MSVC treating a token with a comma in it as a single token when
+// passed to another macro, we need to force it to evaluate it as multiple
+// tokens. We do that by using a "IDENTITY(MACRO PARENTHESIZED_ARGS)" macro. We
+// define one per possible macro that relies on this behavior. Note "_Args" must
+// be parenthesized.
+#define GMOCK_PP_INTERNAL_INTERNAL_16TH(_1, _2, _3, _4, _5, _6, _7, _8, _9, \
+                                        _10, _11, _12, _13, _14, _15, _16,  \
+                                        ...)                                \
+  _16
+#define GMOCK_PP_INTERNAL_16TH(_Args) \
+  GMOCK_PP_IDENTITY(GMOCK_PP_INTERNAL_INTERNAL_16TH _Args)
+#define GMOCK_PP_INTERNAL_INTERNAL_HEAD(_1, ...) _1
+#define GMOCK_PP_INTERNAL_HEAD(_Args) \
+  GMOCK_PP_IDENTITY(GMOCK_PP_INTERNAL_INTERNAL_HEAD _Args)
+#define GMOCK_PP_INTERNAL_INTERNAL_TAIL(_1, ...) __VA_ARGS__
+#define GMOCK_PP_INTERNAL_TAIL(_Args) \
+  GMOCK_PP_IDENTITY(GMOCK_PP_INTERNAL_INTERNAL_TAIL _Args)
+
+#define GMOCK_PP_INTERNAL_IBP_IS_VARIADIC_C(...) 1 _
+#define GMOCK_PP_INTERNAL_IBP_IS_VARIADIC_R_1 1,
+#define GMOCK_PP_INTERNAL_IBP_IS_VARIADIC_R_GMOCK_PP_INTERNAL_IBP_IS_VARIADIC_C \
+  0,
+#define GMOCK_PP_INTERNAL_REMOVE_PARENS(...) __VA_ARGS__
+#define GMOCK_PP_INTERNAL_INC_0 1
+#define GMOCK_PP_INTERNAL_INC_1 2
+#define GMOCK_PP_INTERNAL_INC_2 3
+#define GMOCK_PP_INTERNAL_INC_3 4
+#define GMOCK_PP_INTERNAL_INC_4 5
+#define GMOCK_PP_INTERNAL_INC_5 6
+#define GMOCK_PP_INTERNAL_INC_6 7
+#define GMOCK_PP_INTERNAL_INC_7 8
+#define GMOCK_PP_INTERNAL_INC_8 9
+#define GMOCK_PP_INTERNAL_INC_9 10
+#define GMOCK_PP_INTERNAL_INC_10 11
+#define GMOCK_PP_INTERNAL_INC_11 12
+#define GMOCK_PP_INTERNAL_INC_12 13
+#define GMOCK_PP_INTERNAL_INC_13 14
+#define GMOCK_PP_INTERNAL_INC_14 15
+#define GMOCK_PP_INTERNAL_INC_15 16
+#define GMOCK_PP_INTERNAL_COMMA_IF_0
+#define GMOCK_PP_INTERNAL_COMMA_IF_1 ,
+#define GMOCK_PP_INTERNAL_COMMA_IF_2 ,
+#define GMOCK_PP_INTERNAL_COMMA_IF_3 ,
+#define GMOCK_PP_INTERNAL_COMMA_IF_4 ,
+#define GMOCK_PP_INTERNAL_COMMA_IF_5 ,
+#define GMOCK_PP_INTERNAL_COMMA_IF_6 ,
+#define GMOCK_PP_INTERNAL_COMMA_IF_7 ,
+#define GMOCK_PP_INTERNAL_COMMA_IF_8 ,
+#define GMOCK_PP_INTERNAL_COMMA_IF_9 ,
+#define GMOCK_PP_INTERNAL_COMMA_IF_10 ,
+#define GMOCK_PP_INTERNAL_COMMA_IF_11 ,
+#define GMOCK_PP_INTERNAL_COMMA_IF_12 ,
+#define GMOCK_PP_INTERNAL_COMMA_IF_13 ,
+#define GMOCK_PP_INTERNAL_COMMA_IF_14 ,
+#define GMOCK_PP_INTERNAL_COMMA_IF_15 ,
+#define GMOCK_PP_INTERNAL_CALL_MACRO(_Macro, _i, _Data, _element) \
+  _Macro(_i, _Data, _element)
+#define GMOCK_PP_INTERNAL_FOR_EACH_IMPL_0(_i, _Macro, _Data, _Tuple)
+#define GMOCK_PP_INTERNAL_FOR_EACH_IMPL_1(_i, _Macro, _Data, _Tuple) \
+  GMOCK_PP_INTERNAL_CALL_MACRO(_Macro, _i, _Data, GMOCK_PP_HEAD _Tuple)
+#define GMOCK_PP_INTERNAL_FOR_EACH_IMPL_2(_i, _Macro, _Data, _Tuple)    \
+  GMOCK_PP_INTERNAL_CALL_MACRO(_Macro, _i, _Data, GMOCK_PP_HEAD _Tuple) \
+  GMOCK_PP_INTERNAL_FOR_EACH_IMPL_1(GMOCK_PP_INC(_i), _Macro, _Data,    \
+                                    (GMOCK_PP_TAIL _Tuple))
+#define GMOCK_PP_INTERNAL_FOR_EACH_IMPL_3(_i, _Macro, _Data, _Tuple)    \
+  GMOCK_PP_INTERNAL_CALL_MACRO(_Macro, _i, _Data, GMOCK_PP_HEAD _Tuple) \
+  GMOCK_PP_INTERNAL_FOR_EACH_IMPL_2(GMOCK_PP_INC(_i), _Macro, _Data,    \
+                                    (GMOCK_PP_TAIL _Tuple))
+#define GMOCK_PP_INTERNAL_FOR_EACH_IMPL_4(_i, _Macro, _Data, _Tuple)    \
+  GMOCK_PP_INTERNAL_CALL_MACRO(_Macro, _i, _Data, GMOCK_PP_HEAD _Tuple) \
+  GMOCK_PP_INTERNAL_FOR_EACH_IMPL_3(GMOCK_PP_INC(_i), _Macro, _Data,    \
+                                    (GMOCK_PP_TAIL _Tuple))
+#define GMOCK_PP_INTERNAL_FOR_EACH_IMPL_5(_i, _Macro, _Data, _Tuple)    \
+  GMOCK_PP_INTERNAL_CALL_MACRO(_Macro, _i, _Data, GMOCK_PP_HEAD _Tuple) \
+  GMOCK_PP_INTERNAL_FOR_EACH_IMPL_4(GMOCK_PP_INC(_i), _Macro, _Data,    \
+                                    (GMOCK_PP_TAIL _Tuple))
+#define GMOCK_PP_INTERNAL_FOR_EACH_IMPL_6(_i, _Macro, _Data, _Tuple)    \
+  GMOCK_PP_INTERNAL_CALL_MACRO(_Macro, _i, _Data, GMOCK_PP_HEAD _Tuple) \
+  GMOCK_PP_INTERNAL_FOR_EACH_IMPL_5(GMOCK_PP_INC(_i), _Macro, _Data,    \
+                                    (GMOCK_PP_TAIL _Tuple))
+#define GMOCK_PP_INTERNAL_FOR_EACH_IMPL_7(_i, _Macro, _Data, _Tuple)    \
+  GMOCK_PP_INTERNAL_CALL_MACRO(_Macro, _i, _Data, GMOCK_PP_HEAD _Tuple) \
+  GMOCK_PP_INTERNAL_FOR_EACH_IMPL_6(GMOCK_PP_INC(_i), _Macro, _Data,    \
+                                    (GMOCK_PP_TAIL _Tuple))
+#define GMOCK_PP_INTERNAL_FOR_EACH_IMPL_8(_i, _Macro, _Data, _Tuple)    \
+  GMOCK_PP_INTERNAL_CALL_MACRO(_Macro, _i, _Data, GMOCK_PP_HEAD _Tuple) \
+  GMOCK_PP_INTERNAL_FOR_EACH_IMPL_7(GMOCK_PP_INC(_i), _Macro, _Data,    \
+                                    (GMOCK_PP_TAIL _Tuple))
+#define GMOCK_PP_INTERNAL_FOR_EACH_IMPL_9(_i, _Macro, _Data, _Tuple)    \
+  GMOCK_PP_INTERNAL_CALL_MACRO(_Macro, _i, _Data, GMOCK_PP_HEAD _Tuple) \
+  GMOCK_PP_INTERNAL_FOR_EACH_IMPL_8(GMOCK_PP_INC(_i), _Macro, _Data,    \
+                                    (GMOCK_PP_TAIL _Tuple))
+#define GMOCK_PP_INTERNAL_FOR_EACH_IMPL_10(_i, _Macro, _Data, _Tuple)   \
+  GMOCK_PP_INTERNAL_CALL_MACRO(_Macro, _i, _Data, GMOCK_PP_HEAD _Tuple) \
+  GMOCK_PP_INTERNAL_FOR_EACH_IMPL_9(GMOCK_PP_INC(_i), _Macro, _Data,    \
+                                    (GMOCK_PP_TAIL _Tuple))
+#define GMOCK_PP_INTERNAL_FOR_EACH_IMPL_11(_i, _Macro, _Data, _Tuple)   \
+  GMOCK_PP_INTERNAL_CALL_MACRO(_Macro, _i, _Data, GMOCK_PP_HEAD _Tuple) \
+  GMOCK_PP_INTERNAL_FOR_EACH_IMPL_10(GMOCK_PP_INC(_i), _Macro, _Data,   \
+                                     (GMOCK_PP_TAIL _Tuple))
+#define GMOCK_PP_INTERNAL_FOR_EACH_IMPL_12(_i, _Macro, _Data, _Tuple)   \
+  GMOCK_PP_INTERNAL_CALL_MACRO(_Macro, _i, _Data, GMOCK_PP_HEAD _Tuple) \
+  GMOCK_PP_INTERNAL_FOR_EACH_IMPL_11(GMOCK_PP_INC(_i), _Macro, _Data,   \
+                                     (GMOCK_PP_TAIL _Tuple))
+#define GMOCK_PP_INTERNAL_FOR_EACH_IMPL_13(_i, _Macro, _Data, _Tuple)   \
+  GMOCK_PP_INTERNAL_CALL_MACRO(_Macro, _i, _Data, GMOCK_PP_HEAD _Tuple) \
+  GMOCK_PP_INTERNAL_FOR_EACH_IMPL_12(GMOCK_PP_INC(_i), _Macro, _Data,   \
+                                     (GMOCK_PP_TAIL _Tuple))
+#define GMOCK_PP_INTERNAL_FOR_EACH_IMPL_14(_i, _Macro, _Data, _Tuple)   \
+  GMOCK_PP_INTERNAL_CALL_MACRO(_Macro, _i, _Data, GMOCK_PP_HEAD _Tuple) \
+  GMOCK_PP_INTERNAL_FOR_EACH_IMPL_13(GMOCK_PP_INC(_i), _Macro, _Data,   \
+                                     (GMOCK_PP_TAIL _Tuple))
+#define GMOCK_PP_INTERNAL_FOR_EACH_IMPL_15(_i, _Macro, _Data, _Tuple)   \
+  GMOCK_PP_INTERNAL_CALL_MACRO(_Macro, _i, _Data, GMOCK_PP_HEAD _Tuple) \
+  GMOCK_PP_INTERNAL_FOR_EACH_IMPL_14(GMOCK_PP_INC(_i), _Macro, _Data,   \
+                                     (GMOCK_PP_TAIL _Tuple))
+
+#endif  // GOOGLEMOCK_INCLUDE_GMOCK_INTERNAL_GMOCK_PP_H_

contrib/googletest/googlemock/src/gmock-all.cc

@@ -0,0 +1,46 @@
+// Copyright 2008, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+//
+// Google C++ Mocking Framework (Google Mock)
+//
+// This file #includes all Google Mock implementation .cc files.  The
+// purpose is to allow a user to build Google Mock by compiling this
+// file alone.
+
+// This line ensures that gmock.h can be compiled on its own, even
+// when it's fused.
+#include "gmock/gmock.h"
+
+// The following lines pull in the real gmock *.cc files.
+#include "src/gmock-cardinalities.cc"
+#include "src/gmock-internal-utils.cc"
+#include "src/gmock-matchers.cc"
+#include "src/gmock-spec-builders.cc"
+#include "src/gmock.cc"

contrib/googletest/googlemock/src/gmock-cardinalities.cc

@@ -0,0 +1,155 @@
+// Copyright 2007, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+// Google Mock - a framework for writing C++ mock classes.
+//
+// This file implements cardinalities.
+
+#include "gmock/gmock-cardinalities.h"
+
+#include <limits.h>
+
+#include <ostream>  // NOLINT
+#include <sstream>
+#include <string>
+
+#include "gmock/internal/gmock-internal-utils.h"
+#include "gtest/gtest.h"
+
+namespace testing {
+
+namespace {
+
+// Implements the Between(m, n) cardinality.
+class BetweenCardinalityImpl : public CardinalityInterface {
+ public:
+  BetweenCardinalityImpl(int min, int max)
+      : min_(min >= 0 ? min : 0), max_(max >= min_ ? max : min_) {
+    std::stringstream ss;
+    if (min < 0) {
+      ss << "The invocation lower bound must be >= 0, "
+         << "but is actually " << min << ".";
+      internal::Expect(false, __FILE__, __LINE__, ss.str());
+    } else if (max < 0) {
+      ss << "The invocation upper bound must be >= 0, "
+         << "but is actually " << max << ".";
+      internal::Expect(false, __FILE__, __LINE__, ss.str());
+    } else if (min > max) {
+      ss << "The invocation upper bound (" << max
+         << ") must be >= the invocation lower bound (" << min << ").";
+      internal::Expect(false, __FILE__, __LINE__, ss.str());
+    }
+  }
+
+  // Conservative estimate on the lower/upper bound of the number of
+  // calls allowed.
+  int ConservativeLowerBound() const override { return min_; }
+  int ConservativeUpperBound() const override { return max_; }
+
+  bool IsSatisfiedByCallCount(int call_count) const override {
+    return min_ <= call_count && call_count <= max_;
+  }
+
+  bool IsSaturatedByCallCount(int call_count) const override {
+    return call_count >= max_;
+  }
+
+  void DescribeTo(::std::ostream* os) const override;
+
+ private:
+  const int min_;
+  const int max_;
+
+  BetweenCardinalityImpl(const BetweenCardinalityImpl&) = delete;
+  BetweenCardinalityImpl& operator=(const BetweenCardinalityImpl&) = delete;
+};
+
+// Formats "n times" in a human-friendly way.
+inline std::string FormatTimes(int n) {
+  if (n == 1) {
+    return "once";
+  } else if (n == 2) {
+    return "twice";
+  } else {
+    std::stringstream ss;
+    ss << n << " times";
+    return ss.str();
+  }
+}
+
+// Describes the Between(m, n) cardinality in human-friendly text.
+void BetweenCardinalityImpl::DescribeTo(::std::ostream* os) const {
+  if (min_ == 0) {
+    if (max_ == 0) {
+      *os << "never called";
+    } else if (max_ == INT_MAX) {
+      *os << "called any number of times";
+    } else {
+      *os << "called at most " << FormatTimes(max_);
+    }
+  } else if (min_ == max_) {
+    *os << "called " << FormatTimes(min_);
+  } else if (max_ == INT_MAX) {
+    *os << "called at least " << FormatTimes(min_);
+  } else {
+    // 0 < min_ < max_ < INT_MAX
+    *os << "called between " << min_ << " and " << max_ << " times";
+  }
+}
+
+}  // Unnamed namespace
+
+// Describes the given call count to an ostream.
+void Cardinality::DescribeActualCallCountTo(int actual_call_count,
+                                            ::std::ostream* os) {
+  if (actual_call_count > 0) {
+    *os << "called " << FormatTimes(actual_call_count);
+  } else {
+    *os << "never called";
+  }
+}
+
+// Creates a cardinality that allows at least n calls.
+GTEST_API_ Cardinality AtLeast(int n) { return Between(n, INT_MAX); }
+
+// Creates a cardinality that allows at most n calls.
+GTEST_API_ Cardinality AtMost(int n) { return Between(0, n); }
+
+// Creates a cardinality that allows any number of calls.
+GTEST_API_ Cardinality AnyNumber() { return AtLeast(0); }
+
+// Creates a cardinality that allows between min and max calls.
+GTEST_API_ Cardinality Between(int min, int max) {
+  return Cardinality(new BetweenCardinalityImpl(min, max));
+}
+
+// Creates a cardinality that allows exactly n calls.
+GTEST_API_ Cardinality Exactly(int n) { return Between(n, n); }
+
+}  // namespace testing

contrib/googletest/googlemock/src/gmock-internal-utils.cc

@@ -0,0 +1,257 @@
+// Copyright 2007, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+// Google Mock - a framework for writing C++ mock classes.
+//
+// This file defines some utilities useful for implementing Google
+// Mock.  They are subject to change without notice, so please DO NOT
+// USE THEM IN USER CODE.
+
+#include "gmock/internal/gmock-internal-utils.h"
+
+#include <ctype.h>
+
+#include <array>
+#include <cctype>
+#include <cstdint>
+#include <cstring>
+#include <iostream>
+#include <ostream>  // NOLINT
+#include <string>
+#include <vector>
+
+#include "gmock/gmock.h"
+#include "gmock/internal/gmock-port.h"
+#include "gtest/gtest.h"
+
+namespace testing {
+namespace internal {
+
+// Joins a vector of strings as if they are fields of a tuple; returns
+// the joined string.
+GTEST_API_ std::string JoinAsKeyValueTuple(
+    const std::vector<const char*>& names, const Strings& values) {
+  GTEST_CHECK_(names.size() == values.size());
+  if (values.empty()) {
+    return "";
+  }
+  const auto build_one = [&](const size_t i) {
+    return std::string(names[i]) + ": " + values[i];
+  };
+  std::string result = "(" + build_one(0);
+  for (size_t i = 1; i < values.size(); i++) {
+    result += ", ";
+    result += build_one(i);
+  }
+  result += ")";
+  return result;
+}
+
+// Converts an identifier name to a space-separated list of lower-case
+// words.  Each maximum substring of the form [A-Za-z][a-z]*|\d+ is
+// treated as one word.  For example, both "FooBar123" and
+// "foo_bar_123" are converted to "foo bar 123".
+GTEST_API_ std::string ConvertIdentifierNameToWords(const char* id_name) {
+  std::string result;
+  char prev_char = '\0';
+  for (const char* p = id_name; *p != '\0'; prev_char = *(p++)) {
+    // We don't care about the current locale as the input is
+    // guaranteed to be a valid C++ identifier name.
+    const bool starts_new_word = IsUpper(*p) ||
+                                 (!IsAlpha(prev_char) && IsLower(*p)) ||
+                                 (!IsDigit(prev_char) && IsDigit(*p));
+
+    if (IsAlNum(*p)) {
+      if (starts_new_word && !result.empty()) result += ' ';
+      result += ToLower(*p);
+    }
+  }
+  return result;
+}
+
+// This class reports Google Mock failures as Google Test failures.  A
+// user can define another class in a similar fashion if they intend to
+// use Google Mock with a testing framework other than Google Test.
+class GoogleTestFailureReporter : public FailureReporterInterface {
+ public:
+  void ReportFailure(FailureType type, const char* file, int line,
+                     const std::string& message) override {
+    AssertHelper(type == kFatal ? TestPartResult::kFatalFailure
+                                : TestPartResult::kNonFatalFailure,
+                 file, line, message.c_str()) = Message();
+    if (type == kFatal) {
+      posix::Abort();
+    }
+  }
+};
+
+// Returns the global failure reporter.  Will create a
+// GoogleTestFailureReporter and return it the first time called.
+GTEST_API_ FailureReporterInterface* GetFailureReporter() {
+  // Points to the global failure reporter used by Google Mock.  gcc
+  // guarantees that the following use of failure_reporter is
+  // thread-safe.  We may need to add additional synchronization to
+  // protect failure_reporter if we port Google Mock to other
+  // compilers.
+  static FailureReporterInterface* const failure_reporter =
+      new GoogleTestFailureReporter();
+  return failure_reporter;
+}
+
+// Protects global resources (stdout in particular) used by Log().
+static GTEST_DEFINE_STATIC_MUTEX_(g_log_mutex);
+
+// Returns true if and only if a log with the given severity is visible
+// according to the --gmock_verbose flag.
+GTEST_API_ bool LogIsVisible(LogSeverity severity) {
+  if (GMOCK_FLAG_GET(verbose) == kInfoVerbosity) {
+    // Always show the log if --gmock_verbose=info.
+    return true;
+  } else if (GMOCK_FLAG_GET(verbose) == kErrorVerbosity) {
+    // Always hide it if --gmock_verbose=error.
+    return false;
+  } else {
+    // If --gmock_verbose is neither "info" nor "error", we treat it
+    // as "warning" (its default value).
+    return severity == kWarning;
+  }
+}
+
+// Prints the given message to stdout if and only if 'severity' >= the level
+// specified by the --gmock_verbose flag.  If stack_frames_to_skip >=
+// 0, also prints the stack trace excluding the top
+// stack_frames_to_skip frames.  In opt mode, any positive
+// stack_frames_to_skip is treated as 0, since we don't know which
+// function calls will be inlined by the compiler and need to be
+// conservative.
+GTEST_API_ void Log(LogSeverity severity, const std::string& message,
+                    int stack_frames_to_skip) {
+  if (!LogIsVisible(severity)) return;
+
+  // Ensures that logs from different threads don't interleave.
+  MutexLock l(&g_log_mutex);
+
+  if (severity == kWarning) {
+    // Prints a GMOCK WARNING marker to make the warnings easily searchable.
+    std::cout << "\nGMOCK WARNING:";
+  }
+  // Pre-pends a new-line to message if it doesn't start with one.
+  if (message.empty() || message[0] != '\n') {
+    std::cout << "\n";
+  }
+  std::cout << message;
+  if (stack_frames_to_skip >= 0) {
+#ifdef NDEBUG
+    // In opt mode, we have to be conservative and skip no stack frame.
+    const int actual_to_skip = 0;
+#else
+    // In dbg mode, we can do what the caller tell us to do (plus one
+    // for skipping this function's stack frame).
+    const int actual_to_skip = stack_frames_to_skip + 1;
+#endif  // NDEBUG
+
+    // Appends a new-line to message if it doesn't end with one.
+    if (!message.empty() && *message.rbegin() != '\n') {
+      std::cout << "\n";
+    }
+    std::cout << "Stack trace:\n"
+              << ::testing::internal::GetCurrentOsStackTraceExceptTop(
+                     actual_to_skip);
+  }
+  std::cout << ::std::flush;
+}
+
+GTEST_API_ WithoutMatchers GetWithoutMatchers() { return WithoutMatchers(); }
+
+GTEST_API_ void IllegalDoDefault(const char* file, int line) {
+  internal::Assert(
+      false, file, line,
+      "You are using DoDefault() inside a composite action like "
+      "DoAll() or WithArgs().  This is not supported for technical "
+      "reasons.  Please instead spell out the default action, or "
+      "assign the default action to an Action variable and use "
+      "the variable in various places.");
+}
+
+constexpr char UndoWebSafeEncoding(char c) {
+  return c == '-' ? '+' : c == '_' ? '/' : c;
+}
+
+constexpr char UnBase64Impl(char c, const char* const base64, char carry) {
+  return *base64 == 0 ? static_cast<char>(65)
+         : *base64 == c
+             ? carry
+             : UnBase64Impl(c, base64 + 1, static_cast<char>(carry + 1));
+}
+
+template <size_t... I>
+constexpr std::array<char, 256> UnBase64Impl(IndexSequence<I...>,
+                                             const char* const base64) {
+  return {
+      {UnBase64Impl(UndoWebSafeEncoding(static_cast<char>(I)), base64, 0)...}};
+}
+
+constexpr std::array<char, 256> UnBase64(const char* const base64) {
+  return UnBase64Impl(MakeIndexSequence<256>{}, base64);
+}
+
+static constexpr char kBase64[] =
+    "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
+static constexpr std::array<char, 256> kUnBase64 = UnBase64(kBase64);
+
+bool Base64Unescape(const std::string& encoded, std::string* decoded) {
+  decoded->clear();
+  size_t encoded_len = encoded.size();
+  decoded->reserve(3 * (encoded_len / 4) + (encoded_len % 4));
+  int bit_pos = 0;
+  char dst = 0;
+  for (int src : encoded) {
+    if (std::isspace(src) || src == '=') {
+      continue;
+    }
+    char src_bin = kUnBase64[static_cast<size_t>(src)];
+    if (src_bin >= 64) {
+      decoded->clear();
+      return false;
+    }
+    if (bit_pos == 0) {
+      dst |= static_cast<char>(src_bin << 2);
+      bit_pos = 6;
+    } else {
+      dst |= static_cast<char>(src_bin >> (bit_pos - 2));
+      decoded->push_back(dst);
+      dst = static_cast<char>(src_bin << (10 - bit_pos));
+      bit_pos = (bit_pos + 6) % 8;
+    }
+  }
+  return true;
+}
+
+}  // namespace internal
+}  // namespace testing

contrib/googletest/googlemock/src/gmock-matchers.cc

@@ -0,0 +1,479 @@
+// Copyright 2007, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+// Google Mock - a framework for writing C++ mock classes.
+//
+// This file implements Matcher<const string&>, Matcher<string>, and
+// utilities for defining matchers.
+
+#include "gmock/gmock-matchers.h"
+
+#include <string.h>
+
+#include <iostream>
+#include <sstream>
+#include <string>
+#include <vector>
+
+namespace testing {
+namespace internal {
+
+// Returns the description for a matcher defined using the MATCHER*()
+// macro where the user-supplied description string is "", if
+// 'negation' is false; otherwise returns the description of the
+// negation of the matcher.  'param_values' contains a list of strings
+// that are the print-out of the matcher's parameters.
+GTEST_API_ std::string FormatMatcherDescription(
+    bool negation, const char* matcher_name,
+    const std::vector<const char*>& param_names, const Strings& param_values) {
+  std::string result = ConvertIdentifierNameToWords(matcher_name);
+  if (!param_values.empty()) {
+    result += " " + JoinAsKeyValueTuple(param_names, param_values);
+  }
+  return negation ? "not (" + result + ")" : result;
+}
+
+// FindMaxBipartiteMatching and its helper class.
+//
+// Uses the well-known Ford-Fulkerson max flow method to find a maximum
+// bipartite matching. Flow is considered to be from left to right.
+// There is an implicit source node that is connected to all of the left
+// nodes, and an implicit sink node that is connected to all of the
+// right nodes. All edges have unit capacity.
+//
+// Neither the flow graph nor the residual flow graph are represented
+// explicitly. Instead, they are implied by the information in 'graph' and
+// a vector<int> called 'left_' whose elements are initialized to the
+// value kUnused. This represents the initial state of the algorithm,
+// where the flow graph is empty, and the residual flow graph has the
+// following edges:
+//   - An edge from source to each left_ node
+//   - An edge from each right_ node to sink
+//   - An edge from each left_ node to each right_ node, if the
+//     corresponding edge exists in 'graph'.
+//
+// When the TryAugment() method adds a flow, it sets left_[l] = r for some
+// nodes l and r. This induces the following changes:
+//   - The edges (source, l), (l, r), and (r, sink) are added to the
+//     flow graph.
+//   - The same three edges are removed from the residual flow graph.
+//   - The reverse edges (l, source), (r, l), and (sink, r) are added
+//     to the residual flow graph, which is a directional graph
+//     representing unused flow capacity.
+//
+// When the method augments a flow (moving left_[l] from some r1 to some
+// other r2), this can be thought of as "undoing" the above steps with
+// respect to r1 and "redoing" them with respect to r2.
+//
+// It bears repeating that the flow graph and residual flow graph are
+// never represented explicitly, but can be derived by looking at the
+// information in 'graph' and in left_.
+//
+// As an optimization, there is a second vector<int> called right_ which
+// does not provide any new information. Instead, it enables more
+// efficient queries about edges entering or leaving the right-side nodes
+// of the flow or residual flow graphs. The following invariants are
+// maintained:
+//
+// left[l] == kUnused or right[left[l]] == l
+// right[r] == kUnused or left[right[r]] == r
+//
+// . [ source ]                                        .
+// .   |||                                             .
+// .   |||                                             .
+// .   ||\--> left[0]=1  ---\    right[0]=-1 ----\     .
+// .   ||                   |                    |     .
+// .   |\---> left[1]=-1    \--> right[1]=0  ---\|     .
+// .   |                                        ||     .
+// .   \----> left[2]=2  ------> right[2]=2  --\||     .
+// .                                           |||     .
+// .         elements           matchers       vvv     .
+// .                                         [ sink ]  .
+//
+// See Also:
+//   [1] Cormen, et al (2001). "Section 26.2: The Ford-Fulkerson method".
+//       "Introduction to Algorithms (Second ed.)", pp. 651-664.
+//   [2] "Ford-Fulkerson algorithm", Wikipedia,
+//       'http://en.wikipedia.org/wiki/Ford%E2%80%93Fulkerson_algorithm'
+class MaxBipartiteMatchState {
+ public:
+  explicit MaxBipartiteMatchState(const MatchMatrix& graph)
+      : graph_(&graph),
+        left_(graph_->LhsSize(), kUnused),
+        right_(graph_->RhsSize(), kUnused) {}
+
+  // Returns the edges of a maximal match, each in the form {left, right}.
+  ElementMatcherPairs Compute() {
+    // 'seen' is used for path finding { 0: unseen, 1: seen }.
+    ::std::vector<char> seen;
+    // Searches the residual flow graph for a path from each left node to
+    // the sink in the residual flow graph, and if one is found, add flow
+    // to the graph. It's okay to search through the left nodes once. The
+    // edge from the implicit source node to each previously-visited left
+    // node will have flow if that left node has any path to the sink
+    // whatsoever. Subsequent augmentations can only add flow to the
+    // network, and cannot take away that previous flow unit from the source.
+    // Since the source-to-left edge can only carry one flow unit (or,
+    // each element can be matched to only one matcher), there is no need
+    // to visit the left nodes more than once looking for augmented paths.
+    // The flow is known to be possible or impossible by looking at the
+    // node once.
+    for (size_t ilhs = 0; ilhs < graph_->LhsSize(); ++ilhs) {
+      // Reset the path-marking vector and try to find a path from
+      // source to sink starting at the left_[ilhs] node.
+      GTEST_CHECK_(left_[ilhs] == kUnused)
+          << "ilhs: " << ilhs << ", left_[ilhs]: " << left_[ilhs];
+      // 'seen' initialized to 'graph_->RhsSize()' copies of 0.
+      seen.assign(graph_->RhsSize(), 0);
+      TryAugment(ilhs, &seen);
+    }
+    ElementMatcherPairs result;
+    for (size_t ilhs = 0; ilhs < left_.size(); ++ilhs) {
+      size_t irhs = left_[ilhs];
+      if (irhs == kUnused) continue;
+      result.push_back(ElementMatcherPair(ilhs, irhs));
+    }
+    return result;
+  }
+
+ private:
+  static const size_t kUnused = static_cast<size_t>(-1);
+
+  // Perform a depth-first search from left node ilhs to the sink.  If a
+  // path is found, flow is added to the network by linking the left and
+  // right vector elements corresponding each segment of the path.
+  // Returns true if a path to sink was found, which means that a unit of
+  // flow was added to the network. The 'seen' vector elements correspond
+  // to right nodes and are marked to eliminate cycles from the search.
+  //
+  // Left nodes will only be explored at most once because they
+  // are accessible from at most one right node in the residual flow
+  // graph.
+  //
+  // Note that left_[ilhs] is the only element of left_ that TryAugment will
+  // potentially transition from kUnused to another value. Any other
+  // left_ element holding kUnused before TryAugment will be holding it
+  // when TryAugment returns.
+  //
+  bool TryAugment(size_t ilhs, ::std::vector<char>* seen) {
+    for (size_t irhs = 0; irhs < graph_->RhsSize(); ++irhs) {
+      if ((*seen)[irhs]) continue;
+      if (!graph_->HasEdge(ilhs, irhs)) continue;
+      // There's an available edge from ilhs to irhs.
+      (*seen)[irhs] = 1;
+      // Next a search is performed to determine whether
+      // this edge is a dead end or leads to the sink.
+      //
+      // right_[irhs] == kUnused means that there is residual flow from
+      // right node irhs to the sink, so we can use that to finish this
+      // flow path and return success.
+      //
+      // Otherwise there is residual flow to some ilhs. We push flow
+      // along that path and call ourselves recursively to see if this
+      // ultimately leads to sink.
+      if (right_[irhs] == kUnused || TryAugment(right_[irhs], seen)) {
+        // Add flow from left_[ilhs] to right_[irhs].
+        left_[ilhs] = irhs;
+        right_[irhs] = ilhs;
+        return true;
+      }
+    }
+    return false;
+  }
+
+  const MatchMatrix* graph_;  // not owned
+  // Each element of the left_ vector represents a left hand side node
+  // (i.e. an element) and each element of right_ is a right hand side
+  // node (i.e. a matcher). The values in the left_ vector indicate
+  // outflow from that node to a node on the right_ side. The values
+  // in the right_ indicate inflow, and specify which left_ node is
+  // feeding that right_ node, if any. For example, left_[3] == 1 means
+  // there's a flow from element #3 to matcher #1. Such a flow would also
+  // be redundantly represented in the right_ vector as right_[1] == 3.
+  // Elements of left_ and right_ are either kUnused or mutually
+  // referent. Mutually referent means that left_[right_[i]] = i and
+  // right_[left_[i]] = i.
+  ::std::vector<size_t> left_;
+  ::std::vector<size_t> right_;
+};
+
+const size_t MaxBipartiteMatchState::kUnused;
+
+GTEST_API_ ElementMatcherPairs FindMaxBipartiteMatching(const MatchMatrix& g) {
+  return MaxBipartiteMatchState(g).Compute();
+}
+
+static void LogElementMatcherPairVec(const ElementMatcherPairs& pairs,
+                                     ::std::ostream* stream) {
+  typedef ElementMatcherPairs::const_iterator Iter;
+  ::std::ostream& os = *stream;
+  os << "{";
+  const char* sep = "";
+  for (Iter it = pairs.begin(); it != pairs.end(); ++it) {
+    os << sep << "\n  ("
+       << "element #" << it->first << ", "
+       << "matcher #" << it->second << ")";
+    sep = ",";
+  }
+  os << "\n}";
+}
+
+bool MatchMatrix::NextGraph() {
+  for (size_t ilhs = 0; ilhs < LhsSize(); ++ilhs) {
+    for (size_t irhs = 0; irhs < RhsSize(); ++irhs) {
+      char& b = matched_[SpaceIndex(ilhs, irhs)];
+      if (!b) {
+        b = 1;
+        return true;
+      }
+      b = 0;
+    }
+  }
+  return false;
+}
+
+void MatchMatrix::Randomize() {
+  for (size_t ilhs = 0; ilhs < LhsSize(); ++ilhs) {
+    for (size_t irhs = 0; irhs < RhsSize(); ++irhs) {
+      char& b = matched_[SpaceIndex(ilhs, irhs)];
+      b = static_cast<char>(rand() & 1);  // NOLINT
+    }
+  }
+}
+
+std::string MatchMatrix::DebugString() const {
+  ::std::stringstream ss;
+  const char* sep = "";
+  for (size_t i = 0; i < LhsSize(); ++i) {
+    ss << sep;
+    for (size_t j = 0; j < RhsSize(); ++j) {
+      ss << HasEdge(i, j);
+    }
+    sep = ";";
+  }
+  return ss.str();
+}
+
+void UnorderedElementsAreMatcherImplBase::DescribeToImpl(
+    ::std::ostream* os) const {
+  switch (match_flags()) {
+    case UnorderedMatcherRequire::ExactMatch:
+      if (matcher_describers_.empty()) {
+        *os << "is empty";
+        return;
+      }
+      if (matcher_describers_.size() == 1) {
+        *os << "has " << Elements(1) << " and that element ";
+        matcher_describers_[0]->DescribeTo(os);
+        return;
+      }
+      *os << "has " << Elements(matcher_describers_.size())
+          << " and there exists some permutation of elements such that:\n";
+      break;
+    case UnorderedMatcherRequire::Superset:
+      *os << "a surjection from elements to requirements exists such that:\n";
+      break;
+    case UnorderedMatcherRequire::Subset:
+      *os << "an injection from elements to requirements exists such that:\n";
+      break;
+  }
+
+  const char* sep = "";
+  for (size_t i = 0; i != matcher_describers_.size(); ++i) {
+    *os << sep;
+    if (match_flags() == UnorderedMatcherRequire::ExactMatch) {
+      *os << " - element #" << i << " ";
+    } else {
+      *os << " - an element ";
+    }
+    matcher_describers_[i]->DescribeTo(os);
+    if (match_flags() == UnorderedMatcherRequire::ExactMatch) {
+      sep = ", and\n";
+    } else {
+      sep = "\n";
+    }
+  }
+}
+
+void UnorderedElementsAreMatcherImplBase::DescribeNegationToImpl(
+    ::std::ostream* os) const {
+  switch (match_flags()) {
+    case UnorderedMatcherRequire::ExactMatch:
+      if (matcher_describers_.empty()) {
+        *os << "isn't empty";
+        return;
+      }
+      if (matcher_describers_.size() == 1) {
+        *os << "doesn't have " << Elements(1) << ", or has " << Elements(1)
+            << " that ";
+        matcher_describers_[0]->DescribeNegationTo(os);
+        return;
+      }
+      *os << "doesn't have " << Elements(matcher_describers_.size())
+          << ", or there exists no permutation of elements such that:\n";
+      break;
+    case UnorderedMatcherRequire::Superset:
+      *os << "no surjection from elements to requirements exists such that:\n";
+      break;
+    case UnorderedMatcherRequire::Subset:
+      *os << "no injection from elements to requirements exists such that:\n";
+      break;
+  }
+  const char* sep = "";
+  for (size_t i = 0; i != matcher_describers_.size(); ++i) {
+    *os << sep;
+    if (match_flags() == UnorderedMatcherRequire::ExactMatch) {
+      *os << " - element #" << i << " ";
+    } else {
+      *os << " - an element ";
+    }
+    matcher_describers_[i]->DescribeTo(os);
+    if (match_flags() == UnorderedMatcherRequire::ExactMatch) {
+      sep = ", and\n";
+    } else {
+      sep = "\n";
+    }
+  }
+}
+
+// Checks that all matchers match at least one element, and that all
+// elements match at least one matcher. This enables faster matching
+// and better error reporting.
+// Returns false, writing an explanation to 'listener', if and only
+// if the success criteria are not met.
+bool UnorderedElementsAreMatcherImplBase::VerifyMatchMatrix(
+    const ::std::vector<std::string>& element_printouts,
+    const MatchMatrix& matrix, MatchResultListener* listener) const {
+  if (matrix.LhsSize() == 0 && matrix.RhsSize() == 0) {
+    return true;
+  }
+
+  if (match_flags() == UnorderedMatcherRequire::ExactMatch) {
+    if (matrix.LhsSize() != matrix.RhsSize()) {
+      // The element count doesn't match.  If the container is empty,
+      // there's no need to explain anything as Google Mock already
+      // prints the empty container. Otherwise we just need to show
+      // how many elements there actually are.
+      if (matrix.LhsSize() != 0 && listener->IsInterested()) {
+        *listener << "which has " << Elements(matrix.LhsSize());
+      }
+      return false;
+    }
+  }
+
+  bool result = true;
+  ::std::vector<char> element_matched(matrix.LhsSize(), 0);
+  ::std::vector<char> matcher_matched(matrix.RhsSize(), 0);
+
+  for (size_t ilhs = 0; ilhs < matrix.LhsSize(); ilhs++) {
+    for (size_t irhs = 0; irhs < matrix.RhsSize(); irhs++) {
+      char matched = matrix.HasEdge(ilhs, irhs);
+      element_matched[ilhs] |= matched;
+      matcher_matched[irhs] |= matched;
+    }
+  }
+
+  if (match_flags() & UnorderedMatcherRequire::Superset) {
+    const char* sep =
+        "where the following matchers don't match any elements:\n";
+    for (size_t mi = 0; mi < matcher_matched.size(); ++mi) {
+      if (matcher_matched[mi]) continue;
+      result = false;
+      if (listener->IsInterested()) {
+        *listener << sep << "matcher #" << mi << ": ";
+        matcher_describers_[mi]->DescribeTo(listener->stream());
+        sep = ",\n";
+      }
+    }
+  }
+
+  if (match_flags() & UnorderedMatcherRequire::Subset) {
+    const char* sep =
+        "where the following elements don't match any matchers:\n";
+    const char* outer_sep = "";
+    if (!result) {
+      outer_sep = "\nand ";
+    }
+    for (size_t ei = 0; ei < element_matched.size(); ++ei) {
+      if (element_matched[ei]) continue;
+      result = false;
+      if (listener->IsInterested()) {
+        *listener << outer_sep << sep << "element #" << ei << ": "
+                  << element_printouts[ei];
+        sep = ",\n";
+        outer_sep = "";
+      }
+    }
+  }
+  return result;
+}
+
+bool UnorderedElementsAreMatcherImplBase::FindPairing(
+    const MatchMatrix& matrix, MatchResultListener* listener) const {
+  ElementMatcherPairs matches = FindMaxBipartiteMatching(matrix);
+
+  size_t max_flow = matches.size();
+  if ((match_flags() & UnorderedMatcherRequire::Superset) &&
+      max_flow < matrix.RhsSize()) {
+    if (listener->IsInterested()) {
+      *listener << "where no permutation of the elements can satisfy all "
+                   "matchers, and the closest match is "
+                << max_flow << " of " << matrix.RhsSize()
+                << " matchers with the pairings:\n";
+      LogElementMatcherPairVec(matches, listener->stream());
+    }
+    return false;
+  }
+  if ((match_flags() & UnorderedMatcherRequire::Subset) &&
+      max_flow < matrix.LhsSize()) {
+    if (listener->IsInterested()) {
+      *listener
+          << "where not all elements can be matched, and the closest match is "
+          << max_flow << " of " << matrix.RhsSize()
+          << " matchers with the pairings:\n";
+      LogElementMatcherPairVec(matches, listener->stream());
+    }
+    return false;
+  }
+
+  if (matches.size() > 1) {
+    if (listener->IsInterested()) {
+      const char* sep = "where:\n";
+      for (size_t mi = 0; mi < matches.size(); ++mi) {
+        *listener << sep << " - element #" << matches[mi].first
+                  << " is matched by matcher #" << matches[mi].second;
+        sep = ",\n";
+      }
+    }
+  }
+  return true;
+}
+
+}  // namespace internal
+}  // namespace testing

contrib/googletest/googlemock/src/gmock-spec-builders.cc

@@ -0,0 +1,791 @@
+// Copyright 2007, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+// Google Mock - a framework for writing C++ mock classes.
+//
+// This file implements the spec builder syntax (ON_CALL and
+// EXPECT_CALL).
+
+#include "gmock/gmock-spec-builders.h"
+
+#include <stdlib.h>
+
+#include <iostream>  // NOLINT
+#include <map>
+#include <memory>
+#include <set>
+#include <sstream>
+#include <string>
+#include <unordered_map>
+#include <vector>
+
+#include "gmock/gmock.h"
+#include "gtest/gtest.h"
+#include "gtest/internal/gtest-port.h"
+
+#if defined(GTEST_OS_CYGWIN) || defined(GTEST_OS_LINUX) || defined(GTEST_OS_MAC)
+#include <unistd.h>  // NOLINT
+#endif
+#ifdef GTEST_OS_QURT
+#include <qurt_event.h>
+#endif
+
+// Silence C4800 (C4800: 'int *const ': forcing value
+// to bool 'true' or 'false') for MSVC 15
+#if defined(_MSC_VER) && (_MSC_VER == 1900)
+GTEST_DISABLE_MSC_WARNINGS_PUSH_(4800)
+#endif
+
+namespace testing {
+namespace internal {
+
+// Protects the mock object registry (in class Mock), all function
+// mockers, and all expectations.
+GTEST_API_ GTEST_DEFINE_STATIC_MUTEX_(g_gmock_mutex);
+
+// Logs a message including file and line number information.
+GTEST_API_ void LogWithLocation(testing::internal::LogSeverity severity,
+                                const char* file, int line,
+                                const std::string& message) {
+  ::std::ostringstream s;
+  s << internal::FormatFileLocation(file, line) << " " << message
+    << ::std::endl;
+  Log(severity, s.str(), 0);
+}
+
+// Constructs an ExpectationBase object.
+ExpectationBase::ExpectationBase(const char* a_file, int a_line,
+                                 const std::string& a_source_text)
+    : file_(a_file),
+      line_(a_line),
+      source_text_(a_source_text),
+      cardinality_specified_(false),
+      cardinality_(Exactly(1)),
+      call_count_(0),
+      retired_(false),
+      extra_matcher_specified_(false),
+      repeated_action_specified_(false),
+      retires_on_saturation_(false),
+      last_clause_(kNone),
+      action_count_checked_(false) {}
+
+// Destructs an ExpectationBase object.
+ExpectationBase::~ExpectationBase() = default;
+
+// Explicitly specifies the cardinality of this expectation.  Used by
+// the subclasses to implement the .Times() clause.
+void ExpectationBase::SpecifyCardinality(const Cardinality& a_cardinality) {
+  cardinality_specified_ = true;
+  cardinality_ = a_cardinality;
+}
+
+// Retires all pre-requisites of this expectation.
+void ExpectationBase::RetireAllPreRequisites()
+    GTEST_EXCLUSIVE_LOCK_REQUIRED_(g_gmock_mutex) {
+  if (is_retired()) {
+    // We can take this short-cut as we never retire an expectation
+    // until we have retired all its pre-requisites.
+    return;
+  }
+
+  ::std::vector<ExpectationBase*> expectations(1, this);
+  while (!expectations.empty()) {
+    ExpectationBase* exp = expectations.back();
+    expectations.pop_back();
+
+    for (ExpectationSet::const_iterator it =
+             exp->immediate_prerequisites_.begin();
+         it != exp->immediate_prerequisites_.end(); ++it) {
+      ExpectationBase* next = it->expectation_base().get();
+      if (!next->is_retired()) {
+        next->Retire();
+        expectations.push_back(next);
+      }
+    }
+  }
+}
+
+// Returns true if and only if all pre-requisites of this expectation
+// have been satisfied.
+bool ExpectationBase::AllPrerequisitesAreSatisfied() const
+    GTEST_EXCLUSIVE_LOCK_REQUIRED_(g_gmock_mutex) {
+  g_gmock_mutex.AssertHeld();
+  ::std::vector<const ExpectationBase*> expectations(1, this);
+  while (!expectations.empty()) {
+    const ExpectationBase* exp = expectations.back();
+    expectations.pop_back();
+
+    for (ExpectationSet::const_iterator it =
+             exp->immediate_prerequisites_.begin();
+         it != exp->immediate_prerequisites_.end(); ++it) {
+      const ExpectationBase* next = it->expectation_base().get();
+      if (!next->IsSatisfied()) return false;
+      expectations.push_back(next);
+    }
+  }
+  return true;
+}
+
+// Adds unsatisfied pre-requisites of this expectation to 'result'.
+void ExpectationBase::FindUnsatisfiedPrerequisites(ExpectationSet* result) const
+    GTEST_EXCLUSIVE_LOCK_REQUIRED_(g_gmock_mutex) {
+  g_gmock_mutex.AssertHeld();
+  ::std::vector<const ExpectationBase*> expectations(1, this);
+  while (!expectations.empty()) {
+    const ExpectationBase* exp = expectations.back();
+    expectations.pop_back();
+
+    for (ExpectationSet::const_iterator it =
+             exp->immediate_prerequisites_.begin();
+         it != exp->immediate_prerequisites_.end(); ++it) {
+      const ExpectationBase* next = it->expectation_base().get();
+
+      if (next->IsSatisfied()) {
+        // If *it is satisfied and has a call count of 0, some of its
+        // pre-requisites may not be satisfied yet.
+        if (next->call_count_ == 0) {
+          expectations.push_back(next);
+        }
+      } else {
+        // Now that we know next is unsatisfied, we are not so interested
+        // in whether its pre-requisites are satisfied.  Therefore we
+        // don't iterate into it here.
+        *result += *it;
+      }
+    }
+  }
+}
+
+// Describes how many times a function call matching this
+// expectation has occurred.
+void ExpectationBase::DescribeCallCountTo(::std::ostream* os) const
+    GTEST_EXCLUSIVE_LOCK_REQUIRED_(g_gmock_mutex) {
+  g_gmock_mutex.AssertHeld();
+
+  // Describes how many times the function is expected to be called.
+  *os << "         Expected: to be ";
+  cardinality().DescribeTo(os);
+  *os << "\n           Actual: ";
+  Cardinality::DescribeActualCallCountTo(call_count(), os);
+
+  // Describes the state of the expectation (e.g. is it satisfied?
+  // is it active?).
+  *os << " - "
+      << (IsOverSaturated() ? "over-saturated"
+          : IsSaturated()   ? "saturated"
+          : IsSatisfied()   ? "satisfied"
+                            : "unsatisfied")
+      << " and " << (is_retired() ? "retired" : "active");
+}
+
+// Checks the action count (i.e. the number of WillOnce() and
+// WillRepeatedly() clauses) against the cardinality if this hasn't
+// been done before.  Prints a warning if there are too many or too
+// few actions.
+void ExpectationBase::CheckActionCountIfNotDone() const
+    GTEST_LOCK_EXCLUDED_(mutex_) {
+  bool should_check = false;
+  {
+    MutexLock l(&mutex_);
+    if (!action_count_checked_) {
+      action_count_checked_ = true;
+      should_check = true;
+    }
+  }
+
+  if (should_check) {
+    if (!cardinality_specified_) {
+      // The cardinality was inferred - no need to check the action
+      // count against it.
+      return;
+    }
+
+    // The cardinality was explicitly specified.
+    const int action_count = static_cast<int>(untyped_actions_.size());
+    const int upper_bound = cardinality().ConservativeUpperBound();
+    const int lower_bound = cardinality().ConservativeLowerBound();
+    bool too_many;  // True if there are too many actions, or false
+    // if there are too few.
+    if (action_count > upper_bound ||
+        (action_count == upper_bound && repeated_action_specified_)) {
+      too_many = true;
+    } else if (0 < action_count && action_count < lower_bound &&
+               !repeated_action_specified_) {
+      too_many = false;
+    } else {
+      return;
+    }
+
+    ::std::stringstream ss;
+    DescribeLocationTo(&ss);
+    ss << "Too " << (too_many ? "many" : "few") << " actions specified in "
+       << source_text() << "...\n"
+       << "Expected to be ";
+    cardinality().DescribeTo(&ss);
+    ss << ", but has " << (too_many ? "" : "only ") << action_count
+       << " WillOnce()" << (action_count == 1 ? "" : "s");
+    if (repeated_action_specified_) {
+      ss << " and a WillRepeatedly()";
+    }
+    ss << ".";
+    Log(kWarning, ss.str(), -1);  // -1 means "don't print stack trace".
+  }
+}
+
+// Implements the .Times() clause.
+void ExpectationBase::UntypedTimes(const Cardinality& a_cardinality) {
+  if (last_clause_ == kTimes) {
+    ExpectSpecProperty(false,
+                       ".Times() cannot appear "
+                       "more than once in an EXPECT_CALL().");
+  } else {
+    ExpectSpecProperty(
+        last_clause_ < kTimes,
+        ".Times() may only appear *before* .InSequence(), .WillOnce(), "
+        ".WillRepeatedly(), or .RetiresOnSaturation(), not after.");
+  }
+  last_clause_ = kTimes;
+
+  SpecifyCardinality(a_cardinality);
+}
+
+// Points to the implicit sequence introduced by a living InSequence
+// object (if any) in the current thread or NULL.
+GTEST_API_ ThreadLocal<Sequence*> g_gmock_implicit_sequence;
+
+// Reports an uninteresting call (whose description is in msg) in the
+// manner specified by 'reaction'.
+void ReportUninterestingCall(CallReaction reaction, const std::string& msg) {
+  // Include a stack trace only if --gmock_verbose=info is specified.
+  const int stack_frames_to_skip =
+      GMOCK_FLAG_GET(verbose) == kInfoVerbosity ? 3 : -1;
+  switch (reaction) {
+    case kAllow:
+      Log(kInfo, msg, stack_frames_to_skip);
+      break;
+    case kWarn:
+      Log(kWarning,
+          msg +
+              "\nNOTE: You can safely ignore the above warning unless this "
+              "call should not happen.  Do not suppress it by blindly adding "
+              "an EXPECT_CALL() if you don't mean to enforce the call.  "
+              "See "
+              "https://github.com/google/googletest/blob/main/docs/"
+              "gmock_cook_book.md#"
+              "knowing-when-to-expect-useoncall for details.\n",
+          stack_frames_to_skip);
+      break;
+    default:  // FAIL
+      Expect(false, nullptr, -1, msg);
+  }
+}
+
+UntypedFunctionMockerBase::UntypedFunctionMockerBase()
+    : mock_obj_(nullptr), name_("") {}
+
+UntypedFunctionMockerBase::~UntypedFunctionMockerBase() = default;
+
+// Sets the mock object this mock method belongs to, and registers
+// this information in the global mock registry.  Will be called
+// whenever an EXPECT_CALL() or ON_CALL() is executed on this mock
+// method.
+void UntypedFunctionMockerBase::RegisterOwner(const void* mock_obj)
+    GTEST_LOCK_EXCLUDED_(g_gmock_mutex) {
+  {
+    MutexLock l(&g_gmock_mutex);
+    mock_obj_ = mock_obj;
+  }
+  Mock::Register(mock_obj, this);
+}
+
+// Sets the mock object this mock method belongs to, and sets the name
+// of the mock function.  Will be called upon each invocation of this
+// mock function.
+void UntypedFunctionMockerBase::SetOwnerAndName(const void* mock_obj,
+                                                const char* name)
+    GTEST_LOCK_EXCLUDED_(g_gmock_mutex) {
+  // We protect name_ under g_gmock_mutex in case this mock function
+  // is called from two threads concurrently.
+  MutexLock l(&g_gmock_mutex);
+  mock_obj_ = mock_obj;
+  name_ = name;
+}
+
+// Returns the name of the function being mocked.  Must be called
+// after RegisterOwner() or SetOwnerAndName() has been called.
+const void* UntypedFunctionMockerBase::MockObject() const
+    GTEST_LOCK_EXCLUDED_(g_gmock_mutex) {
+  const void* mock_obj;
+  {
+    // We protect mock_obj_ under g_gmock_mutex in case this mock
+    // function is called from two threads concurrently.
+    MutexLock l(&g_gmock_mutex);
+    Assert(mock_obj_ != nullptr, __FILE__, __LINE__,
+           "MockObject() must not be called before RegisterOwner() or "
+           "SetOwnerAndName() has been called.");
+    mock_obj = mock_obj_;
+  }
+  return mock_obj;
+}
+
+// Returns the name of this mock method.  Must be called after
+// SetOwnerAndName() has been called.
+const char* UntypedFunctionMockerBase::Name() const
+    GTEST_LOCK_EXCLUDED_(g_gmock_mutex) {
+  const char* name;
+  {
+    // We protect name_ under g_gmock_mutex in case this mock
+    // function is called from two threads concurrently.
+    MutexLock l(&g_gmock_mutex);
+    Assert(name_ != nullptr, __FILE__, __LINE__,
+           "Name() must not be called before SetOwnerAndName() has "
+           "been called.");
+    name = name_;
+  }
+  return name;
+}
+
+// Returns an Expectation object that references and co-owns exp,
+// which must be an expectation on this mock function.
+Expectation UntypedFunctionMockerBase::GetHandleOf(ExpectationBase* exp) {
+  // See the definition of untyped_expectations_ for why access to it
+  // is unprotected here.
+  for (UntypedExpectations::const_iterator it = untyped_expectations_.begin();
+       it != untyped_expectations_.end(); ++it) {
+    if (it->get() == exp) {
+      return Expectation(*it);
+    }
+  }
+
+  Assert(false, __FILE__, __LINE__, "Cannot find expectation.");
+  return Expectation();
+  // The above statement is just to make the code compile, and will
+  // never be executed.
+}
+
+// Verifies that all expectations on this mock function have been
+// satisfied.  Reports one or more Google Test non-fatal failures
+// and returns false if not.
+bool UntypedFunctionMockerBase::VerifyAndClearExpectationsLocked()
+    GTEST_EXCLUSIVE_LOCK_REQUIRED_(g_gmock_mutex) {
+  g_gmock_mutex.AssertHeld();
+  bool expectations_met = true;
+  for (UntypedExpectations::const_iterator it = untyped_expectations_.begin();
+       it != untyped_expectations_.end(); ++it) {
+    ExpectationBase* const untyped_expectation = it->get();
+    if (untyped_expectation->IsOverSaturated()) {
+      // There was an upper-bound violation.  Since the error was
+      // already reported when it occurred, there is no need to do
+      // anything here.
+      expectations_met = false;
+    } else if (!untyped_expectation->IsSatisfied()) {
+      expectations_met = false;
+      ::std::stringstream ss;
+
+      const ::std::string& expectation_name =
+          untyped_expectation->GetDescription();
+      ss << "Actual function ";
+      if (!expectation_name.empty()) {
+        ss << "\"" << expectation_name << "\" ";
+      }
+      ss << "call count doesn't match " << untyped_expectation->source_text()
+         << "...\n";
+      // No need to show the source file location of the expectation
+      // in the description, as the Expect() call that follows already
+      // takes care of it.
+      untyped_expectation->MaybeDescribeExtraMatcherTo(&ss);
+      untyped_expectation->DescribeCallCountTo(&ss);
+      Expect(false, untyped_expectation->file(), untyped_expectation->line(),
+             ss.str());
+    }
+  }
+
+  // Deleting our expectations may trigger other mock objects to be deleted, for
+  // example if an action contains a reference counted smart pointer to that
+  // mock object, and that is the last reference. So if we delete our
+  // expectations within the context of the global mutex we may deadlock when
+  // this method is called again. Instead, make a copy of the set of
+  // expectations to delete, clear our set within the mutex, and then clear the
+  // copied set outside of it.
+  UntypedExpectations expectations_to_delete;
+  untyped_expectations_.swap(expectations_to_delete);
+
+  g_gmock_mutex.Unlock();
+  expectations_to_delete.clear();
+  g_gmock_mutex.Lock();
+
+  return expectations_met;
+}
+
+static CallReaction intToCallReaction(int mock_behavior) {
+  if (mock_behavior >= kAllow && mock_behavior <= kFail) {
+    return static_cast<internal::CallReaction>(mock_behavior);
+  }
+  return kWarn;
+}
+
+}  // namespace internal
+
+// Class Mock.
+
+namespace {
+
+typedef std::set<internal::UntypedFunctionMockerBase*> FunctionMockers;
+
+// The current state of a mock object.  Such information is needed for
+// detecting leaked mock objects and explicitly verifying a mock's
+// expectations.
+struct MockObjectState {
+  MockObjectState()
+      : first_used_file(nullptr), first_used_line(-1), leakable(false) {}
+
+  // Where in the source file an ON_CALL or EXPECT_CALL is first
+  // invoked on this mock object.
+  const char* first_used_file;
+  int first_used_line;
+  ::std::string first_used_test_suite;
+  ::std::string first_used_test;
+  bool leakable;  // true if and only if it's OK to leak the object.
+  FunctionMockers function_mockers;  // All registered methods of the object.
+};
+
+// A global registry holding the state of all mock objects that are
+// alive.  A mock object is added to this registry the first time
+// Mock::AllowLeak(), ON_CALL(), or EXPECT_CALL() is called on it.  It
+// is removed from the registry in the mock object's destructor.
+class MockObjectRegistry {
+ public:
+  // Maps a mock object (identified by its address) to its state.
+  typedef std::map<const void*, MockObjectState> StateMap;
+
+  // This destructor will be called when a program exits, after all
+  // tests in it have been run.  By then, there should be no mock
+  // object alive.  Therefore we report any living object as test
+  // failure, unless the user explicitly asked us to ignore it.
+  ~MockObjectRegistry() {
+    if (!GMOCK_FLAG_GET(catch_leaked_mocks)) return;
+
+    int leaked_count = 0;
+    for (StateMap::const_iterator it = states_.begin(); it != states_.end();
+         ++it) {
+      if (it->second.leakable)  // The user said it's fine to leak this object.
+        continue;
+
+      // FIXME: Print the type of the leaked object.
+      // This can help the user identify the leaked object.
+      std::cout << "\n";
+      const MockObjectState& state = it->second;
+      std::cout << internal::FormatFileLocation(state.first_used_file,
+                                                state.first_used_line);
+      std::cout << " ERROR: this mock object";
+      if (!state.first_used_test.empty()) {
+        std::cout << " (used in test " << state.first_used_test_suite << "."
+                  << state.first_used_test << ")";
+      }
+      std::cout << " should be deleted but never is. Its address is @"
+                << it->first << ".";
+      leaked_count++;
+    }
+    if (leaked_count > 0) {
+      std::cout << "\nERROR: " << leaked_count << " leaked mock "
+                << (leaked_count == 1 ? "object" : "objects")
+                << " found at program exit. Expectations on a mock object are "
+                   "verified when the object is destructed. Leaking a mock "
+                   "means that its expectations aren't verified, which is "
+                   "usually a test bug. If you really intend to leak a mock, "
+                   "you can suppress this error using "
+                   "testing::Mock::AllowLeak(mock_object), or you may use a "
+                   "fake or stub instead of a mock.\n";
+      std::cout.flush();
+      ::std::cerr.flush();
+      // RUN_ALL_TESTS() has already returned when this destructor is
+      // called.  Therefore we cannot use the normal Google Test
+      // failure reporting mechanism.
+#ifdef GTEST_OS_QURT
+      qurt_exception_raise_fatal();
+#else
+      _exit(1);  // We cannot call exit() as it is not reentrant and
+                 // may already have been called.
+#endif
+    }
+  }
+
+  StateMap& states() { return states_; }
+
+ private:
+  StateMap states_;
+};
+
+// Protected by g_gmock_mutex.
+MockObjectRegistry g_mock_object_registry;
+
+// Maps a mock object to the reaction Google Mock should have when an
+// uninteresting method is called.  Protected by g_gmock_mutex.
+std::unordered_map<uintptr_t, internal::CallReaction>&
+UninterestingCallReactionMap() {
+  static auto* map = new std::unordered_map<uintptr_t, internal::CallReaction>;
+  return *map;
+}
+
+// Sets the reaction Google Mock should have when an uninteresting
+// method of the given mock object is called.
+void SetReactionOnUninterestingCalls(uintptr_t mock_obj,
+                                     internal::CallReaction reaction)
+    GTEST_LOCK_EXCLUDED_(internal::g_gmock_mutex) {
+  internal::MutexLock l(&internal::g_gmock_mutex);
+  UninterestingCallReactionMap()[mock_obj] = reaction;
+}
+
+}  // namespace
+
+// Tells Google Mock to allow uninteresting calls on the given mock
+// object.
+void Mock::AllowUninterestingCalls(uintptr_t mock_obj)
+    GTEST_LOCK_EXCLUDED_(internal::g_gmock_mutex) {
+  SetReactionOnUninterestingCalls(mock_obj, internal::kAllow);
+}
+
+// Tells Google Mock to warn the user about uninteresting calls on the
+// given mock object.
+void Mock::WarnUninterestingCalls(uintptr_t mock_obj)
+    GTEST_LOCK_EXCLUDED_(internal::g_gmock_mutex) {
+  SetReactionOnUninterestingCalls(mock_obj, internal::kWarn);
+}
+
+// Tells Google Mock to fail uninteresting calls on the given mock
+// object.
+void Mock::FailUninterestingCalls(uintptr_t mock_obj)
+    GTEST_LOCK_EXCLUDED_(internal::g_gmock_mutex) {
+  SetReactionOnUninterestingCalls(mock_obj, internal::kFail);
+}
+
+// Tells Google Mock the given mock object is being destroyed and its
+// entry in the call-reaction table should be removed.
+void Mock::UnregisterCallReaction(uintptr_t mock_obj)
+    GTEST_LOCK_EXCLUDED_(internal::g_gmock_mutex) {
+  internal::MutexLock l(&internal::g_gmock_mutex);
+  UninterestingCallReactionMap().erase(static_cast<uintptr_t>(mock_obj));
+}
+
+// Returns the reaction Google Mock will have on uninteresting calls
+// made on the given mock object.
+internal::CallReaction Mock::GetReactionOnUninterestingCalls(
+    const void* mock_obj) GTEST_LOCK_EXCLUDED_(internal::g_gmock_mutex) {
+  internal::MutexLock l(&internal::g_gmock_mutex);
+  return (UninterestingCallReactionMap().count(
+              reinterpret_cast<uintptr_t>(mock_obj)) == 0)
+             ? internal::intToCallReaction(
+                   GMOCK_FLAG_GET(default_mock_behavior))
+             : UninterestingCallReactionMap()[reinterpret_cast<uintptr_t>(
+                   mock_obj)];
+}
+
+// Tells Google Mock to ignore mock_obj when checking for leaked mock
+// objects.
+void Mock::AllowLeak(const void* mock_obj)
+    GTEST_LOCK_EXCLUDED_(internal::g_gmock_mutex) {
+  internal::MutexLock l(&internal::g_gmock_mutex);
+  g_mock_object_registry.states()[mock_obj].leakable = true;
+}
+
+// Verifies and clears all expectations on the given mock object.  If
+// the expectations aren't satisfied, generates one or more Google
+// Test non-fatal failures and returns false.
+bool Mock::VerifyAndClearExpectations(void* mock_obj)
+    GTEST_LOCK_EXCLUDED_(internal::g_gmock_mutex) {
+  internal::MutexLock l(&internal::g_gmock_mutex);
+  return VerifyAndClearExpectationsLocked(mock_obj);
+}
+
+// Verifies all expectations on the given mock object and clears its
+// default actions and expectations.  Returns true if and only if the
+// verification was successful.
+bool Mock::VerifyAndClear(void* mock_obj)
+    GTEST_LOCK_EXCLUDED_(internal::g_gmock_mutex) {
+  internal::MutexLock l(&internal::g_gmock_mutex);
+  ClearDefaultActionsLocked(mock_obj);
+  return VerifyAndClearExpectationsLocked(mock_obj);
+}
+
+// Verifies and clears all expectations on the given mock object.  If
+// the expectations aren't satisfied, generates one or more Google
+// Test non-fatal failures and returns false.
+bool Mock::VerifyAndClearExpectationsLocked(void* mock_obj)
+    GTEST_EXCLUSIVE_LOCK_REQUIRED_(internal::g_gmock_mutex) {
+  internal::g_gmock_mutex.AssertHeld();
+  if (g_mock_object_registry.states().count(mock_obj) == 0) {
+    // No EXPECT_CALL() was set on the given mock object.
+    return true;
+  }
+
+  // Verifies and clears the expectations on each mock method in the
+  // given mock object.
+  bool expectations_met = true;
+  FunctionMockers& mockers =
+      g_mock_object_registry.states()[mock_obj].function_mockers;
+  for (FunctionMockers::const_iterator it = mockers.begin();
+       it != mockers.end(); ++it) {
+    if (!(*it)->VerifyAndClearExpectationsLocked()) {
+      expectations_met = false;
+    }
+  }
+
+  // We don't clear the content of mockers, as they may still be
+  // needed by ClearDefaultActionsLocked().
+  return expectations_met;
+}
+
+bool Mock::IsNaggy(void* mock_obj)
+    GTEST_LOCK_EXCLUDED_(internal::g_gmock_mutex) {
+  return Mock::GetReactionOnUninterestingCalls(mock_obj) == internal::kWarn;
+}
+bool Mock::IsNice(void* mock_obj)
+    GTEST_LOCK_EXCLUDED_(internal::g_gmock_mutex) {
+  return Mock::GetReactionOnUninterestingCalls(mock_obj) == internal::kAllow;
+}
+bool Mock::IsStrict(void* mock_obj)
+    GTEST_LOCK_EXCLUDED_(internal::g_gmock_mutex) {
+  return Mock::GetReactionOnUninterestingCalls(mock_obj) == internal::kFail;
+}
+
+// Registers a mock object and a mock method it owns.
+void Mock::Register(const void* mock_obj,
+                    internal::UntypedFunctionMockerBase* mocker)
+    GTEST_LOCK_EXCLUDED_(internal::g_gmock_mutex) {
+  internal::MutexLock l(&internal::g_gmock_mutex);
+  g_mock_object_registry.states()[mock_obj].function_mockers.insert(mocker);
+}
+
+// Tells Google Mock where in the source code mock_obj is used in an
+// ON_CALL or EXPECT_CALL.  In case mock_obj is leaked, this
+// information helps the user identify which object it is.
+void Mock::RegisterUseByOnCallOrExpectCall(const void* mock_obj,
+                                           const char* file, int line)
+    GTEST_LOCK_EXCLUDED_(internal::g_gmock_mutex) {
+  internal::MutexLock l(&internal::g_gmock_mutex);
+  MockObjectState& state = g_mock_object_registry.states()[mock_obj];
+  if (state.first_used_file == nullptr) {
+    state.first_used_file = file;
+    state.first_used_line = line;
+    const TestInfo* const test_info =
+        UnitTest::GetInstance()->current_test_info();
+    if (test_info != nullptr) {
+      state.first_used_test_suite = test_info->test_suite_name();
+      state.first_used_test = test_info->name();
+    }
+  }
+}
+
+// Unregisters a mock method; removes the owning mock object from the
+// registry when the last mock method associated with it has been
+// unregistered.  This is called only in the destructor of
+// FunctionMockerBase.
+void Mock::UnregisterLocked(internal::UntypedFunctionMockerBase* mocker)
+    GTEST_EXCLUSIVE_LOCK_REQUIRED_(internal::g_gmock_mutex) {
+  internal::g_gmock_mutex.AssertHeld();
+  for (MockObjectRegistry::StateMap::iterator it =
+           g_mock_object_registry.states().begin();
+       it != g_mock_object_registry.states().end(); ++it) {
+    FunctionMockers& mockers = it->second.function_mockers;
+    if (mockers.erase(mocker) > 0) {
+      // mocker was in mockers and has been just removed.
+      if (mockers.empty()) {
+        g_mock_object_registry.states().erase(it);
+      }
+      return;
+    }
+  }
+}
+
+// Clears all ON_CALL()s set on the given mock object.
+void Mock::ClearDefaultActionsLocked(void* mock_obj)
+    GTEST_EXCLUSIVE_LOCK_REQUIRED_(internal::g_gmock_mutex) {
+  internal::g_gmock_mutex.AssertHeld();
+
+  if (g_mock_object_registry.states().count(mock_obj) == 0) {
+    // No ON_CALL() was set on the given mock object.
+    return;
+  }
+
+  // Clears the default actions for each mock method in the given mock
+  // object.
+  FunctionMockers& mockers =
+      g_mock_object_registry.states()[mock_obj].function_mockers;
+  for (FunctionMockers::const_iterator it = mockers.begin();
+       it != mockers.end(); ++it) {
+    (*it)->ClearDefaultActionsLocked();
+  }
+
+  // We don't clear the content of mockers, as they may still be
+  // needed by VerifyAndClearExpectationsLocked().
+}
+
+Expectation::Expectation() = default;
+
+Expectation::Expectation(
+    const std::shared_ptr<internal::ExpectationBase>& an_expectation_base)
+    : expectation_base_(an_expectation_base) {}
+
+Expectation::~Expectation() = default;
+
+// Adds an expectation to a sequence.
+void Sequence::AddExpectation(const Expectation& expectation) const {
+  if (*last_expectation_ != expectation) {
+    if (last_expectation_->expectation_base() != nullptr) {
+      expectation.expectation_base()->immediate_prerequisites_ +=
+          *last_expectation_;
+    }
+    *last_expectation_ = expectation;
+  }
+}
+
+// Creates the implicit sequence if there isn't one.
+InSequence::InSequence() {
+  if (internal::g_gmock_implicit_sequence.get() == nullptr) {
+    internal::g_gmock_implicit_sequence.set(new Sequence);
+    sequence_created_ = true;
+  } else {
+    sequence_created_ = false;
+  }
+}
+
+// Deletes the implicit sequence if it was created by the constructor
+// of this object.
+InSequence::~InSequence() {
+  if (sequence_created_) {
+    delete internal::g_gmock_implicit_sequence.get();
+    internal::g_gmock_implicit_sequence.set(nullptr);
+  }
+}
+
+}  // namespace testing
+
+#if defined(_MSC_VER) && (_MSC_VER == 1900)
+GTEST_DISABLE_MSC_WARNINGS_POP_()  // 4800
+#endif

contrib/googletest/googlemock/src/gmock.cc

@@ -0,0 +1,225 @@
+// Copyright 2008, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+#include "gmock/gmock.h"
+
+#include <string>
+
+#include "gmock/internal/gmock-port.h"
+
+GMOCK_DEFINE_bool_(catch_leaked_mocks, true,
+                   "true if and only if Google Mock should report leaked "
+                   "mock objects as failures.");
+
+GMOCK_DEFINE_string_(verbose, testing::internal::kWarningVerbosity,
+                     "Controls how verbose Google Mock's output is."
+                     "  Valid values:\n"
+                     "  info    - prints all messages.\n"
+                     "  warning - prints warnings and errors.\n"
+                     "  error   - prints errors only.");
+
+GMOCK_DEFINE_int32_(default_mock_behavior, 1,
+                    "Controls the default behavior of mocks."
+                    "  Valid values:\n"
+                    "  0 - by default, mocks act as NiceMocks.\n"
+                    "  1 - by default, mocks act as NaggyMocks.\n"
+                    "  2 - by default, mocks act as StrictMocks.");
+
+namespace testing {
+namespace internal {
+
+// Parses a string as a command line flag.  The string should have the
+// format "--gmock_flag=value".  When def_optional is true, the
+// "=value" part can be omitted.
+//
+// Returns the value of the flag, or NULL if the parsing failed.
+static const char* ParseGoogleMockFlagValue(const char* str,
+                                            const char* flag_name,
+                                            bool def_optional) {
+  // str and flag must not be NULL.
+  if (str == nullptr || flag_name == nullptr) return nullptr;
+
+  // The flag must start with "--gmock_".
+  const std::string flag_name_str = std::string("--gmock_") + flag_name;
+  const size_t flag_name_len = flag_name_str.length();
+  if (strncmp(str, flag_name_str.c_str(), flag_name_len) != 0) return nullptr;
+
+  // Skips the flag name.
+  const char* flag_end = str + flag_name_len;
+
+  // When def_optional is true, it's OK to not have a "=value" part.
+  if (def_optional && (flag_end[0] == '\0')) {
+    return flag_end;
+  }
+
+  // If def_optional is true and there are more characters after the
+  // flag name, or if def_optional is false, there must be a '=' after
+  // the flag name.
+  if (flag_end[0] != '=') return nullptr;
+
+  // Returns the string after "=".
+  return flag_end + 1;
+}
+
+// Parses a string for a Google Mock bool flag, in the form of
+// "--gmock_flag=value".
+//
+// On success, stores the value of the flag in *value, and returns
+// true.  On failure, returns false without changing *value.
+static bool ParseGoogleMockFlag(const char* str, const char* flag_name,
+                                bool* value) {
+  // Gets the value of the flag as a string.
+  const char* const value_str = ParseGoogleMockFlagValue(str, flag_name, true);
+
+  // Aborts if the parsing failed.
+  if (value_str == nullptr) return false;
+
+  // Converts the string value to a bool.
+  *value = !(*value_str == '0' || *value_str == 'f' || *value_str == 'F');
+  return true;
+}
+
+// Parses a string for a Google Mock string flag, in the form of
+// "--gmock_flag=value".
+//
+// On success, stores the value of the flag in *value, and returns
+// true.  On failure, returns false without changing *value.
+template <typename String>
+static bool ParseGoogleMockFlag(const char* str, const char* flag_name,
+                                String* value) {
+  // Gets the value of the flag as a string.
+  const char* const value_str = ParseGoogleMockFlagValue(str, flag_name, false);
+
+  // Aborts if the parsing failed.
+  if (value_str == nullptr) return false;
+
+  // Sets *value to the value of the flag.
+  *value = value_str;
+  return true;
+}
+
+static bool ParseGoogleMockFlag(const char* str, const char* flag_name,
+                                int32_t* value) {
+  // Gets the value of the flag as a string.
+  const char* const value_str = ParseGoogleMockFlagValue(str, flag_name, true);
+
+  // Aborts if the parsing failed.
+  if (value_str == nullptr) return false;
+
+  // Sets *value to the value of the flag.
+  return ParseInt32(Message() << "The value of flag --" << flag_name, value_str,
+                    value);
+}
+
+// The internal implementation of InitGoogleMock().
+//
+// The type parameter CharType can be instantiated to either char or
+// wchar_t.
+template <typename CharType>
+void InitGoogleMockImpl(int* argc, CharType** argv) {
+  // Makes sure Google Test is initialized.  InitGoogleTest() is
+  // idempotent, so it's fine if the user has already called it.
+  InitGoogleTest(argc, argv);
+  if (*argc <= 0) return;
+
+  for (int i = 1; i != *argc; i++) {
+    const std::string arg_string = StreamableToString(argv[i]);
+    const char* const arg = arg_string.c_str();
+
+    // Do we see a Google Mock flag?
+    bool found_gmock_flag = false;
+
+#define GMOCK_INTERNAL_PARSE_FLAG(flag_name)            \
+  if (!found_gmock_flag) {                              \
+    auto value = GMOCK_FLAG_GET(flag_name);             \
+    if (ParseGoogleMockFlag(arg, #flag_name, &value)) { \
+      GMOCK_FLAG_SET(flag_name, value);                 \
+      found_gmock_flag = true;                          \
+    }                                                   \
+  }
+
+    GMOCK_INTERNAL_PARSE_FLAG(catch_leaked_mocks)
+    GMOCK_INTERNAL_PARSE_FLAG(verbose)
+    GMOCK_INTERNAL_PARSE_FLAG(default_mock_behavior)
+
+    if (found_gmock_flag) {
+      // Yes.  Shift the remainder of the argv list left by one.  Note
+      // that argv has (*argc + 1) elements, the last one always being
+      // NULL.  The following loop moves the trailing NULL element as
+      // well.
+      for (int j = i; j != *argc; j++) {
+        argv[j] = argv[j + 1];
+      }
+
+      // Decrements the argument count.
+      (*argc)--;
+
+      // We also need to decrement the iterator as we just removed
+      // an element.
+      i--;
+    }
+  }
+}
+
+}  // namespace internal
+
+// Initializes Google Mock.  This must be called before running the
+// tests.  In particular, it parses a command line for the flags that
+// Google Mock recognizes.  Whenever a Google Mock flag is seen, it is
+// removed from argv, and *argc is decremented.
+//
+// No value is returned.  Instead, the Google Mock flag variables are
+// updated.
+//
+// Since Google Test is needed for Google Mock to work, this function
+// also initializes Google Test and parses its flags, if that hasn't
+// been done.
+GTEST_API_ void InitGoogleMock(int* argc, char** argv) {
+  internal::InitGoogleMockImpl(argc, argv);
+}
+
+// This overloaded version can be used in Windows programs compiled in
+// UNICODE mode.
+GTEST_API_ void InitGoogleMock(int* argc, wchar_t** argv) {
+  internal::InitGoogleMockImpl(argc, argv);
+}
+
+// This overloaded version can be used on Arduino/embedded platforms where
+// there is no argc/argv.
+GTEST_API_ void InitGoogleMock() {
+  // Since Arduino doesn't have a command line, fake out the argc/argv arguments
+  int argc = 1;
+  const auto arg0 = "dummy";
+  char* argv0 = const_cast<char*>(arg0);
+  char** argv = &argv0;
+
+  internal::InitGoogleMockImpl(&argc, argv);
+}
+
+}  // namespace testing

contrib/googletest/googlemock/src/gmock_main.cc

@@ -0,0 +1,73 @@
+// Copyright 2008, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+#include <iostream>
+
+#include "gmock/gmock.h"
+#include "gtest/gtest.h"
+
+#if defined(GTEST_OS_ESP8266) || defined(GTEST_OS_ESP32) || \
+    (defined(GTEST_OS_NRF52) && defined(ARDUINO))
+#ifdef GTEST_OS_ESP8266
+extern "C" {
+#endif
+void setup() {
+  // Since Google Mock depends on Google Test, InitGoogleMock() is
+  // also responsible for initializing Google Test.  Therefore there's
+  // no need for calling testing::InitGoogleTest() separately.
+  testing::InitGoogleMock();
+}
+void loop() { RUN_ALL_TESTS(); }
+#ifdef GTEST_OS_ESP8266
+}
+#endif
+
+#else
+
+// MS C++ compiler/linker has a bug on Windows (not on Windows CE), which
+// causes a link error when _tmain is defined in a static library and UNICODE
+// is enabled. For this reason instead of _tmain, main function is used on
+// Windows. See the following link to track the current status of this bug:
+// https://web.archive.org/web/20170912203238/connect.microsoft.com/VisualStudio/feedback/details/394464/wmain-link-error-in-the-static-library
+// // NOLINT
+#ifdef GTEST_OS_WINDOWS_MOBILE
+#include <tchar.h>  // NOLINT
+
+GTEST_API_ int _tmain(int argc, TCHAR** argv) {
+#else
+GTEST_API_ int main(int argc, char** argv) {
+#endif  // GTEST_OS_WINDOWS_MOBILE
+  std::cout << "Running main() from gmock_main.cc\n";
+  // Since Google Mock depends on Google Test, InitGoogleMock() is
+  // also responsible for initializing Google Test.  Therefore there's
+  // no need for calling testing::InitGoogleTest() separately.
+  testing::InitGoogleMock(&argc, argv);
+  return RUN_ALL_TESTS();
+}
+#endif

contrib/googletest/googlemock/test/BUILD.bazel

@@ -0,0 +1,118 @@
+# Copyright 2017 Google Inc.
+# All Rights Reserved.
+#
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are
+# met:
+#
+#     * Redistributions of source code must retain the above copyright
+# notice, this list of conditions and the following disclaimer.
+#     * Redistributions in binary form must reproduce the above
+# copyright notice, this list of conditions and the following disclaimer
+# in the documentation and/or other materials provided with the
+# distribution.
+#     * Neither the name of Google Inc. nor the names of its
+# contributors may be used to endorse or promote products derived from
+# this software without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+#
+#   Bazel Build for Google C++ Testing Framework(Google Test)-googlemock
+
+load("@rules_python//python:defs.bzl", "py_library", "py_test")
+
+licenses(["notice"])
+
+# Tests for GMock itself
+cc_test(
+    name = "gmock_all_test",
+    size = "small",
+    srcs = glob(include = ["gmock-*.cc"]) + ["gmock-matchers_test.h"],
+    linkopts = select({
+        "//:qnx": [],
+        "//:windows": [],
+        "//conditions:default": ["-pthread"],
+    }),
+    deps = ["//:gtest"],
+)
+
+# Python tests
+py_library(
+    name = "gmock_test_utils",
+    testonly = 1,
+    srcs = ["gmock_test_utils.py"],
+    deps = [
+        "//googletest/test:gtest_test_utils",
+    ],
+)
+
+cc_binary(
+    name = "gmock_leak_test_",
+    testonly = 1,
+    srcs = ["gmock_leak_test_.cc"],
+    deps = ["//:gtest_main"],
+)
+
+py_test(
+    name = "gmock_leak_test",
+    size = "medium",
+    srcs = ["gmock_leak_test.py"],
+    data = [
+        ":gmock_leak_test_",
+        ":gmock_test_utils",
+    ],
+    tags = [
+        "no_test_msvc2015",
+        "no_test_msvc2017",
+    ],
+)
+
+cc_test(
+    name = "gmock_link_test",
+    size = "small",
+    srcs = [
+        "gmock_link2_test.cc",
+        "gmock_link_test.cc",
+        "gmock_link_test.h",
+    ],
+    deps = ["//:gtest_main"],
+)
+
+cc_binary(
+    name = "gmock_output_test_",
+    srcs = ["gmock_output_test_.cc"],
+    deps = ["//:gtest"],
+)
+
+py_test(
+    name = "gmock_output_test",
+    size = "medium",
+    srcs = ["gmock_output_test.py"],
+    data = [
+        ":gmock_output_test_",
+        ":gmock_output_test_golden.txt",
+    ],
+    tags = [
+        "no_test_msvc2015",
+        "no_test_msvc2017",
+    ],
+    deps = [":gmock_test_utils"],
+)
+
+cc_test(
+    name = "gmock_test",
+    size = "small",
+    srcs = ["gmock_test.cc"],
+    deps = ["//:gtest_main"],
+)

contrib/googletest/googlemock/test/gmock-actions_test.cc

@@ -0,0 +1,2169 @@
+// Copyright 2007, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+// Google Mock - a framework for writing C++ mock classes.
+//
+// This file tests the built-in actions.
+
+#include "gmock/gmock-actions.h"
+
+#include <algorithm>
+#include <functional>
+#include <iterator>
+#include <memory>
+#include <sstream>
+#include <string>
+#include <tuple>
+#include <type_traits>
+#include <utility>
+#include <vector>
+
+#include "gmock/gmock.h"
+#include "gmock/internal/gmock-port.h"
+#include "gtest/gtest-spi.h"
+#include "gtest/gtest.h"
+#include "gtest/internal/gtest-port.h"
+
+// Silence C4100 (unreferenced formal parameter) and C4503 (decorated name
+// length exceeded) for MSVC.
+GTEST_DISABLE_MSC_WARNINGS_PUSH_(4100 4503)
+#if defined(_MSC_VER) && (_MSC_VER == 1900)
+// and silence C4800 (C4800: 'int *const ': forcing value
+// to bool 'true' or 'false') for MSVC 15
+GTEST_DISABLE_MSC_WARNINGS_PUSH_(4800)
+#endif
+
+namespace testing {
+namespace {
+
+using ::testing::internal::BuiltInDefaultValue;
+
+TEST(TypeTraits, Negation) {
+  // Direct use with std types.
+  static_assert(std::is_base_of<std::false_type,
+                                internal::negation<std::true_type>>::value,
+                "");
+
+  static_assert(std::is_base_of<std::true_type,
+                                internal::negation<std::false_type>>::value,
+                "");
+
+  // With other types that fit the requirement of a value member that is
+  // convertible to bool.
+  static_assert(std::is_base_of<
+                    std::true_type,
+                    internal::negation<std::integral_constant<int, 0>>>::value,
+                "");
+
+  static_assert(std::is_base_of<
+                    std::false_type,
+                    internal::negation<std::integral_constant<int, 1>>>::value,
+                "");
+
+  static_assert(std::is_base_of<
+                    std::false_type,
+                    internal::negation<std::integral_constant<int, -1>>>::value,
+                "");
+}
+
+// Weird false/true types that aren't actually bool constants (but should still
+// be legal according to [meta.logical] because `bool(T::value)` is valid), are
+// distinct from std::false_type and std::true_type, and are distinct from other
+// instantiations of the same template.
+//
+// These let us check finicky details mandated by the standard like
+// "std::conjunction should evaluate to a type that inherits from the first
+// false-y input".
+template <int>
+struct MyFalse : std::integral_constant<int, 0> {};
+
+template <int>
+struct MyTrue : std::integral_constant<int, -1> {};
+
+TEST(TypeTraits, Conjunction) {
+  // Base case: always true.
+  static_assert(std::is_base_of<std::true_type, internal::conjunction<>>::value,
+                "");
+
+  // One predicate: inherits from that predicate, regardless of value.
+  static_assert(
+      std::is_base_of<MyFalse<0>, internal::conjunction<MyFalse<0>>>::value,
+      "");
+
+  static_assert(
+      std::is_base_of<MyTrue<0>, internal::conjunction<MyTrue<0>>>::value, "");
+
+  // Multiple predicates, with at least one false: inherits from that one.
+  static_assert(
+      std::is_base_of<MyFalse<1>, internal::conjunction<MyTrue<0>, MyFalse<1>,
+                                                        MyTrue<2>>>::value,
+      "");
+
+  static_assert(
+      std::is_base_of<MyFalse<1>, internal::conjunction<MyTrue<0>, MyFalse<1>,
+                                                        MyFalse<2>>>::value,
+      "");
+
+  // Short circuiting: in the case above, additional predicates need not even
+  // define a value member.
+  struct Empty {};
+  static_assert(
+      std::is_base_of<MyFalse<1>, internal::conjunction<MyTrue<0>, MyFalse<1>,
+                                                        Empty>>::value,
+      "");
+
+  // All predicates true: inherits from the last.
+  static_assert(
+      std::is_base_of<MyTrue<2>, internal::conjunction<MyTrue<0>, MyTrue<1>,
+                                                       MyTrue<2>>>::value,
+      "");
+}
+
+TEST(TypeTraits, Disjunction) {
+  // Base case: always false.
+  static_assert(
+      std::is_base_of<std::false_type, internal::disjunction<>>::value, "");
+
+  // One predicate: inherits from that predicate, regardless of value.
+  static_assert(
+      std::is_base_of<MyFalse<0>, internal::disjunction<MyFalse<0>>>::value,
+      "");
+
+  static_assert(
+      std::is_base_of<MyTrue<0>, internal::disjunction<MyTrue<0>>>::value, "");
+
+  // Multiple predicates, with at least one true: inherits from that one.
+  static_assert(
+      std::is_base_of<MyTrue<1>, internal::disjunction<MyFalse<0>, MyTrue<1>,
+                                                       MyFalse<2>>>::value,
+      "");
+
+  static_assert(
+      std::is_base_of<MyTrue<1>, internal::disjunction<MyFalse<0>, MyTrue<1>,
+                                                       MyTrue<2>>>::value,
+      "");
+
+  // Short circuiting: in the case above, additional predicates need not even
+  // define a value member.
+  struct Empty {};
+  static_assert(
+      std::is_base_of<MyTrue<1>, internal::disjunction<MyFalse<0>, MyTrue<1>,
+                                                       Empty>>::value,
+      "");
+
+  // All predicates false: inherits from the last.
+  static_assert(
+      std::is_base_of<MyFalse<2>, internal::disjunction<MyFalse<0>, MyFalse<1>,
+                                                        MyFalse<2>>>::value,
+      "");
+}
+
+TEST(TypeTraits, IsInvocableRV) {
+  struct C {
+    int operator()() const { return 0; }
+    void operator()(int) & {}
+    std::string operator()(int) && { return ""; };
+  };
+
+  // The first overload is callable for const and non-const rvalues and lvalues.
+  // It can be used to obtain an int, cv void, or anything int is convertible
+  // to.
+  static_assert(internal::is_callable_r<int, C>::value, "");
+  static_assert(internal::is_callable_r<int, C&>::value, "");
+  static_assert(internal::is_callable_r<int, const C>::value, "");
+  static_assert(internal::is_callable_r<int, const C&>::value, "");
+
+  static_assert(internal::is_callable_r<void, C>::value, "");
+  static_assert(internal::is_callable_r<const volatile void, C>::value, "");
+  static_assert(internal::is_callable_r<char, C>::value, "");
+
+  // It's possible to provide an int. If it's given to an lvalue, the result is
+  // void. Otherwise it is std::string (which is also treated as allowed for a
+  // void result type).
+  static_assert(internal::is_callable_r<void, C&, int>::value, "");
+  static_assert(!internal::is_callable_r<int, C&, int>::value, "");
+  static_assert(!internal::is_callable_r<std::string, C&, int>::value, "");
+  static_assert(!internal::is_callable_r<void, const C&, int>::value, "");
+
+  static_assert(internal::is_callable_r<std::string, C, int>::value, "");
+  static_assert(internal::is_callable_r<void, C, int>::value, "");
+  static_assert(!internal::is_callable_r<int, C, int>::value, "");
+
+  // It's not possible to provide other arguments.
+  static_assert(!internal::is_callable_r<void, C, std::string>::value, "");
+  static_assert(!internal::is_callable_r<void, C, int, int>::value, "");
+
+  // In C++17 and above, where it's guaranteed that functions can return
+  // non-moveable objects, everything should work fine for non-moveable rsult
+  // types too.
+#if defined(GTEST_INTERNAL_CPLUSPLUS_LANG) && \
+    GTEST_INTERNAL_CPLUSPLUS_LANG >= 201703L
+  {
+    struct NonMoveable {
+      NonMoveable() = default;
+      NonMoveable(NonMoveable&&) = delete;
+    };
+
+    static_assert(!std::is_move_constructible_v<NonMoveable>);
+
+    struct Callable {
+      NonMoveable operator()() { return NonMoveable(); }
+    };
+
+    static_assert(internal::is_callable_r<NonMoveable, Callable>::value);
+    static_assert(internal::is_callable_r<void, Callable>::value);
+    static_assert(
+        internal::is_callable_r<const volatile void, Callable>::value);
+
+    static_assert(!internal::is_callable_r<int, Callable>::value);
+    static_assert(!internal::is_callable_r<NonMoveable, Callable, int>::value);
+  }
+#endif  // C++17 and above
+
+  // Nothing should choke when we try to call other arguments besides directly
+  // callable objects, but they should not show up as callable.
+  static_assert(!internal::is_callable_r<void, int>::value, "");
+  static_assert(!internal::is_callable_r<void, void (C::*)()>::value, "");
+  static_assert(!internal::is_callable_r<void, void (C::*)(), C*>::value, "");
+}
+
+// Tests that BuiltInDefaultValue<T*>::Get() returns NULL.
+TEST(BuiltInDefaultValueTest, IsNullForPointerTypes) {
+  EXPECT_TRUE(BuiltInDefaultValue<int*>::Get() == nullptr);
+  EXPECT_TRUE(BuiltInDefaultValue<const char*>::Get() == nullptr);
+  EXPECT_TRUE(BuiltInDefaultValue<void*>::Get() == nullptr);
+}
+
+// Tests that BuiltInDefaultValue<T*>::Exists() return true.
+TEST(BuiltInDefaultValueTest, ExistsForPointerTypes) {
+  EXPECT_TRUE(BuiltInDefaultValue<int*>::Exists());
+  EXPECT_TRUE(BuiltInDefaultValue<const char*>::Exists());
+  EXPECT_TRUE(BuiltInDefaultValue<void*>::Exists());
+}
+
+// Tests that BuiltInDefaultValue<T>::Get() returns 0 when T is a
+// built-in numeric type.
+TEST(BuiltInDefaultValueTest, IsZeroForNumericTypes) {
+  EXPECT_EQ(0U, BuiltInDefaultValue<unsigned char>::Get());
+  EXPECT_EQ(0, BuiltInDefaultValue<signed char>::Get());
+  EXPECT_EQ(0, BuiltInDefaultValue<char>::Get());
+#if GMOCK_WCHAR_T_IS_NATIVE_
+#if !defined(__WCHAR_UNSIGNED__)
+  EXPECT_EQ(0, BuiltInDefaultValue<wchar_t>::Get());
+#else
+  EXPECT_EQ(0U, BuiltInDefaultValue<wchar_t>::Get());
+#endif
+#endif
+  EXPECT_EQ(0U, BuiltInDefaultValue<unsigned short>::Get());  // NOLINT
+  EXPECT_EQ(0, BuiltInDefaultValue<signed short>::Get());     // NOLINT
+  EXPECT_EQ(0, BuiltInDefaultValue<short>::Get());            // NOLINT
+  EXPECT_EQ(0U, BuiltInDefaultValue<unsigned int>::Get());
+  EXPECT_EQ(0, BuiltInDefaultValue<signed int>::Get());
+  EXPECT_EQ(0, BuiltInDefaultValue<int>::Get());
+  EXPECT_EQ(0U, BuiltInDefaultValue<unsigned long>::Get());       // NOLINT
+  EXPECT_EQ(0, BuiltInDefaultValue<signed long>::Get());          // NOLINT
+  EXPECT_EQ(0, BuiltInDefaultValue<long>::Get());                 // NOLINT
+  EXPECT_EQ(0U, BuiltInDefaultValue<unsigned long long>::Get());  // NOLINT
+  EXPECT_EQ(0, BuiltInDefaultValue<signed long long>::Get());     // NOLINT
+  EXPECT_EQ(0, BuiltInDefaultValue<long long>::Get());            // NOLINT
+  EXPECT_EQ(0, BuiltInDefaultValue<float>::Get());
+  EXPECT_EQ(0, BuiltInDefaultValue<double>::Get());
+}
+
+// Tests that BuiltInDefaultValue<T>::Exists() returns true when T is a
+// built-in numeric type.
+TEST(BuiltInDefaultValueTest, ExistsForNumericTypes) {
+  EXPECT_TRUE(BuiltInDefaultValue<unsigned char>::Exists());
+  EXPECT_TRUE(BuiltInDefaultValue<signed char>::Exists());
+  EXPECT_TRUE(BuiltInDefaultValue<char>::Exists());
+#if GMOCK_WCHAR_T_IS_NATIVE_
+  EXPECT_TRUE(BuiltInDefaultValue<wchar_t>::Exists());
+#endif
+  EXPECT_TRUE(BuiltInDefaultValue<unsigned short>::Exists());  // NOLINT
+  EXPECT_TRUE(BuiltInDefaultValue<signed short>::Exists());    // NOLINT
+  EXPECT_TRUE(BuiltInDefaultValue<short>::Exists());           // NOLINT
+  EXPECT_TRUE(BuiltInDefaultValue<unsigned int>::Exists());
+  EXPECT_TRUE(BuiltInDefaultValue<signed int>::Exists());
+  EXPECT_TRUE(BuiltInDefaultValue<int>::Exists());
+  EXPECT_TRUE(BuiltInDefaultValue<unsigned long>::Exists());       // NOLINT
+  EXPECT_TRUE(BuiltInDefaultValue<signed long>::Exists());         // NOLINT
+  EXPECT_TRUE(BuiltInDefaultValue<long>::Exists());                // NOLINT
+  EXPECT_TRUE(BuiltInDefaultValue<unsigned long long>::Exists());  // NOLINT
+  EXPECT_TRUE(BuiltInDefaultValue<signed long long>::Exists());    // NOLINT
+  EXPECT_TRUE(BuiltInDefaultValue<long long>::Exists());           // NOLINT
+  EXPECT_TRUE(BuiltInDefaultValue<float>::Exists());
+  EXPECT_TRUE(BuiltInDefaultValue<double>::Exists());
+}
+
+// Tests that BuiltInDefaultValue<bool>::Get() returns false.
+TEST(BuiltInDefaultValueTest, IsFalseForBool) {
+  EXPECT_FALSE(BuiltInDefaultValue<bool>::Get());
+}
+
+// Tests that BuiltInDefaultValue<bool>::Exists() returns true.
+TEST(BuiltInDefaultValueTest, BoolExists) {
+  EXPECT_TRUE(BuiltInDefaultValue<bool>::Exists());
+}
+
+// Tests that BuiltInDefaultValue<T>::Get() returns "" when T is a
+// string type.
+TEST(BuiltInDefaultValueTest, IsEmptyStringForString) {
+  EXPECT_EQ("", BuiltInDefaultValue<::std::string>::Get());
+}
+
+// Tests that BuiltInDefaultValue<T>::Exists() returns true when T is a
+// string type.
+TEST(BuiltInDefaultValueTest, ExistsForString) {
+  EXPECT_TRUE(BuiltInDefaultValue<::std::string>::Exists());
+}
+
+// Tests that BuiltInDefaultValue<const T>::Get() returns the same
+// value as BuiltInDefaultValue<T>::Get() does.
+TEST(BuiltInDefaultValueTest, WorksForConstTypes) {
+  EXPECT_EQ("", BuiltInDefaultValue<const std::string>::Get());
+  EXPECT_EQ(0, BuiltInDefaultValue<const int>::Get());
+  EXPECT_TRUE(BuiltInDefaultValue<char* const>::Get() == nullptr);
+  EXPECT_FALSE(BuiltInDefaultValue<const bool>::Get());
+}
+
+// A type that's default constructible.
+class MyDefaultConstructible {
+ public:
+  MyDefaultConstructible() : value_(42) {}
+
+  int value() const { return value_; }
+
+ private:
+  int value_;
+};
+
+// A type that's not default constructible.
+class MyNonDefaultConstructible {
+ public:
+  // Does not have a default ctor.
+  explicit MyNonDefaultConstructible(int a_value) : value_(a_value) {}
+
+  int value() const { return value_; }
+
+ private:
+  int value_;
+};
+
+TEST(BuiltInDefaultValueTest, ExistsForDefaultConstructibleType) {
+  EXPECT_TRUE(BuiltInDefaultValue<MyDefaultConstructible>::Exists());
+}
+
+TEST(BuiltInDefaultValueTest, IsDefaultConstructedForDefaultConstructibleType) {
+  EXPECT_EQ(42, BuiltInDefaultValue<MyDefaultConstructible>::Get().value());
+}
+
+TEST(BuiltInDefaultValueTest, DoesNotExistForNonDefaultConstructibleType) {
+  EXPECT_FALSE(BuiltInDefaultValue<MyNonDefaultConstructible>::Exists());
+}
+
+// Tests that BuiltInDefaultValue<T&>::Get() aborts the program.
+TEST(BuiltInDefaultValueDeathTest, IsUndefinedForReferences) {
+  EXPECT_DEATH_IF_SUPPORTED({ BuiltInDefaultValue<int&>::Get(); }, "");
+  EXPECT_DEATH_IF_SUPPORTED({ BuiltInDefaultValue<const char&>::Get(); }, "");
+}
+
+TEST(BuiltInDefaultValueDeathTest, IsUndefinedForNonDefaultConstructibleType) {
+  EXPECT_DEATH_IF_SUPPORTED(
+      { BuiltInDefaultValue<MyNonDefaultConstructible>::Get(); }, "");
+}
+
+// Tests that DefaultValue<T>::IsSet() is false initially.
+TEST(DefaultValueTest, IsInitiallyUnset) {
+  EXPECT_FALSE(DefaultValue<int>::IsSet());
+  EXPECT_FALSE(DefaultValue<MyDefaultConstructible>::IsSet());
+  EXPECT_FALSE(DefaultValue<const MyNonDefaultConstructible>::IsSet());
+}
+
+// Tests that DefaultValue<T> can be set and then unset.
+TEST(DefaultValueTest, CanBeSetAndUnset) {
+  EXPECT_TRUE(DefaultValue<int>::Exists());
+  EXPECT_FALSE(DefaultValue<const MyNonDefaultConstructible>::Exists());
+
+  DefaultValue<int>::Set(1);
+  DefaultValue<const MyNonDefaultConstructible>::Set(
+      MyNonDefaultConstructible(42));
+
+  EXPECT_EQ(1, DefaultValue<int>::Get());
+  EXPECT_EQ(42, DefaultValue<const MyNonDefaultConstructible>::Get().value());
+
+  EXPECT_TRUE(DefaultValue<int>::Exists());
+  EXPECT_TRUE(DefaultValue<const MyNonDefaultConstructible>::Exists());
+
+  DefaultValue<int>::Clear();
+  DefaultValue<const MyNonDefaultConstructible>::Clear();
+
+  EXPECT_FALSE(DefaultValue<int>::IsSet());
+  EXPECT_FALSE(DefaultValue<const MyNonDefaultConstructible>::IsSet());
+
+  EXPECT_TRUE(DefaultValue<int>::Exists());
+  EXPECT_FALSE(DefaultValue<const MyNonDefaultConstructible>::Exists());
+}
+
+// Tests that DefaultValue<T>::Get() returns the
+// BuiltInDefaultValue<T>::Get() when DefaultValue<T>::IsSet() is
+// false.
+TEST(DefaultValueDeathTest, GetReturnsBuiltInDefaultValueWhenUnset) {
+  EXPECT_FALSE(DefaultValue<int>::IsSet());
+  EXPECT_TRUE(DefaultValue<int>::Exists());
+  EXPECT_FALSE(DefaultValue<MyNonDefaultConstructible>::IsSet());
+  EXPECT_FALSE(DefaultValue<MyNonDefaultConstructible>::Exists());
+
+  EXPECT_EQ(0, DefaultValue<int>::Get());
+
+  EXPECT_DEATH_IF_SUPPORTED({ DefaultValue<MyNonDefaultConstructible>::Get(); },
+                            "");
+}
+
+TEST(DefaultValueTest, GetWorksForMoveOnlyIfSet) {
+  EXPECT_TRUE(DefaultValue<std::unique_ptr<int>>::Exists());
+  EXPECT_TRUE(DefaultValue<std::unique_ptr<int>>::Get() == nullptr);
+  DefaultValue<std::unique_ptr<int>>::SetFactory(
+      [] { return std::make_unique<int>(42); });
+  EXPECT_TRUE(DefaultValue<std::unique_ptr<int>>::Exists());
+  std::unique_ptr<int> i = DefaultValue<std::unique_ptr<int>>::Get();
+  EXPECT_EQ(42, *i);
+}
+
+// Tests that DefaultValue<void>::Get() returns void.
+TEST(DefaultValueTest, GetWorksForVoid) { return DefaultValue<void>::Get(); }
+
+// Tests using DefaultValue with a reference type.
+
+// Tests that DefaultValue<T&>::IsSet() is false initially.
+TEST(DefaultValueOfReferenceTest, IsInitiallyUnset) {
+  EXPECT_FALSE(DefaultValue<int&>::IsSet());
+  EXPECT_FALSE(DefaultValue<MyDefaultConstructible&>::IsSet());
+  EXPECT_FALSE(DefaultValue<MyNonDefaultConstructible&>::IsSet());
+}
+
+// Tests that DefaultValue<T&>::Exists is false initially.
+TEST(DefaultValueOfReferenceTest, IsInitiallyNotExisting) {
+  EXPECT_FALSE(DefaultValue<int&>::Exists());
+  EXPECT_FALSE(DefaultValue<MyDefaultConstructible&>::Exists());
+  EXPECT_FALSE(DefaultValue<MyNonDefaultConstructible&>::Exists());
+}
+
+// Tests that DefaultValue<T&> can be set and then unset.
+TEST(DefaultValueOfReferenceTest, CanBeSetAndUnset) {
+  int n = 1;
+  DefaultValue<const int&>::Set(n);
+  MyNonDefaultConstructible x(42);
+  DefaultValue<MyNonDefaultConstructible&>::Set(x);
+
+  EXPECT_TRUE(DefaultValue<const int&>::Exists());
+  EXPECT_TRUE(DefaultValue<MyNonDefaultConstructible&>::Exists());
+
+  EXPECT_EQ(&n, &(DefaultValue<const int&>::Get()));
+  EXPECT_EQ(&x, &(DefaultValue<MyNonDefaultConstructible&>::Get()));
+
+  DefaultValue<const int&>::Clear();
+  DefaultValue<MyNonDefaultConstructible&>::Clear();
+
+  EXPECT_FALSE(DefaultValue<const int&>::Exists());
+  EXPECT_FALSE(DefaultValue<MyNonDefaultConstructible&>::Exists());
+
+  EXPECT_FALSE(DefaultValue<const int&>::IsSet());
+  EXPECT_FALSE(DefaultValue<MyNonDefaultConstructible&>::IsSet());
+}
+
+// Tests that DefaultValue<T&>::Get() returns the
+// BuiltInDefaultValue<T&>::Get() when DefaultValue<T&>::IsSet() is
+// false.
+TEST(DefaultValueOfReferenceDeathTest, GetReturnsBuiltInDefaultValueWhenUnset) {
+  EXPECT_FALSE(DefaultValue<int&>::IsSet());
+  EXPECT_FALSE(DefaultValue<MyNonDefaultConstructible&>::IsSet());
+
+  EXPECT_DEATH_IF_SUPPORTED({ DefaultValue<int&>::Get(); }, "");
+  EXPECT_DEATH_IF_SUPPORTED({ DefaultValue<MyNonDefaultConstructible>::Get(); },
+                            "");
+}
+
+// Tests that ActionInterface can be implemented by defining the
+// Perform method.
+
+typedef int MyGlobalFunction(bool, int);
+
+class MyActionImpl : public ActionInterface<MyGlobalFunction> {
+ public:
+  int Perform(const std::tuple<bool, int>& args) override {
+    return std::get<0>(args) ? std::get<1>(args) : 0;
+  }
+};
+
+TEST(ActionInterfaceTest, CanBeImplementedByDefiningPerform) {
+  MyActionImpl my_action_impl;
+  (void)my_action_impl;
+}
+
+TEST(ActionInterfaceTest, MakeAction) {
+  Action<MyGlobalFunction> action = MakeAction(new MyActionImpl);
+
+  // When exercising the Perform() method of Action<F>, we must pass
+  // it a tuple whose size and type are compatible with F's argument
+  // types.  For example, if F is int(), then Perform() takes a
+  // 0-tuple; if F is void(bool, int), then Perform() takes a
+  // std::tuple<bool, int>, and so on.
+  EXPECT_EQ(5, action.Perform(std::make_tuple(true, 5)));
+}
+
+// Tests that Action<F> can be constructed from a pointer to
+// ActionInterface<F>.
+TEST(ActionTest, CanBeConstructedFromActionInterface) {
+  Action<MyGlobalFunction> action(new MyActionImpl);
+}
+
+// Tests that Action<F> delegates actual work to ActionInterface<F>.
+TEST(ActionTest, DelegatesWorkToActionInterface) {
+  const Action<MyGlobalFunction> action(new MyActionImpl);
+
+  EXPECT_EQ(5, action.Perform(std::make_tuple(true, 5)));
+  EXPECT_EQ(0, action.Perform(std::make_tuple(false, 1)));
+}
+
+// Tests that Action<F> can be copied.
+TEST(ActionTest, IsCopyable) {
+  Action<MyGlobalFunction> a1(new MyActionImpl);
+  Action<MyGlobalFunction> a2(a1);  // Tests the copy constructor.
+
+  // a1 should continue to work after being copied from.
+  EXPECT_EQ(5, a1.Perform(std::make_tuple(true, 5)));
+  EXPECT_EQ(0, a1.Perform(std::make_tuple(false, 1)));
+
+  // a2 should work like the action it was copied from.
+  EXPECT_EQ(5, a2.Perform(std::make_tuple(true, 5)));
+  EXPECT_EQ(0, a2.Perform(std::make_tuple(false, 1)));
+
+  a2 = a1;  // Tests the assignment operator.
+
+  // a1 should continue to work after being copied from.
+  EXPECT_EQ(5, a1.Perform(std::make_tuple(true, 5)));
+  EXPECT_EQ(0, a1.Perform(std::make_tuple(false, 1)));
+
+  // a2 should work like the action it was copied from.
+  EXPECT_EQ(5, a2.Perform(std::make_tuple(true, 5)));
+  EXPECT_EQ(0, a2.Perform(std::make_tuple(false, 1)));
+}
+
+// Tests that an Action<From> object can be converted to a
+// compatible Action<To> object.
+
+class IsNotZero : public ActionInterface<bool(int)> {  // NOLINT
+ public:
+  bool Perform(const std::tuple<int>& arg) override {
+    return std::get<0>(arg) != 0;
+  }
+};
+
+TEST(ActionTest, CanBeConvertedToOtherActionType) {
+  const Action<bool(int)> a1(new IsNotZero);           // NOLINT
+  const Action<int(char)> a2 = Action<int(char)>(a1);  // NOLINT
+  EXPECT_EQ(1, a2.Perform(std::make_tuple('a')));
+  EXPECT_EQ(0, a2.Perform(std::make_tuple('\0')));
+}
+
+// The following two classes are for testing MakePolymorphicAction().
+
+// Implements a polymorphic action that returns the second of the
+// arguments it receives.
+class ReturnSecondArgumentAction {
+ public:
+  // We want to verify that MakePolymorphicAction() can work with a
+  // polymorphic action whose Perform() method template is either
+  // const or not.  This lets us verify the non-const case.
+  template <typename Result, typename ArgumentTuple>
+  Result Perform(const ArgumentTuple& args) {
+    return std::get<1>(args);
+  }
+};
+
+// Implements a polymorphic action that can be used in a nullary
+// function to return 0.
+class ReturnZeroFromNullaryFunctionAction {
+ public:
+  // For testing that MakePolymorphicAction() works when the
+  // implementation class' Perform() method template takes only one
+  // template parameter.
+  //
+  // We want to verify that MakePolymorphicAction() can work with a
+  // polymorphic action whose Perform() method template is either
+  // const or not.  This lets us verify the const case.
+  template <typename Result>
+  Result Perform(const std::tuple<>&) const {
+    return 0;
+  }
+};
+
+// These functions verify that MakePolymorphicAction() returns a
+// PolymorphicAction<T> where T is the argument's type.
+
+PolymorphicAction<ReturnSecondArgumentAction> ReturnSecondArgument() {
+  return MakePolymorphicAction(ReturnSecondArgumentAction());
+}
+
+PolymorphicAction<ReturnZeroFromNullaryFunctionAction>
+ReturnZeroFromNullaryFunction() {
+  return MakePolymorphicAction(ReturnZeroFromNullaryFunctionAction());
+}
+
+// Tests that MakePolymorphicAction() turns a polymorphic action
+// implementation class into a polymorphic action.
+TEST(MakePolymorphicActionTest, ConstructsActionFromImpl) {
+  Action<int(bool, int, double)> a1 = ReturnSecondArgument();  // NOLINT
+  EXPECT_EQ(5, a1.Perform(std::make_tuple(false, 5, 2.0)));
+}
+
+// Tests that MakePolymorphicAction() works when the implementation
+// class' Perform() method template has only one template parameter.
+TEST(MakePolymorphicActionTest, WorksWhenPerformHasOneTemplateParameter) {
+  Action<int()> a1 = ReturnZeroFromNullaryFunction();
+  EXPECT_EQ(0, a1.Perform(std::make_tuple()));
+
+  Action<void*()> a2 = ReturnZeroFromNullaryFunction();
+  EXPECT_TRUE(a2.Perform(std::make_tuple()) == nullptr);
+}
+
+// Tests that Return() works as an action for void-returning
+// functions.
+TEST(ReturnTest, WorksForVoid) {
+  const Action<void(int)> ret = Return();  // NOLINT
+  return ret.Perform(std::make_tuple(1));
+}
+
+// Tests that Return(v) returns v.
+TEST(ReturnTest, ReturnsGivenValue) {
+  Action<int()> ret = Return(1);  // NOLINT
+  EXPECT_EQ(1, ret.Perform(std::make_tuple()));
+
+  ret = Return(-5);
+  EXPECT_EQ(-5, ret.Perform(std::make_tuple()));
+}
+
+// Tests that Return("string literal") works.
+TEST(ReturnTest, AcceptsStringLiteral) {
+  Action<const char*()> a1 = Return("Hello");
+  EXPECT_STREQ("Hello", a1.Perform(std::make_tuple()));
+
+  Action<std::string()> a2 = Return("world");
+  EXPECT_EQ("world", a2.Perform(std::make_tuple()));
+}
+
+// Return(x) should work fine when the mock function's return type is a
+// reference-like wrapper for decltype(x), as when x is a std::string and the
+// mock function returns std::string_view.
+TEST(ReturnTest, SupportsReferenceLikeReturnType) {
+  // A reference wrapper for std::vector<int>, implicitly convertible from it.
+  struct Result {
+    const std::vector<int>* v;
+    Result(const std::vector<int>& vec) : v(&vec) {}  // NOLINT
+  };
+
+  // Set up an action for a mock function that returns the reference wrapper
+  // type, initializing it with an actual vector.
+  //
+  // The returned wrapper should be initialized with a copy of that vector
+  // that's embedded within the action itself (which should stay alive as long
+  // as the mock object is alive), rather than e.g. a reference to the temporary
+  // we feed to Return. This should work fine both for WillOnce and
+  // WillRepeatedly.
+  MockFunction<Result()> mock;
+  EXPECT_CALL(mock, Call)
+      .WillOnce(Return(std::vector<int>{17, 19, 23}))
+      .WillRepeatedly(Return(std::vector<int>{29, 31, 37}));
+
+  EXPECT_THAT(mock.AsStdFunction()(),
+              Field(&Result::v, Pointee(ElementsAre(17, 19, 23))));
+
+  EXPECT_THAT(mock.AsStdFunction()(),
+              Field(&Result::v, Pointee(ElementsAre(29, 31, 37))));
+}
+
+TEST(ReturnTest, PrefersConversionOperator) {
+  // Define types In and Out such that:
+  //
+  //  *  In is implicitly convertible to Out.
+  //  *  Out also has an explicit constructor from In.
+  //
+  struct In;
+  struct Out {
+    int x;
+
+    explicit Out(const int val) : x(val) {}
+    explicit Out(const In&) : x(0) {}
+  };
+
+  struct In {
+    operator Out() const { return Out{19}; }  // NOLINT
+  };
+
+  // Assumption check: the C++ language rules are such that a function that
+  // returns Out which uses In a return statement will use the implicit
+  // conversion path rather than the explicit constructor.
+  EXPECT_THAT([]() -> Out { return In(); }(), Field(&Out::x, 19));
+
+  // Return should work the same way: if the mock function's return type is Out
+  // and we feed Return an In value, then the Out should be created through the
+  // implicit conversion path rather than the explicit constructor.
+  MockFunction<Out()> mock;
+  EXPECT_CALL(mock, Call).WillOnce(Return(In()));
+  EXPECT_THAT(mock.AsStdFunction()(), Field(&Out::x, 19));
+}
+
+// It should be possible to use Return(R) with a mock function result type U
+// that is convertible from const R& but *not* R (such as
+// std::reference_wrapper). This should work for both WillOnce and
+// WillRepeatedly.
+TEST(ReturnTest, ConversionRequiresConstLvalueReference) {
+  using R = int;
+  using U = std::reference_wrapper<const int>;
+
+  static_assert(std::is_convertible<const R&, U>::value, "");
+  static_assert(!std::is_convertible<R, U>::value, "");
+
+  MockFunction<U()> mock;
+  EXPECT_CALL(mock, Call).WillOnce(Return(17)).WillRepeatedly(Return(19));
+
+  EXPECT_EQ(17, mock.AsStdFunction()());
+  EXPECT_EQ(19, mock.AsStdFunction()());
+}
+
+// Return(x) should not be usable with a mock function result type that's
+// implicitly convertible from decltype(x) but requires a non-const lvalue
+// reference to the input. It doesn't make sense for the conversion operator to
+// modify the input.
+TEST(ReturnTest, ConversionRequiresMutableLvalueReference) {
+  // Set up a type that is implicitly convertible from std::string&, but not
+  // std::string&& or `const std::string&`.
+  //
+  // Avoid asserting about conversion from std::string on MSVC, which seems to
+  // implement std::is_convertible incorrectly in this case.
+  struct S {
+    S(std::string&) {}  // NOLINT
+  };
+
+  static_assert(std::is_convertible<std::string&, S>::value, "");
+#ifndef _MSC_VER
+  static_assert(!std::is_convertible<std::string&&, S>::value, "");
+#endif
+  static_assert(!std::is_convertible<const std::string&, S>::value, "");
+
+  // It shouldn't be possible to use the result of Return(std::string) in a
+  // context where an S is needed.
+  //
+  // Here too we disable the assertion for MSVC, since its incorrect
+  // implementation of is_convertible causes our SFINAE to be wrong.
+  using RA = decltype(Return(std::string()));
+
+  static_assert(!std::is_convertible<RA, Action<S()>>::value, "");
+#ifndef _MSC_VER
+  static_assert(!std::is_convertible<RA, OnceAction<S()>>::value, "");
+#endif
+}
+
+TEST(ReturnTest, MoveOnlyResultType) {
+  // Return should support move-only result types when used with WillOnce.
+  {
+    MockFunction<std::unique_ptr<int>()> mock;
+    EXPECT_CALL(mock, Call)
+        // NOLINTNEXTLINE
+        .WillOnce(Return(std::unique_ptr<int>(new int(17))));
+
+    EXPECT_THAT(mock.AsStdFunction()(), Pointee(17));
+  }
+
+  // The result of Return should not be convertible to Action (so it can't be
+  // used with WillRepeatedly).
+  static_assert(!std::is_convertible<decltype(Return(std::unique_ptr<int>())),
+                                     Action<std::unique_ptr<int>()>>::value,
+                "");
+}
+
+// Tests that Return(v) is covariant.
+
+struct Base {
+  bool operator==(const Base&) { return true; }
+};
+
+struct Derived : public Base {
+  bool operator==(const Derived&) { return true; }
+};
+
+TEST(ReturnTest, IsCovariant) {
+  Base base;
+  Derived derived;
+  Action<Base*()> ret = Return(&base);
+  EXPECT_EQ(&base, ret.Perform(std::make_tuple()));
+
+  ret = Return(&derived);
+  EXPECT_EQ(&derived, ret.Perform(std::make_tuple()));
+}
+
+// Tests that the type of the value passed into Return is converted into T
+// when the action is cast to Action<T(...)> rather than when the action is
+// performed. See comments on testing::internal::ReturnAction in
+// gmock-actions.h for more information.
+class FromType {
+ public:
+  explicit FromType(bool* is_converted) : converted_(is_converted) {}
+  bool* converted() const { return converted_; }
+
+ private:
+  bool* const converted_;
+};
+
+class ToType {
+ public:
+  // Must allow implicit conversion due to use in ImplicitCast_<T>.
+  ToType(const FromType& x) { *x.converted() = true; }  // NOLINT
+};
+
+TEST(ReturnTest, ConvertsArgumentWhenConverted) {
+  bool converted = false;
+  FromType x(&converted);
+  Action<ToType()> action(Return(x));
+  EXPECT_TRUE(converted) << "Return must convert its argument in its own "
+                         << "conversion operator.";
+  converted = false;
+  action.Perform(std::tuple<>());
+  EXPECT_FALSE(converted) << "Action must NOT convert its argument "
+                          << "when performed.";
+}
+
+// Tests that ReturnNull() returns NULL in a pointer-returning function.
+TEST(ReturnNullTest, WorksInPointerReturningFunction) {
+  const Action<int*()> a1 = ReturnNull();
+  EXPECT_TRUE(a1.Perform(std::make_tuple()) == nullptr);
+
+  const Action<const char*(bool)> a2 = ReturnNull();  // NOLINT
+  EXPECT_TRUE(a2.Perform(std::make_tuple(true)) == nullptr);
+}
+
+// Tests that ReturnNull() returns NULL for shared_ptr and unique_ptr returning
+// functions.
+TEST(ReturnNullTest, WorksInSmartPointerReturningFunction) {
+  const Action<std::unique_ptr<const int>()> a1 = ReturnNull();
+  EXPECT_TRUE(a1.Perform(std::make_tuple()) == nullptr);
+
+  const Action<std::shared_ptr<int>(std::string)> a2 = ReturnNull();
+  EXPECT_TRUE(a2.Perform(std::make_tuple("foo")) == nullptr);
+}
+
+// Tests that ReturnRef(v) works for reference types.
+TEST(ReturnRefTest, WorksForReference) {
+  const int n = 0;
+  const Action<const int&(bool)> ret = ReturnRef(n);  // NOLINT
+
+  EXPECT_EQ(&n, &ret.Perform(std::make_tuple(true)));
+}
+
+// Tests that ReturnRef(v) is covariant.
+TEST(ReturnRefTest, IsCovariant) {
+  Base base;
+  Derived derived;
+  Action<Base&()> a = ReturnRef(base);
+  EXPECT_EQ(&base, &a.Perform(std::make_tuple()));
+
+  a = ReturnRef(derived);
+  EXPECT_EQ(&derived, &a.Perform(std::make_tuple()));
+}
+
+template <typename T, typename = decltype(ReturnRef(std::declval<T&&>()))>
+bool CanCallReturnRef(T&&) {
+  return true;
+}
+bool CanCallReturnRef(Unused) { return false; }
+
+// Tests that ReturnRef(v) is working with non-temporaries (T&)
+TEST(ReturnRefTest, WorksForNonTemporary) {
+  int scalar_value = 123;
+  EXPECT_TRUE(CanCallReturnRef(scalar_value));
+
+  std::string non_scalar_value("ABC");
+  EXPECT_TRUE(CanCallReturnRef(non_scalar_value));
+
+  const int const_scalar_value{321};
+  EXPECT_TRUE(CanCallReturnRef(const_scalar_value));
+
+  const std::string const_non_scalar_value("CBA");
+  EXPECT_TRUE(CanCallReturnRef(const_non_scalar_value));
+}
+
+// Tests that ReturnRef(v) is not working with temporaries (T&&)
+TEST(ReturnRefTest, DoesNotWorkForTemporary) {
+  auto scalar_value = []() -> int { return 123; };
+  EXPECT_FALSE(CanCallReturnRef(scalar_value()));
+
+  auto non_scalar_value = []() -> std::string { return "ABC"; };
+  EXPECT_FALSE(CanCallReturnRef(non_scalar_value()));
+
+  // cannot use here callable returning "const scalar type",
+  // because such const for scalar return type is ignored
+  EXPECT_FALSE(CanCallReturnRef(static_cast<const int>(321)));
+
+  auto const_non_scalar_value = []() -> const std::string { return "CBA"; };
+  EXPECT_FALSE(CanCallReturnRef(const_non_scalar_value()));
+}
+
+// Tests that ReturnRefOfCopy(v) works for reference types.
+TEST(ReturnRefOfCopyTest, WorksForReference) {
+  int n = 42;
+  const Action<const int&()> ret = ReturnRefOfCopy(n);
+
+  EXPECT_NE(&n, &ret.Perform(std::make_tuple()));
+  EXPECT_EQ(42, ret.Perform(std::make_tuple()));
+
+  n = 43;
+  EXPECT_NE(&n, &ret.Perform(std::make_tuple()));
+  EXPECT_EQ(42, ret.Perform(std::make_tuple()));
+}
+
+// Tests that ReturnRefOfCopy(v) is covariant.
+TEST(ReturnRefOfCopyTest, IsCovariant) {
+  Base base;
+  Derived derived;
+  Action<Base&()> a = ReturnRefOfCopy(base);
+  EXPECT_NE(&base, &a.Perform(std::make_tuple()));
+
+  a = ReturnRefOfCopy(derived);
+  EXPECT_NE(&derived, &a.Perform(std::make_tuple()));
+}
+
+// Tests that ReturnRoundRobin(v) works with initializer lists
+TEST(ReturnRoundRobinTest, WorksForInitList) {
+  Action<int()> ret = ReturnRoundRobin({1, 2, 3});
+
+  EXPECT_EQ(1, ret.Perform(std::make_tuple()));
+  EXPECT_EQ(2, ret.Perform(std::make_tuple()));
+  EXPECT_EQ(3, ret.Perform(std::make_tuple()));
+  EXPECT_EQ(1, ret.Perform(std::make_tuple()));
+  EXPECT_EQ(2, ret.Perform(std::make_tuple()));
+  EXPECT_EQ(3, ret.Perform(std::make_tuple()));
+}
+
+// Tests that ReturnRoundRobin(v) works with vectors
+TEST(ReturnRoundRobinTest, WorksForVector) {
+  std::vector<double> v = {4.4, 5.5, 6.6};
+  Action<double()> ret = ReturnRoundRobin(v);
+
+  EXPECT_EQ(4.4, ret.Perform(std::make_tuple()));
+  EXPECT_EQ(5.5, ret.Perform(std::make_tuple()));
+  EXPECT_EQ(6.6, ret.Perform(std::make_tuple()));
+  EXPECT_EQ(4.4, ret.Perform(std::make_tuple()));
+  EXPECT_EQ(5.5, ret.Perform(std::make_tuple()));
+  EXPECT_EQ(6.6, ret.Perform(std::make_tuple()));
+}
+
+// Tests that DoDefault() does the default action for the mock method.
+
+class MockClass {
+ public:
+  MockClass() = default;
+
+  MOCK_METHOD1(IntFunc, int(bool flag));  // NOLINT
+  MOCK_METHOD0(Foo, MyNonDefaultConstructible());
+  MOCK_METHOD0(MakeUnique, std::unique_ptr<int>());
+  MOCK_METHOD0(MakeUniqueBase, std::unique_ptr<Base>());
+  MOCK_METHOD0(MakeVectorUnique, std::vector<std::unique_ptr<int>>());
+  MOCK_METHOD1(TakeUnique, int(std::unique_ptr<int>));
+  MOCK_METHOD2(TakeUnique,
+               int(const std::unique_ptr<int>&, std::unique_ptr<int>));
+
+ private:
+  MockClass(const MockClass&) = delete;
+  MockClass& operator=(const MockClass&) = delete;
+};
+
+// Tests that DoDefault() returns the built-in default value for the
+// return type by default.
+TEST(DoDefaultTest, ReturnsBuiltInDefaultValueByDefault) {
+  MockClass mock;
+  EXPECT_CALL(mock, IntFunc(_)).WillOnce(DoDefault());
+  EXPECT_EQ(0, mock.IntFunc(true));
+}
+
+// Tests that DoDefault() throws (when exceptions are enabled) or aborts
+// the process when there is no built-in default value for the return type.
+TEST(DoDefaultDeathTest, DiesForUnknowType) {
+  MockClass mock;
+  EXPECT_CALL(mock, Foo()).WillRepeatedly(DoDefault());
+#if GTEST_HAS_EXCEPTIONS
+  EXPECT_ANY_THROW(mock.Foo());
+#else
+  EXPECT_DEATH_IF_SUPPORTED({ mock.Foo(); }, "");
+#endif
+}
+
+// Tests that using DoDefault() inside a composite action leads to a
+// run-time error.
+
+void VoidFunc(bool /* flag */) {}
+
+TEST(DoDefaultDeathTest, DiesIfUsedInCompositeAction) {
+  MockClass mock;
+  EXPECT_CALL(mock, IntFunc(_))
+      .WillRepeatedly(DoAll(Invoke(VoidFunc), DoDefault()));
+
+  // Ideally we should verify the error message as well.  Sadly,
+  // EXPECT_DEATH() can only capture stderr, while Google Mock's
+  // errors are printed on stdout.  Therefore we have to settle for
+  // not verifying the message.
+  EXPECT_DEATH_IF_SUPPORTED({ mock.IntFunc(true); }, "");
+}
+
+// Tests that DoDefault() returns the default value set by
+// DefaultValue<T>::Set() when it's not overridden by an ON_CALL().
+TEST(DoDefaultTest, ReturnsUserSpecifiedPerTypeDefaultValueWhenThereIsOne) {
+  DefaultValue<int>::Set(1);
+  MockClass mock;
+  EXPECT_CALL(mock, IntFunc(_)).WillOnce(DoDefault());
+  EXPECT_EQ(1, mock.IntFunc(false));
+  DefaultValue<int>::Clear();
+}
+
+// Tests that DoDefault() does the action specified by ON_CALL().
+TEST(DoDefaultTest, DoesWhatOnCallSpecifies) {
+  MockClass mock;
+  ON_CALL(mock, IntFunc(_)).WillByDefault(Return(2));
+  EXPECT_CALL(mock, IntFunc(_)).WillOnce(DoDefault());
+  EXPECT_EQ(2, mock.IntFunc(false));
+}
+
+// Tests that using DoDefault() in ON_CALL() leads to a run-time failure.
+TEST(DoDefaultTest, CannotBeUsedInOnCall) {
+  MockClass mock;
+  EXPECT_NONFATAL_FAILURE(
+      {  // NOLINT
+        ON_CALL(mock, IntFunc(_)).WillByDefault(DoDefault());
+      },
+      "DoDefault() cannot be used in ON_CALL()");
+}
+
+// Tests that SetArgPointee<N>(v) sets the variable pointed to by
+// the N-th (0-based) argument to v.
+TEST(SetArgPointeeTest, SetsTheNthPointee) {
+  typedef void MyFunction(bool, int*, char*);
+  Action<MyFunction> a = SetArgPointee<1>(2);
+
+  int n = 0;
+  char ch = '\0';
+  a.Perform(std::make_tuple(true, &n, &ch));
+  EXPECT_EQ(2, n);
+  EXPECT_EQ('\0', ch);
+
+  a = SetArgPointee<2>('a');
+  n = 0;
+  ch = '\0';
+  a.Perform(std::make_tuple(true, &n, &ch));
+  EXPECT_EQ(0, n);
+  EXPECT_EQ('a', ch);
+}
+
+// Tests that SetArgPointee<N>() accepts a string literal.
+TEST(SetArgPointeeTest, AcceptsStringLiteral) {
+  typedef void MyFunction(std::string*, const char**);
+  Action<MyFunction> a = SetArgPointee<0>("hi");
+  std::string str;
+  const char* ptr = nullptr;
+  a.Perform(std::make_tuple(&str, &ptr));
+  EXPECT_EQ("hi", str);
+  EXPECT_TRUE(ptr == nullptr);
+
+  a = SetArgPointee<1>("world");
+  str = "";
+  a.Perform(std::make_tuple(&str, &ptr));
+  EXPECT_EQ("", str);
+  EXPECT_STREQ("world", ptr);
+}
+
+TEST(SetArgPointeeTest, AcceptsWideStringLiteral) {
+  typedef void MyFunction(const wchar_t**);
+  Action<MyFunction> a = SetArgPointee<0>(L"world");
+  const wchar_t* ptr = nullptr;
+  a.Perform(std::make_tuple(&ptr));
+  EXPECT_STREQ(L"world", ptr);
+
+#if GTEST_HAS_STD_WSTRING
+
+  typedef void MyStringFunction(std::wstring*);
+  Action<MyStringFunction> a2 = SetArgPointee<0>(L"world");
+  std::wstring str = L"";
+  a2.Perform(std::make_tuple(&str));
+  EXPECT_EQ(L"world", str);
+
+#endif
+}
+
+// Tests that SetArgPointee<N>() accepts a char pointer.
+TEST(SetArgPointeeTest, AcceptsCharPointer) {
+  typedef void MyFunction(bool, std::string*, const char**);
+  const char* const hi = "hi";
+  Action<MyFunction> a = SetArgPointee<1>(hi);
+  std::string str;
+  const char* ptr = nullptr;
+  a.Perform(std::make_tuple(true, &str, &ptr));
+  EXPECT_EQ("hi", str);
+  EXPECT_TRUE(ptr == nullptr);
+
+  char world_array[] = "world";
+  char* const world = world_array;
+  a = SetArgPointee<2>(world);
+  str = "";
+  a.Perform(std::make_tuple(true, &str, &ptr));
+  EXPECT_EQ("", str);
+  EXPECT_EQ(world, ptr);
+}
+
+TEST(SetArgPointeeTest, AcceptsWideCharPointer) {
+  typedef void MyFunction(bool, const wchar_t**);
+  const wchar_t* const hi = L"hi";
+  Action<MyFunction> a = SetArgPointee<1>(hi);
+  const wchar_t* ptr = nullptr;
+  a.Perform(std::make_tuple(true, &ptr));
+  EXPECT_EQ(hi, ptr);
+
+#if GTEST_HAS_STD_WSTRING
+
+  typedef void MyStringFunction(bool, std::wstring*);
+  wchar_t world_array[] = L"world";
+  wchar_t* const world = world_array;
+  Action<MyStringFunction> a2 = SetArgPointee<1>(world);
+  std::wstring str;
+  a2.Perform(std::make_tuple(true, &str));
+  EXPECT_EQ(world_array, str);
+#endif
+}
+
+// Tests that SetArgumentPointee<N>(v) sets the variable pointed to by
+// the N-th (0-based) argument to v.
+TEST(SetArgumentPointeeTest, SetsTheNthPointee) {
+  typedef void MyFunction(bool, int*, char*);
+  Action<MyFunction> a = SetArgumentPointee<1>(2);
+
+  int n = 0;
+  char ch = '\0';
+  a.Perform(std::make_tuple(true, &n, &ch));
+  EXPECT_EQ(2, n);
+  EXPECT_EQ('\0', ch);
+
+  a = SetArgumentPointee<2>('a');
+  n = 0;
+  ch = '\0';
+  a.Perform(std::make_tuple(true, &n, &ch));
+  EXPECT_EQ(0, n);
+  EXPECT_EQ('a', ch);
+}
+
+// Sample functions and functors for testing Invoke() and etc.
+int Nullary() { return 1; }
+
+class NullaryFunctor {
+ public:
+  int operator()() { return 2; }
+};
+
+bool g_done = false;
+void VoidNullary() { g_done = true; }
+
+class VoidNullaryFunctor {
+ public:
+  void operator()() { g_done = true; }
+};
+
+short Short(short n) { return n; }  // NOLINT
+char Char(char ch) { return ch; }
+
+const char* CharPtr(const char* s) { return s; }
+
+bool Unary(int x) { return x < 0; }
+
+const char* Binary(const char* input, short n) { return input + n; }  // NOLINT
+
+void VoidBinary(int, char) { g_done = true; }
+
+int Ternary(int x, char y, short z) { return x + y + z; }  // NOLINT
+
+int SumOf4(int a, int b, int c, int d) { return a + b + c + d; }
+
+class Foo {
+ public:
+  Foo() : value_(123) {}
+
+  int Nullary() const { return value_; }
+
+ private:
+  int value_;
+};
+
+// Tests InvokeWithoutArgs(function).
+TEST(InvokeWithoutArgsTest, Function) {
+  // As an action that takes one argument.
+  Action<int(int)> a = InvokeWithoutArgs(Nullary);  // NOLINT
+  EXPECT_EQ(1, a.Perform(std::make_tuple(2)));
+
+  // As an action that takes two arguments.
+  Action<int(int, double)> a2 = InvokeWithoutArgs(Nullary);  // NOLINT
+  EXPECT_EQ(1, a2.Perform(std::make_tuple(2, 3.5)));
+
+  // As an action that returns void.
+  Action<void(int)> a3 = InvokeWithoutArgs(VoidNullary);  // NOLINT
+  g_done = false;
+  a3.Perform(std::make_tuple(1));
+  EXPECT_TRUE(g_done);
+}
+
+// Tests InvokeWithoutArgs(functor).
+TEST(InvokeWithoutArgsTest, Functor) {
+  // As an action that takes no argument.
+  Action<int()> a = InvokeWithoutArgs(NullaryFunctor());  // NOLINT
+  EXPECT_EQ(2, a.Perform(std::make_tuple()));
+
+  // As an action that takes three arguments.
+  Action<int(int, double, char)> a2 =  // NOLINT
+      InvokeWithoutArgs(NullaryFunctor());
+  EXPECT_EQ(2, a2.Perform(std::make_tuple(3, 3.5, 'a')));
+
+  // As an action that returns void.
+  Action<void()> a3 = InvokeWithoutArgs(VoidNullaryFunctor());
+  g_done = false;
+  a3.Perform(std::make_tuple());
+  EXPECT_TRUE(g_done);
+}
+
+// Tests InvokeWithoutArgs(obj_ptr, method).
+TEST(InvokeWithoutArgsTest, Method) {
+  Foo foo;
+  Action<int(bool, char)> a =  // NOLINT
+      InvokeWithoutArgs(&foo, &Foo::Nullary);
+  EXPECT_EQ(123, a.Perform(std::make_tuple(true, 'a')));
+}
+
+// Tests using IgnoreResult() on a polymorphic action.
+TEST(IgnoreResultTest, PolymorphicAction) {
+  Action<void(int)> a = IgnoreResult(Return(5));  // NOLINT
+  a.Perform(std::make_tuple(1));
+}
+
+// Tests using IgnoreResult() on a monomorphic action.
+
+int ReturnOne() {
+  g_done = true;
+  return 1;
+}
+
+TEST(IgnoreResultTest, MonomorphicAction) {
+  g_done = false;
+  Action<void()> a = IgnoreResult(Invoke(ReturnOne));
+  a.Perform(std::make_tuple());
+  EXPECT_TRUE(g_done);
+}
+
+// Tests using IgnoreResult() on an action that returns a class type.
+
+MyNonDefaultConstructible ReturnMyNonDefaultConstructible(double /* x */) {
+  g_done = true;
+  return MyNonDefaultConstructible(42);
+}
+
+TEST(IgnoreResultTest, ActionReturningClass) {
+  g_done = false;
+  Action<void(int)> a =
+      IgnoreResult(Invoke(ReturnMyNonDefaultConstructible));  // NOLINT
+  a.Perform(std::make_tuple(2));
+  EXPECT_TRUE(g_done);
+}
+
+TEST(AssignTest, Int) {
+  int x = 0;
+  Action<void(int)> a = Assign(&x, 5);
+  a.Perform(std::make_tuple(0));
+  EXPECT_EQ(5, x);
+}
+
+TEST(AssignTest, String) {
+  ::std::string x;
+  Action<void(void)> a = Assign(&x, "Hello, world");
+  a.Perform(std::make_tuple());
+  EXPECT_EQ("Hello, world", x);
+}
+
+TEST(AssignTest, CompatibleTypes) {
+  double x = 0;
+  Action<void(int)> a = Assign(&x, 5);
+  a.Perform(std::make_tuple(0));
+  EXPECT_DOUBLE_EQ(5, x);
+}
+
+// DoAll should support &&-qualified actions when used with WillOnce.
+TEST(DoAll, SupportsRefQualifiedActions) {
+  struct InitialAction {
+    void operator()(const int arg) && { EXPECT_EQ(17, arg); }
+  };
+
+  struct FinalAction {
+    int operator()() && { return 19; }
+  };
+
+  MockFunction<int(int)> mock;
+  EXPECT_CALL(mock, Call).WillOnce(DoAll(InitialAction{}, FinalAction{}));
+  EXPECT_EQ(19, mock.AsStdFunction()(17));
+}
+
+// DoAll should never provide rvalue references to the initial actions. If the
+// mock action itself accepts an rvalue reference or a non-scalar object by
+// value then the final action should receive an rvalue reference, but initial
+// actions should receive only lvalue references.
+TEST(DoAll, ProvidesLvalueReferencesToInitialActions) {
+  struct Obj {};
+
+  // Mock action accepts by value: the initial action should be fed a const
+  // lvalue reference, and the final action an rvalue reference.
+  {
+    struct InitialAction {
+      void operator()(Obj&) const { FAIL() << "Unexpected call"; }
+      void operator()(const Obj&) const {}
+      void operator()(Obj&&) const { FAIL() << "Unexpected call"; }
+      void operator()(const Obj&&) const { FAIL() << "Unexpected call"; }
+    };
+
+    MockFunction<void(Obj)> mock;
+    EXPECT_CALL(mock, Call)
+        .WillOnce(DoAll(InitialAction{}, InitialAction{}, [](Obj&&) {}))
+        .WillRepeatedly(DoAll(InitialAction{}, InitialAction{}, [](Obj&&) {}));
+
+    mock.AsStdFunction()(Obj{});
+    mock.AsStdFunction()(Obj{});
+  }
+
+  // Mock action accepts by const lvalue reference: both actions should receive
+  // a const lvalue reference.
+  {
+    struct InitialAction {
+      void operator()(Obj&) const { FAIL() << "Unexpected call"; }
+      void operator()(const Obj&) const {}
+      void operator()(Obj&&) const { FAIL() << "Unexpected call"; }
+      void operator()(const Obj&&) const { FAIL() << "Unexpected call"; }
+    };
+
+    MockFunction<void(const Obj&)> mock;
+    EXPECT_CALL(mock, Call)
+        .WillOnce(DoAll(InitialAction{}, InitialAction{}, [](const Obj&) {}))
+        .WillRepeatedly(
+            DoAll(InitialAction{}, InitialAction{}, [](const Obj&) {}));
+
+    mock.AsStdFunction()(Obj{});
+    mock.AsStdFunction()(Obj{});
+  }
+
+  // Mock action accepts by non-const lvalue reference: both actions should get
+  // a non-const lvalue reference if they want them.
+  {
+    struct InitialAction {
+      void operator()(Obj&) const {}
+      void operator()(Obj&&) const { FAIL() << "Unexpected call"; }
+    };
+
+    MockFunction<void(Obj&)> mock;
+    EXPECT_CALL(mock, Call)
+        .WillOnce(DoAll(InitialAction{}, InitialAction{}, [](Obj&) {}))
+        .WillRepeatedly(DoAll(InitialAction{}, InitialAction{}, [](Obj&) {}));
+
+    Obj obj;
+    mock.AsStdFunction()(obj);
+    mock.AsStdFunction()(obj);
+  }
+
+  // Mock action accepts by rvalue reference: the initial actions should receive
+  // a non-const lvalue reference if it wants it, and the final action an rvalue
+  // reference.
+  {
+    struct InitialAction {
+      void operator()(Obj&) const {}
+      void operator()(Obj&&) const { FAIL() << "Unexpected call"; }
+    };
+
+    MockFunction<void(Obj&&)> mock;
+    EXPECT_CALL(mock, Call)
+        .WillOnce(DoAll(InitialAction{}, InitialAction{}, [](Obj&&) {}))
+        .WillRepeatedly(DoAll(InitialAction{}, InitialAction{}, [](Obj&&) {}));
+
+    mock.AsStdFunction()(Obj{});
+    mock.AsStdFunction()(Obj{});
+  }
+
+  // &&-qualified initial actions should also be allowed with WillOnce.
+  {
+    struct InitialAction {
+      void operator()(Obj&) && {}
+    };
+
+    MockFunction<void(Obj&)> mock;
+    EXPECT_CALL(mock, Call)
+        .WillOnce(DoAll(InitialAction{}, InitialAction{}, [](Obj&) {}));
+
+    Obj obj;
+    mock.AsStdFunction()(obj);
+  }
+
+  {
+    struct InitialAction {
+      void operator()(Obj&) && {}
+    };
+
+    MockFunction<void(Obj&&)> mock;
+    EXPECT_CALL(mock, Call)
+        .WillOnce(DoAll(InitialAction{}, InitialAction{}, [](Obj&&) {}));
+
+    mock.AsStdFunction()(Obj{});
+  }
+}
+
+// DoAll should support being used with type-erased Action objects, both through
+// WillOnce and WillRepeatedly.
+TEST(DoAll, SupportsTypeErasedActions) {
+  // With only type-erased actions.
+  const Action<void()> initial_action = [] {};
+  const Action<int()> final_action = [] { return 17; };
+
+  MockFunction<int()> mock;
+  EXPECT_CALL(mock, Call)
+      .WillOnce(DoAll(initial_action, initial_action, final_action))
+      .WillRepeatedly(DoAll(initial_action, initial_action, final_action));
+
+  EXPECT_EQ(17, mock.AsStdFunction()());
+
+  // With &&-qualified and move-only final action.
+  {
+    struct FinalAction {
+      FinalAction() = default;
+      FinalAction(FinalAction&&) = default;
+
+      int operator()() && { return 17; }
+    };
+
+    EXPECT_CALL(mock, Call)
+        .WillOnce(DoAll(initial_action, initial_action, FinalAction{}));
+
+    EXPECT_EQ(17, mock.AsStdFunction()());
+  }
+}
+
+// Tests using WithArgs and with an action that takes 1 argument.
+TEST(WithArgsTest, OneArg) {
+  Action<bool(double x, int n)> a = WithArgs<1>(Invoke(Unary));  // NOLINT
+  EXPECT_TRUE(a.Perform(std::make_tuple(1.5, -1)));
+  EXPECT_FALSE(a.Perform(std::make_tuple(1.5, 1)));
+}
+
+// Tests using WithArgs with an action that takes 2 arguments.
+TEST(WithArgsTest, TwoArgs) {
+  Action<const char*(const char* s, double x, short n)> a =  // NOLINT
+      WithArgs<0, 2>(Invoke(Binary));
+  const char s[] = "Hello";
+  EXPECT_EQ(s + 2, a.Perform(std::make_tuple(CharPtr(s), 0.5, Short(2))));
+}
+
+struct ConcatAll {
+  std::string operator()() const { return {}; }
+  template <typename... I>
+  std::string operator()(const char* a, I... i) const {
+    return a + ConcatAll()(i...);
+  }
+};
+
+// Tests using WithArgs with an action that takes 10 arguments.
+TEST(WithArgsTest, TenArgs) {
+  Action<std::string(const char*, const char*, const char*, const char*)> a =
+      WithArgs<0, 1, 2, 3, 2, 1, 0, 1, 2, 3>(Invoke(ConcatAll{}));
+  EXPECT_EQ("0123210123",
+            a.Perform(std::make_tuple(CharPtr("0"), CharPtr("1"), CharPtr("2"),
+                                      CharPtr("3"))));
+}
+
+// Tests using WithArgs with an action that is not Invoke().
+class SubtractAction : public ActionInterface<int(int, int)> {
+ public:
+  int Perform(const std::tuple<int, int>& args) override {
+    return std::get<0>(args) - std::get<1>(args);
+  }
+};
+
+TEST(WithArgsTest, NonInvokeAction) {
+  Action<int(const std::string&, int, int)> a =
+      WithArgs<2, 1>(MakeAction(new SubtractAction));
+  std::tuple<std::string, int, int> dummy =
+      std::make_tuple(std::string("hi"), 2, 10);
+  EXPECT_EQ(8, a.Perform(dummy));
+}
+
+// Tests using WithArgs to pass all original arguments in the original order.
+TEST(WithArgsTest, Identity) {
+  Action<int(int x, char y, short z)> a =  // NOLINT
+      WithArgs<0, 1, 2>(Invoke(Ternary));
+  EXPECT_EQ(123, a.Perform(std::make_tuple(100, Char(20), Short(3))));
+}
+
+// Tests using WithArgs with repeated arguments.
+TEST(WithArgsTest, RepeatedArguments) {
+  Action<int(bool, int m, int n)> a =  // NOLINT
+      WithArgs<1, 1, 1, 1>(Invoke(SumOf4));
+  EXPECT_EQ(4, a.Perform(std::make_tuple(false, 1, 10)));
+}
+
+// Tests using WithArgs with reversed argument order.
+TEST(WithArgsTest, ReversedArgumentOrder) {
+  Action<const char*(short n, const char* input)> a =  // NOLINT
+      WithArgs<1, 0>(Invoke(Binary));
+  const char s[] = "Hello";
+  EXPECT_EQ(s + 2, a.Perform(std::make_tuple(Short(2), CharPtr(s))));
+}
+
+// Tests using WithArgs with compatible, but not identical, argument types.
+TEST(WithArgsTest, ArgsOfCompatibleTypes) {
+  Action<long(short x, char y, double z, char c)> a =  // NOLINT
+      WithArgs<0, 1, 3>(Invoke(Ternary));
+  EXPECT_EQ(123,
+            a.Perform(std::make_tuple(Short(100), Char(20), 5.6, Char(3))));
+}
+
+// Tests using WithArgs with an action that returns void.
+TEST(WithArgsTest, VoidAction) {
+  Action<void(double x, char c, int n)> a = WithArgs<2, 1>(Invoke(VoidBinary));
+  g_done = false;
+  a.Perform(std::make_tuple(1.5, 'a', 3));
+  EXPECT_TRUE(g_done);
+}
+
+TEST(WithArgsTest, ReturnReference) {
+  Action<int&(int&, void*)> aa = WithArgs<0>([](int& a) -> int& { return a; });
+  int i = 0;
+  const int& res = aa.Perform(std::forward_as_tuple(i, nullptr));
+  EXPECT_EQ(&i, &res);
+}
+
+TEST(WithArgsTest, InnerActionWithConversion) {
+  Action<Derived*()> inner = [] { return nullptr; };
+
+  MockFunction<Base*(double)> mock;
+  EXPECT_CALL(mock, Call)
+      .WillOnce(WithoutArgs(inner))
+      .WillRepeatedly(WithoutArgs(inner));
+
+  EXPECT_EQ(nullptr, mock.AsStdFunction()(1.1));
+  EXPECT_EQ(nullptr, mock.AsStdFunction()(1.1));
+}
+
+// It should be possible to use an &&-qualified inner action as long as the
+// whole shebang is used as an rvalue with WillOnce.
+TEST(WithArgsTest, RefQualifiedInnerAction) {
+  struct SomeAction {
+    int operator()(const int arg) && {
+      EXPECT_EQ(17, arg);
+      return 19;
+    }
+  };
+
+  MockFunction<int(int, int)> mock;
+  EXPECT_CALL(mock, Call).WillOnce(WithArg<1>(SomeAction{}));
+  EXPECT_EQ(19, mock.AsStdFunction()(0, 17));
+}
+
+#ifndef GTEST_OS_WINDOWS_MOBILE
+
+class SetErrnoAndReturnTest : public testing::Test {
+ protected:
+  void SetUp() override { errno = 0; }
+  void TearDown() override { errno = 0; }
+};
+
+TEST_F(SetErrnoAndReturnTest, Int) {
+  Action<int(void)> a = SetErrnoAndReturn(ENOTTY, -5);
+  EXPECT_EQ(-5, a.Perform(std::make_tuple()));
+  EXPECT_EQ(ENOTTY, errno);
+}
+
+TEST_F(SetErrnoAndReturnTest, Ptr) {
+  int x;
+  Action<int*(void)> a = SetErrnoAndReturn(ENOTTY, &x);
+  EXPECT_EQ(&x, a.Perform(std::make_tuple()));
+  EXPECT_EQ(ENOTTY, errno);
+}
+
+TEST_F(SetErrnoAndReturnTest, CompatibleTypes) {
+  Action<double()> a = SetErrnoAndReturn(EINVAL, 5);
+  EXPECT_DOUBLE_EQ(5.0, a.Perform(std::make_tuple()));
+  EXPECT_EQ(EINVAL, errno);
+}
+
+#endif  // !GTEST_OS_WINDOWS_MOBILE
+
+// Tests ByRef().
+
+// Tests that the result of ByRef() is copyable.
+TEST(ByRefTest, IsCopyable) {
+  const std::string s1 = "Hi";
+  const std::string s2 = "Hello";
+
+  auto ref_wrapper = ByRef(s1);
+  const std::string& r1 = ref_wrapper;
+  EXPECT_EQ(&s1, &r1);
+
+  // Assigns a new value to ref_wrapper.
+  ref_wrapper = ByRef(s2);
+  const std::string& r2 = ref_wrapper;
+  EXPECT_EQ(&s2, &r2);
+
+  auto ref_wrapper1 = ByRef(s1);
+  // Copies ref_wrapper1 to ref_wrapper.
+  ref_wrapper = ref_wrapper1;
+  const std::string& r3 = ref_wrapper;
+  EXPECT_EQ(&s1, &r3);
+}
+
+// Tests using ByRef() on a const value.
+TEST(ByRefTest, ConstValue) {
+  const int n = 0;
+  // int& ref = ByRef(n);  // This shouldn't compile - we have a
+  // negative compilation test to catch it.
+  const int& const_ref = ByRef(n);
+  EXPECT_EQ(&n, &const_ref);
+}
+
+// Tests using ByRef() on a non-const value.
+TEST(ByRefTest, NonConstValue) {
+  int n = 0;
+
+  // ByRef(n) can be used as either an int&,
+  int& ref = ByRef(n);
+  EXPECT_EQ(&n, &ref);
+
+  // or a const int&.
+  const int& const_ref = ByRef(n);
+  EXPECT_EQ(&n, &const_ref);
+}
+
+// Tests explicitly specifying the type when using ByRef().
+TEST(ByRefTest, ExplicitType) {
+  int n = 0;
+  const int& r1 = ByRef<const int>(n);
+  EXPECT_EQ(&n, &r1);
+
+  // ByRef<char>(n);  // This shouldn't compile - we have a negative
+  // compilation test to catch it.
+
+  Derived d;
+  Derived& r2 = ByRef<Derived>(d);
+  EXPECT_EQ(&d, &r2);
+
+  const Derived& r3 = ByRef<const Derived>(d);
+  EXPECT_EQ(&d, &r3);
+
+  Base& r4 = ByRef<Base>(d);
+  EXPECT_EQ(&d, &r4);
+
+  const Base& r5 = ByRef<const Base>(d);
+  EXPECT_EQ(&d, &r5);
+
+  // The following shouldn't compile - we have a negative compilation
+  // test for it.
+  //
+  // Base b;
+  // ByRef<Derived>(b);
+}
+
+// Tests that Google Mock prints expression ByRef(x) as a reference to x.
+TEST(ByRefTest, PrintsCorrectly) {
+  int n = 42;
+  ::std::stringstream expected, actual;
+  testing::internal::UniversalPrinter<const int&>::Print(n, &expected);
+  testing::internal::UniversalPrint(ByRef(n), &actual);
+  EXPECT_EQ(expected.str(), actual.str());
+}
+
+struct UnaryConstructorClass {
+  explicit UnaryConstructorClass(int v) : value(v) {}
+  int value;
+};
+
+// Tests using ReturnNew() with a unary constructor.
+TEST(ReturnNewTest, Unary) {
+  Action<UnaryConstructorClass*()> a = ReturnNew<UnaryConstructorClass>(4000);
+  UnaryConstructorClass* c = a.Perform(std::make_tuple());
+  EXPECT_EQ(4000, c->value);
+  delete c;
+}
+
+TEST(ReturnNewTest, UnaryWorksWhenMockMethodHasArgs) {
+  Action<UnaryConstructorClass*(bool, int)> a =
+      ReturnNew<UnaryConstructorClass>(4000);
+  UnaryConstructorClass* c = a.Perform(std::make_tuple(false, 5));
+  EXPECT_EQ(4000, c->value);
+  delete c;
+}
+
+TEST(ReturnNewTest, UnaryWorksWhenMockMethodReturnsPointerToConst) {
+  Action<const UnaryConstructorClass*()> a =
+      ReturnNew<UnaryConstructorClass>(4000);
+  const UnaryConstructorClass* c = a.Perform(std::make_tuple());
+  EXPECT_EQ(4000, c->value);
+  delete c;
+}
+
+class TenArgConstructorClass {
+ public:
+  TenArgConstructorClass(int a1, int a2, int a3, int a4, int a5, int a6, int a7,
+                         int a8, int a9, int a10)
+      : value_(a1 + a2 + a3 + a4 + a5 + a6 + a7 + a8 + a9 + a10) {}
+  int value_;
+};
+
+// Tests using ReturnNew() with a 10-argument constructor.
+TEST(ReturnNewTest, ConstructorThatTakes10Arguments) {
+  Action<TenArgConstructorClass*()> a = ReturnNew<TenArgConstructorClass>(
+      1000000000, 200000000, 30000000, 4000000, 500000, 60000, 7000, 800, 90,
+      0);
+  TenArgConstructorClass* c = a.Perform(std::make_tuple());
+  EXPECT_EQ(1234567890, c->value_);
+  delete c;
+}
+
+std::unique_ptr<int> UniquePtrSource() { return std::make_unique<int>(19); }
+
+std::vector<std::unique_ptr<int>> VectorUniquePtrSource() {
+  std::vector<std::unique_ptr<int>> out;
+  out.emplace_back(new int(7));
+  return out;
+}
+
+TEST(MockMethodTest, CanReturnMoveOnlyValue_Return) {
+  MockClass mock;
+  std::unique_ptr<int> i(new int(19));
+  EXPECT_CALL(mock, MakeUnique()).WillOnce(Return(ByMove(std::move(i))));
+  EXPECT_CALL(mock, MakeVectorUnique())
+      .WillOnce(Return(ByMove(VectorUniquePtrSource())));
+  Derived* d = new Derived;
+  EXPECT_CALL(mock, MakeUniqueBase())
+      .WillOnce(Return(ByMove(std::unique_ptr<Derived>(d))));
+
+  std::unique_ptr<int> result1 = mock.MakeUnique();
+  EXPECT_EQ(19, *result1);
+
+  std::vector<std::unique_ptr<int>> vresult = mock.MakeVectorUnique();
+  EXPECT_EQ(1u, vresult.size());
+  EXPECT_NE(nullptr, vresult[0]);
+  EXPECT_EQ(7, *vresult[0]);
+
+  std::unique_ptr<Base> result2 = mock.MakeUniqueBase();
+  EXPECT_EQ(d, result2.get());
+}
+
+TEST(MockMethodTest, CanReturnMoveOnlyValue_DoAllReturn) {
+  testing::MockFunction<void()> mock_function;
+  MockClass mock;
+  std::unique_ptr<int> i(new int(19));
+  EXPECT_CALL(mock_function, Call());
+  EXPECT_CALL(mock, MakeUnique())
+      .WillOnce(DoAll(InvokeWithoutArgs(&mock_function,
+                                        &testing::MockFunction<void()>::Call),
+                      Return(ByMove(std::move(i)))));
+
+  std::unique_ptr<int> result1 = mock.MakeUnique();
+  EXPECT_EQ(19, *result1);
+}
+
+TEST(MockMethodTest, CanReturnMoveOnlyValue_Invoke) {
+  MockClass mock;
+
+  // Check default value
+  DefaultValue<std::unique_ptr<int>>::SetFactory(
+      [] { return std::make_unique<int>(42); });
+  EXPECT_EQ(42, *mock.MakeUnique());
+
+  EXPECT_CALL(mock, MakeUnique()).WillRepeatedly(Invoke(UniquePtrSource));
+  EXPECT_CALL(mock, MakeVectorUnique())
+      .WillRepeatedly(Invoke(VectorUniquePtrSource));
+  std::unique_ptr<int> result1 = mock.MakeUnique();
+  EXPECT_EQ(19, *result1);
+  std::unique_ptr<int> result2 = mock.MakeUnique();
+  EXPECT_EQ(19, *result2);
+  EXPECT_NE(result1, result2);
+
+  std::vector<std::unique_ptr<int>> vresult = mock.MakeVectorUnique();
+  EXPECT_EQ(1u, vresult.size());
+  EXPECT_NE(nullptr, vresult[0]);
+  EXPECT_EQ(7, *vresult[0]);
+}
+
+TEST(MockMethodTest, CanTakeMoveOnlyValue) {
+  MockClass mock;
+  auto make = [](int i) { return std::make_unique<int>(i); };
+
+  EXPECT_CALL(mock, TakeUnique(_)).WillRepeatedly([](std::unique_ptr<int> i) {
+    return *i;
+  });
+  // DoAll() does not compile, since it would move from its arguments twice.
+  // EXPECT_CALL(mock, TakeUnique(_, _))
+  //     .WillRepeatedly(DoAll(Invoke([](std::unique_ptr<int> j) {}),
+  //     Return(1)));
+  EXPECT_CALL(mock, TakeUnique(testing::Pointee(7)))
+      .WillOnce(Return(-7))
+      .RetiresOnSaturation();
+  EXPECT_CALL(mock, TakeUnique(testing::IsNull()))
+      .WillOnce(Return(-1))
+      .RetiresOnSaturation();
+
+  EXPECT_EQ(5, mock.TakeUnique(make(5)));
+  EXPECT_EQ(-7, mock.TakeUnique(make(7)));
+  EXPECT_EQ(7, mock.TakeUnique(make(7)));
+  EXPECT_EQ(7, mock.TakeUnique(make(7)));
+  EXPECT_EQ(-1, mock.TakeUnique({}));
+
+  // Some arguments are moved, some passed by reference.
+  auto lvalue = make(6);
+  EXPECT_CALL(mock, TakeUnique(_, _))
+      .WillOnce([](const std::unique_ptr<int>& i, std::unique_ptr<int> j) {
+        return *i * *j;
+      });
+  EXPECT_EQ(42, mock.TakeUnique(lvalue, make(7)));
+
+  // The unique_ptr can be saved by the action.
+  std::unique_ptr<int> saved;
+  EXPECT_CALL(mock, TakeUnique(_)).WillOnce([&saved](std::unique_ptr<int> i) {
+    saved = std::move(i);
+    return 0;
+  });
+  EXPECT_EQ(0, mock.TakeUnique(make(42)));
+  EXPECT_EQ(42, *saved);
+}
+
+// It should be possible to use callables with an &&-qualified call operator
+// with WillOnce, since they will be called only once. This allows actions to
+// contain and manipulate move-only types.
+TEST(MockMethodTest, ActionHasRvalueRefQualifiedCallOperator) {
+  struct Return17 {
+    int operator()() && { return 17; }
+  };
+
+  // Action is directly compatible with mocked function type.
+  {
+    MockFunction<int()> mock;
+    EXPECT_CALL(mock, Call).WillOnce(Return17());
+
+    EXPECT_EQ(17, mock.AsStdFunction()());
+  }
+
+  // Action doesn't want mocked function arguments.
+  {
+    MockFunction<int(int)> mock;
+    EXPECT_CALL(mock, Call).WillOnce(Return17());
+
+    EXPECT_EQ(17, mock.AsStdFunction()(0));
+  }
+}
+
+// Edge case: if an action has both a const-qualified and an &&-qualified call
+// operator, there should be no "ambiguous call" errors. The &&-qualified
+// operator should be used by WillOnce (since it doesn't need to retain the
+// action beyond one call), and the const-qualified one by WillRepeatedly.
+TEST(MockMethodTest, ActionHasMultipleCallOperators) {
+  struct ReturnInt {
+    int operator()() && { return 17; }
+    int operator()() const& { return 19; }
+  };
+
+  // Directly compatible with mocked function type.
+  {
+    MockFunction<int()> mock;
+    EXPECT_CALL(mock, Call).WillOnce(ReturnInt()).WillRepeatedly(ReturnInt());
+
+    EXPECT_EQ(17, mock.AsStdFunction()());
+    EXPECT_EQ(19, mock.AsStdFunction()());
+    EXPECT_EQ(19, mock.AsStdFunction()());
+  }
+
+  // Ignores function arguments.
+  {
+    MockFunction<int(int)> mock;
+    EXPECT_CALL(mock, Call).WillOnce(ReturnInt()).WillRepeatedly(ReturnInt());
+
+    EXPECT_EQ(17, mock.AsStdFunction()(0));
+    EXPECT_EQ(19, mock.AsStdFunction()(0));
+    EXPECT_EQ(19, mock.AsStdFunction()(0));
+  }
+}
+
+// WillOnce should have no problem coping with a move-only action, whether it is
+// &&-qualified or not.
+TEST(MockMethodTest, MoveOnlyAction) {
+  // &&-qualified
+  {
+    struct Return17 {
+      Return17() = default;
+      Return17(Return17&&) = default;
+
+      Return17(const Return17&) = delete;
+      Return17 operator=(const Return17&) = delete;
+
+      int operator()() && { return 17; }
+    };
+
+    MockFunction<int()> mock;
+    EXPECT_CALL(mock, Call).WillOnce(Return17());
+    EXPECT_EQ(17, mock.AsStdFunction()());
+  }
+
+  // Not &&-qualified
+  {
+    struct Return17 {
+      Return17() = default;
+      Return17(Return17&&) = default;
+
+      Return17(const Return17&) = delete;
+      Return17 operator=(const Return17&) = delete;
+
+      int operator()() const { return 17; }
+    };
+
+    MockFunction<int()> mock;
+    EXPECT_CALL(mock, Call).WillOnce(Return17());
+    EXPECT_EQ(17, mock.AsStdFunction()());
+  }
+}
+
+// It should be possible to use an action that returns a value with a mock
+// function that doesn't, both through WillOnce and WillRepeatedly.
+TEST(MockMethodTest, ActionReturnsIgnoredValue) {
+  struct ReturnInt {
+    int operator()() const { return 0; }
+  };
+
+  MockFunction<void()> mock;
+  EXPECT_CALL(mock, Call).WillOnce(ReturnInt()).WillRepeatedly(ReturnInt());
+
+  mock.AsStdFunction()();
+  mock.AsStdFunction()();
+}
+
+// Despite the fanciness around move-only actions and so on, it should still be
+// possible to hand an lvalue reference to a copyable action to WillOnce.
+TEST(MockMethodTest, WillOnceCanAcceptLvalueReference) {
+  MockFunction<int()> mock;
+
+  const auto action = [] { return 17; };
+  EXPECT_CALL(mock, Call).WillOnce(action);
+
+  EXPECT_EQ(17, mock.AsStdFunction()());
+}
+
+// A callable that doesn't use SFINAE to restrict its call operator's overload
+// set, but is still picky about which arguments it will accept.
+struct StaticAssertSingleArgument {
+  template <typename... Args>
+  static constexpr bool CheckArgs() {
+    static_assert(sizeof...(Args) == 1, "");
+    return true;
+  }
+
+  template <typename... Args, bool = CheckArgs<Args...>()>
+  int operator()(Args...) const {
+    return 17;
+  }
+};
+
+// WillOnce and WillRepeatedly should both work fine with naïve implementations
+// of actions that don't use SFINAE to limit the overload set for their call
+// operator. If they are compatible with the actual mocked signature, we
+// shouldn't probe them with no arguments and trip a static_assert.
+TEST(MockMethodTest, ActionSwallowsAllArguments) {
+  MockFunction<int(int)> mock;
+  EXPECT_CALL(mock, Call)
+      .WillOnce(StaticAssertSingleArgument{})
+      .WillRepeatedly(StaticAssertSingleArgument{});
+
+  EXPECT_EQ(17, mock.AsStdFunction()(0));
+  EXPECT_EQ(17, mock.AsStdFunction()(0));
+}
+
+struct ActionWithTemplatedConversionOperators {
+  template <typename... Args>
+  operator OnceAction<int(Args...)>() && {  // NOLINT
+    return [] { return 17; };
+  }
+
+  template <typename... Args>
+  operator Action<int(Args...)>() const {  // NOLINT
+    return [] { return 19; };
+  }
+};
+
+// It should be fine to hand both WillOnce and WillRepeatedly a function that
+// defines templated conversion operators to OnceAction and Action. WillOnce
+// should prefer the OnceAction version.
+TEST(MockMethodTest, ActionHasTemplatedConversionOperators) {
+  MockFunction<int()> mock;
+  EXPECT_CALL(mock, Call)
+      .WillOnce(ActionWithTemplatedConversionOperators{})
+      .WillRepeatedly(ActionWithTemplatedConversionOperators{});
+
+  EXPECT_EQ(17, mock.AsStdFunction()());
+  EXPECT_EQ(19, mock.AsStdFunction()());
+}
+
+// Tests for std::function based action.
+
+int Add(int val, int& ref, int* ptr) {  // NOLINT
+  int result = val + ref + *ptr;
+  ref = 42;
+  *ptr = 43;
+  return result;
+}
+
+int Deref(std::unique_ptr<int> ptr) { return *ptr; }
+
+struct Double {
+  template <typename T>
+  T operator()(T t) {
+    return 2 * t;
+  }
+};
+
+std::unique_ptr<int> UniqueInt(int i) { return std::make_unique<int>(i); }
+
+TEST(FunctorActionTest, ActionFromFunction) {
+  Action<int(int, int&, int*)> a = &Add;
+  int x = 1, y = 2, z = 3;
+  EXPECT_EQ(6, a.Perform(std::forward_as_tuple(x, y, &z)));
+  EXPECT_EQ(42, y);
+  EXPECT_EQ(43, z);
+
+  Action<int(std::unique_ptr<int>)> a1 = &Deref;
+  EXPECT_EQ(7, a1.Perform(std::make_tuple(UniqueInt(7))));
+}
+
+TEST(FunctorActionTest, ActionFromLambda) {
+  Action<int(bool, int)> a1 = [](bool b, int i) { return b ? i : 0; };
+  EXPECT_EQ(5, a1.Perform(std::make_tuple(true, 5)));
+  EXPECT_EQ(0, a1.Perform(std::make_tuple(false, 5)));
+
+  std::unique_ptr<int> saved;
+  Action<void(std::unique_ptr<int>)> a2 = [&saved](std::unique_ptr<int> p) {
+    saved = std::move(p);
+  };
+  a2.Perform(std::make_tuple(UniqueInt(5)));
+  EXPECT_EQ(5, *saved);
+}
+
+TEST(FunctorActionTest, PolymorphicFunctor) {
+  Action<int(int)> ai = Double();
+  EXPECT_EQ(2, ai.Perform(std::make_tuple(1)));
+  Action<double(double)> ad = Double();  // Double? Double double!
+  EXPECT_EQ(3.0, ad.Perform(std::make_tuple(1.5)));
+}
+
+TEST(FunctorActionTest, TypeConversion) {
+  // Numeric promotions are allowed.
+  const Action<bool(int)> a1 = [](int i) { return i > 1; };
+  const Action<int(bool)> a2 = Action<int(bool)>(a1);
+  EXPECT_EQ(1, a1.Perform(std::make_tuple(42)));
+  EXPECT_EQ(0, a2.Perform(std::make_tuple(42)));
+
+  // Implicit constructors are allowed.
+  const Action<bool(std::string)> s1 = [](std::string s) { return !s.empty(); };
+  const Action<int(const char*)> s2 = Action<int(const char*)>(s1);
+  EXPECT_EQ(0, s2.Perform(std::make_tuple("")));
+  EXPECT_EQ(1, s2.Perform(std::make_tuple("hello")));
+
+  // Also between the lambda and the action itself.
+  const Action<bool(std::string)> x1 = [](Unused) { return 42; };
+  const Action<bool(std::string)> x2 = [] { return 42; };
+  EXPECT_TRUE(x1.Perform(std::make_tuple("hello")));
+  EXPECT_TRUE(x2.Perform(std::make_tuple("hello")));
+
+  // Ensure decay occurs where required.
+  std::function<int()> f = [] { return 7; };
+  Action<int(int)> d = f;
+  f = nullptr;
+  EXPECT_EQ(7, d.Perform(std::make_tuple(1)));
+
+  // Ensure creation of an empty action succeeds.
+  Action<void(int)>(nullptr);
+}
+
+TEST(FunctorActionTest, UnusedArguments) {
+  // Verify that users can ignore uninteresting arguments.
+  Action<int(int, double y, double z)> a = [](int i, Unused, Unused) {
+    return 2 * i;
+  };
+  std::tuple<int, double, double> dummy = std::make_tuple(3, 7.3, 9.44);
+  EXPECT_EQ(6, a.Perform(dummy));
+}
+
+// Test that basic built-in actions work with move-only arguments.
+TEST(MoveOnlyArgumentsTest, ReturningActions) {
+  Action<int(std::unique_ptr<int>)> a = Return(1);
+  EXPECT_EQ(1, a.Perform(std::make_tuple(nullptr)));
+
+  a = testing::WithoutArgs([]() { return 7; });
+  EXPECT_EQ(7, a.Perform(std::make_tuple(nullptr)));
+
+  Action<void(std::unique_ptr<int>, int*)> a2 = testing::SetArgPointee<1>(3);
+  int x = 0;
+  a2.Perform(std::make_tuple(nullptr, &x));
+  EXPECT_EQ(x, 3);
+}
+
+ACTION(ReturnArity) { return std::tuple_size<args_type>::value; }
+
+TEST(ActionMacro, LargeArity) {
+  EXPECT_EQ(
+      1, testing::Action<int(int)>(ReturnArity()).Perform(std::make_tuple(0)));
+  EXPECT_EQ(
+      10,
+      testing::Action<int(int, int, int, int, int, int, int, int, int, int)>(
+          ReturnArity())
+          .Perform(std::make_tuple(0, 1, 2, 3, 4, 5, 6, 7, 8, 9)));
+  EXPECT_EQ(
+      20,
+      testing::Action<int(int, int, int, int, int, int, int, int, int, int, int,
+                          int, int, int, int, int, int, int, int, int)>(
+          ReturnArity())
+          .Perform(std::make_tuple(0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13,
+                                   14, 15, 16, 17, 18, 19)));
+}
+
+}  // namespace
+}  // namespace testing
+
+#if defined(_MSC_VER) && (_MSC_VER == 1900)
+GTEST_DISABLE_MSC_WARNINGS_POP_()  // 4800
+#endif
+GTEST_DISABLE_MSC_WARNINGS_POP_()  // 4100 4503

contrib/googletest/googlemock/test/gmock-cardinalities_test.cc

@@ -0,0 +1,424 @@
+// Copyright 2007, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+// Google Mock - a framework for writing C++ mock classes.
+//
+// This file tests the built-in cardinalities.
+
+#include <ostream>
+
+#include "gmock/gmock.h"
+#include "gtest/gtest-spi.h"
+#include "gtest/gtest.h"
+
+namespace {
+
+using std::stringstream;
+using testing::AnyNumber;
+using testing::AtLeast;
+using testing::AtMost;
+using testing::Between;
+using testing::Cardinality;
+using testing::CardinalityInterface;
+using testing::Exactly;
+using testing::IsSubstring;
+using testing::MakeCardinality;
+
+class MockFoo {
+ public:
+  MockFoo() = default;
+  MOCK_METHOD0(Bar, int());  // NOLINT
+
+ private:
+  MockFoo(const MockFoo&) = delete;
+  MockFoo& operator=(const MockFoo&) = delete;
+};
+
+// Tests that Cardinality objects can be default constructed.
+TEST(CardinalityTest, IsDefaultConstructable) { Cardinality c; }
+
+// Tests that Cardinality objects are copyable.
+TEST(CardinalityTest, IsCopyable) {
+  // Tests the copy constructor.
+  Cardinality c = Exactly(1);
+  EXPECT_FALSE(c.IsSatisfiedByCallCount(0));
+  EXPECT_TRUE(c.IsSatisfiedByCallCount(1));
+  EXPECT_TRUE(c.IsSaturatedByCallCount(1));
+
+  // Tests the assignment operator.
+  c = Exactly(2);
+  EXPECT_FALSE(c.IsSatisfiedByCallCount(1));
+  EXPECT_TRUE(c.IsSatisfiedByCallCount(2));
+  EXPECT_TRUE(c.IsSaturatedByCallCount(2));
+}
+
+TEST(CardinalityTest, IsOverSaturatedByCallCountWorks) {
+  const Cardinality c = AtMost(5);
+  EXPECT_FALSE(c.IsOverSaturatedByCallCount(4));
+  EXPECT_FALSE(c.IsOverSaturatedByCallCount(5));
+  EXPECT_TRUE(c.IsOverSaturatedByCallCount(6));
+}
+
+// Tests that Cardinality::DescribeActualCallCountTo() creates the
+// correct description.
+TEST(CardinalityTest, CanDescribeActualCallCount) {
+  stringstream ss0;
+  Cardinality::DescribeActualCallCountTo(0, &ss0);
+  EXPECT_EQ("never called", ss0.str());
+
+  stringstream ss1;
+  Cardinality::DescribeActualCallCountTo(1, &ss1);
+  EXPECT_EQ("called once", ss1.str());
+
+  stringstream ss2;
+  Cardinality::DescribeActualCallCountTo(2, &ss2);
+  EXPECT_EQ("called twice", ss2.str());
+
+  stringstream ss3;
+  Cardinality::DescribeActualCallCountTo(3, &ss3);
+  EXPECT_EQ("called 3 times", ss3.str());
+}
+
+// Tests AnyNumber()
+TEST(AnyNumber, Works) {
+  const Cardinality c = AnyNumber();
+  EXPECT_TRUE(c.IsSatisfiedByCallCount(0));
+  EXPECT_FALSE(c.IsSaturatedByCallCount(0));
+
+  EXPECT_TRUE(c.IsSatisfiedByCallCount(1));
+  EXPECT_FALSE(c.IsSaturatedByCallCount(1));
+
+  EXPECT_TRUE(c.IsSatisfiedByCallCount(9));
+  EXPECT_FALSE(c.IsSaturatedByCallCount(9));
+
+  stringstream ss;
+  c.DescribeTo(&ss);
+  EXPECT_PRED_FORMAT2(IsSubstring, "called any number of times", ss.str());
+}
+
+TEST(AnyNumberTest, HasCorrectBounds) {
+  const Cardinality c = AnyNumber();
+  EXPECT_EQ(0, c.ConservativeLowerBound());
+  EXPECT_EQ(INT_MAX, c.ConservativeUpperBound());
+}
+
+// Tests AtLeast(n).
+
+TEST(AtLeastTest, OnNegativeNumber) {
+  EXPECT_NONFATAL_FAILURE(
+      {  // NOLINT
+        AtLeast(-1);
+      },
+      "The invocation lower bound must be >= 0");
+}
+
+TEST(AtLeastTest, OnZero) {
+  const Cardinality c = AtLeast(0);
+  EXPECT_TRUE(c.IsSatisfiedByCallCount(0));
+  EXPECT_FALSE(c.IsSaturatedByCallCount(0));
+
+  EXPECT_TRUE(c.IsSatisfiedByCallCount(1));
+  EXPECT_FALSE(c.IsSaturatedByCallCount(1));
+
+  stringstream ss;
+  c.DescribeTo(&ss);
+  EXPECT_PRED_FORMAT2(IsSubstring, "any number of times", ss.str());
+}
+
+TEST(AtLeastTest, OnPositiveNumber) {
+  const Cardinality c = AtLeast(2);
+  EXPECT_FALSE(c.IsSatisfiedByCallCount(0));
+  EXPECT_FALSE(c.IsSaturatedByCallCount(0));
+
+  EXPECT_FALSE(c.IsSatisfiedByCallCount(1));
+  EXPECT_FALSE(c.IsSaturatedByCallCount(1));
+
+  EXPECT_TRUE(c.IsSatisfiedByCallCount(2));
+  EXPECT_FALSE(c.IsSaturatedByCallCount(2));
+
+  stringstream ss1;
+  AtLeast(1).DescribeTo(&ss1);
+  EXPECT_PRED_FORMAT2(IsSubstring, "at least once", ss1.str());
+
+  stringstream ss2;
+  c.DescribeTo(&ss2);
+  EXPECT_PRED_FORMAT2(IsSubstring, "at least twice", ss2.str());
+
+  stringstream ss3;
+  AtLeast(3).DescribeTo(&ss3);
+  EXPECT_PRED_FORMAT2(IsSubstring, "at least 3 times", ss3.str());
+}
+
+TEST(AtLeastTest, HasCorrectBounds) {
+  const Cardinality c = AtLeast(2);
+  EXPECT_EQ(2, c.ConservativeLowerBound());
+  EXPECT_EQ(INT_MAX, c.ConservativeUpperBound());
+}
+
+// Tests AtMost(n).
+
+TEST(AtMostTest, OnNegativeNumber) {
+  EXPECT_NONFATAL_FAILURE(
+      {  // NOLINT
+        AtMost(-1);
+      },
+      "The invocation upper bound must be >= 0");
+}
+
+TEST(AtMostTest, OnZero) {
+  const Cardinality c = AtMost(0);
+  EXPECT_TRUE(c.IsSatisfiedByCallCount(0));
+  EXPECT_TRUE(c.IsSaturatedByCallCount(0));
+
+  EXPECT_FALSE(c.IsSatisfiedByCallCount(1));
+  EXPECT_TRUE(c.IsSaturatedByCallCount(1));
+
+  stringstream ss;
+  c.DescribeTo(&ss);
+  EXPECT_PRED_FORMAT2(IsSubstring, "never called", ss.str());
+}
+
+TEST(AtMostTest, OnPositiveNumber) {
+  const Cardinality c = AtMost(2);
+  EXPECT_TRUE(c.IsSatisfiedByCallCount(0));
+  EXPECT_FALSE(c.IsSaturatedByCallCount(0));
+
+  EXPECT_TRUE(c.IsSatisfiedByCallCount(1));
+  EXPECT_FALSE(c.IsSaturatedByCallCount(1));
+
+  EXPECT_TRUE(c.IsSatisfiedByCallCount(2));
+  EXPECT_TRUE(c.IsSaturatedByCallCount(2));
+
+  stringstream ss1;
+  AtMost(1).DescribeTo(&ss1);
+  EXPECT_PRED_FORMAT2(IsSubstring, "called at most once", ss1.str());
+
+  stringstream ss2;
+  c.DescribeTo(&ss2);
+  EXPECT_PRED_FORMAT2(IsSubstring, "called at most twice", ss2.str());
+
+  stringstream ss3;
+  AtMost(3).DescribeTo(&ss3);
+  EXPECT_PRED_FORMAT2(IsSubstring, "called at most 3 times", ss3.str());
+}
+
+TEST(AtMostTest, HasCorrectBounds) {
+  const Cardinality c = AtMost(2);
+  EXPECT_EQ(0, c.ConservativeLowerBound());
+  EXPECT_EQ(2, c.ConservativeUpperBound());
+}
+
+// Tests Between(m, n).
+
+TEST(BetweenTest, OnNegativeStart) {
+  EXPECT_NONFATAL_FAILURE(
+      {  // NOLINT
+        Between(-1, 2);
+      },
+      "The invocation lower bound must be >= 0, but is actually -1");
+}
+
+TEST(BetweenTest, OnNegativeEnd) {
+  EXPECT_NONFATAL_FAILURE(
+      {  // NOLINT
+        Between(1, -2);
+      },
+      "The invocation upper bound must be >= 0, but is actually -2");
+}
+
+TEST(BetweenTest, OnStartBiggerThanEnd) {
+  EXPECT_NONFATAL_FAILURE(
+      {  // NOLINT
+        Between(2, 1);
+      },
+      "The invocation upper bound (1) must be >= "
+      "the invocation lower bound (2)");
+}
+
+TEST(BetweenTest, OnZeroStartAndZeroEnd) {
+  const Cardinality c = Between(0, 0);
+
+  EXPECT_TRUE(c.IsSatisfiedByCallCount(0));
+  EXPECT_TRUE(c.IsSaturatedByCallCount(0));
+
+  EXPECT_FALSE(c.IsSatisfiedByCallCount(1));
+  EXPECT_TRUE(c.IsSaturatedByCallCount(1));
+
+  stringstream ss;
+  c.DescribeTo(&ss);
+  EXPECT_PRED_FORMAT2(IsSubstring, "never called", ss.str());
+}
+
+TEST(BetweenTest, OnZeroStartAndNonZeroEnd) {
+  const Cardinality c = Between(0, 2);
+
+  EXPECT_TRUE(c.IsSatisfiedByCallCount(0));
+  EXPECT_FALSE(c.IsSaturatedByCallCount(0));
+
+  EXPECT_TRUE(c.IsSatisfiedByCallCount(2));
+  EXPECT_TRUE(c.IsSaturatedByCallCount(2));
+
+  EXPECT_FALSE(c.IsSatisfiedByCallCount(4));
+  EXPECT_TRUE(c.IsSaturatedByCallCount(4));
+
+  stringstream ss;
+  c.DescribeTo(&ss);
+  EXPECT_PRED_FORMAT2(IsSubstring, "called at most twice", ss.str());
+}
+
+TEST(BetweenTest, OnSameStartAndEnd) {
+  const Cardinality c = Between(3, 3);
+
+  EXPECT_FALSE(c.IsSatisfiedByCallCount(2));
+  EXPECT_FALSE(c.IsSaturatedByCallCount(2));
+
+  EXPECT_TRUE(c.IsSatisfiedByCallCount(3));
+  EXPECT_TRUE(c.IsSaturatedByCallCount(3));
+
+  EXPECT_FALSE(c.IsSatisfiedByCallCount(4));
+  EXPECT_TRUE(c.IsSaturatedByCallCount(4));
+
+  stringstream ss;
+  c.DescribeTo(&ss);
+  EXPECT_PRED_FORMAT2(IsSubstring, "called 3 times", ss.str());
+}
+
+TEST(BetweenTest, OnDifferentStartAndEnd) {
+  const Cardinality c = Between(3, 5);
+
+  EXPECT_FALSE(c.IsSatisfiedByCallCount(2));
+  EXPECT_FALSE(c.IsSaturatedByCallCount(2));
+
+  EXPECT_TRUE(c.IsSatisfiedByCallCount(3));
+  EXPECT_FALSE(c.IsSaturatedByCallCount(3));
+
+  EXPECT_TRUE(c.IsSatisfiedByCallCount(5));
+  EXPECT_TRUE(c.IsSaturatedByCallCount(5));
+
+  EXPECT_FALSE(c.IsSatisfiedByCallCount(6));
+  EXPECT_TRUE(c.IsSaturatedByCallCount(6));
+
+  stringstream ss;
+  c.DescribeTo(&ss);
+  EXPECT_PRED_FORMAT2(IsSubstring, "called between 3 and 5 times", ss.str());
+}
+
+TEST(BetweenTest, HasCorrectBounds) {
+  const Cardinality c = Between(3, 5);
+  EXPECT_EQ(3, c.ConservativeLowerBound());
+  EXPECT_EQ(5, c.ConservativeUpperBound());
+}
+
+// Tests Exactly(n).
+
+TEST(ExactlyTest, OnNegativeNumber) {
+  EXPECT_NONFATAL_FAILURE(
+      {  // NOLINT
+        Exactly(-1);
+      },
+      "The invocation lower bound must be >= 0");
+}
+
+TEST(ExactlyTest, OnZero) {
+  const Cardinality c = Exactly(0);
+  EXPECT_TRUE(c.IsSatisfiedByCallCount(0));
+  EXPECT_TRUE(c.IsSaturatedByCallCount(0));
+
+  EXPECT_FALSE(c.IsSatisfiedByCallCount(1));
+  EXPECT_TRUE(c.IsSaturatedByCallCount(1));
+
+  stringstream ss;
+  c.DescribeTo(&ss);
+  EXPECT_PRED_FORMAT2(IsSubstring, "never called", ss.str());
+}
+
+TEST(ExactlyTest, OnPositiveNumber) {
+  const Cardinality c = Exactly(2);
+  EXPECT_FALSE(c.IsSatisfiedByCallCount(0));
+  EXPECT_FALSE(c.IsSaturatedByCallCount(0));
+
+  EXPECT_TRUE(c.IsSatisfiedByCallCount(2));
+  EXPECT_TRUE(c.IsSaturatedByCallCount(2));
+
+  stringstream ss1;
+  Exactly(1).DescribeTo(&ss1);
+  EXPECT_PRED_FORMAT2(IsSubstring, "called once", ss1.str());
+
+  stringstream ss2;
+  c.DescribeTo(&ss2);
+  EXPECT_PRED_FORMAT2(IsSubstring, "called twice", ss2.str());
+
+  stringstream ss3;
+  Exactly(3).DescribeTo(&ss3);
+  EXPECT_PRED_FORMAT2(IsSubstring, "called 3 times", ss3.str());
+}
+
+TEST(ExactlyTest, HasCorrectBounds) {
+  const Cardinality c = Exactly(3);
+  EXPECT_EQ(3, c.ConservativeLowerBound());
+  EXPECT_EQ(3, c.ConservativeUpperBound());
+}
+
+// Tests that a user can make their own cardinality by implementing
+// CardinalityInterface and calling MakeCardinality().
+
+class EvenCardinality : public CardinalityInterface {
+ public:
+  // Returns true if and only if call_count calls will satisfy this
+  // cardinality.
+  bool IsSatisfiedByCallCount(int call_count) const override {
+    return (call_count % 2 == 0);
+  }
+
+  // Returns true if and only if call_count calls will saturate this
+  // cardinality.
+  bool IsSaturatedByCallCount(int /* call_count */) const override {
+    return false;
+  }
+
+  // Describes self to an ostream.
+  void DescribeTo(::std::ostream* ss) const override {
+    *ss << "called even number of times";
+  }
+};
+
+TEST(MakeCardinalityTest, ConstructsCardinalityFromInterface) {
+  const Cardinality c = MakeCardinality(new EvenCardinality);
+
+  EXPECT_TRUE(c.IsSatisfiedByCallCount(2));
+  EXPECT_FALSE(c.IsSatisfiedByCallCount(3));
+
+  EXPECT_FALSE(c.IsSaturatedByCallCount(10000));
+
+  stringstream ss;
+  c.DescribeTo(&ss);
+  EXPECT_EQ("called even number of times", ss.str());
+}
+
+}  // Unnamed namespace

contrib/googletest/googlemock/test/gmock-function-mocker_test.cc

@@ -0,0 +1,998 @@
+// Copyright 2007, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+// Google Mock - a framework for writing C++ mock classes.
+//
+// This file tests the function mocker classes.
+#include "gmock/gmock-function-mocker.h"
+
+// Silence C4503 (decorated name length exceeded) for MSVC.
+GTEST_DISABLE_MSC_WARNINGS_PUSH_(4503)
+
+#ifdef GTEST_OS_WINDOWS
+// MSDN says the header file to be included for STDMETHOD is BaseTyps.h but
+// we are getting compiler errors if we use basetyps.h, hence including
+// objbase.h for definition of STDMETHOD.
+#include <objbase.h>
+#endif  // GTEST_OS_WINDOWS
+
+#include <functional>
+#include <map>
+#include <string>
+#include <type_traits>
+
+#include "gmock/gmock.h"
+#include "gtest/gtest.h"
+
+namespace testing {
+namespace gmock_function_mocker_test {
+
+using testing::_;
+using testing::A;
+using testing::An;
+using testing::AnyNumber;
+using testing::Const;
+using testing::DoDefault;
+using testing::Eq;
+using testing::Lt;
+using testing::MockFunction;
+using testing::Ref;
+using testing::Return;
+using testing::ReturnRef;
+using testing::TypedEq;
+
+template <typename T>
+class TemplatedCopyable {
+ public:
+  TemplatedCopyable() = default;
+
+  template <typename U>
+  TemplatedCopyable(const U& other) {}  // NOLINT
+};
+
+class FooInterface {
+ public:
+  virtual ~FooInterface() = default;
+
+  virtual void VoidReturning(int x) = 0;
+
+  virtual int Nullary() = 0;
+  virtual bool Unary(int x) = 0;
+  virtual long Binary(short x, int y) = 0;                     // NOLINT
+  virtual int Decimal(bool b, char c, short d, int e, long f,  // NOLINT
+                      float g, double h, unsigned i, char* j,
+                      const std::string& k) = 0;
+
+  virtual bool TakesNonConstReference(int& n) = 0;  // NOLINT
+  virtual std::string TakesConstReference(const int& n) = 0;
+  virtual bool TakesConst(const int x) = 0;
+
+  virtual int OverloadedOnArgumentNumber() = 0;
+  virtual int OverloadedOnArgumentNumber(int n) = 0;
+
+  virtual int OverloadedOnArgumentType(int n) = 0;
+  virtual char OverloadedOnArgumentType(char c) = 0;
+
+  virtual int OverloadedOnConstness() = 0;
+  virtual char OverloadedOnConstness() const = 0;
+
+  virtual int TypeWithHole(int (*func)()) = 0;
+  virtual int TypeWithComma(const std::map<int, std::string>& a_map) = 0;
+  virtual int TypeWithTemplatedCopyCtor(const TemplatedCopyable<int>&) = 0;
+
+  virtual int (*ReturnsFunctionPointer1(int))(bool) = 0;
+  using fn_ptr = int (*)(bool);
+  virtual fn_ptr ReturnsFunctionPointer2(int) = 0;
+
+  virtual int RefQualifiedConstRef() const& = 0;
+  virtual int RefQualifiedConstRefRef() const&& = 0;
+  virtual int RefQualifiedRef() & = 0;
+  virtual int RefQualifiedRefRef() && = 0;
+
+  virtual int RefQualifiedOverloaded() const& = 0;
+  virtual int RefQualifiedOverloaded() const&& = 0;
+  virtual int RefQualifiedOverloaded() & = 0;
+  virtual int RefQualifiedOverloaded() && = 0;
+
+#ifdef GTEST_OS_WINDOWS
+  STDMETHOD_(int, CTNullary)() = 0;
+  STDMETHOD_(bool, CTUnary)(int x) = 0;
+  STDMETHOD_(int, CTDecimal)
+  (bool b, char c, short d, int e, long f,  // NOLINT
+   float g, double h, unsigned i, char* j, const std::string& k) = 0;
+  STDMETHOD_(char, CTConst)(int x) const = 0;
+#endif  // GTEST_OS_WINDOWS
+};
+
+// Const qualifiers on arguments were once (incorrectly) considered
+// significant in determining whether two virtual functions had the same
+// signature. This was fixed in Visual Studio 2008. However, the compiler
+// still emits a warning that alerts about this change in behavior.
+GTEST_DISABLE_MSC_WARNINGS_PUSH_(4373)
+class MockFoo : public FooInterface {
+ public:
+  MockFoo() = default;
+
+  // Makes sure that a mock function parameter can be named.
+  MOCK_METHOD(void, VoidReturning, (int n));  // NOLINT
+
+  MOCK_METHOD(int, Nullary, ());  // NOLINT
+
+  // Makes sure that a mock function parameter can be unnamed.
+  MOCK_METHOD(bool, Unary, (int));          // NOLINT
+  MOCK_METHOD(long, Binary, (short, int));  // NOLINT
+  MOCK_METHOD(int, Decimal,
+              (bool, char, short, int, long, float,  // NOLINT
+               double, unsigned, char*, const std::string& str),
+              (override));
+
+  MOCK_METHOD(bool, TakesNonConstReference, (int&));  // NOLINT
+  MOCK_METHOD(std::string, TakesConstReference, (const int&));
+  MOCK_METHOD(bool, TakesConst, (const int));  // NOLINT
+
+  // Tests that the function return type can contain unprotected comma.
+  MOCK_METHOD((std::map<int, std::string>), ReturnTypeWithComma, (), ());
+  MOCK_METHOD((std::map<int, std::string>), ReturnTypeWithComma, (int),
+              (const));  // NOLINT
+
+  MOCK_METHOD(int, OverloadedOnArgumentNumber, ());     // NOLINT
+  MOCK_METHOD(int, OverloadedOnArgumentNumber, (int));  // NOLINT
+
+  MOCK_METHOD(int, OverloadedOnArgumentType, (int));    // NOLINT
+  MOCK_METHOD(char, OverloadedOnArgumentType, (char));  // NOLINT
+
+  MOCK_METHOD(int, OverloadedOnConstness, (), (override));          // NOLINT
+  MOCK_METHOD(char, OverloadedOnConstness, (), (override, const));  // NOLINT
+
+  MOCK_METHOD(int, TypeWithHole, (int (*)()), ());  // NOLINT
+  MOCK_METHOD(int, TypeWithComma, ((const std::map<int, std::string>&)));
+  MOCK_METHOD(int, TypeWithTemplatedCopyCtor,
+              (const TemplatedCopyable<int>&));  // NOLINT
+
+  MOCK_METHOD(int (*)(bool), ReturnsFunctionPointer1, (int), ());
+  MOCK_METHOD(fn_ptr, ReturnsFunctionPointer2, (int), ());
+
+#ifdef GTEST_OS_WINDOWS
+  MOCK_METHOD(int, CTNullary, (), (Calltype(STDMETHODCALLTYPE)));
+  MOCK_METHOD(bool, CTUnary, (int), (Calltype(STDMETHODCALLTYPE)));
+  MOCK_METHOD(int, CTDecimal,
+              (bool b, char c, short d, int e, long f, float g, double h,
+               unsigned i, char* j, const std::string& k),
+              (Calltype(STDMETHODCALLTYPE)));
+  MOCK_METHOD(char, CTConst, (int), (const, Calltype(STDMETHODCALLTYPE)));
+  MOCK_METHOD((std::map<int, std::string>), CTReturnTypeWithComma, (),
+              (Calltype(STDMETHODCALLTYPE)));
+#endif  // GTEST_OS_WINDOWS
+
+  // Test reference qualified functions.
+  MOCK_METHOD(int, RefQualifiedConstRef, (), (const, ref(&), override));
+  MOCK_METHOD(int, RefQualifiedConstRefRef, (), (const, ref(&&), override));
+  MOCK_METHOD(int, RefQualifiedRef, (), (ref(&), override));
+  MOCK_METHOD(int, RefQualifiedRefRef, (), (ref(&&), override));
+
+  MOCK_METHOD(int, RefQualifiedOverloaded, (), (const, ref(&), override));
+  MOCK_METHOD(int, RefQualifiedOverloaded, (), (const, ref(&&), override));
+  MOCK_METHOD(int, RefQualifiedOverloaded, (), (ref(&), override));
+  MOCK_METHOD(int, RefQualifiedOverloaded, (), (ref(&&), override));
+
+ private:
+  MockFoo(const MockFoo&) = delete;
+  MockFoo& operator=(const MockFoo&) = delete;
+};
+
+class LegacyMockFoo : public FooInterface {
+ public:
+  LegacyMockFoo() = default;
+
+  // Makes sure that a mock function parameter can be named.
+  MOCK_METHOD1(VoidReturning, void(int n));  // NOLINT
+
+  MOCK_METHOD0(Nullary, int());  // NOLINT
+
+  // Makes sure that a mock function parameter can be unnamed.
+  MOCK_METHOD1(Unary, bool(int));                                  // NOLINT
+  MOCK_METHOD2(Binary, long(short, int));                          // NOLINT
+  MOCK_METHOD10(Decimal, int(bool, char, short, int, long, float,  // NOLINT
+                             double, unsigned, char*, const std::string& str));
+
+  MOCK_METHOD1(TakesNonConstReference, bool(int&));  // NOLINT
+  MOCK_METHOD1(TakesConstReference, std::string(const int&));
+  MOCK_METHOD1(TakesConst, bool(const int));  // NOLINT
+
+  // Tests that the function return type can contain unprotected comma.
+  MOCK_METHOD0(ReturnTypeWithComma, std::map<int, std::string>());
+  MOCK_CONST_METHOD1(ReturnTypeWithComma,
+                     std::map<int, std::string>(int));  // NOLINT
+
+  MOCK_METHOD0(OverloadedOnArgumentNumber, int());     // NOLINT
+  MOCK_METHOD1(OverloadedOnArgumentNumber, int(int));  // NOLINT
+
+  MOCK_METHOD1(OverloadedOnArgumentType, int(int));    // NOLINT
+  MOCK_METHOD1(OverloadedOnArgumentType, char(char));  // NOLINT
+
+  MOCK_METHOD0(OverloadedOnConstness, int());         // NOLINT
+  MOCK_CONST_METHOD0(OverloadedOnConstness, char());  // NOLINT
+
+  MOCK_METHOD1(TypeWithHole, int(int (*)()));  // NOLINT
+  MOCK_METHOD1(TypeWithComma,
+               int(const std::map<int, std::string>&));  // NOLINT
+  MOCK_METHOD1(TypeWithTemplatedCopyCtor,
+               int(const TemplatedCopyable<int>&));  // NOLINT
+
+  MOCK_METHOD1(ReturnsFunctionPointer1, int (*(int))(bool));
+  MOCK_METHOD1(ReturnsFunctionPointer2, fn_ptr(int));
+
+#ifdef GTEST_OS_WINDOWS
+  MOCK_METHOD0_WITH_CALLTYPE(STDMETHODCALLTYPE, CTNullary, int());
+  MOCK_METHOD1_WITH_CALLTYPE(STDMETHODCALLTYPE, CTUnary, bool(int));  // NOLINT
+  MOCK_METHOD10_WITH_CALLTYPE(STDMETHODCALLTYPE, CTDecimal,
+                              int(bool b, char c, short d, int e,  // NOLINT
+                                  long f, float g, double h,       // NOLINT
+                                  unsigned i, char* j, const std::string& k));
+  MOCK_CONST_METHOD1_WITH_CALLTYPE(STDMETHODCALLTYPE, CTConst,
+                                   char(int));  // NOLINT
+
+  // Tests that the function return type can contain unprotected comma.
+  MOCK_METHOD0_WITH_CALLTYPE(STDMETHODCALLTYPE, CTReturnTypeWithComma,
+                             std::map<int, std::string>());
+#endif  // GTEST_OS_WINDOWS
+
+  // We can't mock these with the old macros, but we need to define them to make
+  // it concrete.
+  int RefQualifiedConstRef() const& override { return 0; }
+  int RefQualifiedConstRefRef() const&& override { return 0; }
+  int RefQualifiedRef() & override { return 0; }
+  int RefQualifiedRefRef() && override { return 0; }
+  int RefQualifiedOverloaded() const& override { return 0; }
+  int RefQualifiedOverloaded() const&& override { return 0; }
+  int RefQualifiedOverloaded() & override { return 0; }
+  int RefQualifiedOverloaded() && override { return 0; }
+
+ private:
+  LegacyMockFoo(const LegacyMockFoo&) = delete;
+  LegacyMockFoo& operator=(const LegacyMockFoo&) = delete;
+};
+
+GTEST_DISABLE_MSC_WARNINGS_POP_()  // 4373
+
+template <class T>
+class FunctionMockerTest : public testing::Test {
+ protected:
+  FunctionMockerTest() : foo_(&mock_foo_) {}
+
+  FooInterface* const foo_;
+  T mock_foo_;
+};
+using FunctionMockerTestTypes = ::testing::Types<MockFoo, LegacyMockFoo>;
+TYPED_TEST_SUITE(FunctionMockerTest, FunctionMockerTestTypes);
+
+// Tests mocking a void-returning function.
+TYPED_TEST(FunctionMockerTest, MocksVoidFunction) {
+  EXPECT_CALL(this->mock_foo_, VoidReturning(Lt(100)));
+  this->foo_->VoidReturning(0);
+}
+
+// Tests mocking a nullary function.
+TYPED_TEST(FunctionMockerTest, MocksNullaryFunction) {
+  EXPECT_CALL(this->mock_foo_, Nullary())
+      .WillOnce(DoDefault())
+      .WillOnce(Return(1));
+
+  EXPECT_EQ(0, this->foo_->Nullary());
+  EXPECT_EQ(1, this->foo_->Nullary());
+}
+
+// Tests mocking a unary function.
+TYPED_TEST(FunctionMockerTest, MocksUnaryFunction) {
+  EXPECT_CALL(this->mock_foo_, Unary(Eq(2))).Times(2).WillOnce(Return(true));
+
+  EXPECT_TRUE(this->foo_->Unary(2));
+  EXPECT_FALSE(this->foo_->Unary(2));
+}
+
+// Tests mocking a binary function.
+TYPED_TEST(FunctionMockerTest, MocksBinaryFunction) {
+  EXPECT_CALL(this->mock_foo_, Binary(2, _)).WillOnce(Return(3));
+
+  EXPECT_EQ(3, this->foo_->Binary(2, 1));
+}
+
+// Tests mocking a decimal function.
+TYPED_TEST(FunctionMockerTest, MocksDecimalFunction) {
+  EXPECT_CALL(this->mock_foo_,
+              Decimal(true, 'a', 0, 0, 1L, A<float>(), Lt(100), 5U, NULL, "hi"))
+      .WillOnce(Return(5));
+
+  EXPECT_EQ(5, this->foo_->Decimal(true, 'a', 0, 0, 1, 0, 0, 5, nullptr, "hi"));
+}
+
+// Tests mocking a function that takes a non-const reference.
+TYPED_TEST(FunctionMockerTest, MocksFunctionWithNonConstReferenceArgument) {
+  int a = 0;
+  EXPECT_CALL(this->mock_foo_, TakesNonConstReference(Ref(a)))
+      .WillOnce(Return(true));
+
+  EXPECT_TRUE(this->foo_->TakesNonConstReference(a));
+}
+
+// Tests mocking a function that takes a const reference.
+TYPED_TEST(FunctionMockerTest, MocksFunctionWithConstReferenceArgument) {
+  int a = 0;
+  EXPECT_CALL(this->mock_foo_, TakesConstReference(Ref(a)))
+      .WillOnce(Return("Hello"));
+
+  EXPECT_EQ("Hello", this->foo_->TakesConstReference(a));
+}
+
+// Tests mocking a function that takes a const variable.
+TYPED_TEST(FunctionMockerTest, MocksFunctionWithConstArgument) {
+  EXPECT_CALL(this->mock_foo_, TakesConst(Lt(10))).WillOnce(DoDefault());
+
+  EXPECT_FALSE(this->foo_->TakesConst(5));
+}
+
+// Tests mocking functions overloaded on the number of arguments.
+TYPED_TEST(FunctionMockerTest, MocksFunctionsOverloadedOnArgumentNumber) {
+  EXPECT_CALL(this->mock_foo_, OverloadedOnArgumentNumber())
+      .WillOnce(Return(1));
+  EXPECT_CALL(this->mock_foo_, OverloadedOnArgumentNumber(_))
+      .WillOnce(Return(2));
+
+  EXPECT_EQ(2, this->foo_->OverloadedOnArgumentNumber(1));
+  EXPECT_EQ(1, this->foo_->OverloadedOnArgumentNumber());
+}
+
+// Tests mocking functions overloaded on the types of argument.
+TYPED_TEST(FunctionMockerTest, MocksFunctionsOverloadedOnArgumentType) {
+  EXPECT_CALL(this->mock_foo_, OverloadedOnArgumentType(An<int>()))
+      .WillOnce(Return(1));
+  EXPECT_CALL(this->mock_foo_, OverloadedOnArgumentType(TypedEq<char>('a')))
+      .WillOnce(Return('b'));
+
+  EXPECT_EQ(1, this->foo_->OverloadedOnArgumentType(0));
+  EXPECT_EQ('b', this->foo_->OverloadedOnArgumentType('a'));
+}
+
+// Tests mocking functions overloaded on the const-ness of this object.
+TYPED_TEST(FunctionMockerTest, MocksFunctionsOverloadedOnConstnessOfThis) {
+  EXPECT_CALL(this->mock_foo_, OverloadedOnConstness());
+  EXPECT_CALL(Const(this->mock_foo_), OverloadedOnConstness())
+      .WillOnce(Return('a'));
+
+  EXPECT_EQ(0, this->foo_->OverloadedOnConstness());
+  EXPECT_EQ('a', Const(*this->foo_).OverloadedOnConstness());
+}
+
+TYPED_TEST(FunctionMockerTest, MocksReturnTypeWithComma) {
+  const std::map<int, std::string> a_map;
+  EXPECT_CALL(this->mock_foo_, ReturnTypeWithComma()).WillOnce(Return(a_map));
+  EXPECT_CALL(this->mock_foo_, ReturnTypeWithComma(42)).WillOnce(Return(a_map));
+
+  EXPECT_EQ(a_map, this->mock_foo_.ReturnTypeWithComma());
+  EXPECT_EQ(a_map, this->mock_foo_.ReturnTypeWithComma(42));
+}
+
+TYPED_TEST(FunctionMockerTest, MocksTypeWithTemplatedCopyCtor) {
+  EXPECT_CALL(this->mock_foo_, TypeWithTemplatedCopyCtor(_))
+      .WillOnce(Return(true));
+  EXPECT_TRUE(this->foo_->TypeWithTemplatedCopyCtor(TemplatedCopyable<int>()));
+}
+
+#ifdef GTEST_OS_WINDOWS
+// Tests mocking a nullary function with calltype.
+TYPED_TEST(FunctionMockerTest, MocksNullaryFunctionWithCallType) {
+  EXPECT_CALL(this->mock_foo_, CTNullary())
+      .WillOnce(Return(-1))
+      .WillOnce(Return(0));
+
+  EXPECT_EQ(-1, this->foo_->CTNullary());
+  EXPECT_EQ(0, this->foo_->CTNullary());
+}
+
+// Tests mocking a unary function with calltype.
+TYPED_TEST(FunctionMockerTest, MocksUnaryFunctionWithCallType) {
+  EXPECT_CALL(this->mock_foo_, CTUnary(Eq(2)))
+      .Times(2)
+      .WillOnce(Return(true))
+      .WillOnce(Return(false));
+
+  EXPECT_TRUE(this->foo_->CTUnary(2));
+  EXPECT_FALSE(this->foo_->CTUnary(2));
+}
+
+// Tests mocking a decimal function with calltype.
+TYPED_TEST(FunctionMockerTest, MocksDecimalFunctionWithCallType) {
+  EXPECT_CALL(this->mock_foo_, CTDecimal(true, 'a', 0, 0, 1L, A<float>(),
+                                         Lt(100), 5U, NULL, "hi"))
+      .WillOnce(Return(10));
+
+  EXPECT_EQ(10, this->foo_->CTDecimal(true, 'a', 0, 0, 1, 0, 0, 5, NULL, "hi"));
+}
+
+// Tests mocking functions overloaded on the const-ness of this object.
+TYPED_TEST(FunctionMockerTest, MocksFunctionsConstFunctionWithCallType) {
+  EXPECT_CALL(Const(this->mock_foo_), CTConst(_)).WillOnce(Return('a'));
+
+  EXPECT_EQ('a', Const(*this->foo_).CTConst(0));
+}
+
+TYPED_TEST(FunctionMockerTest, MocksReturnTypeWithCommaAndCallType) {
+  const std::map<int, std::string> a_map;
+  EXPECT_CALL(this->mock_foo_, CTReturnTypeWithComma()).WillOnce(Return(a_map));
+
+  EXPECT_EQ(a_map, this->mock_foo_.CTReturnTypeWithComma());
+}
+
+#endif  // GTEST_OS_WINDOWS
+
+TEST(FunctionMockerTest, RefQualified) {
+  MockFoo mock_foo;
+
+  EXPECT_CALL(mock_foo, RefQualifiedConstRef).WillOnce(Return(1));
+  EXPECT_CALL(std::move(mock_foo),  // NOLINT
+              RefQualifiedConstRefRef)
+      .WillOnce(Return(2));
+  EXPECT_CALL(mock_foo, RefQualifiedRef).WillOnce(Return(3));
+  EXPECT_CALL(std::move(mock_foo),  // NOLINT
+              RefQualifiedRefRef)
+      .WillOnce(Return(4));
+
+  EXPECT_CALL(static_cast<const MockFoo&>(mock_foo), RefQualifiedOverloaded())
+      .WillOnce(Return(5));
+  EXPECT_CALL(static_cast<const MockFoo&&>(mock_foo), RefQualifiedOverloaded())
+      .WillOnce(Return(6));
+  EXPECT_CALL(static_cast<MockFoo&>(mock_foo), RefQualifiedOverloaded())
+      .WillOnce(Return(7));
+  EXPECT_CALL(static_cast<MockFoo&&>(mock_foo), RefQualifiedOverloaded())
+      .WillOnce(Return(8));
+
+  EXPECT_EQ(mock_foo.RefQualifiedConstRef(), 1);
+  EXPECT_EQ(std::move(mock_foo).RefQualifiedConstRefRef(), 2);  // NOLINT
+  EXPECT_EQ(mock_foo.RefQualifiedRef(), 3);
+  EXPECT_EQ(std::move(mock_foo).RefQualifiedRefRef(), 4);  // NOLINT
+
+  EXPECT_EQ(std::cref(mock_foo).get().RefQualifiedOverloaded(), 5);
+  EXPECT_EQ(std::move(std::cref(mock_foo).get())  // NOLINT
+                .RefQualifiedOverloaded(),
+            6);
+  EXPECT_EQ(mock_foo.RefQualifiedOverloaded(), 7);
+  EXPECT_EQ(std::move(mock_foo).RefQualifiedOverloaded(), 8);  // NOLINT
+}
+
+class MockB {
+ public:
+  MockB() = default;
+
+  MOCK_METHOD(void, DoB, ());
+
+ private:
+  MockB(const MockB&) = delete;
+  MockB& operator=(const MockB&) = delete;
+};
+
+class LegacyMockB {
+ public:
+  LegacyMockB() = default;
+
+  MOCK_METHOD0(DoB, void());
+
+ private:
+  LegacyMockB(const LegacyMockB&) = delete;
+  LegacyMockB& operator=(const LegacyMockB&) = delete;
+};
+
+template <typename T>
+class ExpectCallTest : public ::testing::Test {};
+using ExpectCallTestTypes = ::testing::Types<MockB, LegacyMockB>;
+TYPED_TEST_SUITE(ExpectCallTest, ExpectCallTestTypes);
+
+// Tests that functions with no EXPECT_CALL() rules can be called any
+// number of times.
+TYPED_TEST(ExpectCallTest, UnmentionedFunctionCanBeCalledAnyNumberOfTimes) {
+  { TypeParam b; }
+
+  {
+    TypeParam b;
+    b.DoB();
+  }
+
+  {
+    TypeParam b;
+    b.DoB();
+    b.DoB();
+  }
+}
+
+// Tests mocking template interfaces.
+
+template <typename T>
+class StackInterface {
+ public:
+  virtual ~StackInterface() = default;
+
+  // Template parameter appears in function parameter.
+  virtual void Push(const T& value) = 0;
+  virtual void Pop() = 0;
+  virtual int GetSize() const = 0;
+  // Template parameter appears in function return type.
+  virtual const T& GetTop() const = 0;
+};
+
+template <typename T>
+class MockStack : public StackInterface<T> {
+ public:
+  MockStack() = default;
+
+  MOCK_METHOD(void, Push, (const T& elem), ());
+  MOCK_METHOD(void, Pop, (), (final));
+  MOCK_METHOD(int, GetSize, (), (const, override));
+  MOCK_METHOD(const T&, GetTop, (), (const));
+
+  // Tests that the function return type can contain unprotected comma.
+  MOCK_METHOD((std::map<int, int>), ReturnTypeWithComma, (), ());
+  MOCK_METHOD((std::map<int, int>), ReturnTypeWithComma, (int), (const));
+
+ private:
+  MockStack(const MockStack&) = delete;
+  MockStack& operator=(const MockStack&) = delete;
+};
+
+template <typename T>
+class LegacyMockStack : public StackInterface<T> {
+ public:
+  LegacyMockStack() = default;
+
+  MOCK_METHOD1_T(Push, void(const T& elem));
+  MOCK_METHOD0_T(Pop, void());
+  MOCK_CONST_METHOD0_T(GetSize, int());  // NOLINT
+  MOCK_CONST_METHOD0_T(GetTop, const T&());
+
+  // Tests that the function return type can contain unprotected comma.
+  MOCK_METHOD0_T(ReturnTypeWithComma, std::map<int, int>());
+  MOCK_CONST_METHOD1_T(ReturnTypeWithComma, std::map<int, int>(int));  // NOLINT
+
+ private:
+  LegacyMockStack(const LegacyMockStack&) = delete;
+  LegacyMockStack& operator=(const LegacyMockStack&) = delete;
+};
+
+template <typename T>
+class TemplateMockTest : public ::testing::Test {};
+using TemplateMockTestTypes =
+    ::testing::Types<MockStack<int>, LegacyMockStack<int>>;
+TYPED_TEST_SUITE(TemplateMockTest, TemplateMockTestTypes);
+
+// Tests that template mock works.
+TYPED_TEST(TemplateMockTest, Works) {
+  TypeParam mock;
+
+  EXPECT_CALL(mock, GetSize())
+      .WillOnce(Return(0))
+      .WillOnce(Return(1))
+      .WillOnce(Return(0));
+  EXPECT_CALL(mock, Push(_));
+  int n = 5;
+  EXPECT_CALL(mock, GetTop()).WillOnce(ReturnRef(n));
+  EXPECT_CALL(mock, Pop()).Times(AnyNumber());
+
+  EXPECT_EQ(0, mock.GetSize());
+  mock.Push(5);
+  EXPECT_EQ(1, mock.GetSize());
+  EXPECT_EQ(5, mock.GetTop());
+  mock.Pop();
+  EXPECT_EQ(0, mock.GetSize());
+}
+
+TYPED_TEST(TemplateMockTest, MethodWithCommaInReturnTypeWorks) {
+  TypeParam mock;
+
+  const std::map<int, int> a_map;
+  EXPECT_CALL(mock, ReturnTypeWithComma()).WillOnce(Return(a_map));
+  EXPECT_CALL(mock, ReturnTypeWithComma(1)).WillOnce(Return(a_map));
+
+  EXPECT_EQ(a_map, mock.ReturnTypeWithComma());
+  EXPECT_EQ(a_map, mock.ReturnTypeWithComma(1));
+}
+
+#ifdef GTEST_OS_WINDOWS
+// Tests mocking template interfaces with calltype.
+
+template <typename T>
+class StackInterfaceWithCallType {
+ public:
+  virtual ~StackInterfaceWithCallType() {}
+
+  // Template parameter appears in function parameter.
+  STDMETHOD_(void, Push)(const T& value) = 0;
+  STDMETHOD_(void, Pop)() = 0;
+  STDMETHOD_(int, GetSize)() const = 0;
+  // Template parameter appears in function return type.
+  STDMETHOD_(const T&, GetTop)() const = 0;
+};
+
+template <typename T>
+class MockStackWithCallType : public StackInterfaceWithCallType<T> {
+ public:
+  MockStackWithCallType() {}
+
+  MOCK_METHOD(void, Push, (const T& elem),
+              (Calltype(STDMETHODCALLTYPE), override));
+  MOCK_METHOD(void, Pop, (), (Calltype(STDMETHODCALLTYPE), override));
+  MOCK_METHOD(int, GetSize, (), (Calltype(STDMETHODCALLTYPE), override, const));
+  MOCK_METHOD(const T&, GetTop, (),
+              (Calltype(STDMETHODCALLTYPE), override, const));
+
+ private:
+  MockStackWithCallType(const MockStackWithCallType&) = delete;
+  MockStackWithCallType& operator=(const MockStackWithCallType&) = delete;
+};
+
+template <typename T>
+class LegacyMockStackWithCallType : public StackInterfaceWithCallType<T> {
+ public:
+  LegacyMockStackWithCallType() {}
+
+  MOCK_METHOD1_T_WITH_CALLTYPE(STDMETHODCALLTYPE, Push, void(const T& elem));
+  MOCK_METHOD0_T_WITH_CALLTYPE(STDMETHODCALLTYPE, Pop, void());
+  MOCK_CONST_METHOD0_T_WITH_CALLTYPE(STDMETHODCALLTYPE, GetSize, int());
+  MOCK_CONST_METHOD0_T_WITH_CALLTYPE(STDMETHODCALLTYPE, GetTop, const T&());
+
+ private:
+  LegacyMockStackWithCallType(const LegacyMockStackWithCallType&) = delete;
+  LegacyMockStackWithCallType& operator=(const LegacyMockStackWithCallType&) =
+      delete;
+};
+
+template <typename T>
+class TemplateMockTestWithCallType : public ::testing::Test {};
+using TemplateMockTestWithCallTypeTypes =
+    ::testing::Types<MockStackWithCallType<int>,
+                     LegacyMockStackWithCallType<int>>;
+TYPED_TEST_SUITE(TemplateMockTestWithCallType,
+                 TemplateMockTestWithCallTypeTypes);
+
+// Tests that template mock with calltype works.
+TYPED_TEST(TemplateMockTestWithCallType, Works) {
+  TypeParam mock;
+
+  EXPECT_CALL(mock, GetSize())
+      .WillOnce(Return(0))
+      .WillOnce(Return(1))
+      .WillOnce(Return(0));
+  EXPECT_CALL(mock, Push(_));
+  int n = 5;
+  EXPECT_CALL(mock, GetTop()).WillOnce(ReturnRef(n));
+  EXPECT_CALL(mock, Pop()).Times(AnyNumber());
+
+  EXPECT_EQ(0, mock.GetSize());
+  mock.Push(5);
+  EXPECT_EQ(1, mock.GetSize());
+  EXPECT_EQ(5, mock.GetTop());
+  mock.Pop();
+  EXPECT_EQ(0, mock.GetSize());
+}
+#endif  // GTEST_OS_WINDOWS
+
+#define MY_MOCK_METHODS1_                       \
+  MOCK_METHOD(void, Overloaded, ());            \
+  MOCK_METHOD(int, Overloaded, (int), (const)); \
+  MOCK_METHOD(bool, Overloaded, (bool f, int n))
+
+#define LEGACY_MY_MOCK_METHODS1_              \
+  MOCK_METHOD0(Overloaded, void());           \
+  MOCK_CONST_METHOD1(Overloaded, int(int n)); \
+  MOCK_METHOD2(Overloaded, bool(bool f, int n))
+
+class MockOverloadedOnArgNumber {
+ public:
+  MockOverloadedOnArgNumber() = default;
+
+  MY_MOCK_METHODS1_;
+
+ private:
+  MockOverloadedOnArgNumber(const MockOverloadedOnArgNumber&) = delete;
+  MockOverloadedOnArgNumber& operator=(const MockOverloadedOnArgNumber&) =
+      delete;
+};
+
+class LegacyMockOverloadedOnArgNumber {
+ public:
+  LegacyMockOverloadedOnArgNumber() = default;
+
+  LEGACY_MY_MOCK_METHODS1_;
+
+ private:
+  LegacyMockOverloadedOnArgNumber(const LegacyMockOverloadedOnArgNumber&) =
+      delete;
+  LegacyMockOverloadedOnArgNumber& operator=(
+      const LegacyMockOverloadedOnArgNumber&) = delete;
+};
+
+template <typename T>
+class OverloadedMockMethodTest : public ::testing::Test {};
+using OverloadedMockMethodTestTypes =
+    ::testing::Types<MockOverloadedOnArgNumber,
+                     LegacyMockOverloadedOnArgNumber>;
+TYPED_TEST_SUITE(OverloadedMockMethodTest, OverloadedMockMethodTestTypes);
+
+TYPED_TEST(OverloadedMockMethodTest, CanOverloadOnArgNumberInMacroBody) {
+  TypeParam mock;
+  EXPECT_CALL(mock, Overloaded());
+  EXPECT_CALL(mock, Overloaded(1)).WillOnce(Return(2));
+  EXPECT_CALL(mock, Overloaded(true, 1)).WillOnce(Return(true));
+
+  mock.Overloaded();
+  EXPECT_EQ(2, mock.Overloaded(1));
+  EXPECT_TRUE(mock.Overloaded(true, 1));
+}
+
+#define MY_MOCK_METHODS2_                     \
+  MOCK_CONST_METHOD1(Overloaded, int(int n)); \
+  MOCK_METHOD1(Overloaded, int(int n))
+
+class MockOverloadedOnConstness {
+ public:
+  MockOverloadedOnConstness() = default;
+
+  MY_MOCK_METHODS2_;
+
+ private:
+  MockOverloadedOnConstness(const MockOverloadedOnConstness&) = delete;
+  MockOverloadedOnConstness& operator=(const MockOverloadedOnConstness&) =
+      delete;
+};
+
+TEST(MockMethodOverloadedMockMethodTest, CanOverloadOnConstnessInMacroBody) {
+  MockOverloadedOnConstness mock;
+  const MockOverloadedOnConstness* const_mock = &mock;
+  EXPECT_CALL(mock, Overloaded(1)).WillOnce(Return(2));
+  EXPECT_CALL(*const_mock, Overloaded(1)).WillOnce(Return(3));
+
+  EXPECT_EQ(2, mock.Overloaded(1));
+  EXPECT_EQ(3, const_mock->Overloaded(1));
+}
+
+TEST(MockMethodMockFunctionTest, WorksForVoidNullary) {
+  MockFunction<void()> foo;
+  EXPECT_CALL(foo, Call());
+  foo.Call();
+}
+
+TEST(MockMethodMockFunctionTest, WorksForNonVoidNullary) {
+  MockFunction<int()> foo;
+  EXPECT_CALL(foo, Call()).WillOnce(Return(1)).WillOnce(Return(2));
+  EXPECT_EQ(1, foo.Call());
+  EXPECT_EQ(2, foo.Call());
+}
+
+TEST(MockMethodMockFunctionTest, WorksForVoidUnary) {
+  MockFunction<void(int)> foo;
+  EXPECT_CALL(foo, Call(1));
+  foo.Call(1);
+}
+
+TEST(MockMethodMockFunctionTest, WorksForNonVoidBinary) {
+  MockFunction<int(bool, int)> foo;
+  EXPECT_CALL(foo, Call(false, 42)).WillOnce(Return(1)).WillOnce(Return(2));
+  EXPECT_CALL(foo, Call(true, Ge(100))).WillOnce(Return(3));
+  EXPECT_EQ(1, foo.Call(false, 42));
+  EXPECT_EQ(2, foo.Call(false, 42));
+  EXPECT_EQ(3, foo.Call(true, 120));
+}
+
+TEST(MockMethodMockFunctionTest, WorksFor10Arguments) {
+  MockFunction<int(bool a0, char a1, int a2, int a3, int a4, int a5, int a6,
+                   char a7, int a8, bool a9)>
+      foo;
+  EXPECT_CALL(foo, Call(_, 'a', _, _, _, _, _, _, _, _))
+      .WillOnce(Return(1))
+      .WillOnce(Return(2));
+  EXPECT_EQ(1, foo.Call(false, 'a', 0, 0, 0, 0, 0, 'b', 0, true));
+  EXPECT_EQ(2, foo.Call(true, 'a', 0, 0, 0, 0, 0, 'b', 1, false));
+}
+
+TEST(MockMethodMockFunctionTest, AsStdFunction) {
+  MockFunction<int(int)> foo;
+  auto call = [](const std::function<int(int)>& f, int i) { return f(i); };
+  EXPECT_CALL(foo, Call(1)).WillOnce(Return(-1));
+  EXPECT_CALL(foo, Call(2)).WillOnce(Return(-2));
+  EXPECT_EQ(-1, call(foo.AsStdFunction(), 1));
+  EXPECT_EQ(-2, call(foo.AsStdFunction(), 2));
+}
+
+TEST(MockMethodMockFunctionTest, AsStdFunctionReturnsReference) {
+  MockFunction<int&()> foo;
+  int value = 1;
+  EXPECT_CALL(foo, Call()).WillOnce(ReturnRef(value));
+  int& ref = foo.AsStdFunction()();
+  EXPECT_EQ(1, ref);
+  value = 2;
+  EXPECT_EQ(2, ref);
+}
+
+TEST(MockMethodMockFunctionTest, AsStdFunctionWithReferenceParameter) {
+  MockFunction<int(int&)> foo;
+  auto call = [](const std::function<int(int&)>& f, int& i) { return f(i); };
+  int i = 42;
+  EXPECT_CALL(foo, Call(i)).WillOnce(Return(-1));
+  EXPECT_EQ(-1, call(foo.AsStdFunction(), i));
+}
+
+namespace {
+
+template <typename Expected, typename F>
+static constexpr bool IsMockFunctionTemplateArgumentDeducedTo(
+    const internal::MockFunction<F>&) {
+  return std::is_same<F, Expected>::value;
+}
+
+}  // namespace
+
+template <typename F>
+class MockMethodMockFunctionSignatureTest : public Test {};
+
+using MockMethodMockFunctionSignatureTypes =
+    Types<void(), int(), void(int), int(int), int(bool, int),
+          int(bool, char, int, int, int, int, int, char, int, bool)>;
+TYPED_TEST_SUITE(MockMethodMockFunctionSignatureTest,
+                 MockMethodMockFunctionSignatureTypes);
+
+TYPED_TEST(MockMethodMockFunctionSignatureTest,
+           IsMockFunctionTemplateArgumentDeducedForRawSignature) {
+  using Argument = TypeParam;
+  MockFunction<Argument> foo;
+  EXPECT_TRUE(IsMockFunctionTemplateArgumentDeducedTo<TypeParam>(foo));
+}
+
+TYPED_TEST(MockMethodMockFunctionSignatureTest,
+           IsMockFunctionTemplateArgumentDeducedForStdFunction) {
+  using Argument = std::function<TypeParam>;
+  MockFunction<Argument> foo;
+  EXPECT_TRUE(IsMockFunctionTemplateArgumentDeducedTo<TypeParam>(foo));
+}
+
+TYPED_TEST(
+    MockMethodMockFunctionSignatureTest,
+    IsMockFunctionCallMethodSignatureTheSameForRawSignatureAndStdFunction) {
+  using ForRawSignature = decltype(&MockFunction<TypeParam>::Call);
+  using ForStdFunction =
+      decltype(&MockFunction<std::function<TypeParam>>::Call);
+  EXPECT_TRUE((std::is_same<ForRawSignature, ForStdFunction>::value));
+}
+
+template <typename F>
+struct AlternateCallable {};
+
+TYPED_TEST(MockMethodMockFunctionSignatureTest,
+           IsMockFunctionTemplateArgumentDeducedForAlternateCallable) {
+  using Argument = AlternateCallable<TypeParam>;
+  MockFunction<Argument> foo;
+  EXPECT_TRUE(IsMockFunctionTemplateArgumentDeducedTo<TypeParam>(foo));
+}
+
+TYPED_TEST(MockMethodMockFunctionSignatureTest,
+           IsMockFunctionCallMethodSignatureTheSameForAlternateCallable) {
+  using ForRawSignature = decltype(&MockFunction<TypeParam>::Call);
+  using ForStdFunction =
+      decltype(&MockFunction<std::function<TypeParam>>::Call);
+  EXPECT_TRUE((std::is_same<ForRawSignature, ForStdFunction>::value));
+}
+
+struct MockMethodSizes0 {
+  MOCK_METHOD(void, func, ());
+};
+struct MockMethodSizes1 {
+  MOCK_METHOD(void, func, (int));
+};
+struct MockMethodSizes2 {
+  MOCK_METHOD(void, func, (int, int));
+};
+struct MockMethodSizes3 {
+  MOCK_METHOD(void, func, (int, int, int));
+};
+struct MockMethodSizes4 {
+  MOCK_METHOD(void, func, (int, int, int, int));
+};
+
+struct LegacyMockMethodSizes0 {
+  MOCK_METHOD0(func, void());
+};
+struct LegacyMockMethodSizes1 {
+  MOCK_METHOD1(func, void(int));
+};
+struct LegacyMockMethodSizes2 {
+  MOCK_METHOD2(func, void(int, int));
+};
+struct LegacyMockMethodSizes3 {
+  MOCK_METHOD3(func, void(int, int, int));
+};
+struct LegacyMockMethodSizes4 {
+  MOCK_METHOD4(func, void(int, int, int, int));
+};
+
+TEST(MockMethodMockFunctionTest, MockMethodSizeOverhead) {
+  EXPECT_EQ(sizeof(MockMethodSizes0), sizeof(MockMethodSizes1));
+  EXPECT_EQ(sizeof(MockMethodSizes0), sizeof(MockMethodSizes2));
+  EXPECT_EQ(sizeof(MockMethodSizes0), sizeof(MockMethodSizes3));
+  EXPECT_EQ(sizeof(MockMethodSizes0), sizeof(MockMethodSizes4));
+
+  EXPECT_EQ(sizeof(LegacyMockMethodSizes0), sizeof(LegacyMockMethodSizes1));
+  EXPECT_EQ(sizeof(LegacyMockMethodSizes0), sizeof(LegacyMockMethodSizes2));
+  EXPECT_EQ(sizeof(LegacyMockMethodSizes0), sizeof(LegacyMockMethodSizes3));
+  EXPECT_EQ(sizeof(LegacyMockMethodSizes0), sizeof(LegacyMockMethodSizes4));
+
+  EXPECT_EQ(sizeof(LegacyMockMethodSizes0), sizeof(MockMethodSizes0));
+}
+
+TEST(MockMethodMockFunctionTest, EnsureNoUnusedMemberFunction) {
+#ifdef __clang__
+#pragma clang diagnostic push
+#pragma clang diagnostic error "-Wunused-member-function"
+#endif
+  // https://github.com/google/googletest/issues/4052
+  struct Foo {
+    MOCK_METHOD(void, foo, ());
+  };
+  EXPECT_CALL(Foo(), foo()).Times(0);
+#ifdef __clang__
+#pragma clang diagnostic pop
+#endif
+}
+
+void hasTwoParams(int, int);
+void MaybeThrows();
+void DoesntThrow() noexcept;
+struct MockMethodNoexceptSpecifier {
+  MOCK_METHOD(void, func1, (), (noexcept));
+  MOCK_METHOD(void, func2, (), (noexcept(true)));
+  MOCK_METHOD(void, func3, (), (noexcept(false)));
+  MOCK_METHOD(void, func4, (), (noexcept(noexcept(MaybeThrows()))));
+  MOCK_METHOD(void, func5, (), (noexcept(noexcept(DoesntThrow()))));
+  MOCK_METHOD(void, func6, (), (noexcept(noexcept(DoesntThrow())), const));
+  MOCK_METHOD(void, func7, (), (const, noexcept(noexcept(DoesntThrow()))));
+  // Put commas in the noexcept expression
+  MOCK_METHOD(void, func8, (), (noexcept(noexcept(hasTwoParams(1, 2))), const));
+};
+
+TEST(MockMethodMockFunctionTest, NoexceptSpecifierPreserved) {
+  EXPECT_TRUE(noexcept(std::declval<MockMethodNoexceptSpecifier>().func1()));
+  EXPECT_TRUE(noexcept(std::declval<MockMethodNoexceptSpecifier>().func2()));
+  EXPECT_FALSE(noexcept(std::declval<MockMethodNoexceptSpecifier>().func3()));
+  EXPECT_FALSE(noexcept(std::declval<MockMethodNoexceptSpecifier>().func4()));
+  EXPECT_TRUE(noexcept(std::declval<MockMethodNoexceptSpecifier>().func5()));
+  EXPECT_TRUE(noexcept(std::declval<MockMethodNoexceptSpecifier>().func6()));
+  EXPECT_TRUE(noexcept(std::declval<MockMethodNoexceptSpecifier>().func7()));
+  EXPECT_EQ(noexcept(std::declval<MockMethodNoexceptSpecifier>().func8()),
+            noexcept(hasTwoParams(1, 2)));
+}
+
+}  // namespace gmock_function_mocker_test
+}  // namespace testing
+
+GTEST_DISABLE_MSC_WARNINGS_POP_()  // 4503

contrib/googletest/googlemock/test/gmock-internal-utils_test.cc

@@ -0,0 +1,766 @@
+// Copyright 2007, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+// Google Mock - a framework for writing C++ mock classes.
+//
+// This file tests the internal utilities.
+
+#include "gmock/internal/gmock-internal-utils.h"
+
+#include <stdlib.h>
+
+#include <cstdint>
+#include <map>
+#include <memory>
+#include <sstream>
+#include <string>
+#include <tuple>
+#include <vector>
+
+#include "gmock/gmock.h"
+#include "gmock/internal/gmock-port.h"
+#include "gtest/gtest-spi.h"
+#include "gtest/gtest.h"
+
+// Indicates that this translation unit is part of Google Test's
+// implementation.  It must come before gtest-internal-inl.h is
+// included, or there will be a compiler error.  This trick is to
+// prevent a user from accidentally including gtest-internal-inl.h in
+// their code.
+#define GTEST_IMPLEMENTATION_ 1
+#include "src/gtest-internal-inl.h"
+#undef GTEST_IMPLEMENTATION_
+
+#ifdef GTEST_OS_CYGWIN
+#include <sys/types.h>  // For ssize_t. NOLINT
+#endif
+
+namespace proto2 {
+class Message;
+}  // namespace proto2
+
+namespace testing {
+namespace internal {
+
+namespace {
+
+TEST(JoinAsKeyValueTupleTest, JoinsEmptyTuple) {
+  EXPECT_EQ("", JoinAsKeyValueTuple({}, Strings()));
+}
+
+TEST(JoinAsKeyValueTupleTest, JoinsOneTuple) {
+  EXPECT_EQ("(a: 1)", JoinAsKeyValueTuple({"a"}, {"1"}));
+}
+
+TEST(JoinAsKeyValueTupleTest, JoinsTwoTuple) {
+  EXPECT_EQ("(a: 1, b: 2)", JoinAsKeyValueTuple({"a", "b"}, {"1", "2"}));
+}
+
+TEST(JoinAsKeyValueTupleTest, JoinsTenTuple) {
+  EXPECT_EQ(
+      "(a: 1, b: 2, c: 3, d: 4, e: 5, f: 6, g: 7, h: 8, i: 9, j: 10)",
+      JoinAsKeyValueTuple({"a", "b", "c", "d", "e", "f", "g", "h", "i", "j"},
+                          {"1", "2", "3", "4", "5", "6", "7", "8", "9", "10"}));
+}
+
+TEST(ConvertIdentifierNameToWordsTest, WorksWhenNameContainsNoWord) {
+  EXPECT_EQ("", ConvertIdentifierNameToWords(""));
+  EXPECT_EQ("", ConvertIdentifierNameToWords("_"));
+  EXPECT_EQ("", ConvertIdentifierNameToWords("__"));
+}
+
+TEST(ConvertIdentifierNameToWordsTest, WorksWhenNameContainsDigits) {
+  EXPECT_EQ("1", ConvertIdentifierNameToWords("_1"));
+  EXPECT_EQ("2", ConvertIdentifierNameToWords("2_"));
+  EXPECT_EQ("34", ConvertIdentifierNameToWords("_34_"));
+  EXPECT_EQ("34 56", ConvertIdentifierNameToWords("_34_56"));
+}
+
+TEST(ConvertIdentifierNameToWordsTest, WorksWhenNameContainsCamelCaseWords) {
+  EXPECT_EQ("a big word", ConvertIdentifierNameToWords("ABigWord"));
+  EXPECT_EQ("foo bar", ConvertIdentifierNameToWords("FooBar"));
+  EXPECT_EQ("foo", ConvertIdentifierNameToWords("Foo_"));
+  EXPECT_EQ("foo bar", ConvertIdentifierNameToWords("_Foo_Bar_"));
+  EXPECT_EQ("foo and bar", ConvertIdentifierNameToWords("_Foo__And_Bar"));
+}
+
+TEST(ConvertIdentifierNameToWordsTest, WorksWhenNameContains_SeparatedWords) {
+  EXPECT_EQ("foo bar", ConvertIdentifierNameToWords("foo_bar"));
+  EXPECT_EQ("foo", ConvertIdentifierNameToWords("_foo_"));
+  EXPECT_EQ("foo bar", ConvertIdentifierNameToWords("_foo_bar_"));
+  EXPECT_EQ("foo and bar", ConvertIdentifierNameToWords("_foo__and_bar"));
+}
+
+TEST(ConvertIdentifierNameToWordsTest, WorksWhenNameIsMixture) {
+  EXPECT_EQ("foo bar 123", ConvertIdentifierNameToWords("Foo_bar123"));
+  EXPECT_EQ("chapter 11 section 1",
+            ConvertIdentifierNameToWords("_Chapter11Section_1_"));
+}
+
+TEST(GetRawPointerTest, WorksForSmartPointers) {
+  const char* const raw_p1 = new const char('a');  // NOLINT
+  const std::unique_ptr<const char> p1(raw_p1);
+  EXPECT_EQ(raw_p1, GetRawPointer(p1));
+  double* const raw_p2 = new double(2.5);  // NOLINT
+  const std::shared_ptr<double> p2(raw_p2);
+  EXPECT_EQ(raw_p2, GetRawPointer(p2));
+}
+
+TEST(GetRawPointerTest, WorksForRawPointers) {
+  int* p = nullptr;
+  EXPECT_TRUE(nullptr == GetRawPointer(p));
+  int n = 1;
+  EXPECT_EQ(&n, GetRawPointer(&n));
+}
+
+TEST(GetRawPointerTest, WorksForStdReferenceWrapper) {
+  int n = 1;
+  EXPECT_EQ(&n, GetRawPointer(std::ref(n)));
+  EXPECT_EQ(&n, GetRawPointer(std::cref(n)));
+}
+
+// Tests KindOf<T>.
+
+class Base {};
+class Derived : public Base {};
+
+TEST(KindOfTest, Bool) {
+  EXPECT_EQ(kBool, GMOCK_KIND_OF_(bool));  // NOLINT
+}
+
+TEST(KindOfTest, Integer) {
+  EXPECT_EQ(kInteger, GMOCK_KIND_OF_(char));                // NOLINT
+  EXPECT_EQ(kInteger, GMOCK_KIND_OF_(signed char));         // NOLINT
+  EXPECT_EQ(kInteger, GMOCK_KIND_OF_(unsigned char));       // NOLINT
+  EXPECT_EQ(kInteger, GMOCK_KIND_OF_(short));               // NOLINT
+  EXPECT_EQ(kInteger, GMOCK_KIND_OF_(unsigned short));      // NOLINT
+  EXPECT_EQ(kInteger, GMOCK_KIND_OF_(int));                 // NOLINT
+  EXPECT_EQ(kInteger, GMOCK_KIND_OF_(unsigned int));        // NOLINT
+  EXPECT_EQ(kInteger, GMOCK_KIND_OF_(long));                // NOLINT
+  EXPECT_EQ(kInteger, GMOCK_KIND_OF_(unsigned long));       // NOLINT
+  EXPECT_EQ(kInteger, GMOCK_KIND_OF_(long long));           // NOLINT
+  EXPECT_EQ(kInteger, GMOCK_KIND_OF_(unsigned long long));  // NOLINT
+  EXPECT_EQ(kInteger, GMOCK_KIND_OF_(wchar_t));             // NOLINT
+  EXPECT_EQ(kInteger, GMOCK_KIND_OF_(size_t));              // NOLINT
+#if defined(GTEST_OS_LINUX) || defined(GTEST_OS_MAC) || defined(GTEST_OS_CYGWIN)
+  // ssize_t is not defined on Windows and possibly some other OSes.
+  EXPECT_EQ(kInteger, GMOCK_KIND_OF_(ssize_t));  // NOLINT
+#endif
+}
+
+TEST(KindOfTest, FloatingPoint) {
+  EXPECT_EQ(kFloatingPoint, GMOCK_KIND_OF_(float));        // NOLINT
+  EXPECT_EQ(kFloatingPoint, GMOCK_KIND_OF_(double));       // NOLINT
+  EXPECT_EQ(kFloatingPoint, GMOCK_KIND_OF_(long double));  // NOLINT
+}
+
+TEST(KindOfTest, Other) {
+  EXPECT_EQ(kOther, GMOCK_KIND_OF_(void*));   // NOLINT
+  EXPECT_EQ(kOther, GMOCK_KIND_OF_(char**));  // NOLINT
+  EXPECT_EQ(kOther, GMOCK_KIND_OF_(Base));    // NOLINT
+}
+
+// Tests LosslessArithmeticConvertible<T, U>.
+
+TEST(LosslessArithmeticConvertibleTest, BoolToBool) {
+  EXPECT_TRUE((LosslessArithmeticConvertible<bool, bool>::value));
+}
+
+TEST(LosslessArithmeticConvertibleTest, BoolToInteger) {
+  EXPECT_TRUE((LosslessArithmeticConvertible<bool, char>::value));
+  EXPECT_TRUE((LosslessArithmeticConvertible<bool, int>::value));
+  EXPECT_TRUE(
+      (LosslessArithmeticConvertible<bool, unsigned long>::value));  // NOLINT
+}
+
+TEST(LosslessArithmeticConvertibleTest, BoolToFloatingPoint) {
+  EXPECT_TRUE((LosslessArithmeticConvertible<bool, float>::value));
+  EXPECT_TRUE((LosslessArithmeticConvertible<bool, double>::value));
+}
+
+TEST(LosslessArithmeticConvertibleTest, IntegerToBool) {
+  EXPECT_FALSE((LosslessArithmeticConvertible<unsigned char, bool>::value));
+  EXPECT_FALSE((LosslessArithmeticConvertible<int, bool>::value));
+}
+
+TEST(LosslessArithmeticConvertibleTest, IntegerToInteger) {
+  // Unsigned => larger signed is fine.
+  EXPECT_TRUE((LosslessArithmeticConvertible<unsigned char, int>::value));
+
+  // Unsigned => larger unsigned is fine.
+  EXPECT_TRUE((LosslessArithmeticConvertible<unsigned short,
+                                             uint64_t>::value));  // NOLINT
+
+  // Signed => unsigned is not fine.
+  EXPECT_FALSE(
+      (LosslessArithmeticConvertible<short, uint64_t>::value));  // NOLINT
+  EXPECT_FALSE((LosslessArithmeticConvertible<signed char,
+                                              unsigned int>::value));  // NOLINT
+
+  // Same size and same signedness: fine too.
+  EXPECT_TRUE(
+      (LosslessArithmeticConvertible<unsigned char, unsigned char>::value));
+  EXPECT_TRUE((LosslessArithmeticConvertible<int, int>::value));
+  EXPECT_TRUE((LosslessArithmeticConvertible<wchar_t, wchar_t>::value));
+  EXPECT_TRUE((LosslessArithmeticConvertible<unsigned long,
+                                             unsigned long>::value));  // NOLINT
+
+  // Same size, different signedness: not fine.
+  EXPECT_FALSE(
+      (LosslessArithmeticConvertible<unsigned char, signed char>::value));
+  EXPECT_FALSE((LosslessArithmeticConvertible<int, unsigned int>::value));
+  EXPECT_FALSE((LosslessArithmeticConvertible<uint64_t, int64_t>::value));
+
+  // Larger size => smaller size is not fine.
+  EXPECT_FALSE((LosslessArithmeticConvertible<long, char>::value));  // NOLINT
+  EXPECT_FALSE((LosslessArithmeticConvertible<int, signed char>::value));
+  EXPECT_FALSE((LosslessArithmeticConvertible<int64_t, unsigned int>::value));
+}
+
+TEST(LosslessArithmeticConvertibleTest, IntegerToFloatingPoint) {
+  // Integers cannot be losslessly converted to floating-points, as
+  // the format of the latter is implementation-defined.
+  EXPECT_FALSE((LosslessArithmeticConvertible<char, float>::value));
+  EXPECT_FALSE((LosslessArithmeticConvertible<int, double>::value));
+  EXPECT_FALSE(
+      (LosslessArithmeticConvertible<short, long double>::value));  // NOLINT
+}
+
+TEST(LosslessArithmeticConvertibleTest, FloatingPointToBool) {
+  EXPECT_FALSE((LosslessArithmeticConvertible<float, bool>::value));
+  EXPECT_FALSE((LosslessArithmeticConvertible<double, bool>::value));
+}
+
+TEST(LosslessArithmeticConvertibleTest, FloatingPointToInteger) {
+  EXPECT_FALSE((LosslessArithmeticConvertible<float, long>::value));  // NOLINT
+  EXPECT_FALSE((LosslessArithmeticConvertible<double, int64_t>::value));
+  EXPECT_FALSE((LosslessArithmeticConvertible<long double, int>::value));
+}
+
+TEST(LosslessArithmeticConvertibleTest, FloatingPointToFloatingPoint) {
+  // Smaller size => larger size is fine.
+  EXPECT_TRUE((LosslessArithmeticConvertible<float, double>::value));
+  EXPECT_TRUE((LosslessArithmeticConvertible<float, long double>::value));
+  EXPECT_TRUE((LosslessArithmeticConvertible<double, long double>::value));
+
+  // Same size: fine.
+  EXPECT_TRUE((LosslessArithmeticConvertible<float, float>::value));
+  EXPECT_TRUE((LosslessArithmeticConvertible<double, double>::value));
+
+  // Larger size => smaller size is not fine.
+  EXPECT_FALSE((LosslessArithmeticConvertible<double, float>::value));
+  GTEST_INTENTIONAL_CONST_COND_PUSH_()
+  if (sizeof(double) == sizeof(long double)) {  // NOLINT
+    GTEST_INTENTIONAL_CONST_COND_POP_()
+    // In some implementations (e.g. MSVC), double and long double
+    // have the same size.
+    EXPECT_TRUE((LosslessArithmeticConvertible<long double, double>::value));
+  } else {
+    EXPECT_FALSE((LosslessArithmeticConvertible<long double, double>::value));
+  }
+}
+
+// Tests the TupleMatches() template function.
+
+TEST(TupleMatchesTest, WorksForSize0) {
+  std::tuple<> matchers;
+  std::tuple<> values;
+
+  EXPECT_TRUE(TupleMatches(matchers, values));
+}
+
+TEST(TupleMatchesTest, WorksForSize1) {
+  std::tuple<Matcher<int>> matchers(Eq(1));
+  std::tuple<int> values1(1), values2(2);
+
+  EXPECT_TRUE(TupleMatches(matchers, values1));
+  EXPECT_FALSE(TupleMatches(matchers, values2));
+}
+
+TEST(TupleMatchesTest, WorksForSize2) {
+  std::tuple<Matcher<int>, Matcher<char>> matchers(Eq(1), Eq('a'));
+  std::tuple<int, char> values1(1, 'a'), values2(1, 'b'), values3(2, 'a'),
+      values4(2, 'b');
+
+  EXPECT_TRUE(TupleMatches(matchers, values1));
+  EXPECT_FALSE(TupleMatches(matchers, values2));
+  EXPECT_FALSE(TupleMatches(matchers, values3));
+  EXPECT_FALSE(TupleMatches(matchers, values4));
+}
+
+TEST(TupleMatchesTest, WorksForSize5) {
+  std::tuple<Matcher<int>, Matcher<char>, Matcher<bool>,
+             Matcher<long>,  // NOLINT
+             Matcher<std::string>>
+      matchers(Eq(1), Eq('a'), Eq(true), Eq(2L), Eq("hi"));
+  std::tuple<int, char, bool, long, std::string>  // NOLINT
+      values1(1, 'a', true, 2L, "hi"), values2(1, 'a', true, 2L, "hello"),
+      values3(2, 'a', true, 2L, "hi");
+
+  EXPECT_TRUE(TupleMatches(matchers, values1));
+  EXPECT_FALSE(TupleMatches(matchers, values2));
+  EXPECT_FALSE(TupleMatches(matchers, values3));
+}
+
+// Tests that Assert(true, ...) succeeds.
+TEST(AssertTest, SucceedsOnTrue) {
+  Assert(true, __FILE__, __LINE__, "This should succeed.");
+  Assert(true, __FILE__, __LINE__);  // This should succeed too.
+}
+
+// Tests that Assert(false, ...) generates a fatal failure.
+TEST(AssertTest, FailsFatallyOnFalse) {
+  EXPECT_DEATH_IF_SUPPORTED(
+      { Assert(false, __FILE__, __LINE__, "This should fail."); }, "");
+
+  EXPECT_DEATH_IF_SUPPORTED({ Assert(false, __FILE__, __LINE__); }, "");
+}
+
+// Tests that Expect(true, ...) succeeds.
+TEST(ExpectTest, SucceedsOnTrue) {
+  Expect(true, __FILE__, __LINE__, "This should succeed.");
+  Expect(true, __FILE__, __LINE__);  // This should succeed too.
+}
+
+// Tests that Expect(false, ...) generates a non-fatal failure.
+TEST(ExpectTest, FailsNonfatallyOnFalse) {
+  EXPECT_NONFATAL_FAILURE(
+      {  // NOLINT
+        Expect(false, __FILE__, __LINE__, "This should fail.");
+      },
+      "This should fail");
+
+  EXPECT_NONFATAL_FAILURE(
+      {  // NOLINT
+        Expect(false, __FILE__, __LINE__);
+      },
+      "Expectation failed");
+}
+
+// Tests LogIsVisible().
+
+class LogIsVisibleTest : public ::testing::Test {
+ protected:
+  void SetUp() override { original_verbose_ = GMOCK_FLAG_GET(verbose); }
+
+  void TearDown() override { GMOCK_FLAG_SET(verbose, original_verbose_); }
+
+  std::string original_verbose_;
+};
+
+TEST_F(LogIsVisibleTest, AlwaysReturnsTrueIfVerbosityIsInfo) {
+  GMOCK_FLAG_SET(verbose, kInfoVerbosity);
+  EXPECT_TRUE(LogIsVisible(kInfo));
+  EXPECT_TRUE(LogIsVisible(kWarning));
+}
+
+TEST_F(LogIsVisibleTest, AlwaysReturnsFalseIfVerbosityIsError) {
+  GMOCK_FLAG_SET(verbose, kErrorVerbosity);
+  EXPECT_FALSE(LogIsVisible(kInfo));
+  EXPECT_FALSE(LogIsVisible(kWarning));
+}
+
+TEST_F(LogIsVisibleTest, WorksWhenVerbosityIsWarning) {
+  GMOCK_FLAG_SET(verbose, kWarningVerbosity);
+  EXPECT_FALSE(LogIsVisible(kInfo));
+  EXPECT_TRUE(LogIsVisible(kWarning));
+}
+
+#if GTEST_HAS_STREAM_REDIRECTION
+
+// Tests the Log() function.
+
+// Verifies that Log() behaves correctly for the given verbosity level
+// and log severity.
+void TestLogWithSeverity(const std::string& verbosity, LogSeverity severity,
+                         bool should_print) {
+  const std::string old_flag = GMOCK_FLAG_GET(verbose);
+  GMOCK_FLAG_SET(verbose, verbosity);
+  CaptureStdout();
+  Log(severity, "Test log.\n", 0);
+  if (should_print) {
+    EXPECT_THAT(
+        GetCapturedStdout().c_str(),
+        ContainsRegex(severity == kWarning
+                          ? "^\nGMOCK WARNING:\nTest log\\.\nStack trace:\n"
+                          : "^\nTest log\\.\nStack trace:\n"));
+  } else {
+    EXPECT_STREQ("", GetCapturedStdout().c_str());
+  }
+  GMOCK_FLAG_SET(verbose, old_flag);
+}
+
+// Tests that when the stack_frames_to_skip parameter is negative,
+// Log() doesn't include the stack trace in the output.
+TEST(LogTest, NoStackTraceWhenStackFramesToSkipIsNegative) {
+  const std::string saved_flag = GMOCK_FLAG_GET(verbose);
+  GMOCK_FLAG_SET(verbose, kInfoVerbosity);
+  CaptureStdout();
+  Log(kInfo, "Test log.\n", -1);
+  EXPECT_STREQ("\nTest log.\n", GetCapturedStdout().c_str());
+  GMOCK_FLAG_SET(verbose, saved_flag);
+}
+
+struct MockStackTraceGetter : testing::internal::OsStackTraceGetterInterface {
+  std::string CurrentStackTrace(int max_depth, int skip_count) override {
+    return (testing::Message() << max_depth << "::" << skip_count << "\n")
+        .GetString();
+  }
+  void UponLeavingGTest() override {}
+};
+
+// Tests that in opt mode, a positive stack_frames_to_skip argument is
+// treated as 0.
+TEST(LogTest, NoSkippingStackFrameInOptMode) {
+  MockStackTraceGetter* mock_os_stack_trace_getter = new MockStackTraceGetter;
+  GetUnitTestImpl()->set_os_stack_trace_getter(mock_os_stack_trace_getter);
+
+  CaptureStdout();
+  Log(kWarning, "Test log.\n", 100);
+  const std::string log = GetCapturedStdout();
+
+  std::string expected_trace =
+      (testing::Message() << GTEST_FLAG_GET(stack_trace_depth) << "::")
+          .GetString();
+  std::string expected_message =
+      "\nGMOCK WARNING:\n"
+      "Test log.\n"
+      "Stack trace:\n" +
+      expected_trace;
+  EXPECT_THAT(log, HasSubstr(expected_message));
+  int skip_count = atoi(log.substr(expected_message.size()).c_str());
+
+#if defined(NDEBUG)
+  // In opt mode, no stack frame should be skipped.
+  const int expected_skip_count = 0;
+#else
+  // In dbg mode, the stack frames should be skipped.
+  const int expected_skip_count = 100;
+#endif
+
+  // Note that each inner implementation layer will +1 the number to remove
+  // itself from the trace. This means that the value is a little higher than
+  // expected, but close enough.
+  EXPECT_THAT(skip_count,
+              AllOf(Ge(expected_skip_count), Le(expected_skip_count + 10)));
+
+  // Restores the default OS stack trace getter.
+  GetUnitTestImpl()->set_os_stack_trace_getter(nullptr);
+}
+
+// Tests that all logs are printed when the value of the
+// --gmock_verbose flag is "info".
+TEST(LogTest, AllLogsArePrintedWhenVerbosityIsInfo) {
+  TestLogWithSeverity(kInfoVerbosity, kInfo, true);
+  TestLogWithSeverity(kInfoVerbosity, kWarning, true);
+}
+
+// Tests that only warnings are printed when the value of the
+// --gmock_verbose flag is "warning".
+TEST(LogTest, OnlyWarningsArePrintedWhenVerbosityIsWarning) {
+  TestLogWithSeverity(kWarningVerbosity, kInfo, false);
+  TestLogWithSeverity(kWarningVerbosity, kWarning, true);
+}
+
+// Tests that no logs are printed when the value of the
+// --gmock_verbose flag is "error".
+TEST(LogTest, NoLogsArePrintedWhenVerbosityIsError) {
+  TestLogWithSeverity(kErrorVerbosity, kInfo, false);
+  TestLogWithSeverity(kErrorVerbosity, kWarning, false);
+}
+
+// Tests that only warnings are printed when the value of the
+// --gmock_verbose flag is invalid.
+TEST(LogTest, OnlyWarningsArePrintedWhenVerbosityIsInvalid) {
+  TestLogWithSeverity("invalid", kInfo, false);
+  TestLogWithSeverity("invalid", kWarning, true);
+}
+
+// Verifies that Log() behaves correctly for the given verbosity level
+// and log severity.
+std::string GrabOutput(void (*logger)(), const char* verbosity) {
+  const std::string saved_flag = GMOCK_FLAG_GET(verbose);
+  GMOCK_FLAG_SET(verbose, verbosity);
+  CaptureStdout();
+  logger();
+  GMOCK_FLAG_SET(verbose, saved_flag);
+  return GetCapturedStdout();
+}
+
+class DummyMock {
+ public:
+  MOCK_METHOD0(TestMethod, void());
+  MOCK_METHOD1(TestMethodArg, void(int dummy));
+};
+
+void ExpectCallLogger() {
+  DummyMock mock;
+  EXPECT_CALL(mock, TestMethod());
+  mock.TestMethod();
+}
+
+// Verifies that EXPECT_CALL logs if the --gmock_verbose flag is set to "info".
+TEST(ExpectCallTest, LogsWhenVerbosityIsInfo) {
+  EXPECT_THAT(std::string(GrabOutput(ExpectCallLogger, kInfoVerbosity)),
+              HasSubstr("EXPECT_CALL(mock, TestMethod())"));
+}
+
+// Verifies that EXPECT_CALL doesn't log
+// if the --gmock_verbose flag is set to "warning".
+TEST(ExpectCallTest, DoesNotLogWhenVerbosityIsWarning) {
+  EXPECT_STREQ("", GrabOutput(ExpectCallLogger, kWarningVerbosity).c_str());
+}
+
+// Verifies that EXPECT_CALL doesn't log
+// if the --gmock_verbose flag is set to "error".
+TEST(ExpectCallTest, DoesNotLogWhenVerbosityIsError) {
+  EXPECT_STREQ("", GrabOutput(ExpectCallLogger, kErrorVerbosity).c_str());
+}
+
+void OnCallLogger() {
+  DummyMock mock;
+  ON_CALL(mock, TestMethod());
+}
+
+// Verifies that ON_CALL logs if the --gmock_verbose flag is set to "info".
+TEST(OnCallTest, LogsWhenVerbosityIsInfo) {
+  EXPECT_THAT(std::string(GrabOutput(OnCallLogger, kInfoVerbosity)),
+              HasSubstr("ON_CALL(mock, TestMethod())"));
+}
+
+// Verifies that ON_CALL doesn't log
+// if the --gmock_verbose flag is set to "warning".
+TEST(OnCallTest, DoesNotLogWhenVerbosityIsWarning) {
+  EXPECT_STREQ("", GrabOutput(OnCallLogger, kWarningVerbosity).c_str());
+}
+
+// Verifies that ON_CALL doesn't log if
+// the --gmock_verbose flag is set to "error".
+TEST(OnCallTest, DoesNotLogWhenVerbosityIsError) {
+  EXPECT_STREQ("", GrabOutput(OnCallLogger, kErrorVerbosity).c_str());
+}
+
+void OnCallAnyArgumentLogger() {
+  DummyMock mock;
+  ON_CALL(mock, TestMethodArg(_));
+}
+
+// Verifies that ON_CALL prints provided _ argument.
+TEST(OnCallTest, LogsAnythingArgument) {
+  EXPECT_THAT(std::string(GrabOutput(OnCallAnyArgumentLogger, kInfoVerbosity)),
+              HasSubstr("ON_CALL(mock, TestMethodArg(_)"));
+}
+
+#endif  // GTEST_HAS_STREAM_REDIRECTION
+
+// Tests StlContainerView.
+
+TEST(StlContainerViewTest, WorksForStlContainer) {
+  StaticAssertTypeEq<std::vector<int>,
+                     StlContainerView<std::vector<int>>::type>();
+  StaticAssertTypeEq<const std::vector<double>&,
+                     StlContainerView<std::vector<double>>::const_reference>();
+
+  typedef std::vector<char> Chars;
+  Chars v1;
+  const Chars& v2(StlContainerView<Chars>::ConstReference(v1));
+  EXPECT_EQ(&v1, &v2);
+
+  v1.push_back('a');
+  Chars v3 = StlContainerView<Chars>::Copy(v1);
+  EXPECT_THAT(v3, Eq(v3));
+}
+
+TEST(StlContainerViewTest, WorksForStaticNativeArray) {
+  StaticAssertTypeEq<NativeArray<int>, StlContainerView<int[3]>::type>();
+  StaticAssertTypeEq<NativeArray<double>,
+                     StlContainerView<const double[4]>::type>();
+  StaticAssertTypeEq<NativeArray<char[3]>,
+                     StlContainerView<const char[2][3]>::type>();
+
+  StaticAssertTypeEq<const NativeArray<int>,
+                     StlContainerView<int[2]>::const_reference>();
+
+  int a1[3] = {0, 1, 2};
+  NativeArray<int> a2 = StlContainerView<int[3]>::ConstReference(a1);
+  EXPECT_EQ(3U, a2.size());
+  EXPECT_EQ(a1, a2.begin());
+
+  const NativeArray<int> a3 = StlContainerView<int[3]>::Copy(a1);
+  ASSERT_EQ(3U, a3.size());
+  EXPECT_EQ(0, a3.begin()[0]);
+  EXPECT_EQ(1, a3.begin()[1]);
+  EXPECT_EQ(2, a3.begin()[2]);
+
+  // Makes sure a1 and a3 aren't aliases.
+  a1[0] = 3;
+  EXPECT_EQ(0, a3.begin()[0]);
+}
+
+TEST(StlContainerViewTest, WorksForDynamicNativeArray) {
+  StaticAssertTypeEq<NativeArray<int>,
+                     StlContainerView<std::tuple<const int*, size_t>>::type>();
+  StaticAssertTypeEq<
+      NativeArray<double>,
+      StlContainerView<std::tuple<std::shared_ptr<double>, int>>::type>();
+
+  StaticAssertTypeEq<
+      const NativeArray<int>,
+      StlContainerView<std::tuple<const int*, int>>::const_reference>();
+
+  int a1[3] = {0, 1, 2};
+  const int* const p1 = a1;
+  NativeArray<int> a2 =
+      StlContainerView<std::tuple<const int*, int>>::ConstReference(
+          std::make_tuple(p1, 3));
+  EXPECT_EQ(3U, a2.size());
+  EXPECT_EQ(a1, a2.begin());
+
+  const NativeArray<int> a3 = StlContainerView<std::tuple<int*, size_t>>::Copy(
+      std::make_tuple(static_cast<int*>(a1), 3));
+  ASSERT_EQ(3U, a3.size());
+  EXPECT_EQ(0, a3.begin()[0]);
+  EXPECT_EQ(1, a3.begin()[1]);
+  EXPECT_EQ(2, a3.begin()[2]);
+
+  // Makes sure a1 and a3 aren't aliases.
+  a1[0] = 3;
+  EXPECT_EQ(0, a3.begin()[0]);
+}
+
+// Tests the Function template struct.
+
+TEST(FunctionTest, Nullary) {
+  typedef Function<int()> F;  // NOLINT
+  EXPECT_EQ(0u, F::ArgumentCount);
+  EXPECT_TRUE((std::is_same<int, F::Result>::value));
+  EXPECT_TRUE((std::is_same<std::tuple<>, F::ArgumentTuple>::value));
+  EXPECT_TRUE((std::is_same<std::tuple<>, F::ArgumentMatcherTuple>::value));
+  EXPECT_TRUE((std::is_same<void(), F::MakeResultVoid>::value));
+  EXPECT_TRUE((std::is_same<IgnoredValue(), F::MakeResultIgnoredValue>::value));
+}
+
+TEST(FunctionTest, Unary) {
+  typedef Function<int(bool)> F;  // NOLINT
+  EXPECT_EQ(1u, F::ArgumentCount);
+  EXPECT_TRUE((std::is_same<int, F::Result>::value));
+  EXPECT_TRUE((std::is_same<bool, F::Arg<0>::type>::value));
+  EXPECT_TRUE((std::is_same<std::tuple<bool>, F::ArgumentTuple>::value));
+  EXPECT_TRUE((
+      std::is_same<std::tuple<Matcher<bool>>, F::ArgumentMatcherTuple>::value));
+  EXPECT_TRUE((std::is_same<void(bool), F::MakeResultVoid>::value));  // NOLINT
+  EXPECT_TRUE((std::is_same<IgnoredValue(bool),                       // NOLINT
+                            F::MakeResultIgnoredValue>::value));
+}
+
+TEST(FunctionTest, Binary) {
+  typedef Function<int(bool, const long&)> F;  // NOLINT
+  EXPECT_EQ(2u, F::ArgumentCount);
+  EXPECT_TRUE((std::is_same<int, F::Result>::value));
+  EXPECT_TRUE((std::is_same<bool, F::Arg<0>::type>::value));
+  EXPECT_TRUE((std::is_same<const long&, F::Arg<1>::type>::value));  // NOLINT
+  EXPECT_TRUE((std::is_same<std::tuple<bool, const long&>,           // NOLINT
+                            F::ArgumentTuple>::value));
+  EXPECT_TRUE(
+      (std::is_same<std::tuple<Matcher<bool>, Matcher<const long&>>,  // NOLINT
+                    F::ArgumentMatcherTuple>::value));
+  EXPECT_TRUE((std::is_same<void(bool, const long&),  // NOLINT
+                            F::MakeResultVoid>::value));
+  EXPECT_TRUE((std::is_same<IgnoredValue(bool, const long&),  // NOLINT
+                            F::MakeResultIgnoredValue>::value));
+}
+
+TEST(FunctionTest, LongArgumentList) {
+  typedef Function<char(bool, int, char*, int&, const long&)> F;  // NOLINT
+  EXPECT_EQ(5u, F::ArgumentCount);
+  EXPECT_TRUE((std::is_same<char, F::Result>::value));
+  EXPECT_TRUE((std::is_same<bool, F::Arg<0>::type>::value));
+  EXPECT_TRUE((std::is_same<int, F::Arg<1>::type>::value));
+  EXPECT_TRUE((std::is_same<char*, F::Arg<2>::type>::value));
+  EXPECT_TRUE((std::is_same<int&, F::Arg<3>::type>::value));
+  EXPECT_TRUE((std::is_same<const long&, F::Arg<4>::type>::value));  // NOLINT
+  EXPECT_TRUE(
+      (std::is_same<std::tuple<bool, int, char*, int&, const long&>,  // NOLINT
+                    F::ArgumentTuple>::value));
+  EXPECT_TRUE(
+      (std::is_same<
+          std::tuple<Matcher<bool>, Matcher<int>, Matcher<char*>, Matcher<int&>,
+                     Matcher<const long&>>,  // NOLINT
+          F::ArgumentMatcherTuple>::value));
+  EXPECT_TRUE(
+      (std::is_same<void(bool, int, char*, int&, const long&),  // NOLINT
+                    F::MakeResultVoid>::value));
+  EXPECT_TRUE((
+      std::is_same<IgnoredValue(bool, int, char*, int&, const long&),  // NOLINT
+                   F::MakeResultIgnoredValue>::value));
+}
+
+TEST(Base64Unescape, InvalidString) {
+  std::string unescaped;
+  EXPECT_FALSE(Base64Unescape("(invalid)", &unescaped));
+}
+
+TEST(Base64Unescape, ShortString) {
+  std::string unescaped;
+  EXPECT_TRUE(Base64Unescape("SGVsbG8gd29ybGQh", &unescaped));
+  EXPECT_EQ("Hello world!", unescaped);
+}
+
+TEST(Base64Unescape, ShortStringWithPadding) {
+  std::string unescaped;
+  EXPECT_TRUE(Base64Unescape("SGVsbG8gd29ybGQ=", &unescaped));
+  EXPECT_EQ("Hello world", unescaped);
+}
+
+TEST(Base64Unescape, ShortStringWithoutPadding) {
+  std::string unescaped;
+  EXPECT_TRUE(Base64Unescape("SGVsbG8gd29ybGQ", &unescaped));
+  EXPECT_EQ("Hello world", unescaped);
+}
+
+TEST(Base64Unescape, LongStringWithWhiteSpaces) {
+  std::string escaped =
+      R"(TWFuIGlzIGRpc3Rpbmd1aXNoZWQsIG5vdCBvbmx5IGJ5IGhpcyByZWFzb24sIGJ1dCBieSB0aGlz
+  IHNpbmd1bGFyIHBhc3Npb24gZnJvbSBvdGhlciBhbmltYWxzLCB3aGljaCBpcyBhIGx1c3Qgb2Yg
+  dGhlIG1pbmQsIHRoYXQgYnkgYSBwZXJzZXZlcmFuY2Ugb2YgZGVsaWdodCBpbiB0aGUgY29udGlu
+  dWVkIGFuZCBpbmRlZmF0aWdhYmxlIGdlbmVyYXRpb24gb2Yga25vd2xlZGdlLCBleGNlZWRzIHRo
+  ZSBzaG9ydCB2ZWhlbWVuY2Ugb2YgYW55IGNhcm5hbCBwbGVhc3VyZS4=)";
+  std::string expected =
+      "Man is distinguished, not only by his reason, but by this singular "
+      "passion from other animals, which is a lust of the mind, that by a "
+      "perseverance of delight in the continued and indefatigable generation "
+      "of knowledge, exceeds the short vehemence of any carnal pleasure.";
+  std::string unescaped;
+  EXPECT_TRUE(Base64Unescape(escaped, &unescaped));
+  EXPECT_EQ(expected, unescaped);
+}
+
+}  // namespace
+}  // namespace internal
+}  // namespace testing

contrib/googletest/googlemock/test/gmock-matchers-arithmetic_test.cc

@@ -0,0 +1,1516 @@
+// Copyright 2007, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+// Google Mock - a framework for writing C++ mock classes.
+//
+// This file tests some commonly used argument matchers.
+
+#include <cmath>
+#include <limits>
+#include <memory>
+#include <string>
+
+#include "test/gmock-matchers_test.h"
+
+// Silence warning C4244: 'initializing': conversion from 'int' to 'short',
+// possible loss of data and C4100, unreferenced local parameter
+GTEST_DISABLE_MSC_WARNINGS_PUSH_(4244 4100)
+
+namespace testing {
+namespace gmock_matchers_test {
+namespace {
+
+typedef ::std::tuple<long, int> Tuple2;  // NOLINT
+
+// Tests that Eq() matches a 2-tuple where the first field == the
+// second field.
+TEST(Eq2Test, MatchesEqualArguments) {
+  Matcher<const Tuple2&> m = Eq();
+  EXPECT_TRUE(m.Matches(Tuple2(5L, 5)));
+  EXPECT_FALSE(m.Matches(Tuple2(5L, 6)));
+}
+
+// Tests that Eq() describes itself properly.
+TEST(Eq2Test, CanDescribeSelf) {
+  Matcher<const Tuple2&> m = Eq();
+  EXPECT_EQ("are an equal pair", Describe(m));
+}
+
+// Tests that Ge() matches a 2-tuple where the first field >= the
+// second field.
+TEST(Ge2Test, MatchesGreaterThanOrEqualArguments) {
+  Matcher<const Tuple2&> m = Ge();
+  EXPECT_TRUE(m.Matches(Tuple2(5L, 4)));
+  EXPECT_TRUE(m.Matches(Tuple2(5L, 5)));
+  EXPECT_FALSE(m.Matches(Tuple2(5L, 6)));
+}
+
+// Tests that Ge() describes itself properly.
+TEST(Ge2Test, CanDescribeSelf) {
+  Matcher<const Tuple2&> m = Ge();
+  EXPECT_EQ("are a pair where the first >= the second", Describe(m));
+}
+
+// Tests that Gt() matches a 2-tuple where the first field > the
+// second field.
+TEST(Gt2Test, MatchesGreaterThanArguments) {
+  Matcher<const Tuple2&> m = Gt();
+  EXPECT_TRUE(m.Matches(Tuple2(5L, 4)));
+  EXPECT_FALSE(m.Matches(Tuple2(5L, 5)));
+  EXPECT_FALSE(m.Matches(Tuple2(5L, 6)));
+}
+
+// Tests that Gt() describes itself properly.
+TEST(Gt2Test, CanDescribeSelf) {
+  Matcher<const Tuple2&> m = Gt();
+  EXPECT_EQ("are a pair where the first > the second", Describe(m));
+}
+
+// Tests that Le() matches a 2-tuple where the first field <= the
+// second field.
+TEST(Le2Test, MatchesLessThanOrEqualArguments) {
+  Matcher<const Tuple2&> m = Le();
+  EXPECT_TRUE(m.Matches(Tuple2(5L, 6)));
+  EXPECT_TRUE(m.Matches(Tuple2(5L, 5)));
+  EXPECT_FALSE(m.Matches(Tuple2(5L, 4)));
+}
+
+// Tests that Le() describes itself properly.
+TEST(Le2Test, CanDescribeSelf) {
+  Matcher<const Tuple2&> m = Le();
+  EXPECT_EQ("are a pair where the first <= the second", Describe(m));
+}
+
+// Tests that Lt() matches a 2-tuple where the first field < the
+// second field.
+TEST(Lt2Test, MatchesLessThanArguments) {
+  Matcher<const Tuple2&> m = Lt();
+  EXPECT_TRUE(m.Matches(Tuple2(5L, 6)));
+  EXPECT_FALSE(m.Matches(Tuple2(5L, 5)));
+  EXPECT_FALSE(m.Matches(Tuple2(5L, 4)));
+}
+
+// Tests that Lt() describes itself properly.
+TEST(Lt2Test, CanDescribeSelf) {
+  Matcher<const Tuple2&> m = Lt();
+  EXPECT_EQ("are a pair where the first < the second", Describe(m));
+}
+
+// Tests that Ne() matches a 2-tuple where the first field != the
+// second field.
+TEST(Ne2Test, MatchesUnequalArguments) {
+  Matcher<const Tuple2&> m = Ne();
+  EXPECT_TRUE(m.Matches(Tuple2(5L, 6)));
+  EXPECT_TRUE(m.Matches(Tuple2(5L, 4)));
+  EXPECT_FALSE(m.Matches(Tuple2(5L, 5)));
+}
+
+// Tests that Ne() describes itself properly.
+TEST(Ne2Test, CanDescribeSelf) {
+  Matcher<const Tuple2&> m = Ne();
+  EXPECT_EQ("are an unequal pair", Describe(m));
+}
+
+TEST(PairMatchBaseTest, WorksWithMoveOnly) {
+  using Pointers = std::tuple<std::unique_ptr<int>, std::unique_ptr<int>>;
+  Matcher<Pointers> matcher = Eq();
+  Pointers pointers;
+  // Tested values don't matter; the point is that matcher does not copy the
+  // matched values.
+  EXPECT_TRUE(matcher.Matches(pointers));
+}
+
+// Tests that IsNan() matches a NaN, with float.
+TEST(IsNan, FloatMatchesNan) {
+  float quiet_nan = std::numeric_limits<float>::quiet_NaN();
+  float other_nan = std::nanf("1");
+  float real_value = 1.0f;
+
+  Matcher<float> m = IsNan();
+  EXPECT_TRUE(m.Matches(quiet_nan));
+  EXPECT_TRUE(m.Matches(other_nan));
+  EXPECT_FALSE(m.Matches(real_value));
+
+  Matcher<float&> m_ref = IsNan();
+  EXPECT_TRUE(m_ref.Matches(quiet_nan));
+  EXPECT_TRUE(m_ref.Matches(other_nan));
+  EXPECT_FALSE(m_ref.Matches(real_value));
+
+  Matcher<const float&> m_cref = IsNan();
+  EXPECT_TRUE(m_cref.Matches(quiet_nan));
+  EXPECT_TRUE(m_cref.Matches(other_nan));
+  EXPECT_FALSE(m_cref.Matches(real_value));
+}
+
+// Tests that IsNan() matches a NaN, with double.
+TEST(IsNan, DoubleMatchesNan) {
+  double quiet_nan = std::numeric_limits<double>::quiet_NaN();
+  double other_nan = std::nan("1");
+  double real_value = 1.0;
+
+  Matcher<double> m = IsNan();
+  EXPECT_TRUE(m.Matches(quiet_nan));
+  EXPECT_TRUE(m.Matches(other_nan));
+  EXPECT_FALSE(m.Matches(real_value));
+
+  Matcher<double&> m_ref = IsNan();
+  EXPECT_TRUE(m_ref.Matches(quiet_nan));
+  EXPECT_TRUE(m_ref.Matches(other_nan));
+  EXPECT_FALSE(m_ref.Matches(real_value));
+
+  Matcher<const double&> m_cref = IsNan();
+  EXPECT_TRUE(m_cref.Matches(quiet_nan));
+  EXPECT_TRUE(m_cref.Matches(other_nan));
+  EXPECT_FALSE(m_cref.Matches(real_value));
+}
+
+// Tests that IsNan() matches a NaN, with long double.
+TEST(IsNan, LongDoubleMatchesNan) {
+  long double quiet_nan = std::numeric_limits<long double>::quiet_NaN();
+  long double other_nan = std::nan("1");
+  long double real_value = 1.0;
+
+  Matcher<long double> m = IsNan();
+  EXPECT_TRUE(m.Matches(quiet_nan));
+  EXPECT_TRUE(m.Matches(other_nan));
+  EXPECT_FALSE(m.Matches(real_value));
+
+  Matcher<long double&> m_ref = IsNan();
+  EXPECT_TRUE(m_ref.Matches(quiet_nan));
+  EXPECT_TRUE(m_ref.Matches(other_nan));
+  EXPECT_FALSE(m_ref.Matches(real_value));
+
+  Matcher<const long double&> m_cref = IsNan();
+  EXPECT_TRUE(m_cref.Matches(quiet_nan));
+  EXPECT_TRUE(m_cref.Matches(other_nan));
+  EXPECT_FALSE(m_cref.Matches(real_value));
+}
+
+// Tests that IsNan() works with Not.
+TEST(IsNan, NotMatchesNan) {
+  Matcher<float> mf = Not(IsNan());
+  EXPECT_FALSE(mf.Matches(std::numeric_limits<float>::quiet_NaN()));
+  EXPECT_FALSE(mf.Matches(std::nanf("1")));
+  EXPECT_TRUE(mf.Matches(1.0));
+
+  Matcher<double> md = Not(IsNan());
+  EXPECT_FALSE(md.Matches(std::numeric_limits<double>::quiet_NaN()));
+  EXPECT_FALSE(md.Matches(std::nan("1")));
+  EXPECT_TRUE(md.Matches(1.0));
+
+  Matcher<long double> mld = Not(IsNan());
+  EXPECT_FALSE(mld.Matches(std::numeric_limits<long double>::quiet_NaN()));
+  EXPECT_FALSE(mld.Matches(std::nanl("1")));
+  EXPECT_TRUE(mld.Matches(1.0));
+}
+
+// Tests that IsNan() can describe itself.
+TEST(IsNan, CanDescribeSelf) {
+  Matcher<float> mf = IsNan();
+  EXPECT_EQ("is NaN", Describe(mf));
+
+  Matcher<double> md = IsNan();
+  EXPECT_EQ("is NaN", Describe(md));
+
+  Matcher<long double> mld = IsNan();
+  EXPECT_EQ("is NaN", Describe(mld));
+}
+
+// Tests that IsNan() can describe itself with Not.
+TEST(IsNan, CanDescribeSelfWithNot) {
+  Matcher<float> mf = Not(IsNan());
+  EXPECT_EQ("isn't NaN", Describe(mf));
+
+  Matcher<double> md = Not(IsNan());
+  EXPECT_EQ("isn't NaN", Describe(md));
+
+  Matcher<long double> mld = Not(IsNan());
+  EXPECT_EQ("isn't NaN", Describe(mld));
+}
+
+// Tests that FloatEq() matches a 2-tuple where
+// FloatEq(first field) matches the second field.
+TEST(FloatEq2Test, MatchesEqualArguments) {
+  typedef ::std::tuple<float, float> Tpl;
+  Matcher<const Tpl&> m = FloatEq();
+  EXPECT_TRUE(m.Matches(Tpl(1.0f, 1.0f)));
+  EXPECT_TRUE(m.Matches(Tpl(0.3f, 0.1f + 0.1f + 0.1f)));
+  EXPECT_FALSE(m.Matches(Tpl(1.1f, 1.0f)));
+}
+
+// Tests that FloatEq() describes itself properly.
+TEST(FloatEq2Test, CanDescribeSelf) {
+  Matcher<const ::std::tuple<float, float>&> m = FloatEq();
+  EXPECT_EQ("are an almost-equal pair", Describe(m));
+}
+
+// Tests that NanSensitiveFloatEq() matches a 2-tuple where
+// NanSensitiveFloatEq(first field) matches the second field.
+TEST(NanSensitiveFloatEqTest, MatchesEqualArgumentsWithNaN) {
+  typedef ::std::tuple<float, float> Tpl;
+  Matcher<const Tpl&> m = NanSensitiveFloatEq();
+  EXPECT_TRUE(m.Matches(Tpl(1.0f, 1.0f)));
+  EXPECT_TRUE(m.Matches(Tpl(std::numeric_limits<float>::quiet_NaN(),
+                            std::numeric_limits<float>::quiet_NaN())));
+  EXPECT_FALSE(m.Matches(Tpl(1.1f, 1.0f)));
+  EXPECT_FALSE(m.Matches(Tpl(1.0f, std::numeric_limits<float>::quiet_NaN())));
+  EXPECT_FALSE(m.Matches(Tpl(std::numeric_limits<float>::quiet_NaN(), 1.0f)));
+}
+
+// Tests that NanSensitiveFloatEq() describes itself properly.
+TEST(NanSensitiveFloatEqTest, CanDescribeSelfWithNaNs) {
+  Matcher<const ::std::tuple<float, float>&> m = NanSensitiveFloatEq();
+  EXPECT_EQ("are an almost-equal pair", Describe(m));
+}
+
+// Tests that DoubleEq() matches a 2-tuple where
+// DoubleEq(first field) matches the second field.
+TEST(DoubleEq2Test, MatchesEqualArguments) {
+  typedef ::std::tuple<double, double> Tpl;
+  Matcher<const Tpl&> m = DoubleEq();
+  EXPECT_TRUE(m.Matches(Tpl(1.0, 1.0)));
+  EXPECT_TRUE(m.Matches(Tpl(0.3, 0.1 + 0.1 + 0.1)));
+  EXPECT_FALSE(m.Matches(Tpl(1.1, 1.0)));
+}
+
+// Tests that DoubleEq() describes itself properly.
+TEST(DoubleEq2Test, CanDescribeSelf) {
+  Matcher<const ::std::tuple<double, double>&> m = DoubleEq();
+  EXPECT_EQ("are an almost-equal pair", Describe(m));
+}
+
+// Tests that NanSensitiveDoubleEq() matches a 2-tuple where
+// NanSensitiveDoubleEq(first field) matches the second field.
+TEST(NanSensitiveDoubleEqTest, MatchesEqualArgumentsWithNaN) {
+  typedef ::std::tuple<double, double> Tpl;
+  Matcher<const Tpl&> m = NanSensitiveDoubleEq();
+  EXPECT_TRUE(m.Matches(Tpl(1.0f, 1.0f)));
+  EXPECT_TRUE(m.Matches(Tpl(std::numeric_limits<double>::quiet_NaN(),
+                            std::numeric_limits<double>::quiet_NaN())));
+  EXPECT_FALSE(m.Matches(Tpl(1.1f, 1.0f)));
+  EXPECT_FALSE(m.Matches(Tpl(1.0f, std::numeric_limits<double>::quiet_NaN())));
+  EXPECT_FALSE(m.Matches(Tpl(std::numeric_limits<double>::quiet_NaN(), 1.0f)));
+}
+
+// Tests that DoubleEq() describes itself properly.
+TEST(NanSensitiveDoubleEqTest, CanDescribeSelfWithNaNs) {
+  Matcher<const ::std::tuple<double, double>&> m = NanSensitiveDoubleEq();
+  EXPECT_EQ("are an almost-equal pair", Describe(m));
+}
+
+// Tests that FloatEq() matches a 2-tuple where
+// FloatNear(first field, max_abs_error) matches the second field.
+TEST(FloatNear2Test, MatchesEqualArguments) {
+  typedef ::std::tuple<float, float> Tpl;
+  Matcher<const Tpl&> m = FloatNear(0.5f);
+  EXPECT_TRUE(m.Matches(Tpl(1.0f, 1.0f)));
+  EXPECT_TRUE(m.Matches(Tpl(1.3f, 1.0f)));
+  EXPECT_FALSE(m.Matches(Tpl(1.8f, 1.0f)));
+}
+
+// Tests that FloatNear() describes itself properly.
+TEST(FloatNear2Test, CanDescribeSelf) {
+  Matcher<const ::std::tuple<float, float>&> m = FloatNear(0.5f);
+  EXPECT_EQ("are an almost-equal pair", Describe(m));
+}
+
+// Tests that NanSensitiveFloatNear() matches a 2-tuple where
+// NanSensitiveFloatNear(first field) matches the second field.
+TEST(NanSensitiveFloatNearTest, MatchesNearbyArgumentsWithNaN) {
+  typedef ::std::tuple<float, float> Tpl;
+  Matcher<const Tpl&> m = NanSensitiveFloatNear(0.5f);
+  EXPECT_TRUE(m.Matches(Tpl(1.0f, 1.0f)));
+  EXPECT_TRUE(m.Matches(Tpl(1.1f, 1.0f)));
+  EXPECT_TRUE(m.Matches(Tpl(std::numeric_limits<float>::quiet_NaN(),
+                            std::numeric_limits<float>::quiet_NaN())));
+  EXPECT_FALSE(m.Matches(Tpl(1.6f, 1.0f)));
+  EXPECT_FALSE(m.Matches(Tpl(1.0f, std::numeric_limits<float>::quiet_NaN())));
+  EXPECT_FALSE(m.Matches(Tpl(std::numeric_limits<float>::quiet_NaN(), 1.0f)));
+}
+
+// Tests that NanSensitiveFloatNear() describes itself properly.
+TEST(NanSensitiveFloatNearTest, CanDescribeSelfWithNaNs) {
+  Matcher<const ::std::tuple<float, float>&> m = NanSensitiveFloatNear(0.5f);
+  EXPECT_EQ("are an almost-equal pair", Describe(m));
+}
+
+// Tests that FloatEq() matches a 2-tuple where
+// DoubleNear(first field, max_abs_error) matches the second field.
+TEST(DoubleNear2Test, MatchesEqualArguments) {
+  typedef ::std::tuple<double, double> Tpl;
+  Matcher<const Tpl&> m = DoubleNear(0.5);
+  EXPECT_TRUE(m.Matches(Tpl(1.0, 1.0)));
+  EXPECT_TRUE(m.Matches(Tpl(1.3, 1.0)));
+  EXPECT_FALSE(m.Matches(Tpl(1.8, 1.0)));
+}
+
+// Tests that DoubleNear() describes itself properly.
+TEST(DoubleNear2Test, CanDescribeSelf) {
+  Matcher<const ::std::tuple<double, double>&> m = DoubleNear(0.5);
+  EXPECT_EQ("are an almost-equal pair", Describe(m));
+}
+
+// Tests that NanSensitiveDoubleNear() matches a 2-tuple where
+// NanSensitiveDoubleNear(first field) matches the second field.
+TEST(NanSensitiveDoubleNearTest, MatchesNearbyArgumentsWithNaN) {
+  typedef ::std::tuple<double, double> Tpl;
+  Matcher<const Tpl&> m = NanSensitiveDoubleNear(0.5f);
+  EXPECT_TRUE(m.Matches(Tpl(1.0f, 1.0f)));
+  EXPECT_TRUE(m.Matches(Tpl(1.1f, 1.0f)));
+  EXPECT_TRUE(m.Matches(Tpl(std::numeric_limits<double>::quiet_NaN(),
+                            std::numeric_limits<double>::quiet_NaN())));
+  EXPECT_FALSE(m.Matches(Tpl(1.6f, 1.0f)));
+  EXPECT_FALSE(m.Matches(Tpl(1.0f, std::numeric_limits<double>::quiet_NaN())));
+  EXPECT_FALSE(m.Matches(Tpl(std::numeric_limits<double>::quiet_NaN(), 1.0f)));
+}
+
+// Tests that NanSensitiveDoubleNear() describes itself properly.
+TEST(NanSensitiveDoubleNearTest, CanDescribeSelfWithNaNs) {
+  Matcher<const ::std::tuple<double, double>&> m = NanSensitiveDoubleNear(0.5f);
+  EXPECT_EQ("are an almost-equal pair", Describe(m));
+}
+
+// Tests that Not(m) matches any value that doesn't match m.
+TEST(NotTest, NegatesMatcher) {
+  Matcher<int> m;
+  m = Not(Eq(2));
+  EXPECT_TRUE(m.Matches(3));
+  EXPECT_FALSE(m.Matches(2));
+}
+
+// Tests that Not(m) describes itself properly.
+TEST(NotTest, CanDescribeSelf) {
+  Matcher<int> m = Not(Eq(5));
+  EXPECT_EQ("isn't equal to 5", Describe(m));
+}
+
+// Tests that monomorphic matchers are safely cast by the Not matcher.
+TEST(NotTest, NotMatcherSafelyCastsMonomorphicMatchers) {
+  // greater_than_5 is a monomorphic matcher.
+  Matcher<int> greater_than_5 = Gt(5);
+
+  Matcher<const int&> m = Not(greater_than_5);
+  Matcher<int&> m2 = Not(greater_than_5);
+  Matcher<int&> m3 = Not(m);
+}
+
+// Helper to allow easy testing of AllOf matchers with num parameters.
+void AllOfMatches(int num, const Matcher<int>& m) {
+  SCOPED_TRACE(Describe(m));
+  EXPECT_TRUE(m.Matches(0));
+  for (int i = 1; i <= num; ++i) {
+    EXPECT_FALSE(m.Matches(i));
+  }
+  EXPECT_TRUE(m.Matches(num + 1));
+}
+
+INSTANTIATE_GTEST_MATCHER_TEST_P(AllOfTest);
+
+// Tests that AllOf(m1, ..., mn) matches any value that matches all of
+// the given matchers.
+TEST(AllOfTest, MatchesWhenAllMatch) {
+  Matcher<int> m;
+  m = AllOf(Le(2), Ge(1));
+  EXPECT_TRUE(m.Matches(1));
+  EXPECT_TRUE(m.Matches(2));
+  EXPECT_FALSE(m.Matches(0));
+  EXPECT_FALSE(m.Matches(3));
+
+  m = AllOf(Gt(0), Ne(1), Ne(2));
+  EXPECT_TRUE(m.Matches(3));
+  EXPECT_FALSE(m.Matches(2));
+  EXPECT_FALSE(m.Matches(1));
+  EXPECT_FALSE(m.Matches(0));
+
+  m = AllOf(Gt(0), Ne(1), Ne(2), Ne(3));
+  EXPECT_TRUE(m.Matches(4));
+  EXPECT_FALSE(m.Matches(3));
+  EXPECT_FALSE(m.Matches(2));
+  EXPECT_FALSE(m.Matches(1));
+  EXPECT_FALSE(m.Matches(0));
+
+  m = AllOf(Ge(0), Lt(10), Ne(3), Ne(5), Ne(7));
+  EXPECT_TRUE(m.Matches(0));
+  EXPECT_TRUE(m.Matches(1));
+  EXPECT_FALSE(m.Matches(3));
+
+  // The following tests for varying number of sub-matchers. Due to the way
+  // the sub-matchers are handled it is enough to test every sub-matcher once
+  // with sub-matchers using the same matcher type. Varying matcher types are
+  // checked for above.
+  AllOfMatches(2, AllOf(Ne(1), Ne(2)));
+  AllOfMatches(3, AllOf(Ne(1), Ne(2), Ne(3)));
+  AllOfMatches(4, AllOf(Ne(1), Ne(2), Ne(3), Ne(4)));
+  AllOfMatches(5, AllOf(Ne(1), Ne(2), Ne(3), Ne(4), Ne(5)));
+  AllOfMatches(6, AllOf(Ne(1), Ne(2), Ne(3), Ne(4), Ne(5), Ne(6)));
+  AllOfMatches(7, AllOf(Ne(1), Ne(2), Ne(3), Ne(4), Ne(5), Ne(6), Ne(7)));
+  AllOfMatches(8,
+               AllOf(Ne(1), Ne(2), Ne(3), Ne(4), Ne(5), Ne(6), Ne(7), Ne(8)));
+  AllOfMatches(
+      9, AllOf(Ne(1), Ne(2), Ne(3), Ne(4), Ne(5), Ne(6), Ne(7), Ne(8), Ne(9)));
+  AllOfMatches(10, AllOf(Ne(1), Ne(2), Ne(3), Ne(4), Ne(5), Ne(6), Ne(7), Ne(8),
+                         Ne(9), Ne(10)));
+  AllOfMatches(
+      50, AllOf(Ne(1), Ne(2), Ne(3), Ne(4), Ne(5), Ne(6), Ne(7), Ne(8), Ne(9),
+                Ne(10), Ne(11), Ne(12), Ne(13), Ne(14), Ne(15), Ne(16), Ne(17),
+                Ne(18), Ne(19), Ne(20), Ne(21), Ne(22), Ne(23), Ne(24), Ne(25),
+                Ne(26), Ne(27), Ne(28), Ne(29), Ne(30), Ne(31), Ne(32), Ne(33),
+                Ne(34), Ne(35), Ne(36), Ne(37), Ne(38), Ne(39), Ne(40), Ne(41),
+                Ne(42), Ne(43), Ne(44), Ne(45), Ne(46), Ne(47), Ne(48), Ne(49),
+                Ne(50)));
+}
+
+// Tests that AllOf(m1, ..., mn) describes itself properly.
+TEST(AllOfTest, CanDescribeSelf) {
+  Matcher<int> m;
+  m = AllOf(Le(2), Ge(1));
+  EXPECT_EQ("(is <= 2) and (is >= 1)", Describe(m));
+
+  m = AllOf(Gt(0), Ne(1), Ne(2));
+  std::string expected_descr1 =
+      "(is > 0) and (isn't equal to 1) and (isn't equal to 2)";
+  EXPECT_EQ(expected_descr1, Describe(m));
+
+  m = AllOf(Gt(0), Ne(1), Ne(2), Ne(3));
+  std::string expected_descr2 =
+      "(is > 0) and (isn't equal to 1) and (isn't equal to 2) and (isn't equal "
+      "to 3)";
+  EXPECT_EQ(expected_descr2, Describe(m));
+
+  m = AllOf(Ge(0), Lt(10), Ne(3), Ne(5), Ne(7));
+  std::string expected_descr3 =
+      "(is >= 0) and (is < 10) and (isn't equal to 3) and (isn't equal to 5) "
+      "and (isn't equal to 7)";
+  EXPECT_EQ(expected_descr3, Describe(m));
+}
+
+// Tests that AllOf(m1, ..., mn) describes its negation properly.
+TEST(AllOfTest, CanDescribeNegation) {
+  Matcher<int> m;
+  m = AllOf(Le(2), Ge(1));
+  std::string expected_descr4 = "(isn't <= 2) or (isn't >= 1)";
+  EXPECT_EQ(expected_descr4, DescribeNegation(m));
+
+  m = AllOf(Gt(0), Ne(1), Ne(2));
+  std::string expected_descr5 =
+      "(isn't > 0) or (is equal to 1) or (is equal to 2)";
+  EXPECT_EQ(expected_descr5, DescribeNegation(m));
+
+  m = AllOf(Gt(0), Ne(1), Ne(2), Ne(3));
+  std::string expected_descr6 =
+      "(isn't > 0) or (is equal to 1) or (is equal to 2) or (is equal to 3)";
+  EXPECT_EQ(expected_descr6, DescribeNegation(m));
+
+  m = AllOf(Ge(0), Lt(10), Ne(3), Ne(5), Ne(7));
+  std::string expected_desr7 =
+      "(isn't >= 0) or (isn't < 10) or (is equal to 3) or (is equal to 5) or "
+      "(is equal to 7)";
+  EXPECT_EQ(expected_desr7, DescribeNegation(m));
+
+  m = AllOf(Ne(1), Ne(2), Ne(3), Ne(4), Ne(5), Ne(6), Ne(7), Ne(8), Ne(9),
+            Ne(10), Ne(11));
+  AllOf(1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11);
+  EXPECT_THAT(Describe(m), EndsWith("and (isn't equal to 11)"));
+  AllOfMatches(11, m);
+}
+
+// Tests that monomorphic matchers are safely cast by the AllOf matcher.
+TEST(AllOfTest, AllOfMatcherSafelyCastsMonomorphicMatchers) {
+  // greater_than_5 and less_than_10 are monomorphic matchers.
+  Matcher<int> greater_than_5 = Gt(5);
+  Matcher<int> less_than_10 = Lt(10);
+
+  Matcher<const int&> m = AllOf(greater_than_5, less_than_10);
+  Matcher<int&> m2 = AllOf(greater_than_5, less_than_10);
+  Matcher<int&> m3 = AllOf(greater_than_5, m2);
+
+  // Tests that BothOf works when composing itself.
+  Matcher<const int&> m4 = AllOf(greater_than_5, less_than_10, less_than_10);
+  Matcher<int&> m5 = AllOf(greater_than_5, less_than_10, less_than_10);
+}
+
+TEST_P(AllOfTestP, ExplainsResult) {
+  Matcher<int> m;
+
+  // Successful match.  Both matchers need to explain.  The second
+  // matcher doesn't give an explanation, so only the first matcher's
+  // explanation is printed.
+  m = AllOf(GreaterThan(10), Lt(30));
+  EXPECT_EQ("which is 15 more than 10", Explain(m, 25));
+
+  // Successful match.  Both matchers need to explain.
+  m = AllOf(GreaterThan(10), GreaterThan(20));
+  EXPECT_EQ("which is 20 more than 10, and which is 10 more than 20",
+            Explain(m, 30));
+
+  // Successful match.  All matchers need to explain.  The second
+  // matcher doesn't given an explanation.
+  m = AllOf(GreaterThan(10), Lt(30), GreaterThan(20));
+  EXPECT_EQ("which is 15 more than 10, and which is 5 more than 20",
+            Explain(m, 25));
+
+  // Successful match.  All matchers need to explain.
+  m = AllOf(GreaterThan(10), GreaterThan(20), GreaterThan(30));
+  EXPECT_EQ(
+      "which is 30 more than 10, and which is 20 more than 20, "
+      "and which is 10 more than 30",
+      Explain(m, 40));
+
+  // Failed match.  The first matcher, which failed, needs to
+  // explain.
+  m = AllOf(GreaterThan(10), GreaterThan(20));
+  EXPECT_EQ("which is 5 less than 10", Explain(m, 5));
+
+  // Failed match.  The second matcher, which failed, needs to
+  // explain.  Since it doesn't given an explanation, nothing is
+  // printed.
+  m = AllOf(GreaterThan(10), Lt(30));
+  EXPECT_EQ("", Explain(m, 40));
+
+  // Failed match.  The second matcher, which failed, needs to
+  // explain.
+  m = AllOf(GreaterThan(10), GreaterThan(20));
+  EXPECT_EQ("which is 5 less than 20", Explain(m, 15));
+}
+
+// Helper to allow easy testing of AnyOf matchers with num parameters.
+static void AnyOfMatches(int num, const Matcher<int>& m) {
+  SCOPED_TRACE(Describe(m));
+  EXPECT_FALSE(m.Matches(0));
+  for (int i = 1; i <= num; ++i) {
+    EXPECT_TRUE(m.Matches(i));
+  }
+  EXPECT_FALSE(m.Matches(num + 1));
+}
+
+static void AnyOfStringMatches(int num, const Matcher<std::string>& m) {
+  SCOPED_TRACE(Describe(m));
+  EXPECT_FALSE(m.Matches(std::to_string(0)));
+
+  for (int i = 1; i <= num; ++i) {
+    EXPECT_TRUE(m.Matches(std::to_string(i)));
+  }
+  EXPECT_FALSE(m.Matches(std::to_string(num + 1)));
+}
+
+INSTANTIATE_GTEST_MATCHER_TEST_P(AnyOfTest);
+
+// Tests that AnyOf(m1, ..., mn) matches any value that matches at
+// least one of the given matchers.
+TEST(AnyOfTest, MatchesWhenAnyMatches) {
+  Matcher<int> m;
+  m = AnyOf(Le(1), Ge(3));
+  EXPECT_TRUE(m.Matches(1));
+  EXPECT_TRUE(m.Matches(4));
+  EXPECT_FALSE(m.Matches(2));
+
+  m = AnyOf(Lt(0), Eq(1), Eq(2));
+  EXPECT_TRUE(m.Matches(-1));
+  EXPECT_TRUE(m.Matches(1));
+  EXPECT_TRUE(m.Matches(2));
+  EXPECT_FALSE(m.Matches(0));
+
+  m = AnyOf(Lt(0), Eq(1), Eq(2), Eq(3));
+  EXPECT_TRUE(m.Matches(-1));
+  EXPECT_TRUE(m.Matches(1));
+  EXPECT_TRUE(m.Matches(2));
+  EXPECT_TRUE(m.Matches(3));
+  EXPECT_FALSE(m.Matches(0));
+
+  m = AnyOf(Le(0), Gt(10), 3, 5, 7);
+  EXPECT_TRUE(m.Matches(0));
+  EXPECT_TRUE(m.Matches(11));
+  EXPECT_TRUE(m.Matches(3));
+  EXPECT_FALSE(m.Matches(2));
+
+  // The following tests for varying number of sub-matchers. Due to the way
+  // the sub-matchers are handled it is enough to test every sub-matcher once
+  // with sub-matchers using the same matcher type. Varying matcher types are
+  // checked for above.
+  AnyOfMatches(2, AnyOf(1, 2));
+  AnyOfMatches(3, AnyOf(1, 2, 3));
+  AnyOfMatches(4, AnyOf(1, 2, 3, 4));
+  AnyOfMatches(5, AnyOf(1, 2, 3, 4, 5));
+  AnyOfMatches(6, AnyOf(1, 2, 3, 4, 5, 6));
+  AnyOfMatches(7, AnyOf(1, 2, 3, 4, 5, 6, 7));
+  AnyOfMatches(8, AnyOf(1, 2, 3, 4, 5, 6, 7, 8));
+  AnyOfMatches(9, AnyOf(1, 2, 3, 4, 5, 6, 7, 8, 9));
+  AnyOfMatches(10, AnyOf(1, 2, 3, 4, 5, 6, 7, 8, 9, 10));
+}
+
+// Tests the variadic version of the AnyOfMatcher.
+TEST(AnyOfTest, VariadicMatchesWhenAnyMatches) {
+  // Also make sure AnyOf is defined in the right namespace and does not depend
+  // on ADL.
+  Matcher<int> m = ::testing::AnyOf(1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11);
+
+  EXPECT_THAT(Describe(m), EndsWith("or (is equal to 11)"));
+  AnyOfMatches(11, m);
+  AnyOfMatches(50, AnyOf(1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16,
+                         17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30,
+                         31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44,
+                         45, 46, 47, 48, 49, 50));
+  AnyOfStringMatches(
+      50, AnyOf("1", "2", "3", "4", "5", "6", "7", "8", "9", "10", "11", "12",
+                "13", "14", "15", "16", "17", "18", "19", "20", "21", "22",
+                "23", "24", "25", "26", "27", "28", "29", "30", "31", "32",
+                "33", "34", "35", "36", "37", "38", "39", "40", "41", "42",
+                "43", "44", "45", "46", "47", "48", "49", "50"));
+}
+
+TEST(ConditionalTest, MatchesFirstIfCondition) {
+  Matcher<std::string> eq_red = Eq("red");
+  Matcher<std::string> ne_red = Ne("red");
+  Matcher<std::string> m = Conditional(true, eq_red, ne_red);
+  EXPECT_TRUE(m.Matches("red"));
+  EXPECT_FALSE(m.Matches("green"));
+
+  StringMatchResultListener listener;
+  StringMatchResultListener expected;
+  EXPECT_FALSE(m.MatchAndExplain("green", &listener));
+  EXPECT_FALSE(eq_red.MatchAndExplain("green", &expected));
+  EXPECT_THAT(listener.str(), Eq(expected.str()));
+}
+
+TEST(ConditionalTest, MatchesSecondIfCondition) {
+  Matcher<std::string> eq_red = Eq("red");
+  Matcher<std::string> ne_red = Ne("red");
+  Matcher<std::string> m = Conditional(false, eq_red, ne_red);
+  EXPECT_FALSE(m.Matches("red"));
+  EXPECT_TRUE(m.Matches("green"));
+
+  StringMatchResultListener listener;
+  StringMatchResultListener expected;
+  EXPECT_FALSE(m.MatchAndExplain("red", &listener));
+  EXPECT_FALSE(ne_red.MatchAndExplain("red", &expected));
+  EXPECT_THAT(listener.str(), Eq(expected.str()));
+}
+
+// Tests that AnyOf(m1, ..., mn) describes itself properly.
+TEST(AnyOfTest, CanDescribeSelf) {
+  Matcher<int> m;
+  m = AnyOf(Le(1), Ge(3));
+
+  EXPECT_EQ("(is <= 1) or (is >= 3)", Describe(m));
+
+  m = AnyOf(Lt(0), Eq(1), Eq(2));
+  EXPECT_EQ("(is < 0) or (is equal to 1) or (is equal to 2)", Describe(m));
+
+  m = AnyOf(Lt(0), Eq(1), Eq(2), Eq(3));
+  EXPECT_EQ("(is < 0) or (is equal to 1) or (is equal to 2) or (is equal to 3)",
+            Describe(m));
+
+  m = AnyOf(Le(0), Gt(10), 3, 5, 7);
+  EXPECT_EQ(
+      "(is <= 0) or (is > 10) or (is equal to 3) or (is equal to 5) or (is "
+      "equal to 7)",
+      Describe(m));
+}
+
+// Tests that AnyOf(m1, ..., mn) describes its negation properly.
+TEST(AnyOfTest, CanDescribeNegation) {
+  Matcher<int> m;
+  m = AnyOf(Le(1), Ge(3));
+  EXPECT_EQ("(isn't <= 1) and (isn't >= 3)", DescribeNegation(m));
+
+  m = AnyOf(Lt(0), Eq(1), Eq(2));
+  EXPECT_EQ("(isn't < 0) and (isn't equal to 1) and (isn't equal to 2)",
+            DescribeNegation(m));
+
+  m = AnyOf(Lt(0), Eq(1), Eq(2), Eq(3));
+  EXPECT_EQ(
+      "(isn't < 0) and (isn't equal to 1) and (isn't equal to 2) and (isn't "
+      "equal to 3)",
+      DescribeNegation(m));
+
+  m = AnyOf(Le(0), Gt(10), 3, 5, 7);
+  EXPECT_EQ(
+      "(isn't <= 0) and (isn't > 10) and (isn't equal to 3) and (isn't equal "
+      "to 5) and (isn't equal to 7)",
+      DescribeNegation(m));
+}
+
+// Tests that monomorphic matchers are safely cast by the AnyOf matcher.
+TEST(AnyOfTest, AnyOfMatcherSafelyCastsMonomorphicMatchers) {
+  // greater_than_5 and less_than_10 are monomorphic matchers.
+  Matcher<int> greater_than_5 = Gt(5);
+  Matcher<int> less_than_10 = Lt(10);
+
+  Matcher<const int&> m = AnyOf(greater_than_5, less_than_10);
+  Matcher<int&> m2 = AnyOf(greater_than_5, less_than_10);
+  Matcher<int&> m3 = AnyOf(greater_than_5, m2);
+
+  // Tests that EitherOf works when composing itself.
+  Matcher<const int&> m4 = AnyOf(greater_than_5, less_than_10, less_than_10);
+  Matcher<int&> m5 = AnyOf(greater_than_5, less_than_10, less_than_10);
+}
+
+TEST_P(AnyOfTestP, ExplainsResult) {
+  Matcher<int> m;
+
+  // Failed match.  Both matchers need to explain.  The second
+  // matcher doesn't give an explanation, so only the first matcher's
+  // explanation is printed.
+  m = AnyOf(GreaterThan(10), Lt(0));
+  EXPECT_EQ("which is 5 less than 10", Explain(m, 5));
+
+  // Failed match.  Both matchers need to explain.
+  m = AnyOf(GreaterThan(10), GreaterThan(20));
+  EXPECT_EQ("which is 5 less than 10, and which is 15 less than 20",
+            Explain(m, 5));
+
+  // Failed match.  All matchers need to explain.  The second
+  // matcher doesn't given an explanation.
+  m = AnyOf(GreaterThan(10), Gt(20), GreaterThan(30));
+  EXPECT_EQ("which is 5 less than 10, and which is 25 less than 30",
+            Explain(m, 5));
+
+  // Failed match.  All matchers need to explain.
+  m = AnyOf(GreaterThan(10), GreaterThan(20), GreaterThan(30));
+  EXPECT_EQ(
+      "which is 5 less than 10, and which is 15 less than 20, "
+      "and which is 25 less than 30",
+      Explain(m, 5));
+
+  // Successful match.  The first matcher, which succeeded, needs to
+  // explain.
+  m = AnyOf(GreaterThan(10), GreaterThan(20));
+  EXPECT_EQ("which is 5 more than 10", Explain(m, 15));
+
+  // Successful match.  The second matcher, which succeeded, needs to
+  // explain.  Since it doesn't given an explanation, nothing is
+  // printed.
+  m = AnyOf(GreaterThan(10), Lt(30));
+  EXPECT_EQ("", Explain(m, 0));
+
+  // Successful match.  The second matcher, which succeeded, needs to
+  // explain.
+  m = AnyOf(GreaterThan(30), GreaterThan(20));
+  EXPECT_EQ("which is 5 more than 20", Explain(m, 25));
+}
+
+// The following predicate function and predicate functor are for
+// testing the Truly(predicate) matcher.
+
+// Returns non-zero if the input is positive.  Note that the return
+// type of this function is not bool.  It's OK as Truly() accepts any
+// unary function or functor whose return type can be implicitly
+// converted to bool.
+int IsPositive(double x) { return x > 0 ? 1 : 0; }
+
+// This functor returns true if the input is greater than the given
+// number.
+class IsGreaterThan {
+ public:
+  explicit IsGreaterThan(int threshold) : threshold_(threshold) {}
+
+  bool operator()(int n) const { return n > threshold_; }
+
+ private:
+  int threshold_;
+};
+
+// For testing Truly().
+const int foo = 0;
+
+// This predicate returns true if and only if the argument references foo and
+// has a zero value.
+bool ReferencesFooAndIsZero(const int& n) { return (&n == &foo) && (n == 0); }
+
+// Tests that Truly(predicate) matches what satisfies the given
+// predicate.
+TEST(TrulyTest, MatchesWhatSatisfiesThePredicate) {
+  Matcher<double> m = Truly(IsPositive);
+  EXPECT_TRUE(m.Matches(2.0));
+  EXPECT_FALSE(m.Matches(-1.5));
+}
+
+// Tests that Truly(predicate_functor) works too.
+TEST(TrulyTest, CanBeUsedWithFunctor) {
+  Matcher<int> m = Truly(IsGreaterThan(5));
+  EXPECT_TRUE(m.Matches(6));
+  EXPECT_FALSE(m.Matches(4));
+}
+
+// A class that can be implicitly converted to bool.
+class ConvertibleToBool {
+ public:
+  explicit ConvertibleToBool(int number) : number_(number) {}
+  operator bool() const { return number_ != 0; }
+
+ private:
+  int number_;
+};
+
+ConvertibleToBool IsNotZero(int number) { return ConvertibleToBool(number); }
+
+// Tests that the predicate used in Truly() may return a class that's
+// implicitly convertible to bool, even when the class has no
+// operator!().
+TEST(TrulyTest, PredicateCanReturnAClassConvertibleToBool) {
+  Matcher<int> m = Truly(IsNotZero);
+  EXPECT_TRUE(m.Matches(1));
+  EXPECT_FALSE(m.Matches(0));
+}
+
+// Tests that Truly(predicate) can describe itself properly.
+TEST(TrulyTest, CanDescribeSelf) {
+  Matcher<double> m = Truly(IsPositive);
+  EXPECT_EQ("satisfies the given predicate", Describe(m));
+}
+
+// Tests that Truly(predicate) works when the matcher takes its
+// argument by reference.
+TEST(TrulyTest, WorksForByRefArguments) {
+  Matcher<const int&> m = Truly(ReferencesFooAndIsZero);
+  EXPECT_TRUE(m.Matches(foo));
+  int n = 0;
+  EXPECT_FALSE(m.Matches(n));
+}
+
+// Tests that Truly(predicate) provides a helpful reason when it fails.
+TEST(TrulyTest, ExplainsFailures) {
+  StringMatchResultListener listener;
+  EXPECT_FALSE(ExplainMatchResult(Truly(IsPositive), -1, &listener));
+  EXPECT_EQ(listener.str(), "didn't satisfy the given predicate");
+}
+
+// Tests that Matches(m) is a predicate satisfied by whatever that
+// matches matcher m.
+TEST(MatchesTest, IsSatisfiedByWhatMatchesTheMatcher) {
+  EXPECT_TRUE(Matches(Ge(0))(1));
+  EXPECT_FALSE(Matches(Eq('a'))('b'));
+}
+
+// Tests that Matches(m) works when the matcher takes its argument by
+// reference.
+TEST(MatchesTest, WorksOnByRefArguments) {
+  int m = 0, n = 0;
+  EXPECT_TRUE(Matches(AllOf(Ref(n), Eq(0)))(n));
+  EXPECT_FALSE(Matches(Ref(m))(n));
+}
+
+// Tests that a Matcher on non-reference type can be used in
+// Matches().
+TEST(MatchesTest, WorksWithMatcherOnNonRefType) {
+  Matcher<int> eq5 = Eq(5);
+  EXPECT_TRUE(Matches(eq5)(5));
+  EXPECT_FALSE(Matches(eq5)(2));
+}
+
+// Tests Value(value, matcher).  Since Value() is a simple wrapper for
+// Matches(), which has been tested already, we don't spend a lot of
+// effort on testing Value().
+TEST(ValueTest, WorksWithPolymorphicMatcher) {
+  EXPECT_TRUE(Value("hi", StartsWith("h")));
+  EXPECT_FALSE(Value(5, Gt(10)));
+}
+
+TEST(ValueTest, WorksWithMonomorphicMatcher) {
+  const Matcher<int> is_zero = Eq(0);
+  EXPECT_TRUE(Value(0, is_zero));
+  EXPECT_FALSE(Value('a', is_zero));
+
+  int n = 0;
+  const Matcher<const int&> ref_n = Ref(n);
+  EXPECT_TRUE(Value(n, ref_n));
+  EXPECT_FALSE(Value(1, ref_n));
+}
+
+TEST(AllArgsTest, WorksForTuple) {
+  EXPECT_THAT(std::make_tuple(1, 2L), AllArgs(Lt()));
+  EXPECT_THAT(std::make_tuple(2L, 1), Not(AllArgs(Lt())));
+}
+
+TEST(AllArgsTest, WorksForNonTuple) {
+  EXPECT_THAT(42, AllArgs(Gt(0)));
+  EXPECT_THAT('a', Not(AllArgs(Eq('b'))));
+}
+
+class AllArgsHelper {
+ public:
+  AllArgsHelper() = default;
+
+  MOCK_METHOD2(Helper, int(char x, int y));
+
+ private:
+  AllArgsHelper(const AllArgsHelper&) = delete;
+  AllArgsHelper& operator=(const AllArgsHelper&) = delete;
+};
+
+TEST(AllArgsTest, WorksInWithClause) {
+  AllArgsHelper helper;
+  ON_CALL(helper, Helper(_, _)).With(AllArgs(Lt())).WillByDefault(Return(1));
+  EXPECT_CALL(helper, Helper(_, _));
+  EXPECT_CALL(helper, Helper(_, _)).With(AllArgs(Gt())).WillOnce(Return(2));
+
+  EXPECT_EQ(1, helper.Helper('\1', 2));
+  EXPECT_EQ(2, helper.Helper('a', 1));
+}
+
+class OptionalMatchersHelper {
+ public:
+  OptionalMatchersHelper() = default;
+
+  MOCK_METHOD0(NoArgs, int());
+
+  MOCK_METHOD1(OneArg, int(int y));
+
+  MOCK_METHOD2(TwoArgs, int(char x, int y));
+
+  MOCK_METHOD1(Overloaded, int(char x));
+  MOCK_METHOD2(Overloaded, int(char x, int y));
+
+ private:
+  OptionalMatchersHelper(const OptionalMatchersHelper&) = delete;
+  OptionalMatchersHelper& operator=(const OptionalMatchersHelper&) = delete;
+};
+
+TEST(AllArgsTest, WorksWithoutMatchers) {
+  OptionalMatchersHelper helper;
+
+  ON_CALL(helper, NoArgs).WillByDefault(Return(10));
+  ON_CALL(helper, OneArg).WillByDefault(Return(20));
+  ON_CALL(helper, TwoArgs).WillByDefault(Return(30));
+
+  EXPECT_EQ(10, helper.NoArgs());
+  EXPECT_EQ(20, helper.OneArg(1));
+  EXPECT_EQ(30, helper.TwoArgs('\1', 2));
+
+  EXPECT_CALL(helper, NoArgs).Times(1);
+  EXPECT_CALL(helper, OneArg).WillOnce(Return(100));
+  EXPECT_CALL(helper, OneArg(17)).WillOnce(Return(200));
+  EXPECT_CALL(helper, TwoArgs).Times(0);
+
+  EXPECT_EQ(10, helper.NoArgs());
+  EXPECT_EQ(100, helper.OneArg(1));
+  EXPECT_EQ(200, helper.OneArg(17));
+}
+
+// Tests floating-point matchers.
+template <typename RawType>
+class FloatingPointTest : public testing::Test {
+ protected:
+  typedef testing::internal::FloatingPoint<RawType> Floating;
+  typedef typename Floating::Bits Bits;
+
+  FloatingPointTest()
+      : max_ulps_(Floating::kMaxUlps),
+        zero_bits_(Floating(0).bits()),
+        one_bits_(Floating(1).bits()),
+        infinity_bits_(Floating(Floating::Infinity()).bits()),
+        close_to_positive_zero_(
+            Floating::ReinterpretBits(zero_bits_ + max_ulps_ / 2)),
+        close_to_negative_zero_(
+            -Floating::ReinterpretBits(zero_bits_ + max_ulps_ - max_ulps_ / 2)),
+        further_from_negative_zero_(-Floating::ReinterpretBits(
+            zero_bits_ + max_ulps_ + 1 - max_ulps_ / 2)),
+        close_to_one_(Floating::ReinterpretBits(one_bits_ + max_ulps_)),
+        further_from_one_(Floating::ReinterpretBits(one_bits_ + max_ulps_ + 1)),
+        infinity_(Floating::Infinity()),
+        close_to_infinity_(
+            Floating::ReinterpretBits(infinity_bits_ - max_ulps_)),
+        further_from_infinity_(
+            Floating::ReinterpretBits(infinity_bits_ - max_ulps_ - 1)),
+        max_(std::numeric_limits<RawType>::max()),
+        nan1_(Floating::ReinterpretBits(Floating::kExponentBitMask | 1)),
+        nan2_(Floating::ReinterpretBits(Floating::kExponentBitMask | 200)) {}
+
+  void TestSize() { EXPECT_EQ(sizeof(RawType), sizeof(Bits)); }
+
+  // A battery of tests for FloatingEqMatcher::Matches.
+  // matcher_maker is a pointer to a function which creates a FloatingEqMatcher.
+  void TestMatches(
+      testing::internal::FloatingEqMatcher<RawType> (*matcher_maker)(RawType)) {
+    Matcher<RawType> m1 = matcher_maker(0.0);
+    EXPECT_TRUE(m1.Matches(-0.0));
+    EXPECT_TRUE(m1.Matches(close_to_positive_zero_));
+    EXPECT_TRUE(m1.Matches(close_to_negative_zero_));
+    EXPECT_FALSE(m1.Matches(1.0));
+
+    Matcher<RawType> m2 = matcher_maker(close_to_positive_zero_);
+    EXPECT_FALSE(m2.Matches(further_from_negative_zero_));
+
+    Matcher<RawType> m3 = matcher_maker(1.0);
+    EXPECT_TRUE(m3.Matches(close_to_one_));
+    EXPECT_FALSE(m3.Matches(further_from_one_));
+
+    // Test commutativity: matcher_maker(0.0).Matches(1.0) was tested above.
+    EXPECT_FALSE(m3.Matches(0.0));
+
+    Matcher<RawType> m4 = matcher_maker(-infinity_);
+    EXPECT_TRUE(m4.Matches(-close_to_infinity_));
+
+    Matcher<RawType> m5 = matcher_maker(infinity_);
+    EXPECT_TRUE(m5.Matches(close_to_infinity_));
+
+    // This is interesting as the representations of infinity_ and nan1_
+    // are only 1 DLP apart.
+    EXPECT_FALSE(m5.Matches(nan1_));
+
+    // matcher_maker can produce a Matcher<const RawType&>, which is needed in
+    // some cases.
+    Matcher<const RawType&> m6 = matcher_maker(0.0);
+    EXPECT_TRUE(m6.Matches(-0.0));
+    EXPECT_TRUE(m6.Matches(close_to_positive_zero_));
+    EXPECT_FALSE(m6.Matches(1.0));
+
+    // matcher_maker can produce a Matcher<RawType&>, which is needed in some
+    // cases.
+    Matcher<RawType&> m7 = matcher_maker(0.0);
+    RawType x = 0.0;
+    EXPECT_TRUE(m7.Matches(x));
+    x = 0.01f;
+    EXPECT_FALSE(m7.Matches(x));
+  }
+
+  // Pre-calculated numbers to be used by the tests.
+
+  const Bits max_ulps_;
+
+  const Bits zero_bits_;      // The bits that represent 0.0.
+  const Bits one_bits_;       // The bits that represent 1.0.
+  const Bits infinity_bits_;  // The bits that represent +infinity.
+
+  // Some numbers close to 0.0.
+  const RawType close_to_positive_zero_;
+  const RawType close_to_negative_zero_;
+  const RawType further_from_negative_zero_;
+
+  // Some numbers close to 1.0.
+  const RawType close_to_one_;
+  const RawType further_from_one_;
+
+  // Some numbers close to +infinity.
+  const RawType infinity_;
+  const RawType close_to_infinity_;
+  const RawType further_from_infinity_;
+
+  // Maximum representable value that's not infinity.
+  const RawType max_;
+
+  // Some NaNs.
+  const RawType nan1_;
+  const RawType nan2_;
+};
+
+// Tests floating-point matchers with fixed epsilons.
+template <typename RawType>
+class FloatingPointNearTest : public FloatingPointTest<RawType> {
+ protected:
+  typedef FloatingPointTest<RawType> ParentType;
+
+  // A battery of tests for FloatingEqMatcher::Matches with a fixed epsilon.
+  // matcher_maker is a pointer to a function which creates a FloatingEqMatcher.
+  void TestNearMatches(testing::internal::FloatingEqMatcher<RawType> (
+      *matcher_maker)(RawType, RawType)) {
+    Matcher<RawType> m1 = matcher_maker(0.0, 0.0);
+    EXPECT_TRUE(m1.Matches(0.0));
+    EXPECT_TRUE(m1.Matches(-0.0));
+    EXPECT_FALSE(m1.Matches(ParentType::close_to_positive_zero_));
+    EXPECT_FALSE(m1.Matches(ParentType::close_to_negative_zero_));
+    EXPECT_FALSE(m1.Matches(1.0));
+
+    Matcher<RawType> m2 = matcher_maker(0.0, 1.0);
+    EXPECT_TRUE(m2.Matches(0.0));
+    EXPECT_TRUE(m2.Matches(-0.0));
+    EXPECT_TRUE(m2.Matches(1.0));
+    EXPECT_TRUE(m2.Matches(-1.0));
+    EXPECT_FALSE(m2.Matches(ParentType::close_to_one_));
+    EXPECT_FALSE(m2.Matches(-ParentType::close_to_one_));
+
+    // Check that inf matches inf, regardless of the of the specified max
+    // absolute error.
+    Matcher<RawType> m3 = matcher_maker(ParentType::infinity_, 0.0);
+    EXPECT_TRUE(m3.Matches(ParentType::infinity_));
+    EXPECT_FALSE(m3.Matches(ParentType::close_to_infinity_));
+    EXPECT_FALSE(m3.Matches(-ParentType::infinity_));
+
+    Matcher<RawType> m4 = matcher_maker(-ParentType::infinity_, 0.0);
+    EXPECT_TRUE(m4.Matches(-ParentType::infinity_));
+    EXPECT_FALSE(m4.Matches(-ParentType::close_to_infinity_));
+    EXPECT_FALSE(m4.Matches(ParentType::infinity_));
+
+    // Test various overflow scenarios.
+    Matcher<RawType> m5 = matcher_maker(ParentType::max_, ParentType::max_);
+    EXPECT_TRUE(m5.Matches(ParentType::max_));
+    EXPECT_FALSE(m5.Matches(-ParentType::max_));
+
+    Matcher<RawType> m6 = matcher_maker(-ParentType::max_, ParentType::max_);
+    EXPECT_FALSE(m6.Matches(ParentType::max_));
+    EXPECT_TRUE(m6.Matches(-ParentType::max_));
+
+    Matcher<RawType> m7 = matcher_maker(ParentType::max_, 0);
+    EXPECT_TRUE(m7.Matches(ParentType::max_));
+    EXPECT_FALSE(m7.Matches(-ParentType::max_));
+
+    Matcher<RawType> m8 = matcher_maker(-ParentType::max_, 0);
+    EXPECT_FALSE(m8.Matches(ParentType::max_));
+    EXPECT_TRUE(m8.Matches(-ParentType::max_));
+
+    // The difference between max() and -max() normally overflows to infinity,
+    // but it should still match if the max_abs_error is also infinity.
+    Matcher<RawType> m9 =
+        matcher_maker(ParentType::max_, ParentType::infinity_);
+    EXPECT_TRUE(m8.Matches(-ParentType::max_));
+
+    // matcher_maker can produce a Matcher<const RawType&>, which is needed in
+    // some cases.
+    Matcher<const RawType&> m10 = matcher_maker(0.0, 1.0);
+    EXPECT_TRUE(m10.Matches(-0.0));
+    EXPECT_TRUE(m10.Matches(ParentType::close_to_positive_zero_));
+    EXPECT_FALSE(m10.Matches(ParentType::close_to_one_));
+
+    // matcher_maker can produce a Matcher<RawType&>, which is needed in some
+    // cases.
+    Matcher<RawType&> m11 = matcher_maker(0.0, 1.0);
+    RawType x = 0.0;
+    EXPECT_TRUE(m11.Matches(x));
+    x = 1.0f;
+    EXPECT_TRUE(m11.Matches(x));
+    x = -1.0f;
+    EXPECT_TRUE(m11.Matches(x));
+    x = 1.1f;
+    EXPECT_FALSE(m11.Matches(x));
+    x = -1.1f;
+    EXPECT_FALSE(m11.Matches(x));
+  }
+};
+
+// Instantiate FloatingPointTest for testing floats.
+typedef FloatingPointTest<float> FloatTest;
+
+TEST_F(FloatTest, FloatEqApproximatelyMatchesFloats) { TestMatches(&FloatEq); }
+
+TEST_F(FloatTest, NanSensitiveFloatEqApproximatelyMatchesFloats) {
+  TestMatches(&NanSensitiveFloatEq);
+}
+
+TEST_F(FloatTest, FloatEqCannotMatchNaN) {
+  // FloatEq never matches NaN.
+  Matcher<float> m = FloatEq(nan1_);
+  EXPECT_FALSE(m.Matches(nan1_));
+  EXPECT_FALSE(m.Matches(nan2_));
+  EXPECT_FALSE(m.Matches(1.0));
+}
+
+TEST_F(FloatTest, NanSensitiveFloatEqCanMatchNaN) {
+  // NanSensitiveFloatEq will match NaN.
+  Matcher<float> m = NanSensitiveFloatEq(nan1_);
+  EXPECT_TRUE(m.Matches(nan1_));
+  EXPECT_TRUE(m.Matches(nan2_));
+  EXPECT_FALSE(m.Matches(1.0));
+}
+
+TEST_F(FloatTest, FloatEqCanDescribeSelf) {
+  Matcher<float> m1 = FloatEq(2.0f);
+  EXPECT_EQ("is approximately 2", Describe(m1));
+  EXPECT_EQ("isn't approximately 2", DescribeNegation(m1));
+
+  Matcher<float> m2 = FloatEq(0.5f);
+  EXPECT_EQ("is approximately 0.5", Describe(m2));
+  EXPECT_EQ("isn't approximately 0.5", DescribeNegation(m2));
+
+  Matcher<float> m3 = FloatEq(nan1_);
+  EXPECT_EQ("never matches", Describe(m3));
+  EXPECT_EQ("is anything", DescribeNegation(m3));
+}
+
+TEST_F(FloatTest, NanSensitiveFloatEqCanDescribeSelf) {
+  Matcher<float> m1 = NanSensitiveFloatEq(2.0f);
+  EXPECT_EQ("is approximately 2", Describe(m1));
+  EXPECT_EQ("isn't approximately 2", DescribeNegation(m1));
+
+  Matcher<float> m2 = NanSensitiveFloatEq(0.5f);
+  EXPECT_EQ("is approximately 0.5", Describe(m2));
+  EXPECT_EQ("isn't approximately 0.5", DescribeNegation(m2));
+
+  Matcher<float> m3 = NanSensitiveFloatEq(nan1_);
+  EXPECT_EQ("is NaN", Describe(m3));
+  EXPECT_EQ("isn't NaN", DescribeNegation(m3));
+}
+
+// Instantiate FloatingPointTest for testing floats with a user-specified
+// max absolute error.
+typedef FloatingPointNearTest<float> FloatNearTest;
+
+TEST_F(FloatNearTest, FloatNearMatches) { TestNearMatches(&FloatNear); }
+
+TEST_F(FloatNearTest, NanSensitiveFloatNearApproximatelyMatchesFloats) {
+  TestNearMatches(&NanSensitiveFloatNear);
+}
+
+TEST_F(FloatNearTest, FloatNearCanDescribeSelf) {
+  Matcher<float> m1 = FloatNear(2.0f, 0.5f);
+  EXPECT_EQ("is approximately 2 (absolute error <= 0.5)", Describe(m1));
+  EXPECT_EQ("isn't approximately 2 (absolute error > 0.5)",
+            DescribeNegation(m1));
+
+  Matcher<float> m2 = FloatNear(0.5f, 0.5f);
+  EXPECT_EQ("is approximately 0.5 (absolute error <= 0.5)", Describe(m2));
+  EXPECT_EQ("isn't approximately 0.5 (absolute error > 0.5)",
+            DescribeNegation(m2));
+
+  Matcher<float> m3 = FloatNear(nan1_, 0.0);
+  EXPECT_EQ("never matches", Describe(m3));
+  EXPECT_EQ("is anything", DescribeNegation(m3));
+}
+
+TEST_F(FloatNearTest, NanSensitiveFloatNearCanDescribeSelf) {
+  Matcher<float> m1 = NanSensitiveFloatNear(2.0f, 0.5f);
+  EXPECT_EQ("is approximately 2 (absolute error <= 0.5)", Describe(m1));
+  EXPECT_EQ("isn't approximately 2 (absolute error > 0.5)",
+            DescribeNegation(m1));
+
+  Matcher<float> m2 = NanSensitiveFloatNear(0.5f, 0.5f);
+  EXPECT_EQ("is approximately 0.5 (absolute error <= 0.5)", Describe(m2));
+  EXPECT_EQ("isn't approximately 0.5 (absolute error > 0.5)",
+            DescribeNegation(m2));
+
+  Matcher<float> m3 = NanSensitiveFloatNear(nan1_, 0.1f);
+  EXPECT_EQ("is NaN", Describe(m3));
+  EXPECT_EQ("isn't NaN", DescribeNegation(m3));
+}
+
+TEST_F(FloatNearTest, FloatNearCannotMatchNaN) {
+  // FloatNear never matches NaN.
+  Matcher<float> m = FloatNear(ParentType::nan1_, 0.1f);
+  EXPECT_FALSE(m.Matches(nan1_));
+  EXPECT_FALSE(m.Matches(nan2_));
+  EXPECT_FALSE(m.Matches(1.0));
+}
+
+TEST_F(FloatNearTest, NanSensitiveFloatNearCanMatchNaN) {
+  // NanSensitiveFloatNear will match NaN.
+  Matcher<float> m = NanSensitiveFloatNear(nan1_, 0.1f);
+  EXPECT_TRUE(m.Matches(nan1_));
+  EXPECT_TRUE(m.Matches(nan2_));
+  EXPECT_FALSE(m.Matches(1.0));
+}
+
+// Instantiate FloatingPointTest for testing doubles.
+typedef FloatingPointTest<double> DoubleTest;
+
+TEST_F(DoubleTest, DoubleEqApproximatelyMatchesDoubles) {
+  TestMatches(&DoubleEq);
+}
+
+TEST_F(DoubleTest, NanSensitiveDoubleEqApproximatelyMatchesDoubles) {
+  TestMatches(&NanSensitiveDoubleEq);
+}
+
+TEST_F(DoubleTest, DoubleEqCannotMatchNaN) {
+  // DoubleEq never matches NaN.
+  Matcher<double> m = DoubleEq(nan1_);
+  EXPECT_FALSE(m.Matches(nan1_));
+  EXPECT_FALSE(m.Matches(nan2_));
+  EXPECT_FALSE(m.Matches(1.0));
+}
+
+TEST_F(DoubleTest, NanSensitiveDoubleEqCanMatchNaN) {
+  // NanSensitiveDoubleEq will match NaN.
+  Matcher<double> m = NanSensitiveDoubleEq(nan1_);
+  EXPECT_TRUE(m.Matches(nan1_));
+  EXPECT_TRUE(m.Matches(nan2_));
+  EXPECT_FALSE(m.Matches(1.0));
+}
+
+TEST_F(DoubleTest, DoubleEqCanDescribeSelf) {
+  Matcher<double> m1 = DoubleEq(2.0);
+  EXPECT_EQ("is approximately 2", Describe(m1));
+  EXPECT_EQ("isn't approximately 2", DescribeNegation(m1));
+
+  Matcher<double> m2 = DoubleEq(0.5);
+  EXPECT_EQ("is approximately 0.5", Describe(m2));
+  EXPECT_EQ("isn't approximately 0.5", DescribeNegation(m2));
+
+  Matcher<double> m3 = DoubleEq(nan1_);
+  EXPECT_EQ("never matches", Describe(m3));
+  EXPECT_EQ("is anything", DescribeNegation(m3));
+}
+
+TEST_F(DoubleTest, NanSensitiveDoubleEqCanDescribeSelf) {
+  Matcher<double> m1 = NanSensitiveDoubleEq(2.0);
+  EXPECT_EQ("is approximately 2", Describe(m1));
+  EXPECT_EQ("isn't approximately 2", DescribeNegation(m1));
+
+  Matcher<double> m2 = NanSensitiveDoubleEq(0.5);
+  EXPECT_EQ("is approximately 0.5", Describe(m2));
+  EXPECT_EQ("isn't approximately 0.5", DescribeNegation(m2));
+
+  Matcher<double> m3 = NanSensitiveDoubleEq(nan1_);
+  EXPECT_EQ("is NaN", Describe(m3));
+  EXPECT_EQ("isn't NaN", DescribeNegation(m3));
+}
+
+// Instantiate FloatingPointTest for testing floats with a user-specified
+// max absolute error.
+typedef FloatingPointNearTest<double> DoubleNearTest;
+
+TEST_F(DoubleNearTest, DoubleNearMatches) { TestNearMatches(&DoubleNear); }
+
+TEST_F(DoubleNearTest, NanSensitiveDoubleNearApproximatelyMatchesDoubles) {
+  TestNearMatches(&NanSensitiveDoubleNear);
+}
+
+TEST_F(DoubleNearTest, DoubleNearCanDescribeSelf) {
+  Matcher<double> m1 = DoubleNear(2.0, 0.5);
+  EXPECT_EQ("is approximately 2 (absolute error <= 0.5)", Describe(m1));
+  EXPECT_EQ("isn't approximately 2 (absolute error > 0.5)",
+            DescribeNegation(m1));
+
+  Matcher<double> m2 = DoubleNear(0.5, 0.5);
+  EXPECT_EQ("is approximately 0.5 (absolute error <= 0.5)", Describe(m2));
+  EXPECT_EQ("isn't approximately 0.5 (absolute error > 0.5)",
+            DescribeNegation(m2));
+
+  Matcher<double> m3 = DoubleNear(nan1_, 0.0);
+  EXPECT_EQ("never matches", Describe(m3));
+  EXPECT_EQ("is anything", DescribeNegation(m3));
+}
+
+TEST_F(DoubleNearTest, ExplainsResultWhenMatchFails) {
+  EXPECT_EQ("", Explain(DoubleNear(2.0, 0.1), 2.05));
+  EXPECT_EQ("which is 0.2 from 2", Explain(DoubleNear(2.0, 0.1), 2.2));
+  EXPECT_EQ("which is -0.3 from 2", Explain(DoubleNear(2.0, 0.1), 1.7));
+
+  const std::string explanation =
+      Explain(DoubleNear(2.1, 1e-10), 2.1 + 1.2e-10);
+  // Different C++ implementations may print floating-point numbers
+  // slightly differently.
+  EXPECT_TRUE(explanation == "which is 1.2e-10 from 2.1" ||  // GCC
+              explanation == "which is 1.2e-010 from 2.1")   // MSVC
+      << " where explanation is \"" << explanation << "\".";
+}
+
+TEST_F(DoubleNearTest, NanSensitiveDoubleNearCanDescribeSelf) {
+  Matcher<double> m1 = NanSensitiveDoubleNear(2.0, 0.5);
+  EXPECT_EQ("is approximately 2 (absolute error <= 0.5)", Describe(m1));
+  EXPECT_EQ("isn't approximately 2 (absolute error > 0.5)",
+            DescribeNegation(m1));
+
+  Matcher<double> m2 = NanSensitiveDoubleNear(0.5, 0.5);
+  EXPECT_EQ("is approximately 0.5 (absolute error <= 0.5)", Describe(m2));
+  EXPECT_EQ("isn't approximately 0.5 (absolute error > 0.5)",
+            DescribeNegation(m2));
+
+  Matcher<double> m3 = NanSensitiveDoubleNear(nan1_, 0.1);
+  EXPECT_EQ("is NaN", Describe(m3));
+  EXPECT_EQ("isn't NaN", DescribeNegation(m3));
+}
+
+TEST_F(DoubleNearTest, DoubleNearCannotMatchNaN) {
+  // DoubleNear never matches NaN.
+  Matcher<double> m = DoubleNear(ParentType::nan1_, 0.1);
+  EXPECT_FALSE(m.Matches(nan1_));
+  EXPECT_FALSE(m.Matches(nan2_));
+  EXPECT_FALSE(m.Matches(1.0));
+}
+
+TEST_F(DoubleNearTest, NanSensitiveDoubleNearCanMatchNaN) {
+  // NanSensitiveDoubleNear will match NaN.
+  Matcher<double> m = NanSensitiveDoubleNear(nan1_, 0.1);
+  EXPECT_TRUE(m.Matches(nan1_));
+  EXPECT_TRUE(m.Matches(nan2_));
+  EXPECT_FALSE(m.Matches(1.0));
+}
+
+TEST(NotTest, WorksOnMoveOnlyType) {
+  std::unique_ptr<int> p(new int(3));
+  EXPECT_THAT(p, Pointee(Eq(3)));
+  EXPECT_THAT(p, Not(Pointee(Eq(2))));
+}
+
+TEST(AllOfTest, HugeMatcher) {
+  // Verify that using AllOf with many arguments doesn't cause
+  // the compiler to exceed template instantiation depth limit.
+  EXPECT_THAT(0, testing::AllOf(_, _, _, _, _, _, _, _, _,
+                                testing::AllOf(_, _, _, _, _, _, _, _, _, _)));
+}
+
+TEST(AnyOfTest, HugeMatcher) {
+  // Verify that using AnyOf with many arguments doesn't cause
+  // the compiler to exceed template instantiation depth limit.
+  EXPECT_THAT(0, testing::AnyOf(_, _, _, _, _, _, _, _, _,
+                                testing::AnyOf(_, _, _, _, _, _, _, _, _, _)));
+}
+
+namespace adl_test {
+
+// Verifies that the implementation of ::testing::AllOf and ::testing::AnyOf
+// don't issue unqualified recursive calls.  If they do, the argument dependent
+// name lookup will cause AllOf/AnyOf in the 'adl_test' namespace to be found
+// as a candidate and the compilation will break due to an ambiguous overload.
+
+// The matcher must be in the same namespace as AllOf/AnyOf to make argument
+// dependent lookup find those.
+MATCHER(M, "") {
+  (void)arg;
+  return true;
+}
+
+template <typename T1, typename T2>
+bool AllOf(const T1& /*t1*/, const T2& /*t2*/) {
+  return true;
+}
+
+TEST(AllOfTest, DoesNotCallAllOfUnqualified) {
+  EXPECT_THAT(42,
+              testing::AllOf(M(), M(), M(), M(), M(), M(), M(), M(), M(), M()));
+}
+
+template <typename T1, typename T2>
+bool AnyOf(const T1&, const T2&) {
+  return true;
+}
+
+TEST(AnyOfTest, DoesNotCallAnyOfUnqualified) {
+  EXPECT_THAT(42,
+              testing::AnyOf(M(), M(), M(), M(), M(), M(), M(), M(), M(), M()));
+}
+
+}  // namespace adl_test
+
+TEST(AllOfTest, WorksOnMoveOnlyType) {
+  std::unique_ptr<int> p(new int(3));
+  EXPECT_THAT(p, AllOf(Pointee(Eq(3)), Pointee(Gt(0)), Pointee(Lt(5))));
+  EXPECT_THAT(p, Not(AllOf(Pointee(Eq(3)), Pointee(Gt(0)), Pointee(Lt(3)))));
+}
+
+TEST(AnyOfTest, WorksOnMoveOnlyType) {
+  std::unique_ptr<int> p(new int(3));
+  EXPECT_THAT(p, AnyOf(Pointee(Eq(5)), Pointee(Lt(0)), Pointee(Lt(5))));
+  EXPECT_THAT(p, Not(AnyOf(Pointee(Eq(5)), Pointee(Lt(0)), Pointee(Gt(5)))));
+}
+
+}  // namespace
+}  // namespace gmock_matchers_test
+}  // namespace testing
+
+GTEST_DISABLE_MSC_WARNINGS_POP_()  // 4244 4100

contrib/googletest/googlemock/test/gmock-matchers-comparisons_test.cc

@@ -0,0 +1,2361 @@
+// Copyright 2007, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+// Google Mock - a framework for writing C++ mock classes.
+//
+// This file tests some commonly used argument matchers.
+
+#include <functional>
+#include <memory>
+#include <string>
+#include <tuple>
+#include <vector>
+
+#include "test/gmock-matchers_test.h"
+
+// Silence warning C4244: 'initializing': conversion from 'int' to 'short',
+// possible loss of data and C4100, unreferenced local parameter
+GTEST_DISABLE_MSC_WARNINGS_PUSH_(4244 4100)
+
+
+namespace testing {
+namespace gmock_matchers_test {
+namespace {
+
+INSTANTIATE_GTEST_MATCHER_TEST_P(MonotonicMatcherTest);
+
+TEST_P(MonotonicMatcherTestP, IsPrintable) {
+  stringstream ss;
+  ss << GreaterThan(5);
+  EXPECT_EQ("is > 5", ss.str());
+}
+
+TEST(MatchResultListenerTest, StreamingWorks) {
+  StringMatchResultListener listener;
+  listener << "hi" << 5;
+  EXPECT_EQ("hi5", listener.str());
+
+  listener.Clear();
+  EXPECT_EQ("", listener.str());
+
+  listener << 42;
+  EXPECT_EQ("42", listener.str());
+
+  // Streaming shouldn't crash when the underlying ostream is NULL.
+  DummyMatchResultListener dummy;
+  dummy << "hi" << 5;
+}
+
+TEST(MatchResultListenerTest, CanAccessUnderlyingStream) {
+  EXPECT_TRUE(DummyMatchResultListener().stream() == nullptr);
+  EXPECT_TRUE(StreamMatchResultListener(nullptr).stream() == nullptr);
+
+  EXPECT_EQ(&std::cout, StreamMatchResultListener(&std::cout).stream());
+}
+
+TEST(MatchResultListenerTest, IsInterestedWorks) {
+  EXPECT_TRUE(StringMatchResultListener().IsInterested());
+  EXPECT_TRUE(StreamMatchResultListener(&std::cout).IsInterested());
+
+  EXPECT_FALSE(DummyMatchResultListener().IsInterested());
+  EXPECT_FALSE(StreamMatchResultListener(nullptr).IsInterested());
+}
+
+// Makes sure that the MatcherInterface<T> interface doesn't
+// change.
+class EvenMatcherImpl : public MatcherInterface<int> {
+ public:
+  bool MatchAndExplain(int x,
+                       MatchResultListener* /* listener */) const override {
+    return x % 2 == 0;
+  }
+
+  void DescribeTo(ostream* os) const override { *os << "is an even number"; }
+
+  // We deliberately don't define DescribeNegationTo() and
+  // ExplainMatchResultTo() here, to make sure the definition of these
+  // two methods is optional.
+};
+
+// Makes sure that the MatcherInterface API doesn't change.
+TEST(MatcherInterfaceTest, CanBeImplementedUsingPublishedAPI) {
+  EvenMatcherImpl m;
+}
+
+// Tests implementing a monomorphic matcher using MatchAndExplain().
+
+class NewEvenMatcherImpl : public MatcherInterface<int> {
+ public:
+  bool MatchAndExplain(int x, MatchResultListener* listener) const override {
+    const bool match = x % 2 == 0;
+    // Verifies that we can stream to a listener directly.
+    *listener << "value % " << 2;
+    if (listener->stream() != nullptr) {
+      // Verifies that we can stream to a listener's underlying stream
+      // too.
+      *listener->stream() << " == " << (x % 2);
+    }
+    return match;
+  }
+
+  void DescribeTo(ostream* os) const override { *os << "is an even number"; }
+};
+
+TEST(MatcherInterfaceTest, CanBeImplementedUsingNewAPI) {
+  Matcher<int> m = MakeMatcher(new NewEvenMatcherImpl);
+  EXPECT_TRUE(m.Matches(2));
+  EXPECT_FALSE(m.Matches(3));
+  EXPECT_EQ("value % 2 == 0", Explain(m, 2));
+  EXPECT_EQ("value % 2 == 1", Explain(m, 3));
+}
+
+INSTANTIATE_GTEST_MATCHER_TEST_P(MatcherTest);
+
+// Tests default-constructing a matcher.
+TEST(MatcherTest, CanBeDefaultConstructed) { Matcher<double> m; }
+
+// Tests that Matcher<T> can be constructed from a MatcherInterface<T>*.
+TEST(MatcherTest, CanBeConstructedFromMatcherInterface) {
+  const MatcherInterface<int>* impl = new EvenMatcherImpl;
+  Matcher<int> m(impl);
+  EXPECT_TRUE(m.Matches(4));
+  EXPECT_FALSE(m.Matches(5));
+}
+
+// Tests that value can be used in place of Eq(value).
+TEST(MatcherTest, CanBeImplicitlyConstructedFromValue) {
+  Matcher<int> m1 = 5;
+  EXPECT_TRUE(m1.Matches(5));
+  EXPECT_FALSE(m1.Matches(6));
+}
+
+// Tests that NULL can be used in place of Eq(NULL).
+TEST(MatcherTest, CanBeImplicitlyConstructedFromNULL) {
+  Matcher<int*> m1 = nullptr;
+  EXPECT_TRUE(m1.Matches(nullptr));
+  int n = 0;
+  EXPECT_FALSE(m1.Matches(&n));
+}
+
+// Tests that matchers can be constructed from a variable that is not properly
+// defined. This should be illegal, but many users rely on this accidentally.
+struct Undefined {
+  virtual ~Undefined() = 0;
+  static const int kInt = 1;
+};
+
+TEST(MatcherTest, CanBeConstructedFromUndefinedVariable) {
+  Matcher<int> m1 = Undefined::kInt;
+  EXPECT_TRUE(m1.Matches(1));
+  EXPECT_FALSE(m1.Matches(2));
+}
+
+// Test that a matcher parameterized with an abstract class compiles.
+TEST(MatcherTest, CanAcceptAbstractClass) { Matcher<const Undefined&> m = _; }
+
+// Tests that matchers are copyable.
+TEST(MatcherTest, IsCopyable) {
+  // Tests the copy constructor.
+  Matcher<bool> m1 = Eq(false);
+  EXPECT_TRUE(m1.Matches(false));
+  EXPECT_FALSE(m1.Matches(true));
+
+  // Tests the assignment operator.
+  m1 = Eq(true);
+  EXPECT_TRUE(m1.Matches(true));
+  EXPECT_FALSE(m1.Matches(false));
+}
+
+// Tests that Matcher<T>::DescribeTo() calls
+// MatcherInterface<T>::DescribeTo().
+TEST(MatcherTest, CanDescribeItself) {
+  EXPECT_EQ("is an even number", Describe(Matcher<int>(new EvenMatcherImpl)));
+}
+
+// Tests Matcher<T>::MatchAndExplain().
+TEST_P(MatcherTestP, MatchAndExplain) {
+  Matcher<int> m = GreaterThan(0);
+  StringMatchResultListener listener1;
+  EXPECT_TRUE(m.MatchAndExplain(42, &listener1));
+  EXPECT_EQ("which is 42 more than 0", listener1.str());
+
+  StringMatchResultListener listener2;
+  EXPECT_FALSE(m.MatchAndExplain(-9, &listener2));
+  EXPECT_EQ("which is 9 less than 0", listener2.str());
+}
+
+// Tests that a C-string literal can be implicitly converted to a
+// Matcher<std::string> or Matcher<const std::string&>.
+TEST(StringMatcherTest, CanBeImplicitlyConstructedFromCStringLiteral) {
+  Matcher<std::string> m1 = "hi";
+  EXPECT_TRUE(m1.Matches("hi"));
+  EXPECT_FALSE(m1.Matches("hello"));
+
+  Matcher<const std::string&> m2 = "hi";
+  EXPECT_TRUE(m2.Matches("hi"));
+  EXPECT_FALSE(m2.Matches("hello"));
+}
+
+// Tests that a string object can be implicitly converted to a
+// Matcher<std::string> or Matcher<const std::string&>.
+TEST(StringMatcherTest, CanBeImplicitlyConstructedFromString) {
+  Matcher<std::string> m1 = std::string("hi");
+  EXPECT_TRUE(m1.Matches("hi"));
+  EXPECT_FALSE(m1.Matches("hello"));
+
+  Matcher<const std::string&> m2 = std::string("hi");
+  EXPECT_TRUE(m2.Matches("hi"));
+  EXPECT_FALSE(m2.Matches("hello"));
+}
+
+#if GTEST_INTERNAL_HAS_STRING_VIEW
+// Tests that a C-string literal can be implicitly converted to a
+// Matcher<StringView> or Matcher<const StringView&>.
+TEST(StringViewMatcherTest, CanBeImplicitlyConstructedFromCStringLiteral) {
+  Matcher<internal::StringView> m1 = "cats";
+  EXPECT_TRUE(m1.Matches("cats"));
+  EXPECT_FALSE(m1.Matches("dogs"));
+
+  Matcher<const internal::StringView&> m2 = "cats";
+  EXPECT_TRUE(m2.Matches("cats"));
+  EXPECT_FALSE(m2.Matches("dogs"));
+}
+
+// Tests that a std::string object can be implicitly converted to a
+// Matcher<StringView> or Matcher<const StringView&>.
+TEST(StringViewMatcherTest, CanBeImplicitlyConstructedFromString) {
+  Matcher<internal::StringView> m1 = std::string("cats");
+  EXPECT_TRUE(m1.Matches("cats"));
+  EXPECT_FALSE(m1.Matches("dogs"));
+
+  Matcher<const internal::StringView&> m2 = std::string("cats");
+  EXPECT_TRUE(m2.Matches("cats"));
+  EXPECT_FALSE(m2.Matches("dogs"));
+}
+
+// Tests that a StringView object can be implicitly converted to a
+// Matcher<StringView> or Matcher<const StringView&>.
+TEST(StringViewMatcherTest, CanBeImplicitlyConstructedFromStringView) {
+  Matcher<internal::StringView> m1 = internal::StringView("cats");
+  EXPECT_TRUE(m1.Matches("cats"));
+  EXPECT_FALSE(m1.Matches("dogs"));
+
+  Matcher<const internal::StringView&> m2 = internal::StringView("cats");
+  EXPECT_TRUE(m2.Matches("cats"));
+  EXPECT_FALSE(m2.Matches("dogs"));
+}
+#endif  // GTEST_INTERNAL_HAS_STRING_VIEW
+
+// Tests that a std::reference_wrapper<std::string> object can be implicitly
+// converted to a Matcher<std::string> or Matcher<const std::string&> via Eq().
+TEST(StringMatcherTest,
+     CanBeImplicitlyConstructedFromEqReferenceWrapperString) {
+  std::string value = "cats";
+  Matcher<std::string> m1 = Eq(std::ref(value));
+  EXPECT_TRUE(m1.Matches("cats"));
+  EXPECT_FALSE(m1.Matches("dogs"));
+
+  Matcher<const std::string&> m2 = Eq(std::ref(value));
+  EXPECT_TRUE(m2.Matches("cats"));
+  EXPECT_FALSE(m2.Matches("dogs"));
+}
+
+// Tests that MakeMatcher() constructs a Matcher<T> from a
+// MatcherInterface* without requiring the user to explicitly
+// write the type.
+TEST(MakeMatcherTest, ConstructsMatcherFromMatcherInterface) {
+  const MatcherInterface<int>* dummy_impl = new EvenMatcherImpl;
+  Matcher<int> m = MakeMatcher(dummy_impl);
+}
+
+// Tests that MakePolymorphicMatcher() can construct a polymorphic
+// matcher from its implementation using the old API.
+const int g_bar = 1;
+class ReferencesBarOrIsZeroImpl {
+ public:
+  template <typename T>
+  bool MatchAndExplain(const T& x, MatchResultListener* /* listener */) const {
+    const void* p = &x;
+    return p == &g_bar || x == 0;
+  }
+
+  void DescribeTo(ostream* os) const { *os << "g_bar or zero"; }
+
+  void DescribeNegationTo(ostream* os) const {
+    *os << "doesn't reference g_bar and is not zero";
+  }
+};
+
+// This function verifies that MakePolymorphicMatcher() returns a
+// PolymorphicMatcher<T> where T is the argument's type.
+PolymorphicMatcher<ReferencesBarOrIsZeroImpl> ReferencesBarOrIsZero() {
+  return MakePolymorphicMatcher(ReferencesBarOrIsZeroImpl());
+}
+
+TEST(MakePolymorphicMatcherTest, ConstructsMatcherUsingOldAPI) {
+  // Using a polymorphic matcher to match a reference type.
+  Matcher<const int&> m1 = ReferencesBarOrIsZero();
+  EXPECT_TRUE(m1.Matches(0));
+  // Verifies that the identity of a by-reference argument is preserved.
+  EXPECT_TRUE(m1.Matches(g_bar));
+  EXPECT_FALSE(m1.Matches(1));
+  EXPECT_EQ("g_bar or zero", Describe(m1));
+
+  // Using a polymorphic matcher to match a value type.
+  Matcher<double> m2 = ReferencesBarOrIsZero();
+  EXPECT_TRUE(m2.Matches(0.0));
+  EXPECT_FALSE(m2.Matches(0.1));
+  EXPECT_EQ("g_bar or zero", Describe(m2));
+}
+
+// Tests implementing a polymorphic matcher using MatchAndExplain().
+
+class PolymorphicIsEvenImpl {
+ public:
+  void DescribeTo(ostream* os) const { *os << "is even"; }
+
+  void DescribeNegationTo(ostream* os) const { *os << "is odd"; }
+
+  template <typename T>
+  bool MatchAndExplain(const T& x, MatchResultListener* listener) const {
+    // Verifies that we can stream to the listener directly.
+    *listener << "% " << 2;
+    if (listener->stream() != nullptr) {
+      // Verifies that we can stream to the listener's underlying stream
+      // too.
+      *listener->stream() << " == " << (x % 2);
+    }
+    return (x % 2) == 0;
+  }
+};
+
+PolymorphicMatcher<PolymorphicIsEvenImpl> PolymorphicIsEven() {
+  return MakePolymorphicMatcher(PolymorphicIsEvenImpl());
+}
+
+TEST(MakePolymorphicMatcherTest, ConstructsMatcherUsingNewAPI) {
+  // Using PolymorphicIsEven() as a Matcher<int>.
+  const Matcher<int> m1 = PolymorphicIsEven();
+  EXPECT_TRUE(m1.Matches(42));
+  EXPECT_FALSE(m1.Matches(43));
+  EXPECT_EQ("is even", Describe(m1));
+
+  const Matcher<int> not_m1 = Not(m1);
+  EXPECT_EQ("is odd", Describe(not_m1));
+
+  EXPECT_EQ("% 2 == 0", Explain(m1, 42));
+
+  // Using PolymorphicIsEven() as a Matcher<char>.
+  const Matcher<char> m2 = PolymorphicIsEven();
+  EXPECT_TRUE(m2.Matches('\x42'));
+  EXPECT_FALSE(m2.Matches('\x43'));
+  EXPECT_EQ("is even", Describe(m2));
+
+  const Matcher<char> not_m2 = Not(m2);
+  EXPECT_EQ("is odd", Describe(not_m2));
+
+  EXPECT_EQ("% 2 == 0", Explain(m2, '\x42'));
+}
+
+INSTANTIATE_GTEST_MATCHER_TEST_P(MatcherCastTest);
+
+// Tests that MatcherCast<T>(m) works when m is a polymorphic matcher.
+TEST_P(MatcherCastTestP, FromPolymorphicMatcher) {
+  Matcher<int16_t> m;
+  if (use_gtest_matcher_) {
+    m = MatcherCast<int16_t>(GtestGreaterThan(int64_t{5}));
+  } else {
+    m = MatcherCast<int16_t>(Gt(int64_t{5}));
+  }
+  EXPECT_TRUE(m.Matches(6));
+  EXPECT_FALSE(m.Matches(4));
+}
+
+// For testing casting matchers between compatible types.
+class IntValue {
+ public:
+  // An int can be statically (although not implicitly) cast to a
+  // IntValue.
+  explicit IntValue(int a_value) : value_(a_value) {}
+
+  int value() const { return value_; }
+
+ private:
+  int value_;
+};
+
+// For testing casting matchers between compatible types.
+bool IsPositiveIntValue(const IntValue& foo) { return foo.value() > 0; }
+
+// Tests that MatcherCast<T>(m) works when m is a Matcher<U> where T
+// can be statically converted to U.
+TEST(MatcherCastTest, FromCompatibleType) {
+  Matcher<double> m1 = Eq(2.0);
+  Matcher<int> m2 = MatcherCast<int>(m1);
+  EXPECT_TRUE(m2.Matches(2));
+  EXPECT_FALSE(m2.Matches(3));
+
+  Matcher<IntValue> m3 = Truly(IsPositiveIntValue);
+  Matcher<int> m4 = MatcherCast<int>(m3);
+  // In the following, the arguments 1 and 0 are statically converted
+  // to IntValue objects, and then tested by the IsPositiveIntValue()
+  // predicate.
+  EXPECT_TRUE(m4.Matches(1));
+  EXPECT_FALSE(m4.Matches(0));
+}
+
+// Tests that MatcherCast<T>(m) works when m is a Matcher<const T&>.
+TEST(MatcherCastTest, FromConstReferenceToNonReference) {
+  Matcher<const int&> m1 = Eq(0);
+  Matcher<int> m2 = MatcherCast<int>(m1);
+  EXPECT_TRUE(m2.Matches(0));
+  EXPECT_FALSE(m2.Matches(1));
+}
+
+// Tests that MatcherCast<T>(m) works when m is a Matcher<T&>.
+TEST(MatcherCastTest, FromReferenceToNonReference) {
+  Matcher<int&> m1 = Eq(0);
+  Matcher<int> m2 = MatcherCast<int>(m1);
+  EXPECT_TRUE(m2.Matches(0));
+  EXPECT_FALSE(m2.Matches(1));
+}
+
+// Tests that MatcherCast<const T&>(m) works when m is a Matcher<T>.
+TEST(MatcherCastTest, FromNonReferenceToConstReference) {
+  Matcher<int> m1 = Eq(0);
+  Matcher<const int&> m2 = MatcherCast<const int&>(m1);
+  EXPECT_TRUE(m2.Matches(0));
+  EXPECT_FALSE(m2.Matches(1));
+}
+
+// Tests that MatcherCast<T&>(m) works when m is a Matcher<T>.
+TEST(MatcherCastTest, FromNonReferenceToReference) {
+  Matcher<int> m1 = Eq(0);
+  Matcher<int&> m2 = MatcherCast<int&>(m1);
+  int n = 0;
+  EXPECT_TRUE(m2.Matches(n));
+  n = 1;
+  EXPECT_FALSE(m2.Matches(n));
+}
+
+// Tests that MatcherCast<T>(m) works when m is a Matcher<T>.
+TEST(MatcherCastTest, FromSameType) {
+  Matcher<int> m1 = Eq(0);
+  Matcher<int> m2 = MatcherCast<int>(m1);
+  EXPECT_TRUE(m2.Matches(0));
+  EXPECT_FALSE(m2.Matches(1));
+}
+
+// Tests that MatcherCast<T>(m) works when m is a value of the same type as the
+// value type of the Matcher.
+TEST(MatcherCastTest, FromAValue) {
+  Matcher<int> m = MatcherCast<int>(42);
+  EXPECT_TRUE(m.Matches(42));
+  EXPECT_FALSE(m.Matches(239));
+}
+
+// Tests that MatcherCast<T>(m) works when m is a value of the type implicitly
+// convertible to the value type of the Matcher.
+TEST(MatcherCastTest, FromAnImplicitlyConvertibleValue) {
+  const int kExpected = 'c';
+  Matcher<int> m = MatcherCast<int>('c');
+  EXPECT_TRUE(m.Matches(kExpected));
+  EXPECT_FALSE(m.Matches(kExpected + 1));
+}
+
+struct NonImplicitlyConstructibleTypeWithOperatorEq {
+  friend bool operator==(
+      const NonImplicitlyConstructibleTypeWithOperatorEq& /* ignored */,
+      int rhs) {
+    return 42 == rhs;
+  }
+  friend bool operator==(
+      int lhs,
+      const NonImplicitlyConstructibleTypeWithOperatorEq& /* ignored */) {
+    return lhs == 42;
+  }
+};
+
+// Tests that MatcherCast<T>(m) works when m is a neither a matcher nor
+// implicitly convertible to the value type of the Matcher, but the value type
+// of the matcher has operator==() overload accepting m.
+TEST(MatcherCastTest, NonImplicitlyConstructibleTypeWithOperatorEq) {
+  Matcher<NonImplicitlyConstructibleTypeWithOperatorEq> m1 =
+      MatcherCast<NonImplicitlyConstructibleTypeWithOperatorEq>(42);
+  EXPECT_TRUE(m1.Matches(NonImplicitlyConstructibleTypeWithOperatorEq()));
+
+  Matcher<NonImplicitlyConstructibleTypeWithOperatorEq> m2 =
+      MatcherCast<NonImplicitlyConstructibleTypeWithOperatorEq>(239);
+  EXPECT_FALSE(m2.Matches(NonImplicitlyConstructibleTypeWithOperatorEq()));
+
+  // When updating the following lines please also change the comment to
+  // namespace convertible_from_any.
+  Matcher<int> m3 =
+      MatcherCast<int>(NonImplicitlyConstructibleTypeWithOperatorEq());
+  EXPECT_TRUE(m3.Matches(42));
+  EXPECT_FALSE(m3.Matches(239));
+}
+
+// ConvertibleFromAny does not work with MSVC. resulting in
+// error C2440: 'initializing': cannot convert from 'Eq' to 'M'
+// No constructor could take the source type, or constructor overload
+// resolution was ambiguous
+
+#if !defined _MSC_VER
+
+// The below ConvertibleFromAny struct is implicitly constructible from anything
+// and when in the same namespace can interact with other tests. In particular,
+// if it is in the same namespace as other tests and one removes
+//   NonImplicitlyConstructibleTypeWithOperatorEq::operator==(int lhs, ...);
+// then the corresponding test still compiles (and it should not!) by implicitly
+// converting NonImplicitlyConstructibleTypeWithOperatorEq to ConvertibleFromAny
+// in m3.Matcher().
+namespace convertible_from_any {
+// Implicitly convertible from any type.
+struct ConvertibleFromAny {
+  ConvertibleFromAny(int a_value) : value(a_value) {}
+  template <typename T>
+  ConvertibleFromAny(const T& /*a_value*/) : value(-1) {
+    ADD_FAILURE() << "Conversion constructor called";
+  }
+  int value;
+};
+
+bool operator==(const ConvertibleFromAny& a, const ConvertibleFromAny& b) {
+  return a.value == b.value;
+}
+
+ostream& operator<<(ostream& os, const ConvertibleFromAny& a) {
+  return os << a.value;
+}
+
+TEST(MatcherCastTest, ConversionConstructorIsUsed) {
+  Matcher<ConvertibleFromAny> m = MatcherCast<ConvertibleFromAny>(1);
+  EXPECT_TRUE(m.Matches(ConvertibleFromAny(1)));
+  EXPECT_FALSE(m.Matches(ConvertibleFromAny(2)));
+}
+
+TEST(MatcherCastTest, FromConvertibleFromAny) {
+  Matcher<ConvertibleFromAny> m =
+      MatcherCast<ConvertibleFromAny>(Eq(ConvertibleFromAny(1)));
+  EXPECT_TRUE(m.Matches(ConvertibleFromAny(1)));
+  EXPECT_FALSE(m.Matches(ConvertibleFromAny(2)));
+}
+}  // namespace convertible_from_any
+
+#endif  // !defined _MSC_VER
+
+struct IntReferenceWrapper {
+  IntReferenceWrapper(const int& a_value) : value(&a_value) {}
+  const int* value;
+};
+
+bool operator==(const IntReferenceWrapper& a, const IntReferenceWrapper& b) {
+  return a.value == b.value;
+}
+
+TEST(MatcherCastTest, ValueIsNotCopied) {
+  int n = 42;
+  Matcher<IntReferenceWrapper> m = MatcherCast<IntReferenceWrapper>(n);
+  // Verify that the matcher holds a reference to n, not to its temporary copy.
+  EXPECT_TRUE(m.Matches(n));
+}
+
+class Base {
+ public:
+  virtual ~Base() = default;
+  Base() = default;
+
+ private:
+  Base(const Base&) = delete;
+  Base& operator=(const Base&) = delete;
+};
+
+class Derived : public Base {
+ public:
+  Derived() : Base() {}
+  int i;
+};
+
+class OtherDerived : public Base {};
+
+INSTANTIATE_GTEST_MATCHER_TEST_P(SafeMatcherCastTest);
+
+// Tests that SafeMatcherCast<T>(m) works when m is a polymorphic matcher.
+TEST_P(SafeMatcherCastTestP, FromPolymorphicMatcher) {
+  Matcher<char> m2;
+  if (use_gtest_matcher_) {
+    m2 = SafeMatcherCast<char>(GtestGreaterThan(32));
+  } else {
+    m2 = SafeMatcherCast<char>(Gt(32));
+  }
+  EXPECT_TRUE(m2.Matches('A'));
+  EXPECT_FALSE(m2.Matches('\n'));
+}
+
+// Tests that SafeMatcherCast<T>(m) works when m is a Matcher<U> where
+// T and U are arithmetic types and T can be losslessly converted to
+// U.
+TEST(SafeMatcherCastTest, FromLosslesslyConvertibleArithmeticType) {
+  Matcher<double> m1 = DoubleEq(1.0);
+  Matcher<float> m2 = SafeMatcherCast<float>(m1);
+  EXPECT_TRUE(m2.Matches(1.0f));
+  EXPECT_FALSE(m2.Matches(2.0f));
+
+  Matcher<char> m3 = SafeMatcherCast<char>(TypedEq<int>('a'));
+  EXPECT_TRUE(m3.Matches('a'));
+  EXPECT_FALSE(m3.Matches('b'));
+}
+
+// Tests that SafeMatcherCast<T>(m) works when m is a Matcher<U> where T and U
+// are pointers or references to a derived and a base class, correspondingly.
+TEST(SafeMatcherCastTest, FromBaseClass) {
+  Derived d, d2;
+  Matcher<Base*> m1 = Eq(&d);
+  Matcher<Derived*> m2 = SafeMatcherCast<Derived*>(m1);
+  EXPECT_TRUE(m2.Matches(&d));
+  EXPECT_FALSE(m2.Matches(&d2));
+
+  Matcher<Base&> m3 = Ref(d);
+  Matcher<Derived&> m4 = SafeMatcherCast<Derived&>(m3);
+  EXPECT_TRUE(m4.Matches(d));
+  EXPECT_FALSE(m4.Matches(d2));
+}
+
+// Tests that SafeMatcherCast<T&>(m) works when m is a Matcher<const T&>.
+TEST(SafeMatcherCastTest, FromConstReferenceToReference) {
+  int n = 0;
+  Matcher<const int&> m1 = Ref(n);
+  Matcher<int&> m2 = SafeMatcherCast<int&>(m1);
+  int n1 = 0;
+  EXPECT_TRUE(m2.Matches(n));
+  EXPECT_FALSE(m2.Matches(n1));
+}
+
+// Tests that MatcherCast<const T&>(m) works when m is a Matcher<T>.
+TEST(SafeMatcherCastTest, FromNonReferenceToConstReference) {
+  Matcher<std::unique_ptr<int>> m1 = IsNull();
+  Matcher<const std::unique_ptr<int>&> m2 =
+      SafeMatcherCast<const std::unique_ptr<int>&>(m1);
+  EXPECT_TRUE(m2.Matches(std::unique_ptr<int>()));
+  EXPECT_FALSE(m2.Matches(std::unique_ptr<int>(new int)));
+}
+
+// Tests that SafeMatcherCast<T&>(m) works when m is a Matcher<T>.
+TEST(SafeMatcherCastTest, FromNonReferenceToReference) {
+  Matcher<int> m1 = Eq(0);
+  Matcher<int&> m2 = SafeMatcherCast<int&>(m1);
+  int n = 0;
+  EXPECT_TRUE(m2.Matches(n));
+  n = 1;
+  EXPECT_FALSE(m2.Matches(n));
+}
+
+// Tests that SafeMatcherCast<T>(m) works when m is a Matcher<T>.
+TEST(SafeMatcherCastTest, FromSameType) {
+  Matcher<int> m1 = Eq(0);
+  Matcher<int> m2 = SafeMatcherCast<int>(m1);
+  EXPECT_TRUE(m2.Matches(0));
+  EXPECT_FALSE(m2.Matches(1));
+}
+
+#if !defined _MSC_VER
+
+namespace convertible_from_any {
+TEST(SafeMatcherCastTest, ConversionConstructorIsUsed) {
+  Matcher<ConvertibleFromAny> m = SafeMatcherCast<ConvertibleFromAny>(1);
+  EXPECT_TRUE(m.Matches(ConvertibleFromAny(1)));
+  EXPECT_FALSE(m.Matches(ConvertibleFromAny(2)));
+}
+
+TEST(SafeMatcherCastTest, FromConvertibleFromAny) {
+  Matcher<ConvertibleFromAny> m =
+      SafeMatcherCast<ConvertibleFromAny>(Eq(ConvertibleFromAny(1)));
+  EXPECT_TRUE(m.Matches(ConvertibleFromAny(1)));
+  EXPECT_FALSE(m.Matches(ConvertibleFromAny(2)));
+}
+}  // namespace convertible_from_any
+
+#endif  // !defined _MSC_VER
+
+TEST(SafeMatcherCastTest, ValueIsNotCopied) {
+  int n = 42;
+  Matcher<IntReferenceWrapper> m = SafeMatcherCast<IntReferenceWrapper>(n);
+  // Verify that the matcher holds a reference to n, not to its temporary copy.
+  EXPECT_TRUE(m.Matches(n));
+}
+
+TEST(ExpectThat, TakesLiterals) {
+  EXPECT_THAT(1, 1);
+  EXPECT_THAT(1.0, 1.0);
+  EXPECT_THAT(std::string(), "");
+}
+
+TEST(ExpectThat, TakesFunctions) {
+  struct Helper {
+    static void Func() {}
+  };
+  void (*func)() = Helper::Func;
+  EXPECT_THAT(func, Helper::Func);
+  EXPECT_THAT(func, &Helper::Func);
+}
+
+// Tests that A<T>() matches any value of type T.
+TEST(ATest, MatchesAnyValue) {
+  // Tests a matcher for a value type.
+  Matcher<double> m1 = A<double>();
+  EXPECT_TRUE(m1.Matches(91.43));
+  EXPECT_TRUE(m1.Matches(-15.32));
+
+  // Tests a matcher for a reference type.
+  int a = 2;
+  int b = -6;
+  Matcher<int&> m2 = A<int&>();
+  EXPECT_TRUE(m2.Matches(a));
+  EXPECT_TRUE(m2.Matches(b));
+}
+
+TEST(ATest, WorksForDerivedClass) {
+  Base base;
+  Derived derived;
+  EXPECT_THAT(&base, A<Base*>());
+  // This shouldn't compile: EXPECT_THAT(&base, A<Derived*>());
+  EXPECT_THAT(&derived, A<Base*>());
+  EXPECT_THAT(&derived, A<Derived*>());
+}
+
+// Tests that A<T>() describes itself properly.
+TEST(ATest, CanDescribeSelf) { EXPECT_EQ("is anything", Describe(A<bool>())); }
+
+// Tests that An<T>() matches any value of type T.
+TEST(AnTest, MatchesAnyValue) {
+  // Tests a matcher for a value type.
+  Matcher<int> m1 = An<int>();
+  EXPECT_TRUE(m1.Matches(9143));
+  EXPECT_TRUE(m1.Matches(-1532));
+
+  // Tests a matcher for a reference type.
+  int a = 2;
+  int b = -6;
+  Matcher<int&> m2 = An<int&>();
+  EXPECT_TRUE(m2.Matches(a));
+  EXPECT_TRUE(m2.Matches(b));
+}
+
+// Tests that An<T>() describes itself properly.
+TEST(AnTest, CanDescribeSelf) { EXPECT_EQ("is anything", Describe(An<int>())); }
+
+// Tests that _ can be used as a matcher for any type and matches any
+// value of that type.
+TEST(UnderscoreTest, MatchesAnyValue) {
+  // Uses _ as a matcher for a value type.
+  Matcher<int> m1 = _;
+  EXPECT_TRUE(m1.Matches(123));
+  EXPECT_TRUE(m1.Matches(-242));
+
+  // Uses _ as a matcher for a reference type.
+  bool a = false;
+  const bool b = true;
+  Matcher<const bool&> m2 = _;
+  EXPECT_TRUE(m2.Matches(a));
+  EXPECT_TRUE(m2.Matches(b));
+}
+
+// Tests that _ describes itself properly.
+TEST(UnderscoreTest, CanDescribeSelf) {
+  Matcher<int> m = _;
+  EXPECT_EQ("is anything", Describe(m));
+}
+
+// Tests that Eq(x) matches any value equal to x.
+TEST(EqTest, MatchesEqualValue) {
+  // 2 C-strings with same content but different addresses.
+  const char a1[] = "hi";
+  const char a2[] = "hi";
+
+  Matcher<const char*> m1 = Eq(a1);
+  EXPECT_TRUE(m1.Matches(a1));
+  EXPECT_FALSE(m1.Matches(a2));
+}
+
+// Tests that Eq(v) describes itself properly.
+
+class Unprintable {
+ public:
+  Unprintable() : c_('a') {}
+
+  bool operator==(const Unprintable& /* rhs */) const { return true; }
+  // -Wunused-private-field: dummy accessor for `c_`.
+  char dummy_c() { return c_; }
+
+ private:
+  char c_;
+};
+
+TEST(EqTest, CanDescribeSelf) {
+  Matcher<Unprintable> m = Eq(Unprintable());
+  EXPECT_EQ("is equal to 1-byte object <61>", Describe(m));
+}
+
+// Tests that Eq(v) can be used to match any type that supports
+// comparing with type T, where T is v's type.
+TEST(EqTest, IsPolymorphic) {
+  Matcher<int> m1 = Eq(1);
+  EXPECT_TRUE(m1.Matches(1));
+  EXPECT_FALSE(m1.Matches(2));
+
+  Matcher<char> m2 = Eq(1);
+  EXPECT_TRUE(m2.Matches('\1'));
+  EXPECT_FALSE(m2.Matches('a'));
+}
+
+// Tests that TypedEq<T>(v) matches values of type T that's equal to v.
+TEST(TypedEqTest, ChecksEqualityForGivenType) {
+  Matcher<char> m1 = TypedEq<char>('a');
+  EXPECT_TRUE(m1.Matches('a'));
+  EXPECT_FALSE(m1.Matches('b'));
+
+  Matcher<int> m2 = TypedEq<int>(6);
+  EXPECT_TRUE(m2.Matches(6));
+  EXPECT_FALSE(m2.Matches(7));
+}
+
+// Tests that TypedEq(v) describes itself properly.
+TEST(TypedEqTest, CanDescribeSelf) {
+  EXPECT_EQ("is equal to 2", Describe(TypedEq<int>(2)));
+}
+
+// Tests that TypedEq<T>(v) has type Matcher<T>.
+
+// Type<T>::IsTypeOf(v) compiles if and only if the type of value v is T, where
+// T is a "bare" type (i.e. not in the form of const U or U&).  If v's type is
+// not T, the compiler will generate a message about "undefined reference".
+template <typename T>
+struct Type {
+  static bool IsTypeOf(const T& /* v */) { return true; }
+
+  template <typename T2>
+  static void IsTypeOf(T2 v);
+};
+
+TEST(TypedEqTest, HasSpecifiedType) {
+  // Verifies that the type of TypedEq<T>(v) is Matcher<T>.
+  Type<Matcher<int>>::IsTypeOf(TypedEq<int>(5));
+  Type<Matcher<double>>::IsTypeOf(TypedEq<double>(5));
+}
+
+// Tests that Ge(v) matches anything >= v.
+TEST(GeTest, ImplementsGreaterThanOrEqual) {
+  Matcher<int> m1 = Ge(0);
+  EXPECT_TRUE(m1.Matches(1));
+  EXPECT_TRUE(m1.Matches(0));
+  EXPECT_FALSE(m1.Matches(-1));
+}
+
+// Tests that Ge(v) describes itself properly.
+TEST(GeTest, CanDescribeSelf) {
+  Matcher<int> m = Ge(5);
+  EXPECT_EQ("is >= 5", Describe(m));
+}
+
+// Tests that Gt(v) matches anything > v.
+TEST(GtTest, ImplementsGreaterThan) {
+  Matcher<double> m1 = Gt(0);
+  EXPECT_TRUE(m1.Matches(1.0));
+  EXPECT_FALSE(m1.Matches(0.0));
+  EXPECT_FALSE(m1.Matches(-1.0));
+}
+
+// Tests that Gt(v) describes itself properly.
+TEST(GtTest, CanDescribeSelf) {
+  Matcher<int> m = Gt(5);
+  EXPECT_EQ("is > 5", Describe(m));
+}
+
+// Tests that Le(v) matches anything <= v.
+TEST(LeTest, ImplementsLessThanOrEqual) {
+  Matcher<char> m1 = Le('b');
+  EXPECT_TRUE(m1.Matches('a'));
+  EXPECT_TRUE(m1.Matches('b'));
+  EXPECT_FALSE(m1.Matches('c'));
+}
+
+// Tests that Le(v) describes itself properly.
+TEST(LeTest, CanDescribeSelf) {
+  Matcher<int> m = Le(5);
+  EXPECT_EQ("is <= 5", Describe(m));
+}
+
+// Tests that Lt(v) matches anything < v.
+TEST(LtTest, ImplementsLessThan) {
+  Matcher<const std::string&> m1 = Lt("Hello");
+  EXPECT_TRUE(m1.Matches("Abc"));
+  EXPECT_FALSE(m1.Matches("Hello"));
+  EXPECT_FALSE(m1.Matches("Hello, world!"));
+}
+
+// Tests that Lt(v) describes itself properly.
+TEST(LtTest, CanDescribeSelf) {
+  Matcher<int> m = Lt(5);
+  EXPECT_EQ("is < 5", Describe(m));
+}
+
+// Tests that Ne(v) matches anything != v.
+TEST(NeTest, ImplementsNotEqual) {
+  Matcher<int> m1 = Ne(0);
+  EXPECT_TRUE(m1.Matches(1));
+  EXPECT_TRUE(m1.Matches(-1));
+  EXPECT_FALSE(m1.Matches(0));
+}
+
+// Tests that Ne(v) describes itself properly.
+TEST(NeTest, CanDescribeSelf) {
+  Matcher<int> m = Ne(5);
+  EXPECT_EQ("isn't equal to 5", Describe(m));
+}
+
+class MoveOnly {
+ public:
+  explicit MoveOnly(int i) : i_(i) {}
+  MoveOnly(const MoveOnly&) = delete;
+  MoveOnly(MoveOnly&&) = default;
+  MoveOnly& operator=(const MoveOnly&) = delete;
+  MoveOnly& operator=(MoveOnly&&) = default;
+
+  bool operator==(const MoveOnly& other) const { return i_ == other.i_; }
+  bool operator!=(const MoveOnly& other) const { return i_ != other.i_; }
+  bool operator<(const MoveOnly& other) const { return i_ < other.i_; }
+  bool operator<=(const MoveOnly& other) const { return i_ <= other.i_; }
+  bool operator>(const MoveOnly& other) const { return i_ > other.i_; }
+  bool operator>=(const MoveOnly& other) const { return i_ >= other.i_; }
+
+ private:
+  int i_;
+};
+
+struct MoveHelper {
+  MOCK_METHOD1(Call, void(MoveOnly));
+};
+
+// Disable this test in VS 2015 (version 14), where it fails when SEH is enabled
+#if defined(_MSC_VER) && (_MSC_VER < 1910)
+TEST(ComparisonBaseTest, DISABLED_WorksWithMoveOnly) {
+#else
+TEST(ComparisonBaseTest, WorksWithMoveOnly) {
+#endif
+  MoveOnly m{0};
+  MoveHelper helper;
+
+  EXPECT_CALL(helper, Call(Eq(ByRef(m))));
+  helper.Call(MoveOnly(0));
+  EXPECT_CALL(helper, Call(Ne(ByRef(m))));
+  helper.Call(MoveOnly(1));
+  EXPECT_CALL(helper, Call(Le(ByRef(m))));
+  helper.Call(MoveOnly(0));
+  EXPECT_CALL(helper, Call(Lt(ByRef(m))));
+  helper.Call(MoveOnly(-1));
+  EXPECT_CALL(helper, Call(Ge(ByRef(m))));
+  helper.Call(MoveOnly(0));
+  EXPECT_CALL(helper, Call(Gt(ByRef(m))));
+  helper.Call(MoveOnly(1));
+}
+
+TEST(IsEmptyTest, MatchesContainer) {
+  const Matcher<std::vector<int>> m = IsEmpty();
+  std::vector<int> a = {};
+  std::vector<int> b = {1};
+  EXPECT_TRUE(m.Matches(a));
+  EXPECT_FALSE(m.Matches(b));
+}
+
+TEST(IsEmptyTest, MatchesStdString) {
+  const Matcher<std::string> m = IsEmpty();
+  std::string a = "z";
+  std::string b = "";
+  EXPECT_FALSE(m.Matches(a));
+  EXPECT_TRUE(m.Matches(b));
+}
+
+TEST(IsEmptyTest, MatchesCString) {
+  const Matcher<const char*> m = IsEmpty();
+  const char a[] = "";
+  const char b[] = "x";
+  EXPECT_TRUE(m.Matches(a));
+  EXPECT_FALSE(m.Matches(b));
+}
+
+// Tests that IsNull() matches any NULL pointer of any type.
+TEST(IsNullTest, MatchesNullPointer) {
+  Matcher<int*> m1 = IsNull();
+  int* p1 = nullptr;
+  int n = 0;
+  EXPECT_TRUE(m1.Matches(p1));
+  EXPECT_FALSE(m1.Matches(&n));
+
+  Matcher<const char*> m2 = IsNull();
+  const char* p2 = nullptr;
+  EXPECT_TRUE(m2.Matches(p2));
+  EXPECT_FALSE(m2.Matches("hi"));
+
+  Matcher<void*> m3 = IsNull();
+  void* p3 = nullptr;
+  EXPECT_TRUE(m3.Matches(p3));
+  EXPECT_FALSE(m3.Matches(reinterpret_cast<void*>(0xbeef)));
+}
+
+TEST(IsNullTest, StdFunction) {
+  const Matcher<std::function<void()>> m = IsNull();
+
+  EXPECT_TRUE(m.Matches(std::function<void()>()));
+  EXPECT_FALSE(m.Matches([] {}));
+}
+
+// Tests that IsNull() describes itself properly.
+TEST(IsNullTest, CanDescribeSelf) {
+  Matcher<int*> m = IsNull();
+  EXPECT_EQ("is NULL", Describe(m));
+  EXPECT_EQ("isn't NULL", DescribeNegation(m));
+}
+
+// Tests that NotNull() matches any non-NULL pointer of any type.
+TEST(NotNullTest, MatchesNonNullPointer) {
+  Matcher<int*> m1 = NotNull();
+  int* p1 = nullptr;
+  int n = 0;
+  EXPECT_FALSE(m1.Matches(p1));
+  EXPECT_TRUE(m1.Matches(&n));
+
+  Matcher<const char*> m2 = NotNull();
+  const char* p2 = nullptr;
+  EXPECT_FALSE(m2.Matches(p2));
+  EXPECT_TRUE(m2.Matches("hi"));
+}
+
+TEST(NotNullTest, LinkedPtr) {
+  const Matcher<std::shared_ptr<int>> m = NotNull();
+  const std::shared_ptr<int> null_p;
+  const std::shared_ptr<int> non_null_p(new int);
+
+  EXPECT_FALSE(m.Matches(null_p));
+  EXPECT_TRUE(m.Matches(non_null_p));
+}
+
+TEST(NotNullTest, ReferenceToConstLinkedPtr) {
+  const Matcher<const std::shared_ptr<double>&> m = NotNull();
+  const std::shared_ptr<double> null_p;
+  const std::shared_ptr<double> non_null_p(new double);
+
+  EXPECT_FALSE(m.Matches(null_p));
+  EXPECT_TRUE(m.Matches(non_null_p));
+}
+
+TEST(NotNullTest, StdFunction) {
+  const Matcher<std::function<void()>> m = NotNull();
+
+  EXPECT_TRUE(m.Matches([] {}));
+  EXPECT_FALSE(m.Matches(std::function<void()>()));
+}
+
+// Tests that NotNull() describes itself properly.
+TEST(NotNullTest, CanDescribeSelf) {
+  Matcher<int*> m = NotNull();
+  EXPECT_EQ("isn't NULL", Describe(m));
+}
+
+// Tests that Ref(variable) matches an argument that references
+// 'variable'.
+TEST(RefTest, MatchesSameVariable) {
+  int a = 0;
+  int b = 0;
+  Matcher<int&> m = Ref(a);
+  EXPECT_TRUE(m.Matches(a));
+  EXPECT_FALSE(m.Matches(b));
+}
+
+// Tests that Ref(variable) describes itself properly.
+TEST(RefTest, CanDescribeSelf) {
+  int n = 5;
+  Matcher<int&> m = Ref(n);
+  stringstream ss;
+  ss << "references the variable @" << &n << " 5";
+  EXPECT_EQ(ss.str(), Describe(m));
+}
+
+// Test that Ref(non_const_varialbe) can be used as a matcher for a
+// const reference.
+TEST(RefTest, CanBeUsedAsMatcherForConstReference) {
+  int a = 0;
+  int b = 0;
+  Matcher<const int&> m = Ref(a);
+  EXPECT_TRUE(m.Matches(a));
+  EXPECT_FALSE(m.Matches(b));
+}
+
+// Tests that Ref(variable) is covariant, i.e. Ref(derived) can be
+// used wherever Ref(base) can be used (Ref(derived) is a sub-type
+// of Ref(base), but not vice versa.
+
+TEST(RefTest, IsCovariant) {
+  Base base, base2;
+  Derived derived;
+  Matcher<const Base&> m1 = Ref(base);
+  EXPECT_TRUE(m1.Matches(base));
+  EXPECT_FALSE(m1.Matches(base2));
+  EXPECT_FALSE(m1.Matches(derived));
+
+  m1 = Ref(derived);
+  EXPECT_TRUE(m1.Matches(derived));
+  EXPECT_FALSE(m1.Matches(base));
+  EXPECT_FALSE(m1.Matches(base2));
+}
+
+TEST(RefTest, ExplainsResult) {
+  int n = 0;
+  EXPECT_THAT(Explain(Matcher<const int&>(Ref(n)), n),
+              StartsWith("which is located @"));
+
+  int m = 0;
+  EXPECT_THAT(Explain(Matcher<const int&>(Ref(n)), m),
+              StartsWith("which is located @"));
+}
+
+// Tests string comparison matchers.
+
+template <typename T = std::string>
+std::string FromStringLike(internal::StringLike<T> str) {
+  return std::string(str);
+}
+
+TEST(StringLike, TestConversions) {
+  EXPECT_EQ("foo", FromStringLike("foo"));
+  EXPECT_EQ("foo", FromStringLike(std::string("foo")));
+#if GTEST_INTERNAL_HAS_STRING_VIEW
+  EXPECT_EQ("foo", FromStringLike(internal::StringView("foo")));
+#endif  // GTEST_INTERNAL_HAS_STRING_VIEW
+
+  // Non deducible types.
+  EXPECT_EQ("", FromStringLike({}));
+  EXPECT_EQ("foo", FromStringLike({'f', 'o', 'o'}));
+  const char buf[] = "foo";
+  EXPECT_EQ("foo", FromStringLike({buf, buf + 3}));
+}
+
+TEST(StrEqTest, MatchesEqualString) {
+  Matcher<const char*> m = StrEq(std::string("Hello"));
+  EXPECT_TRUE(m.Matches("Hello"));
+  EXPECT_FALSE(m.Matches("hello"));
+  EXPECT_FALSE(m.Matches(nullptr));
+
+  Matcher<const std::string&> m2 = StrEq("Hello");
+  EXPECT_TRUE(m2.Matches("Hello"));
+  EXPECT_FALSE(m2.Matches("Hi"));
+
+#if GTEST_INTERNAL_HAS_STRING_VIEW
+  Matcher<const internal::StringView&> m3 =
+      StrEq(internal::StringView("Hello"));
+  EXPECT_TRUE(m3.Matches(internal::StringView("Hello")));
+  EXPECT_FALSE(m3.Matches(internal::StringView("hello")));
+  EXPECT_FALSE(m3.Matches(internal::StringView()));
+
+  Matcher<const internal::StringView&> m_empty = StrEq("");
+  EXPECT_TRUE(m_empty.Matches(internal::StringView("")));
+  EXPECT_TRUE(m_empty.Matches(internal::StringView()));
+  EXPECT_FALSE(m_empty.Matches(internal::StringView("hello")));
+#endif  // GTEST_INTERNAL_HAS_STRING_VIEW
+}
+
+TEST(StrEqTest, CanDescribeSelf) {
+  Matcher<std::string> m = StrEq("Hi-\'\"?\\\a\b\f\n\r\t\v\xD3");
+  EXPECT_EQ("is equal to \"Hi-\'\\\"?\\\\\\a\\b\\f\\n\\r\\t\\v\\xD3\"",
+            Describe(m));
+
+  std::string str("01204500800");
+  str[3] = '\0';
+  Matcher<std::string> m2 = StrEq(str);
+  EXPECT_EQ("is equal to \"012\\04500800\"", Describe(m2));
+  str[0] = str[6] = str[7] = str[9] = str[10] = '\0';
+  Matcher<std::string> m3 = StrEq(str);
+  EXPECT_EQ("is equal to \"\\012\\045\\0\\08\\0\\0\"", Describe(m3));
+}
+
+TEST(StrNeTest, MatchesUnequalString) {
+  Matcher<const char*> m = StrNe("Hello");
+  EXPECT_TRUE(m.Matches(""));
+  EXPECT_TRUE(m.Matches(nullptr));
+  EXPECT_FALSE(m.Matches("Hello"));
+
+  Matcher<std::string> m2 = StrNe(std::string("Hello"));
+  EXPECT_TRUE(m2.Matches("hello"));
+  EXPECT_FALSE(m2.Matches("Hello"));
+
+#if GTEST_INTERNAL_HAS_STRING_VIEW
+  Matcher<const internal::StringView> m3 = StrNe(internal::StringView("Hello"));
+  EXPECT_TRUE(m3.Matches(internal::StringView("")));
+  EXPECT_TRUE(m3.Matches(internal::StringView()));
+  EXPECT_FALSE(m3.Matches(internal::StringView("Hello")));
+#endif  // GTEST_INTERNAL_HAS_STRING_VIEW
+}
+
+TEST(StrNeTest, CanDescribeSelf) {
+  Matcher<const char*> m = StrNe("Hi");
+  EXPECT_EQ("isn't equal to \"Hi\"", Describe(m));
+}
+
+TEST(StrCaseEqTest, MatchesEqualStringIgnoringCase) {
+  Matcher<const char*> m = StrCaseEq(std::string("Hello"));
+  EXPECT_TRUE(m.Matches("Hello"));
+  EXPECT_TRUE(m.Matches("hello"));
+  EXPECT_FALSE(m.Matches("Hi"));
+  EXPECT_FALSE(m.Matches(nullptr));
+
+  Matcher<const std::string&> m2 = StrCaseEq("Hello");
+  EXPECT_TRUE(m2.Matches("hello"));
+  EXPECT_FALSE(m2.Matches("Hi"));
+
+#if GTEST_INTERNAL_HAS_STRING_VIEW
+  Matcher<const internal::StringView&> m3 =
+      StrCaseEq(internal::StringView("Hello"));
+  EXPECT_TRUE(m3.Matches(internal::StringView("Hello")));
+  EXPECT_TRUE(m3.Matches(internal::StringView("hello")));
+  EXPECT_FALSE(m3.Matches(internal::StringView("Hi")));
+  EXPECT_FALSE(m3.Matches(internal::StringView()));
+#endif  // GTEST_INTERNAL_HAS_STRING_VIEW
+}
+
+TEST(StrCaseEqTest, MatchesEqualStringWith0IgnoringCase) {
+  std::string str1("oabocdooeoo");
+  std::string str2("OABOCDOOEOO");
+  Matcher<const std::string&> m0 = StrCaseEq(str1);
+  EXPECT_FALSE(m0.Matches(str2 + std::string(1, '\0')));
+
+  str1[3] = str2[3] = '\0';
+  Matcher<const std::string&> m1 = StrCaseEq(str1);
+  EXPECT_TRUE(m1.Matches(str2));
+
+  str1[0] = str1[6] = str1[7] = str1[10] = '\0';
+  str2[0] = str2[6] = str2[7] = str2[10] = '\0';
+  Matcher<const std::string&> m2 = StrCaseEq(str1);
+  str1[9] = str2[9] = '\0';
+  EXPECT_FALSE(m2.Matches(str2));
+
+  Matcher<const std::string&> m3 = StrCaseEq(str1);
+  EXPECT_TRUE(m3.Matches(str2));
+
+  EXPECT_FALSE(m3.Matches(str2 + "x"));
+  str2.append(1, '\0');
+  EXPECT_FALSE(m3.Matches(str2));
+  EXPECT_FALSE(m3.Matches(std::string(str2, 0, 9)));
+}
+
+TEST(StrCaseEqTest, CanDescribeSelf) {
+  Matcher<std::string> m = StrCaseEq("Hi");
+  EXPECT_EQ("is equal to (ignoring case) \"Hi\"", Describe(m));
+}
+
+TEST(StrCaseNeTest, MatchesUnequalStringIgnoringCase) {
+  Matcher<const char*> m = StrCaseNe("Hello");
+  EXPECT_TRUE(m.Matches("Hi"));
+  EXPECT_TRUE(m.Matches(nullptr));
+  EXPECT_FALSE(m.Matches("Hello"));
+  EXPECT_FALSE(m.Matches("hello"));
+
+  Matcher<std::string> m2 = StrCaseNe(std::string("Hello"));
+  EXPECT_TRUE(m2.Matches(""));
+  EXPECT_FALSE(m2.Matches("Hello"));
+
+#if GTEST_INTERNAL_HAS_STRING_VIEW
+  Matcher<const internal::StringView> m3 =
+      StrCaseNe(internal::StringView("Hello"));
+  EXPECT_TRUE(m3.Matches(internal::StringView("Hi")));
+  EXPECT_TRUE(m3.Matches(internal::StringView()));
+  EXPECT_FALSE(m3.Matches(internal::StringView("Hello")));
+  EXPECT_FALSE(m3.Matches(internal::StringView("hello")));
+#endif  // GTEST_INTERNAL_HAS_STRING_VIEW
+}
+
+TEST(StrCaseNeTest, CanDescribeSelf) {
+  Matcher<const char*> m = StrCaseNe("Hi");
+  EXPECT_EQ("isn't equal to (ignoring case) \"Hi\"", Describe(m));
+}
+
+// Tests that HasSubstr() works for matching string-typed values.
+TEST(HasSubstrTest, WorksForStringClasses) {
+  const Matcher<std::string> m1 = HasSubstr("foo");
+  EXPECT_TRUE(m1.Matches(std::string("I love food.")));
+  EXPECT_FALSE(m1.Matches(std::string("tofo")));
+
+  const Matcher<const std::string&> m2 = HasSubstr("foo");
+  EXPECT_TRUE(m2.Matches(std::string("I love food.")));
+  EXPECT_FALSE(m2.Matches(std::string("tofo")));
+
+  const Matcher<std::string> m_empty = HasSubstr("");
+  EXPECT_TRUE(m_empty.Matches(std::string()));
+  EXPECT_TRUE(m_empty.Matches(std::string("not empty")));
+}
+
+// Tests that HasSubstr() works for matching C-string-typed values.
+TEST(HasSubstrTest, WorksForCStrings) {
+  const Matcher<char*> m1 = HasSubstr("foo");
+  EXPECT_TRUE(m1.Matches(const_cast<char*>("I love food.")));
+  EXPECT_FALSE(m1.Matches(const_cast<char*>("tofo")));
+  EXPECT_FALSE(m1.Matches(nullptr));
+
+  const Matcher<const char*> m2 = HasSubstr("foo");
+  EXPECT_TRUE(m2.Matches("I love food."));
+  EXPECT_FALSE(m2.Matches("tofo"));
+  EXPECT_FALSE(m2.Matches(nullptr));
+
+  const Matcher<const char*> m_empty = HasSubstr("");
+  EXPECT_TRUE(m_empty.Matches("not empty"));
+  EXPECT_TRUE(m_empty.Matches(""));
+  EXPECT_FALSE(m_empty.Matches(nullptr));
+}
+
+#if GTEST_INTERNAL_HAS_STRING_VIEW
+// Tests that HasSubstr() works for matching StringView-typed values.
+TEST(HasSubstrTest, WorksForStringViewClasses) {
+  const Matcher<internal::StringView> m1 =
+      HasSubstr(internal::StringView("foo"));
+  EXPECT_TRUE(m1.Matches(internal::StringView("I love food.")));
+  EXPECT_FALSE(m1.Matches(internal::StringView("tofo")));
+  EXPECT_FALSE(m1.Matches(internal::StringView()));
+
+  const Matcher<const internal::StringView&> m2 = HasSubstr("foo");
+  EXPECT_TRUE(m2.Matches(internal::StringView("I love food.")));
+  EXPECT_FALSE(m2.Matches(internal::StringView("tofo")));
+  EXPECT_FALSE(m2.Matches(internal::StringView()));
+
+  const Matcher<const internal::StringView&> m3 = HasSubstr("");
+  EXPECT_TRUE(m3.Matches(internal::StringView("foo")));
+  EXPECT_TRUE(m3.Matches(internal::StringView("")));
+  EXPECT_TRUE(m3.Matches(internal::StringView()));
+}
+#endif  // GTEST_INTERNAL_HAS_STRING_VIEW
+
+// Tests that HasSubstr(s) describes itself properly.
+TEST(HasSubstrTest, CanDescribeSelf) {
+  Matcher<std::string> m = HasSubstr("foo\n\"");
+  EXPECT_EQ("has substring \"foo\\n\\\"\"", Describe(m));
+}
+
+INSTANTIATE_GTEST_MATCHER_TEST_P(KeyTest);
+
+TEST(KeyTest, CanDescribeSelf) {
+  Matcher<const pair<std::string, int>&> m = Key("foo");
+  EXPECT_EQ("has a key that is equal to \"foo\"", Describe(m));
+  EXPECT_EQ("doesn't have a key that is equal to \"foo\"", DescribeNegation(m));
+}
+
+TEST_P(KeyTestP, ExplainsResult) {
+  Matcher<pair<int, bool>> m = Key(GreaterThan(10));
+  EXPECT_EQ("whose first field is a value which is 5 less than 10",
+            Explain(m, make_pair(5, true)));
+  EXPECT_EQ("whose first field is a value which is 5 more than 10",
+            Explain(m, make_pair(15, true)));
+}
+
+TEST(KeyTest, MatchesCorrectly) {
+  pair<int, std::string> p(25, "foo");
+  EXPECT_THAT(p, Key(25));
+  EXPECT_THAT(p, Not(Key(42)));
+  EXPECT_THAT(p, Key(Ge(20)));
+  EXPECT_THAT(p, Not(Key(Lt(25))));
+}
+
+TEST(KeyTest, WorksWithMoveOnly) {
+  pair<std::unique_ptr<int>, std::unique_ptr<int>> p;
+  EXPECT_THAT(p, Key(Eq(nullptr)));
+}
+
+INSTANTIATE_GTEST_MATCHER_TEST_P(PairTest);
+
+template <size_t I>
+struct Tag {};
+
+struct PairWithGet {
+  int member_1;
+  std::string member_2;
+  using first_type = int;
+  using second_type = std::string;
+
+  const int& GetImpl(Tag<0>) const { return member_1; }
+  const std::string& GetImpl(Tag<1>) const { return member_2; }
+};
+template <size_t I>
+auto get(const PairWithGet& value) -> decltype(value.GetImpl(Tag<I>())) {
+  return value.GetImpl(Tag<I>());
+}
+TEST(PairTest, MatchesPairWithGetCorrectly) {
+  PairWithGet p{25, "foo"};
+  EXPECT_THAT(p, Key(25));
+  EXPECT_THAT(p, Not(Key(42)));
+  EXPECT_THAT(p, Key(Ge(20)));
+  EXPECT_THAT(p, Not(Key(Lt(25))));
+
+  std::vector<PairWithGet> v = {{11, "Foo"}, {29, "gMockIsBestMock"}};
+  EXPECT_THAT(v, Contains(Key(29)));
+}
+
+TEST(KeyTest, SafelyCastsInnerMatcher) {
+  Matcher<int> is_positive = Gt(0);
+  Matcher<int> is_negative = Lt(0);
+  pair<char, bool> p('a', true);
+  EXPECT_THAT(p, Key(is_positive));
+  EXPECT_THAT(p, Not(Key(is_negative)));
+}
+
+TEST(KeyTest, InsideContainsUsingMap) {
+  map<int, char> container;
+  container.insert(make_pair(1, 'a'));
+  container.insert(make_pair(2, 'b'));
+  container.insert(make_pair(4, 'c'));
+  EXPECT_THAT(container, Contains(Key(1)));
+  EXPECT_THAT(container, Not(Contains(Key(3))));
+}
+
+TEST(KeyTest, InsideContainsUsingMultimap) {
+  multimap<int, char> container;
+  container.insert(make_pair(1, 'a'));
+  container.insert(make_pair(2, 'b'));
+  container.insert(make_pair(4, 'c'));
+
+  EXPECT_THAT(container, Not(Contains(Key(25))));
+  container.insert(make_pair(25, 'd'));
+  EXPECT_THAT(container, Contains(Key(25)));
+  container.insert(make_pair(25, 'e'));
+  EXPECT_THAT(container, Contains(Key(25)));
+
+  EXPECT_THAT(container, Contains(Key(1)));
+  EXPECT_THAT(container, Not(Contains(Key(3))));
+}
+
+TEST(PairTest, Typing) {
+  // Test verifies the following type conversions can be compiled.
+  Matcher<const pair<const char*, int>&> m1 = Pair("foo", 42);
+  Matcher<const pair<const char*, int>> m2 = Pair("foo", 42);
+  Matcher<pair<const char*, int>> m3 = Pair("foo", 42);
+
+  Matcher<pair<int, const std::string>> m4 = Pair(25, "42");
+  Matcher<pair<const std::string, int>> m5 = Pair("25", 42);
+}
+
+TEST(PairTest, CanDescribeSelf) {
+  Matcher<const pair<std::string, int>&> m1 = Pair("foo", 42);
+  EXPECT_EQ(
+      "has a first field that is equal to \"foo\""
+      ", and has a second field that is equal to 42",
+      Describe(m1));
+  EXPECT_EQ(
+      "has a first field that isn't equal to \"foo\""
+      ", or has a second field that isn't equal to 42",
+      DescribeNegation(m1));
+  // Double and triple negation (1 or 2 times not and description of negation).
+  Matcher<const pair<int, int>&> m2 = Not(Pair(Not(13), 42));
+  EXPECT_EQ(
+      "has a first field that isn't equal to 13"
+      ", and has a second field that is equal to 42",
+      DescribeNegation(m2));
+}
+
+TEST_P(PairTestP, CanExplainMatchResultTo) {
+  // If neither field matches, Pair() should explain about the first
+  // field.
+  const Matcher<pair<int, int>> m = Pair(GreaterThan(0), GreaterThan(0));
+  EXPECT_EQ("whose first field does not match, which is 1 less than 0",
+            Explain(m, make_pair(-1, -2)));
+
+  // If the first field matches but the second doesn't, Pair() should
+  // explain about the second field.
+  EXPECT_EQ("whose second field does not match, which is 2 less than 0",
+            Explain(m, make_pair(1, -2)));
+
+  // If the first field doesn't match but the second does, Pair()
+  // should explain about the first field.
+  EXPECT_EQ("whose first field does not match, which is 1 less than 0",
+            Explain(m, make_pair(-1, 2)));
+
+  // If both fields match, Pair() should explain about them both.
+  EXPECT_EQ(
+      "whose both fields match, where the first field is a value "
+      "which is 1 more than 0, and the second field is a value "
+      "which is 2 more than 0",
+      Explain(m, make_pair(1, 2)));
+
+  // If only the first match has an explanation, only this explanation should
+  // be printed.
+  const Matcher<pair<int, int>> explain_first = Pair(GreaterThan(0), 0);
+  EXPECT_EQ(
+      "whose both fields match, where the first field is a value "
+      "which is 1 more than 0",
+      Explain(explain_first, make_pair(1, 0)));
+
+  // If only the second match has an explanation, only this explanation should
+  // be printed.
+  const Matcher<pair<int, int>> explain_second = Pair(0, GreaterThan(0));
+  EXPECT_EQ(
+      "whose both fields match, where the second field is a value "
+      "which is 1 more than 0",
+      Explain(explain_second, make_pair(0, 1)));
+}
+
+TEST(PairTest, MatchesCorrectly) {
+  pair<int, std::string> p(25, "foo");
+
+  // Both fields match.
+  EXPECT_THAT(p, Pair(25, "foo"));
+  EXPECT_THAT(p, Pair(Ge(20), HasSubstr("o")));
+
+  // 'first' doesn't match, but 'second' matches.
+  EXPECT_THAT(p, Not(Pair(42, "foo")));
+  EXPECT_THAT(p, Not(Pair(Lt(25), "foo")));
+
+  // 'first' matches, but 'second' doesn't match.
+  EXPECT_THAT(p, Not(Pair(25, "bar")));
+  EXPECT_THAT(p, Not(Pair(25, Not("foo"))));
+
+  // Neither field matches.
+  EXPECT_THAT(p, Not(Pair(13, "bar")));
+  EXPECT_THAT(p, Not(Pair(Lt(13), HasSubstr("a"))));
+}
+
+TEST(PairTest, WorksWithMoveOnly) {
+  pair<std::unique_ptr<int>, std::unique_ptr<int>> p;
+  p.second = std::make_unique<int>(7);
+  EXPECT_THAT(p, Pair(Eq(nullptr), Ne(nullptr)));
+}
+
+TEST(PairTest, SafelyCastsInnerMatchers) {
+  Matcher<int> is_positive = Gt(0);
+  Matcher<int> is_negative = Lt(0);
+  pair<char, bool> p('a', true);
+  EXPECT_THAT(p, Pair(is_positive, _));
+  EXPECT_THAT(p, Not(Pair(is_negative, _)));
+  EXPECT_THAT(p, Pair(_, is_positive));
+  EXPECT_THAT(p, Not(Pair(_, is_negative)));
+}
+
+TEST(PairTest, InsideContainsUsingMap) {
+  map<int, char> container;
+  container.insert(make_pair(1, 'a'));
+  container.insert(make_pair(2, 'b'));
+  container.insert(make_pair(4, 'c'));
+  EXPECT_THAT(container, Contains(Pair(1, 'a')));
+  EXPECT_THAT(container, Contains(Pair(1, _)));
+  EXPECT_THAT(container, Contains(Pair(_, 'a')));
+  EXPECT_THAT(container, Not(Contains(Pair(3, _))));
+}
+
+INSTANTIATE_GTEST_MATCHER_TEST_P(FieldsAreTest);
+
+TEST(FieldsAreTest, MatchesCorrectly) {
+  std::tuple<int, std::string, double> p(25, "foo", .5);
+
+  // All fields match.
+  EXPECT_THAT(p, FieldsAre(25, "foo", .5));
+  EXPECT_THAT(p, FieldsAre(Ge(20), HasSubstr("o"), DoubleEq(.5)));
+
+  // Some don't match.
+  EXPECT_THAT(p, Not(FieldsAre(26, "foo", .5)));
+  EXPECT_THAT(p, Not(FieldsAre(25, "fo", .5)));
+  EXPECT_THAT(p, Not(FieldsAre(25, "foo", .6)));
+}
+
+TEST(FieldsAreTest, CanDescribeSelf) {
+  Matcher<const pair<std::string, int>&> m1 = FieldsAre("foo", 42);
+  EXPECT_EQ(
+      "has field #0 that is equal to \"foo\""
+      ", and has field #1 that is equal to 42",
+      Describe(m1));
+  EXPECT_EQ(
+      "has field #0 that isn't equal to \"foo\""
+      ", or has field #1 that isn't equal to 42",
+      DescribeNegation(m1));
+}
+
+TEST_P(FieldsAreTestP, CanExplainMatchResultTo) {
+  // The first one that fails is the one that gives the error.
+  Matcher<std::tuple<int, int, int>> m =
+      FieldsAre(GreaterThan(0), GreaterThan(0), GreaterThan(0));
+
+  EXPECT_EQ("whose field #0 does not match, which is 1 less than 0",
+            Explain(m, std::make_tuple(-1, -2, -3)));
+  EXPECT_EQ("whose field #1 does not match, which is 2 less than 0",
+            Explain(m, std::make_tuple(1, -2, -3)));
+  EXPECT_EQ("whose field #2 does not match, which is 3 less than 0",
+            Explain(m, std::make_tuple(1, 2, -3)));
+
+  // If they all match, we get a long explanation of success.
+  EXPECT_EQ(
+      "whose all elements match, "
+      "where field #0 is a value which is 1 more than 0"
+      ", and field #1 is a value which is 2 more than 0"
+      ", and field #2 is a value which is 3 more than 0",
+      Explain(m, std::make_tuple(1, 2, 3)));
+
+  // Only print those that have an explanation.
+  m = FieldsAre(GreaterThan(0), 0, GreaterThan(0));
+  EXPECT_EQ(
+      "whose all elements match, "
+      "where field #0 is a value which is 1 more than 0"
+      ", and field #2 is a value which is 3 more than 0",
+      Explain(m, std::make_tuple(1, 0, 3)));
+
+  // If only one has an explanation, then print that one.
+  m = FieldsAre(0, GreaterThan(0), 0);
+  EXPECT_EQ(
+      "whose all elements match, "
+      "where field #1 is a value which is 1 more than 0",
+      Explain(m, std::make_tuple(0, 1, 0)));
+}
+
+#if defined(__cpp_structured_bindings) && __cpp_structured_bindings >= 201606
+TEST(FieldsAreTest, StructuredBindings) {
+  // testing::FieldsAre can also match aggregates and such with C++17 and up.
+  struct MyType {
+    int i;
+    std::string str;
+  };
+  EXPECT_THAT((MyType{17, "foo"}), FieldsAre(Eq(17), HasSubstr("oo")));
+
+  // Test all the supported arities.
+  struct MyVarType1 {
+    int a;
+  };
+  EXPECT_THAT(MyVarType1{}, FieldsAre(0));
+  struct MyVarType2 {
+    int a, b;
+  };
+  EXPECT_THAT(MyVarType2{}, FieldsAre(0, 0));
+  struct MyVarType3 {
+    int a, b, c;
+  };
+  EXPECT_THAT(MyVarType3{}, FieldsAre(0, 0, 0));
+  struct MyVarType4 {
+    int a, b, c, d;
+  };
+  EXPECT_THAT(MyVarType4{}, FieldsAre(0, 0, 0, 0));
+  struct MyVarType5 {
+    int a, b, c, d, e;
+  };
+  EXPECT_THAT(MyVarType5{}, FieldsAre(0, 0, 0, 0, 0));
+  struct MyVarType6 {
+    int a, b, c, d, e, f;
+  };
+  EXPECT_THAT(MyVarType6{}, FieldsAre(0, 0, 0, 0, 0, 0));
+  struct MyVarType7 {
+    int a, b, c, d, e, f, g;
+  };
+  EXPECT_THAT(MyVarType7{}, FieldsAre(0, 0, 0, 0, 0, 0, 0));
+  struct MyVarType8 {
+    int a, b, c, d, e, f, g, h;
+  };
+  EXPECT_THAT(MyVarType8{}, FieldsAre(0, 0, 0, 0, 0, 0, 0, 0));
+  struct MyVarType9 {
+    int a, b, c, d, e, f, g, h, i;
+  };
+  EXPECT_THAT(MyVarType9{}, FieldsAre(0, 0, 0, 0, 0, 0, 0, 0, 0));
+  struct MyVarType10 {
+    int a, b, c, d, e, f, g, h, i, j;
+  };
+  EXPECT_THAT(MyVarType10{}, FieldsAre(0, 0, 0, 0, 0, 0, 0, 0, 0, 0));
+  struct MyVarType11 {
+    int a, b, c, d, e, f, g, h, i, j, k;
+  };
+  EXPECT_THAT(MyVarType11{}, FieldsAre(0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0));
+  struct MyVarType12 {
+    int a, b, c, d, e, f, g, h, i, j, k, l;
+  };
+  EXPECT_THAT(MyVarType12{}, FieldsAre(0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0));
+  struct MyVarType13 {
+    int a, b, c, d, e, f, g, h, i, j, k, l, m;
+  };
+  EXPECT_THAT(MyVarType13{}, FieldsAre(0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0));
+  struct MyVarType14 {
+    int a, b, c, d, e, f, g, h, i, j, k, l, m, n;
+  };
+  EXPECT_THAT(MyVarType14{},
+              FieldsAre(0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0));
+  struct MyVarType15 {
+    int a, b, c, d, e, f, g, h, i, j, k, l, m, n, o;
+  };
+  EXPECT_THAT(MyVarType15{},
+              FieldsAre(0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0));
+  struct MyVarType16 {
+    int a, b, c, d, e, f, g, h, i, j, k, l, m, n, o, p;
+  };
+  EXPECT_THAT(MyVarType16{},
+              FieldsAre(0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0));
+  struct MyVarType17 {
+    int a, b, c, d, e, f, g, h, i, j, k, l, m, n, o, p, q;
+  };
+  EXPECT_THAT(MyVarType17{},
+              FieldsAre(0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0));
+  struct MyVarType18 {
+    int a, b, c, d, e, f, g, h, i, j, k, l, m, n, o, p, q, r;
+  };
+  EXPECT_THAT(MyVarType18{},
+              FieldsAre(0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0));
+  struct MyVarType19 {
+    int a, b, c, d, e, f, g, h, i, j, k, l, m, n, o, p, q, r, s;
+  };
+  EXPECT_THAT(MyVarType19{}, FieldsAre(0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+                                       0, 0, 0, 0, 0));
+}
+#endif
+
+TEST(PairTest, UseGetInsteadOfMembers) {
+  PairWithGet pair{7, "ABC"};
+  EXPECT_THAT(pair, Pair(7, "ABC"));
+  EXPECT_THAT(pair, Pair(Ge(7), HasSubstr("AB")));
+  EXPECT_THAT(pair, Not(Pair(Lt(7), "ABC")));
+
+  std::vector<PairWithGet> v = {{11, "Foo"}, {29, "gMockIsBestMock"}};
+  EXPECT_THAT(v,
+              ElementsAre(Pair(11, std::string("Foo")), Pair(Ge(10), Not(""))));
+}
+
+// Tests StartsWith(s).
+
+TEST(StartsWithTest, MatchesStringWithGivenPrefix) {
+  const Matcher<const char*> m1 = StartsWith(std::string(""));
+  EXPECT_TRUE(m1.Matches("Hi"));
+  EXPECT_TRUE(m1.Matches(""));
+  EXPECT_FALSE(m1.Matches(nullptr));
+
+  const Matcher<const std::string&> m2 = StartsWith("Hi");
+  EXPECT_TRUE(m2.Matches("Hi"));
+  EXPECT_TRUE(m2.Matches("Hi Hi!"));
+  EXPECT_TRUE(m2.Matches("High"));
+  EXPECT_FALSE(m2.Matches("H"));
+  EXPECT_FALSE(m2.Matches(" Hi"));
+
+#if GTEST_INTERNAL_HAS_STRING_VIEW
+  const Matcher<internal::StringView> m_empty =
+      StartsWith(internal::StringView(""));
+  EXPECT_TRUE(m_empty.Matches(internal::StringView()));
+  EXPECT_TRUE(m_empty.Matches(internal::StringView("")));
+  EXPECT_TRUE(m_empty.Matches(internal::StringView("not empty")));
+#endif  // GTEST_INTERNAL_HAS_STRING_VIEW
+}
+
+TEST(StartsWithTest, CanDescribeSelf) {
+  Matcher<const std::string> m = StartsWith("Hi");
+  EXPECT_EQ("starts with \"Hi\"", Describe(m));
+}
+
+// Tests EndsWith(s).
+
+TEST(EndsWithTest, MatchesStringWithGivenSuffix) {
+  const Matcher<const char*> m1 = EndsWith("");
+  EXPECT_TRUE(m1.Matches("Hi"));
+  EXPECT_TRUE(m1.Matches(""));
+  EXPECT_FALSE(m1.Matches(nullptr));
+
+  const Matcher<const std::string&> m2 = EndsWith(std::string("Hi"));
+  EXPECT_TRUE(m2.Matches("Hi"));
+  EXPECT_TRUE(m2.Matches("Wow Hi Hi"));
+  EXPECT_TRUE(m2.Matches("Super Hi"));
+  EXPECT_FALSE(m2.Matches("i"));
+  EXPECT_FALSE(m2.Matches("Hi "));
+
+#if GTEST_INTERNAL_HAS_STRING_VIEW
+  const Matcher<const internal::StringView&> m4 =
+      EndsWith(internal::StringView(""));
+  EXPECT_TRUE(m4.Matches("Hi"));
+  EXPECT_TRUE(m4.Matches(""));
+  EXPECT_TRUE(m4.Matches(internal::StringView()));
+  EXPECT_TRUE(m4.Matches(internal::StringView("")));
+#endif  // GTEST_INTERNAL_HAS_STRING_VIEW
+}
+
+TEST(EndsWithTest, CanDescribeSelf) {
+  Matcher<const std::string> m = EndsWith("Hi");
+  EXPECT_EQ("ends with \"Hi\"", Describe(m));
+}
+
+// Tests WhenBase64Unescaped.
+
+TEST(WhenBase64UnescapedTest, MatchesUnescapedBase64Strings) {
+  const Matcher<const char*> m1 = WhenBase64Unescaped(EndsWith("!"));
+  EXPECT_FALSE(m1.Matches("invalid base64"));
+  EXPECT_FALSE(m1.Matches("aGVsbG8gd29ybGQ="));  // hello world
+  EXPECT_TRUE(m1.Matches("aGVsbG8gd29ybGQh"));   // hello world!
+  EXPECT_TRUE(m1.Matches("+/-_IQ"));             // \xfb\xff\xbf!
+
+  const Matcher<const std::string&> m2 = WhenBase64Unescaped(EndsWith("!"));
+  EXPECT_FALSE(m2.Matches("invalid base64"));
+  EXPECT_FALSE(m2.Matches("aGVsbG8gd29ybGQ="));  // hello world
+  EXPECT_TRUE(m2.Matches("aGVsbG8gd29ybGQh"));   // hello world!
+  EXPECT_TRUE(m2.Matches("+/-_IQ"));             // \xfb\xff\xbf!
+
+#if GTEST_INTERNAL_HAS_STRING_VIEW
+  const Matcher<const internal::StringView&> m3 =
+      WhenBase64Unescaped(EndsWith("!"));
+  EXPECT_FALSE(m3.Matches("invalid base64"));
+  EXPECT_FALSE(m3.Matches("aGVsbG8gd29ybGQ="));  // hello world
+  EXPECT_TRUE(m3.Matches("aGVsbG8gd29ybGQh"));   // hello world!
+  EXPECT_TRUE(m3.Matches("+/-_IQ"));             // \xfb\xff\xbf!
+#endif  // GTEST_INTERNAL_HAS_STRING_VIEW
+}
+
+TEST(WhenBase64UnescapedTest, CanDescribeSelf) {
+  const Matcher<const char*> m = WhenBase64Unescaped(EndsWith("!"));
+  EXPECT_EQ("matches after Base64Unescape ends with \"!\"", Describe(m));
+}
+
+// Tests MatchesRegex().
+
+TEST(MatchesRegexTest, MatchesStringMatchingGivenRegex) {
+  const Matcher<const char*> m1 = MatchesRegex("a.*z");
+  EXPECT_TRUE(m1.Matches("az"));
+  EXPECT_TRUE(m1.Matches("abcz"));
+  EXPECT_FALSE(m1.Matches(nullptr));
+
+  const Matcher<const std::string&> m2 = MatchesRegex(new RE("a.*z"));
+  EXPECT_TRUE(m2.Matches("azbz"));
+  EXPECT_FALSE(m2.Matches("az1"));
+  EXPECT_FALSE(m2.Matches("1az"));
+
+#if GTEST_INTERNAL_HAS_STRING_VIEW
+  const Matcher<const internal::StringView&> m3 = MatchesRegex("a.*z");
+  EXPECT_TRUE(m3.Matches(internal::StringView("az")));
+  EXPECT_TRUE(m3.Matches(internal::StringView("abcz")));
+  EXPECT_FALSE(m3.Matches(internal::StringView("1az")));
+  EXPECT_FALSE(m3.Matches(internal::StringView()));
+  const Matcher<const internal::StringView&> m4 =
+      MatchesRegex(internal::StringView(""));
+  EXPECT_TRUE(m4.Matches(internal::StringView("")));
+  EXPECT_TRUE(m4.Matches(internal::StringView()));
+#endif  // GTEST_INTERNAL_HAS_STRING_VIEW
+}
+
+TEST(MatchesRegexTest, CanDescribeSelf) {
+  Matcher<const std::string> m1 = MatchesRegex(std::string("Hi.*"));
+  EXPECT_EQ("matches regular expression \"Hi.*\"", Describe(m1));
+
+  Matcher<const char*> m2 = MatchesRegex(new RE("a.*"));
+  EXPECT_EQ("matches regular expression \"a.*\"", Describe(m2));
+
+#if GTEST_INTERNAL_HAS_STRING_VIEW
+  Matcher<const internal::StringView> m3 = MatchesRegex(new RE("0.*"));
+  EXPECT_EQ("matches regular expression \"0.*\"", Describe(m3));
+#endif  // GTEST_INTERNAL_HAS_STRING_VIEW
+}
+
+// Tests ContainsRegex().
+
+TEST(ContainsRegexTest, MatchesStringContainingGivenRegex) {
+  const Matcher<const char*> m1 = ContainsRegex(std::string("a.*z"));
+  EXPECT_TRUE(m1.Matches("az"));
+  EXPECT_TRUE(m1.Matches("0abcz1"));
+  EXPECT_FALSE(m1.Matches(nullptr));
+
+  const Matcher<const std::string&> m2 = ContainsRegex(new RE("a.*z"));
+  EXPECT_TRUE(m2.Matches("azbz"));
+  EXPECT_TRUE(m2.Matches("az1"));
+  EXPECT_FALSE(m2.Matches("1a"));
+
+#if GTEST_INTERNAL_HAS_STRING_VIEW
+  const Matcher<const internal::StringView&> m3 = ContainsRegex(new RE("a.*z"));
+  EXPECT_TRUE(m3.Matches(internal::StringView("azbz")));
+  EXPECT_TRUE(m3.Matches(internal::StringView("az1")));
+  EXPECT_FALSE(m3.Matches(internal::StringView("1a")));
+  EXPECT_FALSE(m3.Matches(internal::StringView()));
+  const Matcher<const internal::StringView&> m4 =
+      ContainsRegex(internal::StringView(""));
+  EXPECT_TRUE(m4.Matches(internal::StringView("")));
+  EXPECT_TRUE(m4.Matches(internal::StringView()));
+#endif  // GTEST_INTERNAL_HAS_STRING_VIEW
+}
+
+TEST(ContainsRegexTest, CanDescribeSelf) {
+  Matcher<const std::string> m1 = ContainsRegex("Hi.*");
+  EXPECT_EQ("contains regular expression \"Hi.*\"", Describe(m1));
+
+  Matcher<const char*> m2 = ContainsRegex(new RE("a.*"));
+  EXPECT_EQ("contains regular expression \"a.*\"", Describe(m2));
+
+#if GTEST_INTERNAL_HAS_STRING_VIEW
+  Matcher<const internal::StringView> m3 = ContainsRegex(new RE("0.*"));
+  EXPECT_EQ("contains regular expression \"0.*\"", Describe(m3));
+#endif  // GTEST_INTERNAL_HAS_STRING_VIEW
+}
+
+// Tests for wide strings.
+#if GTEST_HAS_STD_WSTRING
+TEST(StdWideStrEqTest, MatchesEqual) {
+  Matcher<const wchar_t*> m = StrEq(::std::wstring(L"Hello"));
+  EXPECT_TRUE(m.Matches(L"Hello"));
+  EXPECT_FALSE(m.Matches(L"hello"));
+  EXPECT_FALSE(m.Matches(nullptr));
+
+  Matcher<const ::std::wstring&> m2 = StrEq(L"Hello");
+  EXPECT_TRUE(m2.Matches(L"Hello"));
+  EXPECT_FALSE(m2.Matches(L"Hi"));
+
+  Matcher<const ::std::wstring&> m3 = StrEq(L"\xD3\x576\x8D3\xC74D");
+  EXPECT_TRUE(m3.Matches(L"\xD3\x576\x8D3\xC74D"));
+  EXPECT_FALSE(m3.Matches(L"\xD3\x576\x8D3\xC74E"));
+
+  ::std::wstring str(L"01204500800");
+  str[3] = L'\0';
+  Matcher<const ::std::wstring&> m4 = StrEq(str);
+  EXPECT_TRUE(m4.Matches(str));
+  str[0] = str[6] = str[7] = str[9] = str[10] = L'\0';
+  Matcher<const ::std::wstring&> m5 = StrEq(str);
+  EXPECT_TRUE(m5.Matches(str));
+}
+
+TEST(StdWideStrEqTest, CanDescribeSelf) {
+  Matcher<::std::wstring> m = StrEq(L"Hi-\'\"?\\\a\b\f\n\r\t\v");
+  EXPECT_EQ("is equal to L\"Hi-\'\\\"?\\\\\\a\\b\\f\\n\\r\\t\\v\"",
+            Describe(m));
+
+  Matcher<::std::wstring> m2 = StrEq(L"\xD3\x576\x8D3\xC74D");
+  EXPECT_EQ("is equal to L\"\\xD3\\x576\\x8D3\\xC74D\"", Describe(m2));
+
+  ::std::wstring str(L"01204500800");
+  str[3] = L'\0';
+  Matcher<const ::std::wstring&> m4 = StrEq(str);
+  EXPECT_EQ("is equal to L\"012\\04500800\"", Describe(m4));
+  str[0] = str[6] = str[7] = str[9] = str[10] = L'\0';
+  Matcher<const ::std::wstring&> m5 = StrEq(str);
+  EXPECT_EQ("is equal to L\"\\012\\045\\0\\08\\0\\0\"", Describe(m5));
+}
+
+TEST(StdWideStrNeTest, MatchesUnequalString) {
+  Matcher<const wchar_t*> m = StrNe(L"Hello");
+  EXPECT_TRUE(m.Matches(L""));
+  EXPECT_TRUE(m.Matches(nullptr));
+  EXPECT_FALSE(m.Matches(L"Hello"));
+
+  Matcher<::std::wstring> m2 = StrNe(::std::wstring(L"Hello"));
+  EXPECT_TRUE(m2.Matches(L"hello"));
+  EXPECT_FALSE(m2.Matches(L"Hello"));
+}
+
+TEST(StdWideStrNeTest, CanDescribeSelf) {
+  Matcher<const wchar_t*> m = StrNe(L"Hi");
+  EXPECT_EQ("isn't equal to L\"Hi\"", Describe(m));
+}
+
+TEST(StdWideStrCaseEqTest, MatchesEqualStringIgnoringCase) {
+  Matcher<const wchar_t*> m = StrCaseEq(::std::wstring(L"Hello"));
+  EXPECT_TRUE(m.Matches(L"Hello"));
+  EXPECT_TRUE(m.Matches(L"hello"));
+  EXPECT_FALSE(m.Matches(L"Hi"));
+  EXPECT_FALSE(m.Matches(nullptr));
+
+  Matcher<const ::std::wstring&> m2 = StrCaseEq(L"Hello");
+  EXPECT_TRUE(m2.Matches(L"hello"));
+  EXPECT_FALSE(m2.Matches(L"Hi"));
+}
+
+TEST(StdWideStrCaseEqTest, MatchesEqualStringWith0IgnoringCase) {
+  ::std::wstring str1(L"oabocdooeoo");
+  ::std::wstring str2(L"OABOCDOOEOO");
+  Matcher<const ::std::wstring&> m0 = StrCaseEq(str1);
+  EXPECT_FALSE(m0.Matches(str2 + ::std::wstring(1, L'\0')));
+
+  str1[3] = str2[3] = L'\0';
+  Matcher<const ::std::wstring&> m1 = StrCaseEq(str1);
+  EXPECT_TRUE(m1.Matches(str2));
+
+  str1[0] = str1[6] = str1[7] = str1[10] = L'\0';
+  str2[0] = str2[6] = str2[7] = str2[10] = L'\0';
+  Matcher<const ::std::wstring&> m2 = StrCaseEq(str1);
+  str1[9] = str2[9] = L'\0';
+  EXPECT_FALSE(m2.Matches(str2));
+
+  Matcher<const ::std::wstring&> m3 = StrCaseEq(str1);
+  EXPECT_TRUE(m3.Matches(str2));
+
+  EXPECT_FALSE(m3.Matches(str2 + L"x"));
+  str2.append(1, L'\0');
+  EXPECT_FALSE(m3.Matches(str2));
+  EXPECT_FALSE(m3.Matches(::std::wstring(str2, 0, 9)));
+}
+
+TEST(StdWideStrCaseEqTest, CanDescribeSelf) {
+  Matcher<::std::wstring> m = StrCaseEq(L"Hi");
+  EXPECT_EQ("is equal to (ignoring case) L\"Hi\"", Describe(m));
+}
+
+TEST(StdWideStrCaseNeTest, MatchesUnequalStringIgnoringCase) {
+  Matcher<const wchar_t*> m = StrCaseNe(L"Hello");
+  EXPECT_TRUE(m.Matches(L"Hi"));
+  EXPECT_TRUE(m.Matches(nullptr));
+  EXPECT_FALSE(m.Matches(L"Hello"));
+  EXPECT_FALSE(m.Matches(L"hello"));
+
+  Matcher<::std::wstring> m2 = StrCaseNe(::std::wstring(L"Hello"));
+  EXPECT_TRUE(m2.Matches(L""));
+  EXPECT_FALSE(m2.Matches(L"Hello"));
+}
+
+TEST(StdWideStrCaseNeTest, CanDescribeSelf) {
+  Matcher<const wchar_t*> m = StrCaseNe(L"Hi");
+  EXPECT_EQ("isn't equal to (ignoring case) L\"Hi\"", Describe(m));
+}
+
+// Tests that HasSubstr() works for matching wstring-typed values.
+TEST(StdWideHasSubstrTest, WorksForStringClasses) {
+  const Matcher<::std::wstring> m1 = HasSubstr(L"foo");
+  EXPECT_TRUE(m1.Matches(::std::wstring(L"I love food.")));
+  EXPECT_FALSE(m1.Matches(::std::wstring(L"tofo")));
+
+  const Matcher<const ::std::wstring&> m2 = HasSubstr(L"foo");
+  EXPECT_TRUE(m2.Matches(::std::wstring(L"I love food.")));
+  EXPECT_FALSE(m2.Matches(::std::wstring(L"tofo")));
+}
+
+// Tests that HasSubstr() works for matching C-wide-string-typed values.
+TEST(StdWideHasSubstrTest, WorksForCStrings) {
+  const Matcher<wchar_t*> m1 = HasSubstr(L"foo");
+  EXPECT_TRUE(m1.Matches(const_cast<wchar_t*>(L"I love food.")));
+  EXPECT_FALSE(m1.Matches(const_cast<wchar_t*>(L"tofo")));
+  EXPECT_FALSE(m1.Matches(nullptr));
+
+  const Matcher<const wchar_t*> m2 = HasSubstr(L"foo");
+  EXPECT_TRUE(m2.Matches(L"I love food."));
+  EXPECT_FALSE(m2.Matches(L"tofo"));
+  EXPECT_FALSE(m2.Matches(nullptr));
+}
+
+// Tests that HasSubstr(s) describes itself properly.
+TEST(StdWideHasSubstrTest, CanDescribeSelf) {
+  Matcher<::std::wstring> m = HasSubstr(L"foo\n\"");
+  EXPECT_EQ("has substring L\"foo\\n\\\"\"", Describe(m));
+}
+
+// Tests StartsWith(s).
+
+TEST(StdWideStartsWithTest, MatchesStringWithGivenPrefix) {
+  const Matcher<const wchar_t*> m1 = StartsWith(::std::wstring(L""));
+  EXPECT_TRUE(m1.Matches(L"Hi"));
+  EXPECT_TRUE(m1.Matches(L""));
+  EXPECT_FALSE(m1.Matches(nullptr));
+
+  const Matcher<const ::std::wstring&> m2 = StartsWith(L"Hi");
+  EXPECT_TRUE(m2.Matches(L"Hi"));
+  EXPECT_TRUE(m2.Matches(L"Hi Hi!"));
+  EXPECT_TRUE(m2.Matches(L"High"));
+  EXPECT_FALSE(m2.Matches(L"H"));
+  EXPECT_FALSE(m2.Matches(L" Hi"));
+}
+
+TEST(StdWideStartsWithTest, CanDescribeSelf) {
+  Matcher<const ::std::wstring> m = StartsWith(L"Hi");
+  EXPECT_EQ("starts with L\"Hi\"", Describe(m));
+}
+
+// Tests EndsWith(s).
+
+TEST(StdWideEndsWithTest, MatchesStringWithGivenSuffix) {
+  const Matcher<const wchar_t*> m1 = EndsWith(L"");
+  EXPECT_TRUE(m1.Matches(L"Hi"));
+  EXPECT_TRUE(m1.Matches(L""));
+  EXPECT_FALSE(m1.Matches(nullptr));
+
+  const Matcher<const ::std::wstring&> m2 = EndsWith(::std::wstring(L"Hi"));
+  EXPECT_TRUE(m2.Matches(L"Hi"));
+  EXPECT_TRUE(m2.Matches(L"Wow Hi Hi"));
+  EXPECT_TRUE(m2.Matches(L"Super Hi"));
+  EXPECT_FALSE(m2.Matches(L"i"));
+  EXPECT_FALSE(m2.Matches(L"Hi "));
+}
+
+TEST(StdWideEndsWithTest, CanDescribeSelf) {
+  Matcher<const ::std::wstring> m = EndsWith(L"Hi");
+  EXPECT_EQ("ends with L\"Hi\"", Describe(m));
+}
+
+#endif  // GTEST_HAS_STD_WSTRING
+
+TEST(ExplainMatchResultTest, WorksWithPolymorphicMatcher) {
+  StringMatchResultListener listener1;
+  EXPECT_TRUE(ExplainMatchResult(PolymorphicIsEven(), 42, &listener1));
+  EXPECT_EQ("% 2 == 0", listener1.str());
+
+  StringMatchResultListener listener2;
+  EXPECT_FALSE(ExplainMatchResult(Ge(42), 1.5, &listener2));
+  EXPECT_EQ("", listener2.str());
+}
+
+TEST(ExplainMatchResultTest, WorksWithMonomorphicMatcher) {
+  const Matcher<int> is_even = PolymorphicIsEven();
+  StringMatchResultListener listener1;
+  EXPECT_TRUE(ExplainMatchResult(is_even, 42, &listener1));
+  EXPECT_EQ("% 2 == 0", listener1.str());
+
+  const Matcher<const double&> is_zero = Eq(0);
+  StringMatchResultListener listener2;
+  EXPECT_FALSE(ExplainMatchResult(is_zero, 1.5, &listener2));
+  EXPECT_EQ("", listener2.str());
+}
+
+MATCHER(ConstructNoArg, "") { return true; }
+MATCHER_P(Construct1Arg, arg1, "") { return true; }
+MATCHER_P2(Construct2Args, arg1, arg2, "") { return true; }
+
+TEST(MatcherConstruct, ExplicitVsImplicit) {
+  {
+    // No arg constructor can be constructed with empty brace.
+    ConstructNoArgMatcher m = {};
+    (void)m;
+    // And with no args
+    ConstructNoArgMatcher m2;
+    (void)m2;
+  }
+  {
+    // The one arg constructor has an explicit constructor.
+    // This is to prevent the implicit conversion.
+    using M = Construct1ArgMatcherP<int>;
+    EXPECT_TRUE((std::is_constructible<M, int>::value));
+    EXPECT_FALSE((std::is_convertible<int, M>::value));
+  }
+  {
+    // Multiple arg matchers can be constructed with an implicit construction.
+    Construct2ArgsMatcherP2<int, double> m = {1, 2.2};
+    (void)m;
+  }
+}
+
+MATCHER_P(Really, inner_matcher, "") {
+  return ExplainMatchResult(inner_matcher, arg, result_listener);
+}
+
+TEST(ExplainMatchResultTest, WorksInsideMATCHER) {
+  EXPECT_THAT(0, Really(Eq(0)));
+}
+
+TEST(DescribeMatcherTest, WorksWithValue) {
+  EXPECT_EQ("is equal to 42", DescribeMatcher<int>(42));
+  EXPECT_EQ("isn't equal to 42", DescribeMatcher<int>(42, true));
+}
+
+TEST(DescribeMatcherTest, WorksWithMonomorphicMatcher) {
+  const Matcher<int> monomorphic = Le(0);
+  EXPECT_EQ("is <= 0", DescribeMatcher<int>(monomorphic));
+  EXPECT_EQ("isn't <= 0", DescribeMatcher<int>(monomorphic, true));
+}
+
+TEST(DescribeMatcherTest, WorksWithPolymorphicMatcher) {
+  EXPECT_EQ("is even", DescribeMatcher<int>(PolymorphicIsEven()));
+  EXPECT_EQ("is odd", DescribeMatcher<int>(PolymorphicIsEven(), true));
+}
+
+MATCHER_P(FieldIIs, inner_matcher, "") {
+  return ExplainMatchResult(inner_matcher, arg.i, result_listener);
+}
+
+#if GTEST_HAS_RTTI
+TEST(WhenDynamicCastToTest, SameType) {
+  Derived derived;
+  derived.i = 4;
+
+  // Right type. A pointer is passed down.
+  Base* as_base_ptr = &derived;
+  EXPECT_THAT(as_base_ptr, WhenDynamicCastTo<Derived*>(Not(IsNull())));
+  EXPECT_THAT(as_base_ptr, WhenDynamicCastTo<Derived*>(Pointee(FieldIIs(4))));
+  EXPECT_THAT(as_base_ptr,
+              Not(WhenDynamicCastTo<Derived*>(Pointee(FieldIIs(5)))));
+}
+
+TEST(WhenDynamicCastToTest, WrongTypes) {
+  Base base;
+  Derived derived;
+  OtherDerived other_derived;
+
+  // Wrong types. NULL is passed.
+  EXPECT_THAT(&base, Not(WhenDynamicCastTo<Derived*>(Pointee(_))));
+  EXPECT_THAT(&base, WhenDynamicCastTo<Derived*>(IsNull()));
+  Base* as_base_ptr = &derived;
+  EXPECT_THAT(as_base_ptr, Not(WhenDynamicCastTo<OtherDerived*>(Pointee(_))));
+  EXPECT_THAT(as_base_ptr, WhenDynamicCastTo<OtherDerived*>(IsNull()));
+  as_base_ptr = &other_derived;
+  EXPECT_THAT(as_base_ptr, Not(WhenDynamicCastTo<Derived*>(Pointee(_))));
+  EXPECT_THAT(as_base_ptr, WhenDynamicCastTo<Derived*>(IsNull()));
+}
+
+TEST(WhenDynamicCastToTest, AlreadyNull) {
+  // Already NULL.
+  Base* as_base_ptr = nullptr;
+  EXPECT_THAT(as_base_ptr, WhenDynamicCastTo<Derived*>(IsNull()));
+}
+
+struct AmbiguousCastTypes {
+  class VirtualDerived : public virtual Base {};
+  class DerivedSub1 : public VirtualDerived {};
+  class DerivedSub2 : public VirtualDerived {};
+  class ManyDerivedInHierarchy : public DerivedSub1, public DerivedSub2 {};
+};
+
+TEST(WhenDynamicCastToTest, AmbiguousCast) {
+  AmbiguousCastTypes::DerivedSub1 sub1;
+  AmbiguousCastTypes::ManyDerivedInHierarchy many_derived;
+  // Multiply derived from Base. dynamic_cast<> returns NULL.
+  Base* as_base_ptr =
+      static_cast<AmbiguousCastTypes::DerivedSub1*>(&many_derived);
+  EXPECT_THAT(as_base_ptr,
+              WhenDynamicCastTo<AmbiguousCastTypes::VirtualDerived*>(IsNull()));
+  as_base_ptr = &sub1;
+  EXPECT_THAT(
+      as_base_ptr,
+      WhenDynamicCastTo<AmbiguousCastTypes::VirtualDerived*>(Not(IsNull())));
+}
+
+TEST(WhenDynamicCastToTest, Describe) {
+  Matcher<Base*> matcher = WhenDynamicCastTo<Derived*>(Pointee(_));
+  const std::string prefix =
+      "when dynamic_cast to " + internal::GetTypeName<Derived*>() + ", ";
+  EXPECT_EQ(prefix + "points to a value that is anything", Describe(matcher));
+  EXPECT_EQ(prefix + "does not point to a value that is anything",
+            DescribeNegation(matcher));
+}
+
+TEST(WhenDynamicCastToTest, Explain) {
+  Matcher<Base*> matcher = WhenDynamicCastTo<Derived*>(Pointee(_));
+  Base* null = nullptr;
+  EXPECT_THAT(Explain(matcher, null), HasSubstr("NULL"));
+  Derived derived;
+  EXPECT_TRUE(matcher.Matches(&derived));
+  EXPECT_THAT(Explain(matcher, &derived), HasSubstr("which points to "));
+
+  // With references, the matcher itself can fail. Test for that one.
+  Matcher<const Base&> ref_matcher = WhenDynamicCastTo<const OtherDerived&>(_);
+  EXPECT_THAT(Explain(ref_matcher, derived),
+              HasSubstr("which cannot be dynamic_cast"));
+}
+
+TEST(WhenDynamicCastToTest, GoodReference) {
+  Derived derived;
+  derived.i = 4;
+  Base& as_base_ref = derived;
+  EXPECT_THAT(as_base_ref, WhenDynamicCastTo<const Derived&>(FieldIIs(4)));
+  EXPECT_THAT(as_base_ref, WhenDynamicCastTo<const Derived&>(Not(FieldIIs(5))));
+}
+
+TEST(WhenDynamicCastToTest, BadReference) {
+  Derived derived;
+  Base& as_base_ref = derived;
+  EXPECT_THAT(as_base_ref, Not(WhenDynamicCastTo<const OtherDerived&>(_)));
+}
+#endif  // GTEST_HAS_RTTI
+
+class DivisibleByImpl {
+ public:
+  explicit DivisibleByImpl(int a_divider) : divider_(a_divider) {}
+
+  // For testing using ExplainMatchResultTo() with polymorphic matchers.
+  template <typename T>
+  bool MatchAndExplain(const T& n, MatchResultListener* listener) const {
+    *listener << "which is " << (n % divider_) << " modulo " << divider_;
+    return (n % divider_) == 0;
+  }
+
+  void DescribeTo(ostream* os) const { *os << "is divisible by " << divider_; }
+
+  void DescribeNegationTo(ostream* os) const {
+    *os << "is not divisible by " << divider_;
+  }
+
+  void set_divider(int a_divider) { divider_ = a_divider; }
+  int divider() const { return divider_; }
+
+ private:
+  int divider_;
+};
+
+PolymorphicMatcher<DivisibleByImpl> DivisibleBy(int n) {
+  return MakePolymorphicMatcher(DivisibleByImpl(n));
+}
+
+// Tests that when AllOf() fails, only the first failing matcher is
+// asked to explain why.
+TEST(ExplainMatchResultTest, AllOf_False_False) {
+  const Matcher<int> m = AllOf(DivisibleBy(4), DivisibleBy(3));
+  EXPECT_EQ("which is 1 modulo 4", Explain(m, 5));
+}
+
+// Tests that when AllOf() fails, only the first failing matcher is
+// asked to explain why.
+TEST(ExplainMatchResultTest, AllOf_False_True) {
+  const Matcher<int> m = AllOf(DivisibleBy(4), DivisibleBy(3));
+  EXPECT_EQ("which is 2 modulo 4", Explain(m, 6));
+}
+
+// Tests that when AllOf() fails, only the first failing matcher is
+// asked to explain why.
+TEST(ExplainMatchResultTest, AllOf_True_False) {
+  const Matcher<int> m = AllOf(Ge(1), DivisibleBy(3));
+  EXPECT_EQ("which is 2 modulo 3", Explain(m, 5));
+}
+
+// Tests that when AllOf() succeeds, all matchers are asked to explain
+// why.
+TEST(ExplainMatchResultTest, AllOf_True_True) {
+  const Matcher<int> m = AllOf(DivisibleBy(2), DivisibleBy(3));
+  EXPECT_EQ("which is 0 modulo 2, and which is 0 modulo 3", Explain(m, 6));
+}
+
+TEST(ExplainMatchResultTest, AllOf_True_True_2) {
+  const Matcher<int> m = AllOf(Ge(2), Le(3));
+  EXPECT_EQ("", Explain(m, 2));
+}
+
+INSTANTIATE_GTEST_MATCHER_TEST_P(ExplainmatcherResultTest);
+
+TEST_P(ExplainmatcherResultTestP, MonomorphicMatcher) {
+  const Matcher<int> m = GreaterThan(5);
+  EXPECT_EQ("which is 1 more than 5", Explain(m, 6));
+}
+
+// Tests PolymorphicMatcher::mutable_impl().
+TEST(PolymorphicMatcherTest, CanAccessMutableImpl) {
+  PolymorphicMatcher<DivisibleByImpl> m(DivisibleByImpl(42));
+  DivisibleByImpl& impl = m.mutable_impl();
+  EXPECT_EQ(42, impl.divider());
+
+  impl.set_divider(0);
+  EXPECT_EQ(0, m.mutable_impl().divider());
+}
+
+// Tests PolymorphicMatcher::impl().
+TEST(PolymorphicMatcherTest, CanAccessImpl) {
+  const PolymorphicMatcher<DivisibleByImpl> m(DivisibleByImpl(42));
+  const DivisibleByImpl& impl = m.impl();
+  EXPECT_EQ(42, impl.divider());
+}
+
+}  // namespace
+}  // namespace gmock_matchers_test
+}  // namespace testing
+
+GTEST_DISABLE_MSC_WARNINGS_POP_()  // 4244 4100

contrib/googletest/googlemock/test/gmock-matchers-containers_test.cc

@@ -0,0 +1,3137 @@
+// Copyright 2007, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+// Google Mock - a framework for writing C++ mock classes.
+//
+// This file tests some commonly used argument matchers.
+
+#include <algorithm>
+#include <array>
+#include <deque>
+#include <forward_list>
+#include <iterator>
+#include <list>
+#include <memory>
+#include <ostream>
+#include <string>
+#include <tuple>
+#include <vector>
+
+#include "gtest/gtest.h"
+
+// Silence warning C4244: 'initializing': conversion from 'int' to 'short',
+// possible loss of data and C4100, unreferenced local parameter
+GTEST_DISABLE_MSC_WARNINGS_PUSH_(4244 4100)
+
+#include "test/gmock-matchers_test.h"
+
+namespace testing {
+namespace gmock_matchers_test {
+namespace {
+
+std::vector<std::unique_ptr<int>> MakeUniquePtrs(const std::vector<int>& ints) {
+  std::vector<std::unique_ptr<int>> pointers;
+  for (int i : ints) pointers.emplace_back(new int(i));
+  return pointers;
+}
+
+std::string OfType(const std::string& type_name) {
+#if GTEST_HAS_RTTI
+  return IsReadableTypeName(type_name) ? " (of type " + type_name + ")" : "";
+#else
+  return "";
+#endif
+}
+
+TEST(ContainsTest, WorksWithMoveOnly) {
+  ContainerHelper helper;
+  EXPECT_CALL(helper, Call(Contains(Pointee(2))));
+  helper.Call(MakeUniquePtrs({1, 2}));
+}
+
+INSTANTIATE_GTEST_MATCHER_TEST_P(ElementsAreTest);
+
+// Tests the variadic version of the ElementsAreMatcher
+TEST(ElementsAreTest, HugeMatcher) {
+  vector<int> test_vector{1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12};
+
+  EXPECT_THAT(test_vector,
+              ElementsAre(Eq(1), Eq(2), Lt(13), Eq(4), Eq(5), Eq(6), Eq(7),
+                          Eq(8), Eq(9), Eq(10), Gt(1), Eq(12)));
+}
+
+// Tests the variadic version of the UnorderedElementsAreMatcher
+TEST(ElementsAreTest, HugeMatcherStr) {
+  vector<std::string> test_vector{
+      "literal_string", "", "", "", "", "", "", "", "", "", "", ""};
+
+  EXPECT_THAT(test_vector, UnorderedElementsAre("literal_string", _, _, _, _, _,
+                                                _, _, _, _, _, _));
+}
+
+// Tests the variadic version of the UnorderedElementsAreMatcher
+TEST(ElementsAreTest, HugeMatcherUnordered) {
+  vector<int> test_vector{2, 1, 8, 5, 4, 6, 7, 3, 9, 12, 11, 10};
+
+  EXPECT_THAT(test_vector, UnorderedElementsAre(
+                               Eq(2), Eq(1), Gt(7), Eq(5), Eq(4), Eq(6), Eq(7),
+                               Eq(3), Eq(9), Eq(12), Eq(11), Ne(122)));
+}
+
+// Tests that ASSERT_THAT() and EXPECT_THAT() work when the value
+// matches the matcher.
+TEST(MatcherAssertionTest, WorksWhenMatcherIsSatisfied) {
+  ASSERT_THAT(5, Ge(2)) << "This should succeed.";
+  ASSERT_THAT("Foo", EndsWith("oo"));
+  EXPECT_THAT(2, AllOf(Le(7), Ge(0))) << "This should succeed too.";
+  EXPECT_THAT("Hello", StartsWith("Hell"));
+}
+
+// Tests that ASSERT_THAT() and EXPECT_THAT() work when the value
+// doesn't match the matcher.
+TEST(MatcherAssertionTest, WorksWhenMatcherIsNotSatisfied) {
+  // 'n' must be static as it is used in an EXPECT_FATAL_FAILURE(),
+  // which cannot reference auto variables.
+  static unsigned short n;  // NOLINT
+  n = 5;
+
+  EXPECT_FATAL_FAILURE(ASSERT_THAT(n, Gt(10)),
+                       "Value of: n\n"
+                       "Expected: is > 10\n"
+                       "  Actual: 5" +
+                           OfType("unsigned short"));
+  n = 0;
+  EXPECT_NONFATAL_FAILURE(EXPECT_THAT(n, AllOf(Le(7), Ge(5))),
+                          "Value of: n\n"
+                          "Expected: (is <= 7) and (is >= 5)\n"
+                          "  Actual: 0" +
+                              OfType("unsigned short"));
+}
+
+// Tests that ASSERT_THAT() and EXPECT_THAT() work when the argument
+// has a reference type.
+TEST(MatcherAssertionTest, WorksForByRefArguments) {
+  // We use a static variable here as EXPECT_FATAL_FAILURE() cannot
+  // reference auto variables.
+  static int n;
+  n = 0;
+  EXPECT_THAT(n, AllOf(Le(7), Ref(n)));
+  EXPECT_FATAL_FAILURE(ASSERT_THAT(n, Not(Ref(n))),
+                       "Value of: n\n"
+                       "Expected: does not reference the variable @");
+  // Tests the "Actual" part.
+  EXPECT_FATAL_FAILURE(ASSERT_THAT(n, Not(Ref(n))),
+                       "Actual: 0" + OfType("int") + ", which is located @");
+}
+
+// Tests that ASSERT_THAT() and EXPECT_THAT() work when the matcher is
+// monomorphic.
+TEST(MatcherAssertionTest, WorksForMonomorphicMatcher) {
+  Matcher<const char*> starts_with_he = StartsWith("he");
+  ASSERT_THAT("hello", starts_with_he);
+
+  Matcher<const std::string&> ends_with_ok = EndsWith("ok");
+  ASSERT_THAT("book", ends_with_ok);
+  const std::string bad = "bad";
+  EXPECT_NONFATAL_FAILURE(EXPECT_THAT(bad, ends_with_ok),
+                          "Value of: bad\n"
+                          "Expected: ends with \"ok\"\n"
+                          "  Actual: \"bad\"");
+  Matcher<int> is_greater_than_5 = Gt(5);
+  EXPECT_NONFATAL_FAILURE(EXPECT_THAT(5, is_greater_than_5),
+                          "Value of: 5\n"
+                          "Expected: is > 5\n"
+                          "  Actual: 5" +
+                              OfType("int"));
+}
+
+TEST(PointeeTest, RawPointer) {
+  const Matcher<int*> m = Pointee(Ge(0));
+
+  int n = 1;
+  EXPECT_TRUE(m.Matches(&n));
+  n = -1;
+  EXPECT_FALSE(m.Matches(&n));
+  EXPECT_FALSE(m.Matches(nullptr));
+}
+
+TEST(PointeeTest, RawPointerToConst) {
+  const Matcher<const double*> m = Pointee(Ge(0));
+
+  double x = 1;
+  EXPECT_TRUE(m.Matches(&x));
+  x = -1;
+  EXPECT_FALSE(m.Matches(&x));
+  EXPECT_FALSE(m.Matches(nullptr));
+}
+
+TEST(PointeeTest, ReferenceToConstRawPointer) {
+  const Matcher<int* const&> m = Pointee(Ge(0));
+
+  int n = 1;
+  EXPECT_TRUE(m.Matches(&n));
+  n = -1;
+  EXPECT_FALSE(m.Matches(&n));
+  EXPECT_FALSE(m.Matches(nullptr));
+}
+
+TEST(PointeeTest, ReferenceToNonConstRawPointer) {
+  const Matcher<double*&> m = Pointee(Ge(0));
+
+  double x = 1.0;
+  double* p = &x;
+  EXPECT_TRUE(m.Matches(p));
+  x = -1;
+  EXPECT_FALSE(m.Matches(p));
+  p = nullptr;
+  EXPECT_FALSE(m.Matches(p));
+}
+
+TEST(PointeeTest, SmartPointer) {
+  const Matcher<std::unique_ptr<int>> m = Pointee(Ge(0));
+
+  std::unique_ptr<int> n(new int(1));
+  EXPECT_TRUE(m.Matches(n));
+}
+
+TEST(PointeeTest, SmartPointerToConst) {
+  const Matcher<std::unique_ptr<const int>> m = Pointee(Ge(0));
+
+  // There's no implicit conversion from unique_ptr<int> to const
+  // unique_ptr<const int>, so we must pass a unique_ptr<const int> into the
+  // matcher.
+  std::unique_ptr<const int> n(new int(1));
+  EXPECT_TRUE(m.Matches(n));
+}
+
+TEST(PointerTest, RawPointer) {
+  int n = 1;
+  const Matcher<int*> m = Pointer(Eq(&n));
+
+  EXPECT_TRUE(m.Matches(&n));
+
+  int* p = nullptr;
+  EXPECT_FALSE(m.Matches(p));
+  EXPECT_FALSE(m.Matches(nullptr));
+}
+
+TEST(PointerTest, RawPointerToConst) {
+  int n = 1;
+  const Matcher<const int*> m = Pointer(Eq(&n));
+
+  EXPECT_TRUE(m.Matches(&n));
+
+  int* p = nullptr;
+  EXPECT_FALSE(m.Matches(p));
+  EXPECT_FALSE(m.Matches(nullptr));
+}
+
+TEST(PointerTest, SmartPointer) {
+  std::unique_ptr<int> n(new int(10));
+  int* raw_n = n.get();
+  const Matcher<std::unique_ptr<int>> m = Pointer(Eq(raw_n));
+
+  EXPECT_TRUE(m.Matches(n));
+}
+
+TEST(PointerTest, SmartPointerToConst) {
+  std::unique_ptr<const int> n(new int(10));
+  const int* raw_n = n.get();
+  const Matcher<std::unique_ptr<const int>> m = Pointer(Eq(raw_n));
+
+  // There's no implicit conversion from unique_ptr<int> to const
+  // unique_ptr<const int>, so we must pass a unique_ptr<const int> into the
+  // matcher.
+  std::unique_ptr<const int> p(new int(10));
+  EXPECT_FALSE(m.Matches(p));
+}
+
+// Minimal const-propagating pointer.
+template <typename T>
+class ConstPropagatingPtr {
+ public:
+  typedef T element_type;
+
+  ConstPropagatingPtr() : val_() {}
+  explicit ConstPropagatingPtr(T* t) : val_(t) {}
+  ConstPropagatingPtr(const ConstPropagatingPtr& other) : val_(other.val_) {}
+
+  T* get() { return val_; }
+  T& operator*() { return *val_; }
+  // Most smart pointers return non-const T* and T& from the next methods.
+  const T* get() const { return val_; }
+  const T& operator*() const { return *val_; }
+
+ private:
+  T* val_;
+};
+
+INSTANTIATE_GTEST_MATCHER_TEST_P(PointeeTest);
+
+TEST(PointeeTest, WorksWithConstPropagatingPointers) {
+  const Matcher<ConstPropagatingPtr<int>> m = Pointee(Lt(5));
+  int three = 3;
+  const ConstPropagatingPtr<int> co(&three);
+  ConstPropagatingPtr<int> o(&three);
+  EXPECT_TRUE(m.Matches(o));
+  EXPECT_TRUE(m.Matches(co));
+  *o = 6;
+  EXPECT_FALSE(m.Matches(o));
+  EXPECT_FALSE(m.Matches(ConstPropagatingPtr<int>()));
+}
+
+TEST(PointeeTest, NeverMatchesNull) {
+  const Matcher<const char*> m = Pointee(_);
+  EXPECT_FALSE(m.Matches(nullptr));
+}
+
+// Tests that we can write Pointee(value) instead of Pointee(Eq(value)).
+TEST(PointeeTest, MatchesAgainstAValue) {
+  const Matcher<int*> m = Pointee(5);
+
+  int n = 5;
+  EXPECT_TRUE(m.Matches(&n));
+  n = -1;
+  EXPECT_FALSE(m.Matches(&n));
+  EXPECT_FALSE(m.Matches(nullptr));
+}
+
+TEST(PointeeTest, CanDescribeSelf) {
+  const Matcher<int*> m = Pointee(Gt(3));
+  EXPECT_EQ("points to a value that is > 3", Describe(m));
+  EXPECT_EQ("does not point to a value that is > 3", DescribeNegation(m));
+}
+
+TEST_P(PointeeTestP, CanExplainMatchResult) {
+  const Matcher<const std::string*> m = Pointee(StartsWith("Hi"));
+
+  EXPECT_EQ("", Explain(m, static_cast<const std::string*>(nullptr)));
+
+  const Matcher<long*> m2 = Pointee(GreaterThan(1));  // NOLINT
+  long n = 3;                                         // NOLINT
+  EXPECT_EQ("which points to 3" + OfType("long") + ", which is 2 more than 1",
+            Explain(m2, &n));
+}
+
+TEST(PointeeTest, AlwaysExplainsPointee) {
+  const Matcher<int*> m = Pointee(0);
+  int n = 42;
+  EXPECT_EQ("which points to 42" + OfType("int"), Explain(m, &n));
+}
+
+// An uncopyable class.
+class Uncopyable {
+ public:
+  Uncopyable() : value_(-1) {}
+  explicit Uncopyable(int a_value) : value_(a_value) {}
+
+  int value() const { return value_; }
+  void set_value(int i) { value_ = i; }
+
+ private:
+  int value_;
+  Uncopyable(const Uncopyable&) = delete;
+  Uncopyable& operator=(const Uncopyable&) = delete;
+};
+
+// Returns true if and only if x.value() is positive.
+bool ValueIsPositive(const Uncopyable& x) { return x.value() > 0; }
+
+MATCHER_P(UncopyableIs, inner_matcher, "") {
+  return ExplainMatchResult(inner_matcher, arg.value(), result_listener);
+}
+
+// A user-defined struct for testing Field().
+struct AStruct {
+  AStruct() : x(0), y(1.0), z(5), p(nullptr) {}
+  AStruct(const AStruct& rhs)
+      : x(rhs.x), y(rhs.y), z(rhs.z.value()), p(rhs.p) {}
+
+  int x;           // A non-const field.
+  const double y;  // A const field.
+  Uncopyable z;    // An uncopyable field.
+  const char* p;   // A pointer field.
+};
+
+// A derived struct for testing Field().
+struct DerivedStruct : public AStruct {
+  char ch;
+};
+
+INSTANTIATE_GTEST_MATCHER_TEST_P(FieldTest);
+
+// Tests that Field(&Foo::field, ...) works when field is non-const.
+TEST(FieldTest, WorksForNonConstField) {
+  Matcher<AStruct> m = Field(&AStruct::x, Ge(0));
+  Matcher<AStruct> m_with_name = Field("x", &AStruct::x, Ge(0));
+
+  AStruct a;
+  EXPECT_TRUE(m.Matches(a));
+  EXPECT_TRUE(m_with_name.Matches(a));
+  a.x = -1;
+  EXPECT_FALSE(m.Matches(a));
+  EXPECT_FALSE(m_with_name.Matches(a));
+}
+
+// Tests that Field(&Foo::field, ...) works when field is const.
+TEST(FieldTest, WorksForConstField) {
+  AStruct a;
+
+  Matcher<AStruct> m = Field(&AStruct::y, Ge(0.0));
+  Matcher<AStruct> m_with_name = Field("y", &AStruct::y, Ge(0.0));
+  EXPECT_TRUE(m.Matches(a));
+  EXPECT_TRUE(m_with_name.Matches(a));
+  m = Field(&AStruct::y, Le(0.0));
+  m_with_name = Field("y", &AStruct::y, Le(0.0));
+  EXPECT_FALSE(m.Matches(a));
+  EXPECT_FALSE(m_with_name.Matches(a));
+}
+
+// Tests that Field(&Foo::field, ...) works when field is not copyable.
+TEST(FieldTest, WorksForUncopyableField) {
+  AStruct a;
+
+  Matcher<AStruct> m = Field(&AStruct::z, Truly(ValueIsPositive));
+  EXPECT_TRUE(m.Matches(a));
+  m = Field(&AStruct::z, Not(Truly(ValueIsPositive)));
+  EXPECT_FALSE(m.Matches(a));
+}
+
+// Tests that Field(&Foo::field, ...) works when field is a pointer.
+TEST(FieldTest, WorksForPointerField) {
+  // Matching against NULL.
+  Matcher<AStruct> m = Field(&AStruct::p, static_cast<const char*>(nullptr));
+  AStruct a;
+  EXPECT_TRUE(m.Matches(a));
+  a.p = "hi";
+  EXPECT_FALSE(m.Matches(a));
+
+  // Matching a pointer that is not NULL.
+  m = Field(&AStruct::p, StartsWith("hi"));
+  a.p = "hill";
+  EXPECT_TRUE(m.Matches(a));
+  a.p = "hole";
+  EXPECT_FALSE(m.Matches(a));
+}
+
+// Tests that Field() works when the object is passed by reference.
+TEST(FieldTest, WorksForByRefArgument) {
+  Matcher<const AStruct&> m = Field(&AStruct::x, Ge(0));
+
+  AStruct a;
+  EXPECT_TRUE(m.Matches(a));
+  a.x = -1;
+  EXPECT_FALSE(m.Matches(a));
+}
+
+// Tests that Field(&Foo::field, ...) works when the argument's type
+// is a sub-type of Foo.
+TEST(FieldTest, WorksForArgumentOfSubType) {
+  // Note that the matcher expects DerivedStruct but we say AStruct
+  // inside Field().
+  Matcher<const DerivedStruct&> m = Field(&AStruct::x, Ge(0));
+
+  DerivedStruct d;
+  EXPECT_TRUE(m.Matches(d));
+  d.x = -1;
+  EXPECT_FALSE(m.Matches(d));
+}
+
+// Tests that Field(&Foo::field, m) works when field's type and m's
+// argument type are compatible but not the same.
+TEST(FieldTest, WorksForCompatibleMatcherType) {
+  // The field is an int, but the inner matcher expects a signed char.
+  Matcher<const AStruct&> m = Field(&AStruct::x, Matcher<signed char>(Ge(0)));
+
+  AStruct a;
+  EXPECT_TRUE(m.Matches(a));
+  a.x = -1;
+  EXPECT_FALSE(m.Matches(a));
+}
+
+// Tests that Field() can describe itself.
+TEST(FieldTest, CanDescribeSelf) {
+  Matcher<const AStruct&> m = Field(&AStruct::x, Ge(0));
+
+  EXPECT_EQ("is an object whose given field is >= 0", Describe(m));
+  EXPECT_EQ("is an object whose given field isn't >= 0", DescribeNegation(m));
+}
+
+TEST(FieldTest, CanDescribeSelfWithFieldName) {
+  Matcher<const AStruct&> m = Field("field_name", &AStruct::x, Ge(0));
+
+  EXPECT_EQ("is an object whose field `field_name` is >= 0", Describe(m));
+  EXPECT_EQ("is an object whose field `field_name` isn't >= 0",
+            DescribeNegation(m));
+}
+
+// Tests that Field() can explain the match result.
+TEST_P(FieldTestP, CanExplainMatchResult) {
+  Matcher<const AStruct&> m = Field(&AStruct::x, Ge(0));
+
+  AStruct a;
+  a.x = 1;
+  EXPECT_EQ("whose given field is 1" + OfType("int"), Explain(m, a));
+
+  m = Field(&AStruct::x, GreaterThan(0));
+  EXPECT_EQ(
+      "whose given field is 1" + OfType("int") + ", which is 1 more than 0",
+      Explain(m, a));
+}
+
+TEST_P(FieldTestP, CanExplainMatchResultWithFieldName) {
+  Matcher<const AStruct&> m = Field("field_name", &AStruct::x, Ge(0));
+
+  AStruct a;
+  a.x = 1;
+  EXPECT_EQ("whose field `field_name` is 1" + OfType("int"), Explain(m, a));
+
+  m = Field("field_name", &AStruct::x, GreaterThan(0));
+  EXPECT_EQ("whose field `field_name` is 1" + OfType("int") +
+                ", which is 1 more than 0",
+            Explain(m, a));
+}
+
+INSTANTIATE_GTEST_MATCHER_TEST_P(FieldForPointerTest);
+
+// Tests that Field() works when the argument is a pointer to const.
+TEST(FieldForPointerTest, WorksForPointerToConst) {
+  Matcher<const AStruct*> m = Field(&AStruct::x, Ge(0));
+
+  AStruct a;
+  EXPECT_TRUE(m.Matches(&a));
+  a.x = -1;
+  EXPECT_FALSE(m.Matches(&a));
+}
+
+// Tests that Field() works when the argument is a pointer to non-const.
+TEST(FieldForPointerTest, WorksForPointerToNonConst) {
+  Matcher<AStruct*> m = Field(&AStruct::x, Ge(0));
+
+  AStruct a;
+  EXPECT_TRUE(m.Matches(&a));
+  a.x = -1;
+  EXPECT_FALSE(m.Matches(&a));
+}
+
+// Tests that Field() works when the argument is a reference to a const pointer.
+TEST(FieldForPointerTest, WorksForReferenceToConstPointer) {
+  Matcher<AStruct* const&> m = Field(&AStruct::x, Ge(0));
+
+  AStruct a;
+  EXPECT_TRUE(m.Matches(&a));
+  a.x = -1;
+  EXPECT_FALSE(m.Matches(&a));
+}
+
+// Tests that Field() does not match the NULL pointer.
+TEST(FieldForPointerTest, DoesNotMatchNull) {
+  Matcher<const AStruct*> m = Field(&AStruct::x, _);
+  EXPECT_FALSE(m.Matches(nullptr));
+}
+
+// Tests that Field(&Foo::field, ...) works when the argument's type
+// is a sub-type of const Foo*.
+TEST(FieldForPointerTest, WorksForArgumentOfSubType) {
+  // Note that the matcher expects DerivedStruct but we say AStruct
+  // inside Field().
+  Matcher<DerivedStruct*> m = Field(&AStruct::x, Ge(0));
+
+  DerivedStruct d;
+  EXPECT_TRUE(m.Matches(&d));
+  d.x = -1;
+  EXPECT_FALSE(m.Matches(&d));
+}
+
+// Tests that Field() can describe itself when used to match a pointer.
+TEST(FieldForPointerTest, CanDescribeSelf) {
+  Matcher<const AStruct*> m = Field(&AStruct::x, Ge(0));
+
+  EXPECT_EQ("is an object whose given field is >= 0", Describe(m));
+  EXPECT_EQ("is an object whose given field isn't >= 0", DescribeNegation(m));
+}
+
+TEST(FieldForPointerTest, CanDescribeSelfWithFieldName) {
+  Matcher<const AStruct*> m = Field("field_name", &AStruct::x, Ge(0));
+
+  EXPECT_EQ("is an object whose field `field_name` is >= 0", Describe(m));
+  EXPECT_EQ("is an object whose field `field_name` isn't >= 0",
+            DescribeNegation(m));
+}
+
+// Tests that Field() can explain the result of matching a pointer.
+TEST_P(FieldForPointerTestP, CanExplainMatchResult) {
+  Matcher<const AStruct*> m = Field(&AStruct::x, Ge(0));
+
+  AStruct a;
+  a.x = 1;
+  EXPECT_EQ("", Explain(m, static_cast<const AStruct*>(nullptr)));
+  EXPECT_EQ("which points to an object whose given field is 1" + OfType("int"),
+            Explain(m, &a));
+
+  m = Field(&AStruct::x, GreaterThan(0));
+  EXPECT_EQ("which points to an object whose given field is 1" + OfType("int") +
+                ", which is 1 more than 0",
+            Explain(m, &a));
+}
+
+TEST_P(FieldForPointerTestP, CanExplainMatchResultWithFieldName) {
+  Matcher<const AStruct*> m = Field("field_name", &AStruct::x, Ge(0));
+
+  AStruct a;
+  a.x = 1;
+  EXPECT_EQ("", Explain(m, static_cast<const AStruct*>(nullptr)));
+  EXPECT_EQ(
+      "which points to an object whose field `field_name` is 1" + OfType("int"),
+      Explain(m, &a));
+
+  m = Field("field_name", &AStruct::x, GreaterThan(0));
+  EXPECT_EQ("which points to an object whose field `field_name` is 1" +
+                OfType("int") + ", which is 1 more than 0",
+            Explain(m, &a));
+}
+
+// A user-defined class for testing Property().
+class AClass {
+ public:
+  AClass() : n_(0) {}
+
+  // A getter that returns a non-reference.
+  int n() const { return n_; }
+
+  void set_n(int new_n) { n_ = new_n; }
+
+  // A getter that returns a reference to const.
+  const std::string& s() const { return s_; }
+
+  const std::string& s_ref() const& { return s_; }
+
+  void set_s(const std::string& new_s) { s_ = new_s; }
+
+  // A getter that returns a reference to non-const.
+  double& x() const { return x_; }
+
+ private:
+  int n_;
+  std::string s_;
+
+  static double x_;
+};
+
+double AClass::x_ = 0.0;
+
+// A derived class for testing Property().
+class DerivedClass : public AClass {
+ public:
+  int k() const { return k_; }
+
+ private:
+  int k_;
+};
+
+INSTANTIATE_GTEST_MATCHER_TEST_P(PropertyTest);
+
+// Tests that Property(&Foo::property, ...) works when property()
+// returns a non-reference.
+TEST(PropertyTest, WorksForNonReferenceProperty) {
+  Matcher<const AClass&> m = Property(&AClass::n, Ge(0));
+  Matcher<const AClass&> m_with_name = Property("n", &AClass::n, Ge(0));
+
+  AClass a;
+  a.set_n(1);
+  EXPECT_TRUE(m.Matches(a));
+  EXPECT_TRUE(m_with_name.Matches(a));
+
+  a.set_n(-1);
+  EXPECT_FALSE(m.Matches(a));
+  EXPECT_FALSE(m_with_name.Matches(a));
+}
+
+// Tests that Property(&Foo::property, ...) works when property()
+// returns a reference to const.
+TEST(PropertyTest, WorksForReferenceToConstProperty) {
+  Matcher<const AClass&> m = Property(&AClass::s, StartsWith("hi"));
+  Matcher<const AClass&> m_with_name =
+      Property("s", &AClass::s, StartsWith("hi"));
+
+  AClass a;
+  a.set_s("hill");
+  EXPECT_TRUE(m.Matches(a));
+  EXPECT_TRUE(m_with_name.Matches(a));
+
+  a.set_s("hole");
+  EXPECT_FALSE(m.Matches(a));
+  EXPECT_FALSE(m_with_name.Matches(a));
+}
+
+// Tests that Property(&Foo::property, ...) works when property() is
+// ref-qualified.
+TEST(PropertyTest, WorksForRefQualifiedProperty) {
+  Matcher<const AClass&> m = Property(&AClass::s_ref, StartsWith("hi"));
+  Matcher<const AClass&> m_with_name =
+      Property("s", &AClass::s_ref, StartsWith("hi"));
+
+  AClass a;
+  a.set_s("hill");
+  EXPECT_TRUE(m.Matches(a));
+  EXPECT_TRUE(m_with_name.Matches(a));
+
+  a.set_s("hole");
+  EXPECT_FALSE(m.Matches(a));
+  EXPECT_FALSE(m_with_name.Matches(a));
+}
+
+// Tests that Property(&Foo::property, ...) works when property()
+// returns a reference to non-const.
+TEST(PropertyTest, WorksForReferenceToNonConstProperty) {
+  double x = 0.0;
+  AClass a;
+
+  Matcher<const AClass&> m = Property(&AClass::x, Ref(x));
+  EXPECT_FALSE(m.Matches(a));
+
+  m = Property(&AClass::x, Not(Ref(x)));
+  EXPECT_TRUE(m.Matches(a));
+}
+
+// Tests that Property(&Foo::property, ...) works when the argument is
+// passed by value.
+TEST(PropertyTest, WorksForByValueArgument) {
+  Matcher<AClass> m = Property(&AClass::s, StartsWith("hi"));
+
+  AClass a;
+  a.set_s("hill");
+  EXPECT_TRUE(m.Matches(a));
+
+  a.set_s("hole");
+  EXPECT_FALSE(m.Matches(a));
+}
+
+// Tests that Property(&Foo::property, ...) works when the argument's
+// type is a sub-type of Foo.
+TEST(PropertyTest, WorksForArgumentOfSubType) {
+  // The matcher expects a DerivedClass, but inside the Property() we
+  // say AClass.
+  Matcher<const DerivedClass&> m = Property(&AClass::n, Ge(0));
+
+  DerivedClass d;
+  d.set_n(1);
+  EXPECT_TRUE(m.Matches(d));
+
+  d.set_n(-1);
+  EXPECT_FALSE(m.Matches(d));
+}
+
+// Tests that Property(&Foo::property, m) works when property()'s type
+// and m's argument type are compatible but different.
+TEST(PropertyTest, WorksForCompatibleMatcherType) {
+  // n() returns an int but the inner matcher expects a signed char.
+  Matcher<const AClass&> m = Property(&AClass::n, Matcher<signed char>(Ge(0)));
+
+  Matcher<const AClass&> m_with_name =
+      Property("n", &AClass::n, Matcher<signed char>(Ge(0)));
+
+  AClass a;
+  EXPECT_TRUE(m.Matches(a));
+  EXPECT_TRUE(m_with_name.Matches(a));
+  a.set_n(-1);
+  EXPECT_FALSE(m.Matches(a));
+  EXPECT_FALSE(m_with_name.Matches(a));
+}
+
+// Tests that Property() can describe itself.
+TEST(PropertyTest, CanDescribeSelf) {
+  Matcher<const AClass&> m = Property(&AClass::n, Ge(0));
+
+  EXPECT_EQ("is an object whose given property is >= 0", Describe(m));
+  EXPECT_EQ("is an object whose given property isn't >= 0",
+            DescribeNegation(m));
+}
+
+TEST(PropertyTest, CanDescribeSelfWithPropertyName) {
+  Matcher<const AClass&> m = Property("fancy_name", &AClass::n, Ge(0));
+
+  EXPECT_EQ("is an object whose property `fancy_name` is >= 0", Describe(m));
+  EXPECT_EQ("is an object whose property `fancy_name` isn't >= 0",
+            DescribeNegation(m));
+}
+
+// Tests that Property() can explain the match result.
+TEST_P(PropertyTestP, CanExplainMatchResult) {
+  Matcher<const AClass&> m = Property(&AClass::n, Ge(0));
+
+  AClass a;
+  a.set_n(1);
+  EXPECT_EQ("whose given property is 1" + OfType("int"), Explain(m, a));
+
+  m = Property(&AClass::n, GreaterThan(0));
+  EXPECT_EQ(
+      "whose given property is 1" + OfType("int") + ", which is 1 more than 0",
+      Explain(m, a));
+}
+
+TEST_P(PropertyTestP, CanExplainMatchResultWithPropertyName) {
+  Matcher<const AClass&> m = Property("fancy_name", &AClass::n, Ge(0));
+
+  AClass a;
+  a.set_n(1);
+  EXPECT_EQ("whose property `fancy_name` is 1" + OfType("int"), Explain(m, a));
+
+  m = Property("fancy_name", &AClass::n, GreaterThan(0));
+  EXPECT_EQ("whose property `fancy_name` is 1" + OfType("int") +
+                ", which is 1 more than 0",
+            Explain(m, a));
+}
+
+INSTANTIATE_GTEST_MATCHER_TEST_P(PropertyForPointerTest);
+
+// Tests that Property() works when the argument is a pointer to const.
+TEST(PropertyForPointerTest, WorksForPointerToConst) {
+  Matcher<const AClass*> m = Property(&AClass::n, Ge(0));
+
+  AClass a;
+  a.set_n(1);
+  EXPECT_TRUE(m.Matches(&a));
+
+  a.set_n(-1);
+  EXPECT_FALSE(m.Matches(&a));
+}
+
+// Tests that Property() works when the argument is a pointer to non-const.
+TEST(PropertyForPointerTest, WorksForPointerToNonConst) {
+  Matcher<AClass*> m = Property(&AClass::s, StartsWith("hi"));
+
+  AClass a;
+  a.set_s("hill");
+  EXPECT_TRUE(m.Matches(&a));
+
+  a.set_s("hole");
+  EXPECT_FALSE(m.Matches(&a));
+}
+
+// Tests that Property() works when the argument is a reference to a
+// const pointer.
+TEST(PropertyForPointerTest, WorksForReferenceToConstPointer) {
+  Matcher<AClass* const&> m = Property(&AClass::s, StartsWith("hi"));
+
+  AClass a;
+  a.set_s("hill");
+  EXPECT_TRUE(m.Matches(&a));
+
+  a.set_s("hole");
+  EXPECT_FALSE(m.Matches(&a));
+}
+
+// Tests that Property() does not match the NULL pointer.
+TEST(PropertyForPointerTest, WorksForReferenceToNonConstProperty) {
+  Matcher<const AClass*> m = Property(&AClass::x, _);
+  EXPECT_FALSE(m.Matches(nullptr));
+}
+
+// Tests that Property(&Foo::property, ...) works when the argument's
+// type is a sub-type of const Foo*.
+TEST(PropertyForPointerTest, WorksForArgumentOfSubType) {
+  // The matcher expects a DerivedClass, but inside the Property() we
+  // say AClass.
+  Matcher<const DerivedClass*> m = Property(&AClass::n, Ge(0));
+
+  DerivedClass d;
+  d.set_n(1);
+  EXPECT_TRUE(m.Matches(&d));
+
+  d.set_n(-1);
+  EXPECT_FALSE(m.Matches(&d));
+}
+
+// Tests that Property() can describe itself when used to match a pointer.
+TEST(PropertyForPointerTest, CanDescribeSelf) {
+  Matcher<const AClass*> m = Property(&AClass::n, Ge(0));
+
+  EXPECT_EQ("is an object whose given property is >= 0", Describe(m));
+  EXPECT_EQ("is an object whose given property isn't >= 0",
+            DescribeNegation(m));
+}
+
+TEST(PropertyForPointerTest, CanDescribeSelfWithPropertyDescription) {
+  Matcher<const AClass*> m = Property("fancy_name", &AClass::n, Ge(0));
+
+  EXPECT_EQ("is an object whose property `fancy_name` is >= 0", Describe(m));
+  EXPECT_EQ("is an object whose property `fancy_name` isn't >= 0",
+            DescribeNegation(m));
+}
+
+// Tests that Property() can explain the result of matching a pointer.
+TEST_P(PropertyForPointerTestP, CanExplainMatchResult) {
+  Matcher<const AClass*> m = Property(&AClass::n, Ge(0));
+
+  AClass a;
+  a.set_n(1);
+  EXPECT_EQ("", Explain(m, static_cast<const AClass*>(nullptr)));
+  EXPECT_EQ(
+      "which points to an object whose given property is 1" + OfType("int"),
+      Explain(m, &a));
+
+  m = Property(&AClass::n, GreaterThan(0));
+  EXPECT_EQ("which points to an object whose given property is 1" +
+                OfType("int") + ", which is 1 more than 0",
+            Explain(m, &a));
+}
+
+TEST_P(PropertyForPointerTestP, CanExplainMatchResultWithPropertyName) {
+  Matcher<const AClass*> m = Property("fancy_name", &AClass::n, Ge(0));
+
+  AClass a;
+  a.set_n(1);
+  EXPECT_EQ("", Explain(m, static_cast<const AClass*>(nullptr)));
+  EXPECT_EQ("which points to an object whose property `fancy_name` is 1" +
+                OfType("int"),
+            Explain(m, &a));
+
+  m = Property("fancy_name", &AClass::n, GreaterThan(0));
+  EXPECT_EQ("which points to an object whose property `fancy_name` is 1" +
+                OfType("int") + ", which is 1 more than 0",
+            Explain(m, &a));
+}
+
+// Tests ResultOf.
+
+// Tests that ResultOf(f, ...) compiles and works as expected when f is a
+// function pointer.
+std::string IntToStringFunction(int input) {
+  return input == 1 ? "foo" : "bar";
+}
+
+INSTANTIATE_GTEST_MATCHER_TEST_P(ResultOfTest);
+
+TEST(ResultOfTest, WorksForFunctionPointers) {
+  Matcher<int> matcher = ResultOf(&IntToStringFunction, Eq(std::string("foo")));
+
+  EXPECT_TRUE(matcher.Matches(1));
+  EXPECT_FALSE(matcher.Matches(2));
+}
+
+// Tests that ResultOf() can describe itself.
+TEST(ResultOfTest, CanDescribeItself) {
+  Matcher<int> matcher = ResultOf(&IntToStringFunction, StrEq("foo"));
+
+  EXPECT_EQ(
+      "is mapped by the given callable to a value that "
+      "is equal to \"foo\"",
+      Describe(matcher));
+  EXPECT_EQ(
+      "is mapped by the given callable to a value that "
+      "isn't equal to \"foo\"",
+      DescribeNegation(matcher));
+}
+
+// Tests that ResultOf() can describe itself when provided a result description.
+TEST(ResultOfTest, CanDescribeItselfWithResultDescription) {
+  Matcher<int> matcher =
+      ResultOf("string conversion", &IntToStringFunction, StrEq("foo"));
+
+  EXPECT_EQ("whose string conversion is equal to \"foo\"", Describe(matcher));
+  EXPECT_EQ("whose string conversion isn't equal to \"foo\"",
+            DescribeNegation(matcher));
+}
+
+// Tests that ResultOf() can explain the match result.
+int IntFunction(int input) { return input == 42 ? 80 : 90; }
+
+TEST_P(ResultOfTestP, CanExplainMatchResult) {
+  Matcher<int> matcher = ResultOf(&IntFunction, Ge(85));
+  EXPECT_EQ("which is mapped by the given callable to 90" + OfType("int"),
+            Explain(matcher, 36));
+
+  matcher = ResultOf(&IntFunction, GreaterThan(85));
+  EXPECT_EQ("which is mapped by the given callable to 90" + OfType("int") +
+                ", which is 5 more than 85",
+            Explain(matcher, 36));
+}
+
+TEST_P(ResultOfTestP, CanExplainMatchResultWithResultDescription) {
+  Matcher<int> matcher = ResultOf("magic int conversion", &IntFunction, Ge(85));
+  EXPECT_EQ("whose magic int conversion is 90" + OfType("int"),
+            Explain(matcher, 36));
+
+  matcher = ResultOf("magic int conversion", &IntFunction, GreaterThan(85));
+  EXPECT_EQ("whose magic int conversion is 90" + OfType("int") +
+                ", which is 5 more than 85",
+            Explain(matcher, 36));
+}
+
+// Tests that ResultOf(f, ...) compiles and works as expected when f(x)
+// returns a non-reference.
+TEST(ResultOfTest, WorksForNonReferenceResults) {
+  Matcher<int> matcher = ResultOf(&IntFunction, Eq(80));
+
+  EXPECT_TRUE(matcher.Matches(42));
+  EXPECT_FALSE(matcher.Matches(36));
+}
+
+// Tests that ResultOf(f, ...) compiles and works as expected when f(x)
+// returns a reference to non-const.
+double& DoubleFunction(double& input) { return input; }  // NOLINT
+
+Uncopyable& RefUncopyableFunction(Uncopyable& obj) {  // NOLINT
+  return obj;
+}
+
+TEST(ResultOfTest, WorksForReferenceToNonConstResults) {
+  double x = 3.14;
+  double x2 = x;
+  Matcher<double&> matcher = ResultOf(&DoubleFunction, Ref(x));
+
+  EXPECT_TRUE(matcher.Matches(x));
+  EXPECT_FALSE(matcher.Matches(x2));
+
+  // Test that ResultOf works with uncopyable objects
+  Uncopyable obj(0);
+  Uncopyable obj2(0);
+  Matcher<Uncopyable&> matcher2 = ResultOf(&RefUncopyableFunction, Ref(obj));
+
+  EXPECT_TRUE(matcher2.Matches(obj));
+  EXPECT_FALSE(matcher2.Matches(obj2));
+}
+
+// Tests that ResultOf(f, ...) compiles and works as expected when f(x)
+// returns a reference to const.
+const std::string& StringFunction(const std::string& input) { return input; }
+
+TEST(ResultOfTest, WorksForReferenceToConstResults) {
+  std::string s = "foo";
+  std::string s2 = s;
+  Matcher<const std::string&> matcher = ResultOf(&StringFunction, Ref(s));
+
+  EXPECT_TRUE(matcher.Matches(s));
+  EXPECT_FALSE(matcher.Matches(s2));
+}
+
+// Tests that ResultOf(f, m) works when f(x) and m's
+// argument types are compatible but different.
+TEST(ResultOfTest, WorksForCompatibleMatcherTypes) {
+  // IntFunction() returns int but the inner matcher expects a signed char.
+  Matcher<int> matcher = ResultOf(IntFunction, Matcher<signed char>(Ge(85)));
+
+  EXPECT_TRUE(matcher.Matches(36));
+  EXPECT_FALSE(matcher.Matches(42));
+}
+
+// Tests that the program aborts when ResultOf is passed
+// a NULL function pointer.
+TEST(ResultOfDeathTest, DiesOnNullFunctionPointers) {
+  EXPECT_DEATH_IF_SUPPORTED(
+      ResultOf(static_cast<std::string (*)(int dummy)>(nullptr),
+               Eq(std::string("foo"))),
+      "NULL function pointer is passed into ResultOf\\(\\)\\.");
+}
+
+// Tests that ResultOf(f, ...) compiles and works as expected when f is a
+// function reference.
+TEST(ResultOfTest, WorksForFunctionReferences) {
+  Matcher<int> matcher = ResultOf(IntToStringFunction, StrEq("foo"));
+  EXPECT_TRUE(matcher.Matches(1));
+  EXPECT_FALSE(matcher.Matches(2));
+}
+
+// Tests that ResultOf(f, ...) compiles and works as expected when f is a
+// function object.
+struct Functor {
+  std::string operator()(int input) const { return IntToStringFunction(input); }
+};
+
+TEST(ResultOfTest, WorksForFunctors) {
+  Matcher<int> matcher = ResultOf(Functor(), Eq(std::string("foo")));
+
+  EXPECT_TRUE(matcher.Matches(1));
+  EXPECT_FALSE(matcher.Matches(2));
+}
+
+// Tests that ResultOf(f, ...) compiles and works as expected when f is a
+// functor with more than one operator() defined. ResultOf() must work
+// for each defined operator().
+struct PolymorphicFunctor {
+  typedef int result_type;
+  int operator()(int n) { return n; }
+  int operator()(const char* s) { return static_cast<int>(strlen(s)); }
+  std::string operator()(int* p) { return p ? "good ptr" : "null"; }
+};
+
+TEST(ResultOfTest, WorksForPolymorphicFunctors) {
+  Matcher<int> matcher_int = ResultOf(PolymorphicFunctor(), Ge(5));
+
+  EXPECT_TRUE(matcher_int.Matches(10));
+  EXPECT_FALSE(matcher_int.Matches(2));
+
+  Matcher<const char*> matcher_string = ResultOf(PolymorphicFunctor(), Ge(5));
+
+  EXPECT_TRUE(matcher_string.Matches("long string"));
+  EXPECT_FALSE(matcher_string.Matches("shrt"));
+}
+
+TEST(ResultOfTest, WorksForPolymorphicFunctorsIgnoringResultType) {
+  Matcher<int*> matcher = ResultOf(PolymorphicFunctor(), "good ptr");
+
+  int n = 0;
+  EXPECT_TRUE(matcher.Matches(&n));
+  EXPECT_FALSE(matcher.Matches(nullptr));
+}
+
+TEST(ResultOfTest, WorksForLambdas) {
+  Matcher<int> matcher = ResultOf(
+      [](int str_len) {
+        return std::string(static_cast<size_t>(str_len), 'x');
+      },
+      "xxx");
+  EXPECT_TRUE(matcher.Matches(3));
+  EXPECT_FALSE(matcher.Matches(1));
+}
+
+TEST(ResultOfTest, WorksForNonCopyableArguments) {
+  Matcher<std::unique_ptr<int>> matcher = ResultOf(
+      [](const std::unique_ptr<int>& str_len) {
+        return std::string(static_cast<size_t>(*str_len), 'x');
+      },
+      "xxx");
+  EXPECT_TRUE(matcher.Matches(std::unique_ptr<int>(new int(3))));
+  EXPECT_FALSE(matcher.Matches(std::unique_ptr<int>(new int(1))));
+}
+
+const int* ReferencingFunction(const int& n) { return &n; }
+
+struct ReferencingFunctor {
+  typedef const int* result_type;
+  result_type operator()(const int& n) { return &n; }
+};
+
+TEST(ResultOfTest, WorksForReferencingCallables) {
+  const int n = 1;
+  const int n2 = 1;
+  Matcher<const int&> matcher2 = ResultOf(ReferencingFunction, Eq(&n));
+  EXPECT_TRUE(matcher2.Matches(n));
+  EXPECT_FALSE(matcher2.Matches(n2));
+
+  Matcher<const int&> matcher3 = ResultOf(ReferencingFunctor(), Eq(&n));
+  EXPECT_TRUE(matcher3.Matches(n));
+  EXPECT_FALSE(matcher3.Matches(n2));
+}
+
+TEST(SizeIsTest, ImplementsSizeIs) {
+  vector<int> container;
+  EXPECT_THAT(container, SizeIs(0));
+  EXPECT_THAT(container, Not(SizeIs(1)));
+  container.push_back(0);
+  EXPECT_THAT(container, Not(SizeIs(0)));
+  EXPECT_THAT(container, SizeIs(1));
+  container.push_back(0);
+  EXPECT_THAT(container, Not(SizeIs(0)));
+  EXPECT_THAT(container, SizeIs(2));
+}
+
+TEST(SizeIsTest, WorksWithMap) {
+  map<std::string, int> container;
+  EXPECT_THAT(container, SizeIs(0));
+  EXPECT_THAT(container, Not(SizeIs(1)));
+  container.insert(make_pair("foo", 1));
+  EXPECT_THAT(container, Not(SizeIs(0)));
+  EXPECT_THAT(container, SizeIs(1));
+  container.insert(make_pair("bar", 2));
+  EXPECT_THAT(container, Not(SizeIs(0)));
+  EXPECT_THAT(container, SizeIs(2));
+}
+
+TEST(SizeIsTest, WorksWithReferences) {
+  vector<int> container;
+  Matcher<const vector<int>&> m = SizeIs(1);
+  EXPECT_THAT(container, Not(m));
+  container.push_back(0);
+  EXPECT_THAT(container, m);
+}
+
+TEST(SizeIsTest, WorksWithMoveOnly) {
+  ContainerHelper helper;
+  EXPECT_CALL(helper, Call(SizeIs(3)));
+  helper.Call(MakeUniquePtrs({1, 2, 3}));
+}
+
+// SizeIs should work for any type that provides a size() member function.
+// For example, a size_type member type should not need to be provided.
+struct MinimalistCustomType {
+  int size() const { return 1; }
+};
+TEST(SizeIsTest, WorksWithMinimalistCustomType) {
+  MinimalistCustomType container;
+  EXPECT_THAT(container, SizeIs(1));
+  EXPECT_THAT(container, Not(SizeIs(0)));
+}
+
+TEST(SizeIsTest, CanDescribeSelf) {
+  Matcher<vector<int>> m = SizeIs(2);
+  EXPECT_EQ("has a size that is equal to 2", Describe(m));
+  EXPECT_EQ("has a size that isn't equal to 2", DescribeNegation(m));
+}
+
+TEST(SizeIsTest, ExplainsResult) {
+  Matcher<vector<int>> m1 = SizeIs(2);
+  Matcher<vector<int>> m2 = SizeIs(Lt(2u));
+  Matcher<vector<int>> m3 = SizeIs(AnyOf(0, 3));
+  Matcher<vector<int>> m4 = SizeIs(Gt(1u));
+  vector<int> container;
+  EXPECT_EQ("whose size 0 doesn't match", Explain(m1, container));
+  EXPECT_EQ("whose size 0 matches", Explain(m2, container));
+  EXPECT_EQ("whose size 0 matches", Explain(m3, container));
+  EXPECT_EQ("whose size 0 doesn't match", Explain(m4, container));
+  container.push_back(0);
+  container.push_back(0);
+  EXPECT_EQ("whose size 2 matches", Explain(m1, container));
+  EXPECT_EQ("whose size 2 doesn't match", Explain(m2, container));
+  EXPECT_EQ("whose size 2 doesn't match", Explain(m3, container));
+  EXPECT_EQ("whose size 2 matches", Explain(m4, container));
+}
+
+TEST(WhenSortedByTest, WorksForEmptyContainer) {
+  const vector<int> numbers;
+  EXPECT_THAT(numbers, WhenSortedBy(less<int>(), ElementsAre()));
+  EXPECT_THAT(numbers, Not(WhenSortedBy(less<int>(), ElementsAre(1))));
+}
+
+TEST(WhenSortedByTest, WorksForNonEmptyContainer) {
+  vector<unsigned> numbers;
+  numbers.push_back(3);
+  numbers.push_back(1);
+  numbers.push_back(2);
+  numbers.push_back(2);
+  EXPECT_THAT(numbers,
+              WhenSortedBy(greater<unsigned>(), ElementsAre(3, 2, 2, 1)));
+  EXPECT_THAT(numbers,
+              Not(WhenSortedBy(greater<unsigned>(), ElementsAre(1, 2, 2, 3))));
+}
+
+TEST(WhenSortedByTest, WorksForNonVectorContainer) {
+  list<std::string> words;
+  words.push_back("say");
+  words.push_back("hello");
+  words.push_back("world");
+  EXPECT_THAT(words, WhenSortedBy(less<std::string>(),
+                                  ElementsAre("hello", "say", "world")));
+  EXPECT_THAT(words, Not(WhenSortedBy(less<std::string>(),
+                                      ElementsAre("say", "hello", "world"))));
+}
+
+TEST(WhenSortedByTest, WorksForNativeArray) {
+  const int numbers[] = {1, 3, 2, 4};
+  const int sorted_numbers[] = {1, 2, 3, 4};
+  EXPECT_THAT(numbers, WhenSortedBy(less<int>(), ElementsAre(1, 2, 3, 4)));
+  EXPECT_THAT(numbers,
+              WhenSortedBy(less<int>(), ElementsAreArray(sorted_numbers)));
+  EXPECT_THAT(numbers, Not(WhenSortedBy(less<int>(), ElementsAre(1, 3, 2, 4))));
+}
+
+TEST(WhenSortedByTest, CanDescribeSelf) {
+  const Matcher<vector<int>> m = WhenSortedBy(less<int>(), ElementsAre(1, 2));
+  EXPECT_EQ(
+      "(when sorted) has 2 elements where\n"
+      "element #0 is equal to 1,\n"
+      "element #1 is equal to 2",
+      Describe(m));
+  EXPECT_EQ(
+      "(when sorted) doesn't have 2 elements, or\n"
+      "element #0 isn't equal to 1, or\n"
+      "element #1 isn't equal to 2",
+      DescribeNegation(m));
+}
+
+TEST(WhenSortedByTest, ExplainsMatchResult) {
+  const int a[] = {2, 1};
+  EXPECT_EQ("which is { 1, 2 } when sorted, whose element #0 doesn't match",
+            Explain(WhenSortedBy(less<int>(), ElementsAre(2, 3)), a));
+  EXPECT_EQ("which is { 1, 2 } when sorted",
+            Explain(WhenSortedBy(less<int>(), ElementsAre(1, 2)), a));
+}
+
+// WhenSorted() is a simple wrapper on WhenSortedBy().  Hence we don't
+// need to test it as exhaustively as we test the latter.
+
+TEST(WhenSortedTest, WorksForEmptyContainer) {
+  const vector<int> numbers;
+  EXPECT_THAT(numbers, WhenSorted(ElementsAre()));
+  EXPECT_THAT(numbers, Not(WhenSorted(ElementsAre(1))));
+}
+
+TEST(WhenSortedTest, WorksForNonEmptyContainer) {
+  list<std::string> words;
+  words.push_back("3");
+  words.push_back("1");
+  words.push_back("2");
+  words.push_back("2");
+  EXPECT_THAT(words, WhenSorted(ElementsAre("1", "2", "2", "3")));
+  EXPECT_THAT(words, Not(WhenSorted(ElementsAre("3", "1", "2", "2"))));
+}
+
+TEST(WhenSortedTest, WorksForMapTypes) {
+  map<std::string, int> word_counts;
+  word_counts["and"] = 1;
+  word_counts["the"] = 1;
+  word_counts["buffalo"] = 2;
+  EXPECT_THAT(word_counts,
+              WhenSorted(ElementsAre(Pair("and", 1), Pair("buffalo", 2),
+                                     Pair("the", 1))));
+  EXPECT_THAT(word_counts,
+              Not(WhenSorted(ElementsAre(Pair("and", 1), Pair("the", 1),
+                                         Pair("buffalo", 2)))));
+}
+
+TEST(WhenSortedTest, WorksForMultiMapTypes) {
+  multimap<int, int> ifib;
+  ifib.insert(make_pair(8, 6));
+  ifib.insert(make_pair(2, 3));
+  ifib.insert(make_pair(1, 1));
+  ifib.insert(make_pair(3, 4));
+  ifib.insert(make_pair(1, 2));
+  ifib.insert(make_pair(5, 5));
+  EXPECT_THAT(ifib,
+              WhenSorted(ElementsAre(Pair(1, 1), Pair(1, 2), Pair(2, 3),
+                                     Pair(3, 4), Pair(5, 5), Pair(8, 6))));
+  EXPECT_THAT(ifib,
+              Not(WhenSorted(ElementsAre(Pair(8, 6), Pair(2, 3), Pair(1, 1),
+                                         Pair(3, 4), Pair(1, 2), Pair(5, 5)))));
+}
+
+TEST(WhenSortedTest, WorksForPolymorphicMatcher) {
+  std::deque<int> d;
+  d.push_back(2);
+  d.push_back(1);
+  EXPECT_THAT(d, WhenSorted(ElementsAre(1, 2)));
+  EXPECT_THAT(d, Not(WhenSorted(ElementsAre(2, 1))));
+}
+
+TEST(WhenSortedTest, WorksForVectorConstRefMatcher) {
+  std::deque<int> d;
+  d.push_back(2);
+  d.push_back(1);
+  Matcher<const std::vector<int>&> vector_match = ElementsAre(1, 2);
+  EXPECT_THAT(d, WhenSorted(vector_match));
+  Matcher<const std::vector<int>&> not_vector_match = ElementsAre(2, 1);
+  EXPECT_THAT(d, Not(WhenSorted(not_vector_match)));
+}
+
+// Deliberately bare pseudo-container.
+// Offers only begin() and end() accessors, yielding InputIterator.
+template <typename T>
+class Streamlike {
+ private:
+  class ConstIter;
+
+ public:
+  typedef ConstIter const_iterator;
+  typedef T value_type;
+
+  template <typename InIter>
+  Streamlike(InIter first, InIter last) : remainder_(first, last) {}
+
+  const_iterator begin() const {
+    return const_iterator(this, remainder_.begin());
+  }
+  const_iterator end() const { return const_iterator(this, remainder_.end()); }
+
+ private:
+  class ConstIter {
+   public:
+    using iterator_category = std::input_iterator_tag;
+    using value_type = T;
+    using difference_type = ptrdiff_t;
+    using pointer = const value_type*;
+    using reference = const value_type&;
+
+    ConstIter(const Streamlike* s, typename std::list<value_type>::iterator pos)
+        : s_(s), pos_(pos) {}
+
+    const value_type& operator*() const { return *pos_; }
+    const value_type* operator->() const { return &*pos_; }
+    ConstIter& operator++() {
+      s_->remainder_.erase(pos_++);
+      return *this;
+    }
+
+    // *iter++ is required to work (see std::istreambuf_iterator).
+    // (void)iter++ is also required to work.
+    class PostIncrProxy {
+     public:
+      explicit PostIncrProxy(const value_type& value) : value_(value) {}
+      value_type operator*() const { return value_; }
+
+     private:
+      value_type value_;
+    };
+    PostIncrProxy operator++(int) {
+      PostIncrProxy proxy(**this);
+      ++(*this);
+      return proxy;
+    }
+
+    friend bool operator==(const ConstIter& a, const ConstIter& b) {
+      return a.s_ == b.s_ && a.pos_ == b.pos_;
+    }
+    friend bool operator!=(const ConstIter& a, const ConstIter& b) {
+      return !(a == b);
+    }
+
+   private:
+    const Streamlike* s_;
+    typename std::list<value_type>::iterator pos_;
+  };
+
+  friend std::ostream& operator<<(std::ostream& os, const Streamlike& s) {
+    os << "[";
+    typedef typename std::list<value_type>::const_iterator Iter;
+    const char* sep = "";
+    for (Iter it = s.remainder_.begin(); it != s.remainder_.end(); ++it) {
+      os << sep << *it;
+      sep = ",";
+    }
+    os << "]";
+    return os;
+  }
+
+  mutable std::list<value_type> remainder_;  // modified by iteration
+};
+
+TEST(StreamlikeTest, Iteration) {
+  const int a[5] = {2, 1, 4, 5, 3};
+  Streamlike<int> s(a, a + 5);
+  Streamlike<int>::const_iterator it = s.begin();
+  const int* ip = a;
+  while (it != s.end()) {
+    SCOPED_TRACE(ip - a);
+    EXPECT_EQ(*ip++, *it++);
+  }
+}
+
+INSTANTIATE_GTEST_MATCHER_TEST_P(BeginEndDistanceIsTest);
+
+TEST(BeginEndDistanceIsTest, WorksWithForwardList) {
+  std::forward_list<int> container;
+  EXPECT_THAT(container, BeginEndDistanceIs(0));
+  EXPECT_THAT(container, Not(BeginEndDistanceIs(1)));
+  container.push_front(0);
+  EXPECT_THAT(container, Not(BeginEndDistanceIs(0)));
+  EXPECT_THAT(container, BeginEndDistanceIs(1));
+  container.push_front(0);
+  EXPECT_THAT(container, Not(BeginEndDistanceIs(0)));
+  EXPECT_THAT(container, BeginEndDistanceIs(2));
+}
+
+TEST(BeginEndDistanceIsTest, WorksWithNonStdList) {
+  const int a[5] = {1, 2, 3, 4, 5};
+  Streamlike<int> s(a, a + 5);
+  EXPECT_THAT(s, BeginEndDistanceIs(5));
+}
+
+TEST(BeginEndDistanceIsTest, CanDescribeSelf) {
+  Matcher<vector<int>> m = BeginEndDistanceIs(2);
+  EXPECT_EQ("distance between begin() and end() is equal to 2", Describe(m));
+  EXPECT_EQ("distance between begin() and end() isn't equal to 2",
+            DescribeNegation(m));
+}
+
+TEST(BeginEndDistanceIsTest, WorksWithMoveOnly) {
+  ContainerHelper helper;
+  EXPECT_CALL(helper, Call(BeginEndDistanceIs(2)));
+  helper.Call(MakeUniquePtrs({1, 2}));
+}
+
+TEST_P(BeginEndDistanceIsTestP, ExplainsResult) {
+  Matcher<vector<int>> m1 = BeginEndDistanceIs(2);
+  Matcher<vector<int>> m2 = BeginEndDistanceIs(Lt(2));
+  Matcher<vector<int>> m3 = BeginEndDistanceIs(AnyOf(0, 3));
+  Matcher<vector<int>> m4 = BeginEndDistanceIs(GreaterThan(1));
+  vector<int> container;
+  EXPECT_EQ("whose distance between begin() and end() 0 doesn't match",
+            Explain(m1, container));
+  EXPECT_EQ("whose distance between begin() and end() 0 matches",
+            Explain(m2, container));
+  EXPECT_EQ("whose distance between begin() and end() 0 matches",
+            Explain(m3, container));
+  EXPECT_EQ(
+      "whose distance between begin() and end() 0 doesn't match, which is 1 "
+      "less than 1",
+      Explain(m4, container));
+  container.push_back(0);
+  container.push_back(0);
+  EXPECT_EQ("whose distance between begin() and end() 2 matches",
+            Explain(m1, container));
+  EXPECT_EQ("whose distance between begin() and end() 2 doesn't match",
+            Explain(m2, container));
+  EXPECT_EQ("whose distance between begin() and end() 2 doesn't match",
+            Explain(m3, container));
+  EXPECT_EQ(
+      "whose distance between begin() and end() 2 matches, which is 1 more "
+      "than 1",
+      Explain(m4, container));
+}
+
+TEST(WhenSortedTest, WorksForStreamlike) {
+  // Streamlike 'container' provides only minimal iterator support.
+  // Its iterators are tagged with input_iterator_tag.
+  const int a[5] = {2, 1, 4, 5, 3};
+  Streamlike<int> s(std::begin(a), std::end(a));
+  EXPECT_THAT(s, WhenSorted(ElementsAre(1, 2, 3, 4, 5)));
+  EXPECT_THAT(s, Not(WhenSorted(ElementsAre(2, 1, 4, 5, 3))));
+}
+
+TEST(WhenSortedTest, WorksForVectorConstRefMatcherOnStreamlike) {
+  const int a[] = {2, 1, 4, 5, 3};
+  Streamlike<int> s(std::begin(a), std::end(a));
+  Matcher<const std::vector<int>&> vector_match = ElementsAre(1, 2, 3, 4, 5);
+  EXPECT_THAT(s, WhenSorted(vector_match));
+  EXPECT_THAT(s, Not(WhenSorted(ElementsAre(2, 1, 4, 5, 3))));
+}
+
+TEST(IsSupersetOfTest, WorksForNativeArray) {
+  const int subset[] = {1, 4};
+  const int superset[] = {1, 2, 4};
+  const int disjoint[] = {1, 0, 3};
+  EXPECT_THAT(subset, IsSupersetOf(subset));
+  EXPECT_THAT(subset, Not(IsSupersetOf(superset)));
+  EXPECT_THAT(superset, IsSupersetOf(subset));
+  EXPECT_THAT(subset, Not(IsSupersetOf(disjoint)));
+  EXPECT_THAT(disjoint, Not(IsSupersetOf(subset)));
+}
+
+TEST(IsSupersetOfTest, WorksWithDuplicates) {
+  const int not_enough[] = {1, 2};
+  const int enough[] = {1, 1, 2};
+  const int expected[] = {1, 1};
+  EXPECT_THAT(not_enough, Not(IsSupersetOf(expected)));
+  EXPECT_THAT(enough, IsSupersetOf(expected));
+}
+
+TEST(IsSupersetOfTest, WorksForEmpty) {
+  vector<int> numbers;
+  vector<int> expected;
+  EXPECT_THAT(numbers, IsSupersetOf(expected));
+  expected.push_back(1);
+  EXPECT_THAT(numbers, Not(IsSupersetOf(expected)));
+  expected.clear();
+  numbers.push_back(1);
+  numbers.push_back(2);
+  EXPECT_THAT(numbers, IsSupersetOf(expected));
+  expected.push_back(1);
+  EXPECT_THAT(numbers, IsSupersetOf(expected));
+  expected.push_back(2);
+  EXPECT_THAT(numbers, IsSupersetOf(expected));
+  expected.push_back(3);
+  EXPECT_THAT(numbers, Not(IsSupersetOf(expected)));
+}
+
+TEST(IsSupersetOfTest, WorksForStreamlike) {
+  const int a[5] = {1, 2, 3, 4, 5};
+  Streamlike<int> s(std::begin(a), std::end(a));
+
+  vector<int> expected;
+  expected.push_back(1);
+  expected.push_back(2);
+  expected.push_back(5);
+  EXPECT_THAT(s, IsSupersetOf(expected));
+
+  expected.push_back(0);
+  EXPECT_THAT(s, Not(IsSupersetOf(expected)));
+}
+
+TEST(IsSupersetOfTest, TakesStlContainer) {
+  const int actual[] = {3, 1, 2};
+
+  ::std::list<int> expected;
+  expected.push_back(1);
+  expected.push_back(3);
+  EXPECT_THAT(actual, IsSupersetOf(expected));
+
+  expected.push_back(4);
+  EXPECT_THAT(actual, Not(IsSupersetOf(expected)));
+}
+
+TEST(IsSupersetOfTest, Describe) {
+  typedef std::vector<int> IntVec;
+  IntVec expected;
+  expected.push_back(111);
+  expected.push_back(222);
+  expected.push_back(333);
+  EXPECT_THAT(
+      Describe<IntVec>(IsSupersetOf(expected)),
+      Eq("a surjection from elements to requirements exists such that:\n"
+         " - an element is equal to 111\n"
+         " - an element is equal to 222\n"
+         " - an element is equal to 333"));
+}
+
+TEST(IsSupersetOfTest, DescribeNegation) {
+  typedef std::vector<int> IntVec;
+  IntVec expected;
+  expected.push_back(111);
+  expected.push_back(222);
+  expected.push_back(333);
+  EXPECT_THAT(
+      DescribeNegation<IntVec>(IsSupersetOf(expected)),
+      Eq("no surjection from elements to requirements exists such that:\n"
+         " - an element is equal to 111\n"
+         " - an element is equal to 222\n"
+         " - an element is equal to 333"));
+}
+
+TEST(IsSupersetOfTest, MatchAndExplain) {
+  std::vector<int> v;
+  v.push_back(2);
+  v.push_back(3);
+  std::vector<int> expected;
+  expected.push_back(1);
+  expected.push_back(2);
+  StringMatchResultListener listener;
+  ASSERT_FALSE(ExplainMatchResult(IsSupersetOf(expected), v, &listener))
+      << listener.str();
+  EXPECT_THAT(listener.str(),
+              Eq("where the following matchers don't match any elements:\n"
+                 "matcher #0: is equal to 1"));
+
+  v.push_back(1);
+  listener.Clear();
+  ASSERT_TRUE(ExplainMatchResult(IsSupersetOf(expected), v, &listener))
+      << listener.str();
+  EXPECT_THAT(listener.str(), Eq("where:\n"
+                                 " - element #0 is matched by matcher #1,\n"
+                                 " - element #2 is matched by matcher #0"));
+}
+
+TEST(IsSupersetOfTest, WorksForRhsInitializerList) {
+  const int numbers[] = {1, 3, 6, 2, 4, 5};
+  EXPECT_THAT(numbers, IsSupersetOf({1, 2}));
+  EXPECT_THAT(numbers, Not(IsSupersetOf({3, 0})));
+}
+
+TEST(IsSupersetOfTest, WorksWithMoveOnly) {
+  ContainerHelper helper;
+  EXPECT_CALL(helper, Call(IsSupersetOf({Pointee(1)})));
+  helper.Call(MakeUniquePtrs({1, 2}));
+  EXPECT_CALL(helper, Call(Not(IsSupersetOf({Pointee(1), Pointee(2)}))));
+  helper.Call(MakeUniquePtrs({2}));
+}
+
+TEST(IsSubsetOfTest, WorksForNativeArray) {
+  const int subset[] = {1, 4};
+  const int superset[] = {1, 2, 4};
+  const int disjoint[] = {1, 0, 3};
+  EXPECT_THAT(subset, IsSubsetOf(subset));
+  EXPECT_THAT(subset, IsSubsetOf(superset));
+  EXPECT_THAT(superset, Not(IsSubsetOf(subset)));
+  EXPECT_THAT(subset, Not(IsSubsetOf(disjoint)));
+  EXPECT_THAT(disjoint, Not(IsSubsetOf(subset)));
+}
+
+TEST(IsSubsetOfTest, WorksWithDuplicates) {
+  const int not_enough[] = {1, 2};
+  const int enough[] = {1, 1, 2};
+  const int actual[] = {1, 1};
+  EXPECT_THAT(actual, Not(IsSubsetOf(not_enough)));
+  EXPECT_THAT(actual, IsSubsetOf(enough));
+}
+
+TEST(IsSubsetOfTest, WorksForEmpty) {
+  vector<int> numbers;
+  vector<int> expected;
+  EXPECT_THAT(numbers, IsSubsetOf(expected));
+  expected.push_back(1);
+  EXPECT_THAT(numbers, IsSubsetOf(expected));
+  expected.clear();
+  numbers.push_back(1);
+  numbers.push_back(2);
+  EXPECT_THAT(numbers, Not(IsSubsetOf(expected)));
+  expected.push_back(1);
+  EXPECT_THAT(numbers, Not(IsSubsetOf(expected)));
+  expected.push_back(2);
+  EXPECT_THAT(numbers, IsSubsetOf(expected));
+  expected.push_back(3);
+  EXPECT_THAT(numbers, IsSubsetOf(expected));
+}
+
+TEST(IsSubsetOfTest, WorksForStreamlike) {
+  const int a[5] = {1, 2};
+  Streamlike<int> s(std::begin(a), std::end(a));
+
+  vector<int> expected;
+  expected.push_back(1);
+  EXPECT_THAT(s, Not(IsSubsetOf(expected)));
+  expected.push_back(2);
+  expected.push_back(5);
+  EXPECT_THAT(s, IsSubsetOf(expected));
+}
+
+TEST(IsSubsetOfTest, TakesStlContainer) {
+  const int actual[] = {3, 1, 2};
+
+  ::std::list<int> expected;
+  expected.push_back(1);
+  expected.push_back(3);
+  EXPECT_THAT(actual, Not(IsSubsetOf(expected)));
+
+  expected.push_back(2);
+  expected.push_back(4);
+  EXPECT_THAT(actual, IsSubsetOf(expected));
+}
+
+TEST(IsSubsetOfTest, Describe) {
+  typedef std::vector<int> IntVec;
+  IntVec expected;
+  expected.push_back(111);
+  expected.push_back(222);
+  expected.push_back(333);
+
+  EXPECT_THAT(
+      Describe<IntVec>(IsSubsetOf(expected)),
+      Eq("an injection from elements to requirements exists such that:\n"
+         " - an element is equal to 111\n"
+         " - an element is equal to 222\n"
+         " - an element is equal to 333"));
+}
+
+TEST(IsSubsetOfTest, DescribeNegation) {
+  typedef std::vector<int> IntVec;
+  IntVec expected;
+  expected.push_back(111);
+  expected.push_back(222);
+  expected.push_back(333);
+  EXPECT_THAT(
+      DescribeNegation<IntVec>(IsSubsetOf(expected)),
+      Eq("no injection from elements to requirements exists such that:\n"
+         " - an element is equal to 111\n"
+         " - an element is equal to 222\n"
+         " - an element is equal to 333"));
+}
+
+TEST(IsSubsetOfTest, MatchAndExplain) {
+  std::vector<int> v;
+  v.push_back(2);
+  v.push_back(3);
+  std::vector<int> expected;
+  expected.push_back(1);
+  expected.push_back(2);
+  StringMatchResultListener listener;
+  ASSERT_FALSE(ExplainMatchResult(IsSubsetOf(expected), v, &listener))
+      << listener.str();
+  EXPECT_THAT(listener.str(),
+              Eq("where the following elements don't match any matchers:\n"
+                 "element #1: 3"));
+
+  expected.push_back(3);
+  listener.Clear();
+  ASSERT_TRUE(ExplainMatchResult(IsSubsetOf(expected), v, &listener))
+      << listener.str();
+  EXPECT_THAT(listener.str(), Eq("where:\n"
+                                 " - element #0 is matched by matcher #1,\n"
+                                 " - element #1 is matched by matcher #2"));
+}
+
+TEST(IsSubsetOfTest, WorksForRhsInitializerList) {
+  const int numbers[] = {1, 2, 3};
+  EXPECT_THAT(numbers, IsSubsetOf({1, 2, 3, 4}));
+  EXPECT_THAT(numbers, Not(IsSubsetOf({1, 2})));
+}
+
+TEST(IsSubsetOfTest, WorksWithMoveOnly) {
+  ContainerHelper helper;
+  EXPECT_CALL(helper, Call(IsSubsetOf({Pointee(1), Pointee(2)})));
+  helper.Call(MakeUniquePtrs({1}));
+  EXPECT_CALL(helper, Call(Not(IsSubsetOf({Pointee(1)}))));
+  helper.Call(MakeUniquePtrs({2}));
+}
+
+// Tests using ElementsAre() and ElementsAreArray() with stream-like
+// "containers".
+
+TEST(ElemensAreStreamTest, WorksForStreamlike) {
+  const int a[5] = {1, 2, 3, 4, 5};
+  Streamlike<int> s(std::begin(a), std::end(a));
+  EXPECT_THAT(s, ElementsAre(1, 2, 3, 4, 5));
+  EXPECT_THAT(s, Not(ElementsAre(2, 1, 4, 5, 3)));
+}
+
+TEST(ElemensAreArrayStreamTest, WorksForStreamlike) {
+  const int a[5] = {1, 2, 3, 4, 5};
+  Streamlike<int> s(std::begin(a), std::end(a));
+
+  vector<int> expected;
+  expected.push_back(1);
+  expected.push_back(2);
+  expected.push_back(3);
+  expected.push_back(4);
+  expected.push_back(5);
+  EXPECT_THAT(s, ElementsAreArray(expected));
+
+  expected[3] = 0;
+  EXPECT_THAT(s, Not(ElementsAreArray(expected)));
+}
+
+TEST(ElementsAreTest, WorksWithUncopyable) {
+  Uncopyable objs[2];
+  objs[0].set_value(-3);
+  objs[1].set_value(1);
+  EXPECT_THAT(objs, ElementsAre(UncopyableIs(-3), Truly(ValueIsPositive)));
+}
+
+TEST(ElementsAreTest, WorksWithMoveOnly) {
+  ContainerHelper helper;
+  EXPECT_CALL(helper, Call(ElementsAre(Pointee(1), Pointee(2))));
+  helper.Call(MakeUniquePtrs({1, 2}));
+
+  EXPECT_CALL(helper, Call(ElementsAreArray({Pointee(3), Pointee(4)})));
+  helper.Call(MakeUniquePtrs({3, 4}));
+}
+
+TEST(ElementsAreTest, TakesStlContainer) {
+  const int actual[] = {3, 1, 2};
+
+  ::std::list<int> expected;
+  expected.push_back(3);
+  expected.push_back(1);
+  expected.push_back(2);
+  EXPECT_THAT(actual, ElementsAreArray(expected));
+
+  expected.push_back(4);
+  EXPECT_THAT(actual, Not(ElementsAreArray(expected)));
+}
+
+// Tests for UnorderedElementsAreArray()
+
+TEST(UnorderedElementsAreArrayTest, SucceedsWhenExpected) {
+  const int a[] = {0, 1, 2, 3, 4};
+  std::vector<int> s(std::begin(a), std::end(a));
+  do {
+    StringMatchResultListener listener;
+    EXPECT_TRUE(ExplainMatchResult(UnorderedElementsAreArray(a), s, &listener))
+        << listener.str();
+  } while (std::next_permutation(s.begin(), s.end()));
+}
+
+TEST(UnorderedElementsAreArrayTest, VectorBool) {
+  const bool a[] = {false, true, false, true, true};
+  const bool b[] = {true, false, true, true, false};
+  std::vector<bool> expected(std::begin(a), std::end(a));
+  std::vector<bool> actual(std::begin(b), std::end(b));
+  StringMatchResultListener listener;
+  EXPECT_TRUE(ExplainMatchResult(UnorderedElementsAreArray(expected), actual,
+                                 &listener))
+      << listener.str();
+}
+
+TEST(UnorderedElementsAreArrayTest, WorksForStreamlike) {
+  // Streamlike 'container' provides only minimal iterator support.
+  // Its iterators are tagged with input_iterator_tag, and it has no
+  // size() or empty() methods.
+  const int a[5] = {2, 1, 4, 5, 3};
+  Streamlike<int> s(std::begin(a), std::end(a));
+
+  ::std::vector<int> expected;
+  expected.push_back(1);
+  expected.push_back(2);
+  expected.push_back(3);
+  expected.push_back(4);
+  expected.push_back(5);
+  EXPECT_THAT(s, UnorderedElementsAreArray(expected));
+
+  expected.push_back(6);
+  EXPECT_THAT(s, Not(UnorderedElementsAreArray(expected)));
+}
+
+TEST(UnorderedElementsAreArrayTest, TakesStlContainer) {
+  const int actual[] = {3, 1, 2};
+
+  ::std::list<int> expected;
+  expected.push_back(1);
+  expected.push_back(2);
+  expected.push_back(3);
+  EXPECT_THAT(actual, UnorderedElementsAreArray(expected));
+
+  expected.push_back(4);
+  EXPECT_THAT(actual, Not(UnorderedElementsAreArray(expected)));
+}
+
+TEST(UnorderedElementsAreArrayTest, TakesInitializerList) {
+  const int a[5] = {2, 1, 4, 5, 3};
+  EXPECT_THAT(a, UnorderedElementsAreArray({1, 2, 3, 4, 5}));
+  EXPECT_THAT(a, Not(UnorderedElementsAreArray({1, 2, 3, 4, 6})));
+}
+
+TEST(UnorderedElementsAreArrayTest, TakesInitializerListOfCStrings) {
+  const std::string a[5] = {"a", "b", "c", "d", "e"};
+  EXPECT_THAT(a, UnorderedElementsAreArray({"a", "b", "c", "d", "e"}));
+  EXPECT_THAT(a, Not(UnorderedElementsAreArray({"a", "b", "c", "d", "ef"})));
+}
+
+TEST(UnorderedElementsAreArrayTest, TakesInitializerListOfSameTypedMatchers) {
+  const int a[5] = {2, 1, 4, 5, 3};
+  EXPECT_THAT(a,
+              UnorderedElementsAreArray({Eq(1), Eq(2), Eq(3), Eq(4), Eq(5)}));
+  EXPECT_THAT(
+      a, Not(UnorderedElementsAreArray({Eq(1), Eq(2), Eq(3), Eq(4), Eq(6)})));
+}
+
+TEST(UnorderedElementsAreArrayTest,
+     TakesInitializerListOfDifferentTypedMatchers) {
+  const int a[5] = {2, 1, 4, 5, 3};
+  // The compiler cannot infer the type of the initializer list if its
+  // elements have different types.  We must explicitly specify the
+  // unified element type in this case.
+  EXPECT_THAT(a, UnorderedElementsAreArray<Matcher<int>>(
+                     {Eq(1), Ne(-2), Ge(3), Le(4), Eq(5)}));
+  EXPECT_THAT(a, Not(UnorderedElementsAreArray<Matcher<int>>(
+                     {Eq(1), Ne(-2), Ge(3), Le(4), Eq(6)})));
+}
+
+TEST(UnorderedElementsAreArrayTest, WorksWithMoveOnly) {
+  ContainerHelper helper;
+  EXPECT_CALL(helper,
+              Call(UnorderedElementsAreArray({Pointee(1), Pointee(2)})));
+  helper.Call(MakeUniquePtrs({2, 1}));
+}
+
+class UnorderedElementsAreTest : public testing::Test {
+ protected:
+  typedef std::vector<int> IntVec;
+};
+
+TEST_F(UnorderedElementsAreTest, WorksWithUncopyable) {
+  Uncopyable objs[2];
+  objs[0].set_value(-3);
+  objs[1].set_value(1);
+  EXPECT_THAT(objs,
+              UnorderedElementsAre(Truly(ValueIsPositive), UncopyableIs(-3)));
+}
+
+TEST_F(UnorderedElementsAreTest, SucceedsWhenExpected) {
+  const int a[] = {1, 2, 3};
+  std::vector<int> s(std::begin(a), std::end(a));
+  do {
+    StringMatchResultListener listener;
+    EXPECT_TRUE(ExplainMatchResult(UnorderedElementsAre(1, 2, 3), s, &listener))
+        << listener.str();
+  } while (std::next_permutation(s.begin(), s.end()));
+}
+
+TEST_F(UnorderedElementsAreTest, FailsWhenAnElementMatchesNoMatcher) {
+  const int a[] = {1, 2, 3};
+  std::vector<int> s(std::begin(a), std::end(a));
+  std::vector<Matcher<int>> mv;
+  mv.push_back(1);
+  mv.push_back(2);
+  mv.push_back(2);
+  // The element with value '3' matches nothing: fail fast.
+  StringMatchResultListener listener;
+  EXPECT_FALSE(ExplainMatchResult(UnorderedElementsAreArray(mv), s, &listener))
+      << listener.str();
+}
+
+TEST_F(UnorderedElementsAreTest, WorksForStreamlike) {
+  // Streamlike 'container' provides only minimal iterator support.
+  // Its iterators are tagged with input_iterator_tag, and it has no
+  // size() or empty() methods.
+  const int a[5] = {2, 1, 4, 5, 3};
+  Streamlike<int> s(std::begin(a), std::end(a));
+
+  EXPECT_THAT(s, UnorderedElementsAre(1, 2, 3, 4, 5));
+  EXPECT_THAT(s, Not(UnorderedElementsAre(2, 2, 3, 4, 5)));
+}
+
+TEST_F(UnorderedElementsAreTest, WorksWithMoveOnly) {
+  ContainerHelper helper;
+  EXPECT_CALL(helper, Call(UnorderedElementsAre(Pointee(1), Pointee(2))));
+  helper.Call(MakeUniquePtrs({2, 1}));
+}
+
+// One naive implementation of the matcher runs in O(N!) time, which is too
+// slow for many real-world inputs. This test shows that our matcher can match
+// 100 inputs very quickly (a few milliseconds).  An O(100!) is 10^158
+// iterations and obviously effectively incomputable.
+// [ RUN      ] UnorderedElementsAreTest.Performance
+// [       OK ] UnorderedElementsAreTest.Performance (4 ms)
+TEST_F(UnorderedElementsAreTest, Performance) {
+  std::vector<int> s;
+  std::vector<Matcher<int>> mv;
+  for (int i = 0; i < 100; ++i) {
+    s.push_back(i);
+    mv.push_back(_);
+  }
+  mv[50] = Eq(0);
+  StringMatchResultListener listener;
+  EXPECT_TRUE(ExplainMatchResult(UnorderedElementsAreArray(mv), s, &listener))
+      << listener.str();
+}
+
+// Another variant of 'Performance' with similar expectations.
+// [ RUN      ] UnorderedElementsAreTest.PerformanceHalfStrict
+// [       OK ] UnorderedElementsAreTest.PerformanceHalfStrict (4 ms)
+TEST_F(UnorderedElementsAreTest, PerformanceHalfStrict) {
+  std::vector<int> s;
+  std::vector<Matcher<int>> mv;
+  for (int i = 0; i < 100; ++i) {
+    s.push_back(i);
+    if (i & 1) {
+      mv.push_back(_);
+    } else {
+      mv.push_back(i);
+    }
+  }
+  StringMatchResultListener listener;
+  EXPECT_TRUE(ExplainMatchResult(UnorderedElementsAreArray(mv), s, &listener))
+      << listener.str();
+}
+
+TEST_F(UnorderedElementsAreTest, FailMessageCountWrong) {
+  std::vector<int> v;
+  v.push_back(4);
+  StringMatchResultListener listener;
+  EXPECT_FALSE(ExplainMatchResult(UnorderedElementsAre(1, 2, 3), v, &listener))
+      << listener.str();
+  EXPECT_THAT(listener.str(), Eq("which has 1 element"));
+}
+
+TEST_F(UnorderedElementsAreTest, FailMessageCountWrongZero) {
+  std::vector<int> v;
+  StringMatchResultListener listener;
+  EXPECT_FALSE(ExplainMatchResult(UnorderedElementsAre(1, 2, 3), v, &listener))
+      << listener.str();
+  EXPECT_THAT(listener.str(), Eq(""));
+}
+
+TEST_F(UnorderedElementsAreTest, FailMessageUnmatchedMatchers) {
+  std::vector<int> v;
+  v.push_back(1);
+  v.push_back(1);
+  StringMatchResultListener listener;
+  EXPECT_FALSE(ExplainMatchResult(UnorderedElementsAre(1, 2), v, &listener))
+      << listener.str();
+  EXPECT_THAT(listener.str(),
+              Eq("where the following matchers don't match any elements:\n"
+                 "matcher #1: is equal to 2"));
+}
+
+TEST_F(UnorderedElementsAreTest, FailMessageUnmatchedElements) {
+  std::vector<int> v;
+  v.push_back(1);
+  v.push_back(2);
+  StringMatchResultListener listener;
+  EXPECT_FALSE(ExplainMatchResult(UnorderedElementsAre(1, 1), v, &listener))
+      << listener.str();
+  EXPECT_THAT(listener.str(),
+              Eq("where the following elements don't match any matchers:\n"
+                 "element #1: 2"));
+}
+
+TEST_F(UnorderedElementsAreTest, FailMessageUnmatchedMatcherAndElement) {
+  std::vector<int> v;
+  v.push_back(2);
+  v.push_back(3);
+  StringMatchResultListener listener;
+  EXPECT_FALSE(ExplainMatchResult(UnorderedElementsAre(1, 2), v, &listener))
+      << listener.str();
+  EXPECT_THAT(listener.str(),
+              Eq("where"
+                 " the following matchers don't match any elements:\n"
+                 "matcher #0: is equal to 1\n"
+                 "and"
+                 " where"
+                 " the following elements don't match any matchers:\n"
+                 "element #1: 3"));
+}
+
+// Test helper for formatting element, matcher index pairs in expectations.
+static std::string EMString(int element, int matcher) {
+  stringstream ss;
+  ss << "(element #" << element << ", matcher #" << matcher << ")";
+  return ss.str();
+}
+
+TEST_F(UnorderedElementsAreTest, FailMessageImperfectMatchOnly) {
+  // A situation where all elements and matchers have a match
+  // associated with them, but the max matching is not perfect.
+  std::vector<std::string> v;
+  v.push_back("a");
+  v.push_back("b");
+  v.push_back("c");
+  StringMatchResultListener listener;
+  EXPECT_FALSE(ExplainMatchResult(
+      UnorderedElementsAre("a", "a", AnyOf("b", "c")), v, &listener))
+      << listener.str();
+
+  std::string prefix =
+      "where no permutation of the elements can satisfy all matchers, "
+      "and the closest match is 2 of 3 matchers with the "
+      "pairings:\n";
+
+  // We have to be a bit loose here, because there are 4 valid max matches.
+  EXPECT_THAT(
+      listener.str(),
+      AnyOf(
+          prefix + "{\n  " + EMString(0, 0) + ",\n  " + EMString(1, 2) + "\n}",
+          prefix + "{\n  " + EMString(0, 1) + ",\n  " + EMString(1, 2) + "\n}",
+          prefix + "{\n  " + EMString(0, 0) + ",\n  " + EMString(2, 2) + "\n}",
+          prefix + "{\n  " + EMString(0, 1) + ",\n  " + EMString(2, 2) +
+              "\n}"));
+}
+
+TEST_F(UnorderedElementsAreTest, Describe) {
+  EXPECT_THAT(Describe<IntVec>(UnorderedElementsAre()), Eq("is empty"));
+  EXPECT_THAT(Describe<IntVec>(UnorderedElementsAre(345)),
+              Eq("has 1 element and that element is equal to 345"));
+  EXPECT_THAT(Describe<IntVec>(UnorderedElementsAre(111, 222, 333)),
+              Eq("has 3 elements and there exists some permutation "
+                 "of elements such that:\n"
+                 " - element #0 is equal to 111, and\n"
+                 " - element #1 is equal to 222, and\n"
+                 " - element #2 is equal to 333"));
+}
+
+TEST_F(UnorderedElementsAreTest, DescribeNegation) {
+  EXPECT_THAT(DescribeNegation<IntVec>(UnorderedElementsAre()),
+              Eq("isn't empty"));
+  EXPECT_THAT(
+      DescribeNegation<IntVec>(UnorderedElementsAre(345)),
+      Eq("doesn't have 1 element, or has 1 element that isn't equal to 345"));
+  EXPECT_THAT(DescribeNegation<IntVec>(UnorderedElementsAre(123, 234, 345)),
+              Eq("doesn't have 3 elements, or there exists no permutation "
+                 "of elements such that:\n"
+                 " - element #0 is equal to 123, and\n"
+                 " - element #1 is equal to 234, and\n"
+                 " - element #2 is equal to 345"));
+}
+
+// Tests Each().
+
+INSTANTIATE_GTEST_MATCHER_TEST_P(EachTest);
+
+TEST_P(EachTestP, ExplainsMatchResultCorrectly) {
+  set<int> a;  // empty
+
+  Matcher<set<int>> m = Each(2);
+  EXPECT_EQ("", Explain(m, a));
+
+  Matcher<const int(&)[1]> n = Each(1);  // NOLINT
+
+  const int b[1] = {1};
+  EXPECT_EQ("", Explain(n, b));
+
+  n = Each(3);
+  EXPECT_EQ("whose element #0 doesn't match", Explain(n, b));
+
+  a.insert(1);
+  a.insert(2);
+  a.insert(3);
+  m = Each(GreaterThan(0));
+  EXPECT_EQ("", Explain(m, a));
+
+  m = Each(GreaterThan(10));
+  EXPECT_EQ("whose element #0 doesn't match, which is 9 less than 10",
+            Explain(m, a));
+}
+
+TEST(EachTest, DescribesItselfCorrectly) {
+  Matcher<vector<int>> m = Each(1);
+  EXPECT_EQ("only contains elements that is equal to 1", Describe(m));
+
+  Matcher<vector<int>> m2 = Not(m);
+  EXPECT_EQ("contains some element that isn't equal to 1", Describe(m2));
+}
+
+TEST(EachTest, MatchesVectorWhenAllElementsMatch) {
+  vector<int> some_vector;
+  EXPECT_THAT(some_vector, Each(1));
+  some_vector.push_back(3);
+  EXPECT_THAT(some_vector, Not(Each(1)));
+  EXPECT_THAT(some_vector, Each(3));
+  some_vector.push_back(1);
+  some_vector.push_back(2);
+  EXPECT_THAT(some_vector, Not(Each(3)));
+  EXPECT_THAT(some_vector, Each(Lt(3.5)));
+
+  vector<std::string> another_vector;
+  another_vector.push_back("fee");
+  EXPECT_THAT(another_vector, Each(std::string("fee")));
+  another_vector.push_back("fie");
+  another_vector.push_back("foe");
+  another_vector.push_back("fum");
+  EXPECT_THAT(another_vector, Not(Each(std::string("fee"))));
+}
+
+TEST(EachTest, MatchesMapWhenAllElementsMatch) {
+  map<const char*, int> my_map;
+  const char* bar = "a string";
+  my_map[bar] = 2;
+  EXPECT_THAT(my_map, Each(make_pair(bar, 2)));
+
+  map<std::string, int> another_map;
+  EXPECT_THAT(another_map, Each(make_pair(std::string("fee"), 1)));
+  another_map["fee"] = 1;
+  EXPECT_THAT(another_map, Each(make_pair(std::string("fee"), 1)));
+  another_map["fie"] = 2;
+  another_map["foe"] = 3;
+  another_map["fum"] = 4;
+  EXPECT_THAT(another_map, Not(Each(make_pair(std::string("fee"), 1))));
+  EXPECT_THAT(another_map, Not(Each(make_pair(std::string("fum"), 1))));
+  EXPECT_THAT(another_map, Each(Pair(_, Gt(0))));
+}
+
+TEST(EachTest, AcceptsMatcher) {
+  const int a[] = {1, 2, 3};
+  EXPECT_THAT(a, Each(Gt(0)));
+  EXPECT_THAT(a, Not(Each(Gt(1))));
+}
+
+TEST(EachTest, WorksForNativeArrayAsTuple) {
+  const int a[] = {1, 2};
+  const int* const pointer = a;
+  EXPECT_THAT(std::make_tuple(pointer, 2), Each(Gt(0)));
+  EXPECT_THAT(std::make_tuple(pointer, 2), Not(Each(Gt(1))));
+}
+
+TEST(EachTest, WorksWithMoveOnly) {
+  ContainerHelper helper;
+  EXPECT_CALL(helper, Call(Each(Pointee(Gt(0)))));
+  helper.Call(MakeUniquePtrs({1, 2}));
+}
+
+// For testing Pointwise().
+class IsHalfOfMatcher {
+ public:
+  template <typename T1, typename T2>
+  bool MatchAndExplain(const std::tuple<T1, T2>& a_pair,
+                       MatchResultListener* listener) const {
+    if (std::get<0>(a_pair) == std::get<1>(a_pair) / 2) {
+      *listener << "where the second is " << std::get<1>(a_pair);
+      return true;
+    } else {
+      *listener << "where the second/2 is " << std::get<1>(a_pair) / 2;
+      return false;
+    }
+  }
+
+  void DescribeTo(ostream* os) const {
+    *os << "are a pair where the first is half of the second";
+  }
+
+  void DescribeNegationTo(ostream* os) const {
+    *os << "are a pair where the first isn't half of the second";
+  }
+};
+
+PolymorphicMatcher<IsHalfOfMatcher> IsHalfOf() {
+  return MakePolymorphicMatcher(IsHalfOfMatcher());
+}
+
+TEST(PointwiseTest, DescribesSelf) {
+  vector<int> rhs;
+  rhs.push_back(1);
+  rhs.push_back(2);
+  rhs.push_back(3);
+  const Matcher<const vector<int>&> m = Pointwise(IsHalfOf(), rhs);
+  EXPECT_EQ(
+      "contains 3 values, where each value and its corresponding value "
+      "in { 1, 2, 3 } are a pair where the first is half of the second",
+      Describe(m));
+  EXPECT_EQ(
+      "doesn't contain exactly 3 values, or contains a value x at some "
+      "index i where x and the i-th value of { 1, 2, 3 } are a pair "
+      "where the first isn't half of the second",
+      DescribeNegation(m));
+}
+
+TEST(PointwiseTest, MakesCopyOfRhs) {
+  list<signed char> rhs;
+  rhs.push_back(2);
+  rhs.push_back(4);
+
+  int lhs[] = {1, 2};
+  const Matcher<const int(&)[2]> m = Pointwise(IsHalfOf(), rhs);
+  EXPECT_THAT(lhs, m);
+
+  // Changing rhs now shouldn't affect m, which made a copy of rhs.
+  rhs.push_back(6);
+  EXPECT_THAT(lhs, m);
+}
+
+TEST(PointwiseTest, WorksForLhsNativeArray) {
+  const int lhs[] = {1, 2, 3};
+  vector<int> rhs;
+  rhs.push_back(2);
+  rhs.push_back(4);
+  rhs.push_back(6);
+  EXPECT_THAT(lhs, Pointwise(Lt(), rhs));
+  EXPECT_THAT(lhs, Not(Pointwise(Gt(), rhs)));
+}
+
+TEST(PointwiseTest, WorksForRhsNativeArray) {
+  const int rhs[] = {1, 2, 3};
+  vector<int> lhs;
+  lhs.push_back(2);
+  lhs.push_back(4);
+  lhs.push_back(6);
+  EXPECT_THAT(lhs, Pointwise(Gt(), rhs));
+  EXPECT_THAT(lhs, Not(Pointwise(Lt(), rhs)));
+}
+
+// Test is effective only with sanitizers.
+TEST(PointwiseTest, WorksForVectorOfBool) {
+  vector<bool> rhs(3, false);
+  rhs[1] = true;
+  vector<bool> lhs = rhs;
+  EXPECT_THAT(lhs, Pointwise(Eq(), rhs));
+  rhs[0] = true;
+  EXPECT_THAT(lhs, Not(Pointwise(Eq(), rhs)));
+}
+
+TEST(PointwiseTest, WorksForRhsInitializerList) {
+  const vector<int> lhs{2, 4, 6};
+  EXPECT_THAT(lhs, Pointwise(Gt(), {1, 2, 3}));
+  EXPECT_THAT(lhs, Not(Pointwise(Lt(), {3, 3, 7})));
+}
+
+TEST(PointwiseTest, RejectsWrongSize) {
+  const double lhs[2] = {1, 2};
+  const int rhs[1] = {0};
+  EXPECT_THAT(lhs, Not(Pointwise(Gt(), rhs)));
+  EXPECT_EQ("which contains 2 values", Explain(Pointwise(Gt(), rhs), lhs));
+
+  const int rhs2[3] = {0, 1, 2};
+  EXPECT_THAT(lhs, Not(Pointwise(Gt(), rhs2)));
+}
+
+TEST(PointwiseTest, RejectsWrongContent) {
+  const double lhs[3] = {1, 2, 3};
+  const int rhs[3] = {2, 6, 4};
+  EXPECT_THAT(lhs, Not(Pointwise(IsHalfOf(), rhs)));
+  EXPECT_EQ(
+      "where the value pair (2, 6) at index #1 don't match, "
+      "where the second/2 is 3",
+      Explain(Pointwise(IsHalfOf(), rhs), lhs));
+}
+
+TEST(PointwiseTest, AcceptsCorrectContent) {
+  const double lhs[3] = {1, 2, 3};
+  const int rhs[3] = {2, 4, 6};
+  EXPECT_THAT(lhs, Pointwise(IsHalfOf(), rhs));
+  EXPECT_EQ("", Explain(Pointwise(IsHalfOf(), rhs), lhs));
+}
+
+TEST(PointwiseTest, AllowsMonomorphicInnerMatcher) {
+  const double lhs[3] = {1, 2, 3};
+  const int rhs[3] = {2, 4, 6};
+  const Matcher<std::tuple<const double&, const int&>> m1 = IsHalfOf();
+  EXPECT_THAT(lhs, Pointwise(m1, rhs));
+  EXPECT_EQ("", Explain(Pointwise(m1, rhs), lhs));
+
+  // This type works as a std::tuple<const double&, const int&> can be
+  // implicitly cast to std::tuple<double, int>.
+  const Matcher<std::tuple<double, int>> m2 = IsHalfOf();
+  EXPECT_THAT(lhs, Pointwise(m2, rhs));
+  EXPECT_EQ("", Explain(Pointwise(m2, rhs), lhs));
+}
+
+MATCHER(PointeeEquals, "Points to an equal value") {
+  return ExplainMatchResult(::testing::Pointee(::testing::get<1>(arg)),
+                            ::testing::get<0>(arg), result_listener);
+}
+
+TEST(PointwiseTest, WorksWithMoveOnly) {
+  ContainerHelper helper;
+  EXPECT_CALL(helper, Call(Pointwise(PointeeEquals(), std::vector<int>{1, 2})));
+  helper.Call(MakeUniquePtrs({1, 2}));
+}
+
+TEST(UnorderedPointwiseTest, DescribesSelf) {
+  vector<int> rhs;
+  rhs.push_back(1);
+  rhs.push_back(2);
+  rhs.push_back(3);
+  const Matcher<const vector<int>&> m = UnorderedPointwise(IsHalfOf(), rhs);
+  EXPECT_EQ(
+      "has 3 elements and there exists some permutation of elements such "
+      "that:\n"
+      " - element #0 and 1 are a pair where the first is half of the second, "
+      "and\n"
+      " - element #1 and 2 are a pair where the first is half of the second, "
+      "and\n"
+      " - element #2 and 3 are a pair where the first is half of the second",
+      Describe(m));
+  EXPECT_EQ(
+      "doesn't have 3 elements, or there exists no permutation of elements "
+      "such that:\n"
+      " - element #0 and 1 are a pair where the first is half of the second, "
+      "and\n"
+      " - element #1 and 2 are a pair where the first is half of the second, "
+      "and\n"
+      " - element #2 and 3 are a pair where the first is half of the second",
+      DescribeNegation(m));
+}
+
+TEST(UnorderedPointwiseTest, MakesCopyOfRhs) {
+  list<signed char> rhs;
+  rhs.push_back(2);
+  rhs.push_back(4);
+
+  int lhs[] = {2, 1};
+  const Matcher<const int(&)[2]> m = UnorderedPointwise(IsHalfOf(), rhs);
+  EXPECT_THAT(lhs, m);
+
+  // Changing rhs now shouldn't affect m, which made a copy of rhs.
+  rhs.push_back(6);
+  EXPECT_THAT(lhs, m);
+}
+
+TEST(UnorderedPointwiseTest, WorksForLhsNativeArray) {
+  const int lhs[] = {1, 2, 3};
+  vector<int> rhs;
+  rhs.push_back(4);
+  rhs.push_back(6);
+  rhs.push_back(2);
+  EXPECT_THAT(lhs, UnorderedPointwise(Lt(), rhs));
+  EXPECT_THAT(lhs, Not(UnorderedPointwise(Gt(), rhs)));
+}
+
+TEST(UnorderedPointwiseTest, WorksForRhsNativeArray) {
+  const int rhs[] = {1, 2, 3};
+  vector<int> lhs;
+  lhs.push_back(4);
+  lhs.push_back(2);
+  lhs.push_back(6);
+  EXPECT_THAT(lhs, UnorderedPointwise(Gt(), rhs));
+  EXPECT_THAT(lhs, Not(UnorderedPointwise(Lt(), rhs)));
+}
+
+TEST(UnorderedPointwiseTest, WorksForRhsInitializerList) {
+  const vector<int> lhs{2, 4, 6};
+  EXPECT_THAT(lhs, UnorderedPointwise(Gt(), {5, 1, 3}));
+  EXPECT_THAT(lhs, Not(UnorderedPointwise(Lt(), {1, 1, 7})));
+}
+
+TEST(UnorderedPointwiseTest, RejectsWrongSize) {
+  const double lhs[2] = {1, 2};
+  const int rhs[1] = {0};
+  EXPECT_THAT(lhs, Not(UnorderedPointwise(Gt(), rhs)));
+  EXPECT_EQ("which has 2 elements",
+            Explain(UnorderedPointwise(Gt(), rhs), lhs));
+
+  const int rhs2[3] = {0, 1, 2};
+  EXPECT_THAT(lhs, Not(UnorderedPointwise(Gt(), rhs2)));
+}
+
+TEST(UnorderedPointwiseTest, RejectsWrongContent) {
+  const double lhs[3] = {1, 2, 3};
+  const int rhs[3] = {2, 6, 6};
+  EXPECT_THAT(lhs, Not(UnorderedPointwise(IsHalfOf(), rhs)));
+  EXPECT_EQ(
+      "where the following elements don't match any matchers:\n"
+      "element #1: 2",
+      Explain(UnorderedPointwise(IsHalfOf(), rhs), lhs));
+}
+
+TEST(UnorderedPointwiseTest, AcceptsCorrectContentInSameOrder) {
+  const double lhs[3] = {1, 2, 3};
+  const int rhs[3] = {2, 4, 6};
+  EXPECT_THAT(lhs, UnorderedPointwise(IsHalfOf(), rhs));
+}
+
+TEST(UnorderedPointwiseTest, AcceptsCorrectContentInDifferentOrder) {
+  const double lhs[3] = {1, 2, 3};
+  const int rhs[3] = {6, 4, 2};
+  EXPECT_THAT(lhs, UnorderedPointwise(IsHalfOf(), rhs));
+}
+
+TEST(UnorderedPointwiseTest, AllowsMonomorphicInnerMatcher) {
+  const double lhs[3] = {1, 2, 3};
+  const int rhs[3] = {4, 6, 2};
+  const Matcher<std::tuple<const double&, const int&>> m1 = IsHalfOf();
+  EXPECT_THAT(lhs, UnorderedPointwise(m1, rhs));
+
+  // This type works as a std::tuple<const double&, const int&> can be
+  // implicitly cast to std::tuple<double, int>.
+  const Matcher<std::tuple<double, int>> m2 = IsHalfOf();
+  EXPECT_THAT(lhs, UnorderedPointwise(m2, rhs));
+}
+
+TEST(UnorderedPointwiseTest, WorksWithMoveOnly) {
+  ContainerHelper helper;
+  EXPECT_CALL(helper, Call(UnorderedPointwise(PointeeEquals(),
+                                              std::vector<int>{1, 2})));
+  helper.Call(MakeUniquePtrs({2, 1}));
+}
+
+TEST(PointeeTest, WorksOnMoveOnlyType) {
+  std::unique_ptr<int> p(new int(3));
+  EXPECT_THAT(p, Pointee(Eq(3)));
+  EXPECT_THAT(p, Not(Pointee(Eq(2))));
+}
+
+class PredicateFormatterFromMatcherTest : public ::testing::Test {
+ protected:
+  enum Behavior { kInitialSuccess, kAlwaysFail, kFlaky };
+
+  // A matcher that can return different results when used multiple times on the
+  // same input. No real matcher should do this; but this lets us test that we
+  // detect such behavior and fail appropriately.
+  class MockMatcher : public MatcherInterface<Behavior> {
+   public:
+    bool MatchAndExplain(Behavior behavior,
+                         MatchResultListener* listener) const override {
+      *listener << "[MatchAndExplain]";
+      switch (behavior) {
+        case kInitialSuccess:
+          // The first call to MatchAndExplain should use a "not interested"
+          // listener; so this is expected to return |true|. There should be no
+          // subsequent calls.
+          return !listener->IsInterested();
+
+        case kAlwaysFail:
+          return false;
+
+        case kFlaky:
+          // The first call to MatchAndExplain should use a "not interested"
+          // listener; so this will return |false|. Subsequent calls should have
+          // an "interested" listener; so this will return |true|, thus
+          // simulating a flaky matcher.
+          return listener->IsInterested();
+      }
+
+      GTEST_LOG_(FATAL) << "This should never be reached";
+      return false;
+    }
+
+    void DescribeTo(ostream* os) const override { *os << "[DescribeTo]"; }
+
+    void DescribeNegationTo(ostream* os) const override {
+      *os << "[DescribeNegationTo]";
+    }
+  };
+
+  AssertionResult RunPredicateFormatter(Behavior behavior) {
+    auto matcher = MakeMatcher(new MockMatcher);
+    PredicateFormatterFromMatcher<Matcher<Behavior>> predicate_formatter(
+        matcher);
+    return predicate_formatter("dummy-name", behavior);
+  }
+};
+
+TEST_F(PredicateFormatterFromMatcherTest, ShortCircuitOnSuccess) {
+  AssertionResult result = RunPredicateFormatter(kInitialSuccess);
+  EXPECT_TRUE(result);  // Implicit cast to bool.
+  std::string expect;
+  EXPECT_EQ(expect, result.message());
+}
+
+TEST_F(PredicateFormatterFromMatcherTest, NoShortCircuitOnFailure) {
+  AssertionResult result = RunPredicateFormatter(kAlwaysFail);
+  EXPECT_FALSE(result);  // Implicit cast to bool.
+  std::string expect =
+      "Value of: dummy-name\nExpected: [DescribeTo]\n"
+      "  Actual: 1" +
+      OfType(internal::GetTypeName<Behavior>()) + ", [MatchAndExplain]";
+  EXPECT_EQ(expect, result.message());
+}
+
+TEST_F(PredicateFormatterFromMatcherTest, DetectsFlakyShortCircuit) {
+  AssertionResult result = RunPredicateFormatter(kFlaky);
+  EXPECT_FALSE(result);  // Implicit cast to bool.
+  std::string expect =
+      "Value of: dummy-name\nExpected: [DescribeTo]\n"
+      "  The matcher failed on the initial attempt; but passed when rerun to "
+      "generate the explanation.\n"
+      "  Actual: 2" +
+      OfType(internal::GetTypeName<Behavior>()) + ", [MatchAndExplain]";
+  EXPECT_EQ(expect, result.message());
+}
+
+// Tests for ElementsAre().
+
+TEST(ElementsAreTest, CanDescribeExpectingNoElement) {
+  Matcher<const vector<int>&> m = ElementsAre();
+  EXPECT_EQ("is empty", Describe(m));
+}
+
+TEST(ElementsAreTest, CanDescribeExpectingOneElement) {
+  Matcher<vector<int>> m = ElementsAre(Gt(5));
+  EXPECT_EQ("has 1 element that is > 5", Describe(m));
+}
+
+TEST(ElementsAreTest, CanDescribeExpectingManyElements) {
+  Matcher<list<std::string>> m = ElementsAre(StrEq("one"), "two");
+  EXPECT_EQ(
+      "has 2 elements where\n"
+      "element #0 is equal to \"one\",\n"
+      "element #1 is equal to \"two\"",
+      Describe(m));
+}
+
+TEST(ElementsAreTest, CanDescribeNegationOfExpectingNoElement) {
+  Matcher<vector<int>> m = ElementsAre();
+  EXPECT_EQ("isn't empty", DescribeNegation(m));
+}
+
+TEST(ElementsAreTest, CanDescribeNegationOfExpectingOneElement) {
+  Matcher<const list<int>&> m = ElementsAre(Gt(5));
+  EXPECT_EQ(
+      "doesn't have 1 element, or\n"
+      "element #0 isn't > 5",
+      DescribeNegation(m));
+}
+
+TEST(ElementsAreTest, CanDescribeNegationOfExpectingManyElements) {
+  Matcher<const list<std::string>&> m = ElementsAre("one", "two");
+  EXPECT_EQ(
+      "doesn't have 2 elements, or\n"
+      "element #0 isn't equal to \"one\", or\n"
+      "element #1 isn't equal to \"two\"",
+      DescribeNegation(m));
+}
+
+TEST(ElementsAreTest, DoesNotExplainTrivialMatch) {
+  Matcher<const list<int>&> m = ElementsAre(1, Ne(2));
+
+  list<int> test_list;
+  test_list.push_back(1);
+  test_list.push_back(3);
+  EXPECT_EQ("", Explain(m, test_list));  // No need to explain anything.
+}
+
+TEST_P(ElementsAreTestP, ExplainsNonTrivialMatch) {
+  Matcher<const vector<int>&> m =
+      ElementsAre(GreaterThan(1), 0, GreaterThan(2));
+
+  const int a[] = {10, 0, 100};
+  vector<int> test_vector(std::begin(a), std::end(a));
+  EXPECT_EQ(
+      "whose element #0 matches, which is 9 more than 1,\n"
+      "and whose element #2 matches, which is 98 more than 2",
+      Explain(m, test_vector));
+}
+
+TEST(ElementsAreTest, CanExplainMismatchWrongSize) {
+  Matcher<const list<int>&> m = ElementsAre(1, 3);
+
+  list<int> test_list;
+  // No need to explain when the container is empty.
+  EXPECT_EQ("", Explain(m, test_list));
+
+  test_list.push_back(1);
+  EXPECT_EQ("which has 1 element", Explain(m, test_list));
+}
+
+TEST_P(ElementsAreTestP, CanExplainMismatchRightSize) {
+  Matcher<const vector<int>&> m = ElementsAre(1, GreaterThan(5));
+
+  vector<int> v;
+  v.push_back(2);
+  v.push_back(1);
+  EXPECT_EQ("whose element #0 doesn't match", Explain(m, v));
+
+  v[0] = 1;
+  EXPECT_EQ("whose element #1 doesn't match, which is 4 less than 5",
+            Explain(m, v));
+}
+
+TEST(ElementsAreTest, MatchesOneElementVector) {
+  vector<std::string> test_vector;
+  test_vector.push_back("test string");
+
+  EXPECT_THAT(test_vector, ElementsAre(StrEq("test string")));
+}
+
+TEST(ElementsAreTest, MatchesOneElementList) {
+  list<std::string> test_list;
+  test_list.push_back("test string");
+
+  EXPECT_THAT(test_list, ElementsAre("test string"));
+}
+
+TEST(ElementsAreTest, MatchesThreeElementVector) {
+  vector<std::string> test_vector;
+  test_vector.push_back("one");
+  test_vector.push_back("two");
+  test_vector.push_back("three");
+
+  EXPECT_THAT(test_vector, ElementsAre("one", StrEq("two"), _));
+}
+
+TEST(ElementsAreTest, MatchesOneElementEqMatcher) {
+  vector<int> test_vector;
+  test_vector.push_back(4);
+
+  EXPECT_THAT(test_vector, ElementsAre(Eq(4)));
+}
+
+TEST(ElementsAreTest, MatchesOneElementAnyMatcher) {
+  vector<int> test_vector;
+  test_vector.push_back(4);
+
+  EXPECT_THAT(test_vector, ElementsAre(_));
+}
+
+TEST(ElementsAreTest, MatchesOneElementValue) {
+  vector<int> test_vector;
+  test_vector.push_back(4);
+
+  EXPECT_THAT(test_vector, ElementsAre(4));
+}
+
+TEST(ElementsAreTest, MatchesThreeElementsMixedMatchers) {
+  vector<int> test_vector;
+  test_vector.push_back(1);
+  test_vector.push_back(2);
+  test_vector.push_back(3);
+
+  EXPECT_THAT(test_vector, ElementsAre(1, Eq(2), _));
+}
+
+TEST(ElementsAreTest, MatchesTenElementVector) {
+  const int a[] = {0, 1, 2, 3, 4, 5, 6, 7, 8, 9};
+  vector<int> test_vector(std::begin(a), std::end(a));
+
+  EXPECT_THAT(test_vector,
+              // The element list can contain values and/or matchers
+              // of different types.
+              ElementsAre(0, Ge(0), _, 3, 4, Ne(2), Eq(6), 7, 8, _));
+}
+
+TEST(ElementsAreTest, DoesNotMatchWrongSize) {
+  vector<std::string> test_vector;
+  test_vector.push_back("test string");
+  test_vector.push_back("test string");
+
+  Matcher<vector<std::string>> m = ElementsAre(StrEq("test string"));
+  EXPECT_FALSE(m.Matches(test_vector));
+}
+
+TEST(ElementsAreTest, DoesNotMatchWrongValue) {
+  vector<std::string> test_vector;
+  test_vector.push_back("other string");
+
+  Matcher<vector<std::string>> m = ElementsAre(StrEq("test string"));
+  EXPECT_FALSE(m.Matches(test_vector));
+}
+
+TEST(ElementsAreTest, DoesNotMatchWrongOrder) {
+  vector<std::string> test_vector;
+  test_vector.push_back("one");
+  test_vector.push_back("three");
+  test_vector.push_back("two");
+
+  Matcher<vector<std::string>> m =
+      ElementsAre(StrEq("one"), StrEq("two"), StrEq("three"));
+  EXPECT_FALSE(m.Matches(test_vector));
+}
+
+TEST(ElementsAreTest, WorksForNestedContainer) {
+  constexpr std::array<const char*, 2> strings = {{"Hi", "world"}};
+
+  vector<list<char>> nested;
+  for (const auto& s : strings) {
+    nested.emplace_back(s, s + strlen(s));
+  }
+
+  EXPECT_THAT(nested, ElementsAre(ElementsAre('H', Ne('e')),
+                                  ElementsAre('w', 'o', _, _, 'd')));
+  EXPECT_THAT(nested, Not(ElementsAre(ElementsAre('H', 'e'),
+                                      ElementsAre('w', 'o', _, _, 'd'))));
+}
+
+TEST(ElementsAreTest, WorksWithByRefElementMatchers) {
+  int a[] = {0, 1, 2};
+  vector<int> v(std::begin(a), std::end(a));
+
+  EXPECT_THAT(v, ElementsAre(Ref(v[0]), Ref(v[1]), Ref(v[2])));
+  EXPECT_THAT(v, Not(ElementsAre(Ref(v[0]), Ref(v[1]), Ref(a[2]))));
+}
+
+TEST(ElementsAreTest, WorksWithContainerPointerUsingPointee) {
+  int a[] = {0, 1, 2};
+  vector<int> v(std::begin(a), std::end(a));
+
+  EXPECT_THAT(&v, Pointee(ElementsAre(0, 1, _)));
+  EXPECT_THAT(&v, Not(Pointee(ElementsAre(0, _, 3))));
+}
+
+TEST(ElementsAreTest, WorksWithNativeArrayPassedByReference) {
+  int array[] = {0, 1, 2};
+  EXPECT_THAT(array, ElementsAre(0, 1, _));
+  EXPECT_THAT(array, Not(ElementsAre(1, _, _)));
+  EXPECT_THAT(array, Not(ElementsAre(0, _)));
+}
+
+class NativeArrayPassedAsPointerAndSize {
+ public:
+  NativeArrayPassedAsPointerAndSize() = default;
+
+  MOCK_METHOD(void, Helper, (int* array, int size));
+
+ private:
+  NativeArrayPassedAsPointerAndSize(const NativeArrayPassedAsPointerAndSize&) =
+      delete;
+  NativeArrayPassedAsPointerAndSize& operator=(
+      const NativeArrayPassedAsPointerAndSize&) = delete;
+};
+
+TEST(ElementsAreTest, WorksWithNativeArrayPassedAsPointerAndSize) {
+  int array[] = {0, 1};
+  ::std::tuple<int*, size_t> array_as_tuple(array, 2);
+  EXPECT_THAT(array_as_tuple, ElementsAre(0, 1));
+  EXPECT_THAT(array_as_tuple, Not(ElementsAre(0)));
+
+  NativeArrayPassedAsPointerAndSize helper;
+  EXPECT_CALL(helper, Helper(_, _)).With(ElementsAre(0, 1));
+  helper.Helper(array, 2);
+}
+
+TEST(ElementsAreTest, WorksWithTwoDimensionalNativeArray) {
+  const char a2[][3] = {"hi", "lo"};
+  EXPECT_THAT(a2, ElementsAre(ElementsAre('h', 'i', '\0'),
+                              ElementsAre('l', 'o', '\0')));
+  EXPECT_THAT(a2, ElementsAre(StrEq("hi"), StrEq("lo")));
+  EXPECT_THAT(a2, ElementsAre(Not(ElementsAre('h', 'o', '\0')),
+                              ElementsAre('l', 'o', '\0')));
+}
+
+TEST(ElementsAreTest, AcceptsStringLiteral) {
+  std::string array[] = {"hi", "one", "two"};
+  EXPECT_THAT(array, ElementsAre("hi", "one", "two"));
+  EXPECT_THAT(array, Not(ElementsAre("hi", "one", "too")));
+}
+
+// Declared here with the size unknown.  Defined AFTER the following test.
+extern const char kHi[];
+
+TEST(ElementsAreTest, AcceptsArrayWithUnknownSize) {
+  // The size of kHi is not known in this test, but ElementsAre() should
+  // still accept it.
+
+  std::string array1[] = {"hi"};
+  EXPECT_THAT(array1, ElementsAre(kHi));
+
+  std::string array2[] = {"ho"};
+  EXPECT_THAT(array2, Not(ElementsAre(kHi)));
+}
+
+const char kHi[] = "hi";
+
+TEST(ElementsAreTest, MakesCopyOfArguments) {
+  int x = 1;
+  int y = 2;
+  // This should make a copy of x and y.
+  ::testing::internal::ElementsAreMatcher<std::tuple<int, int>>
+      polymorphic_matcher = ElementsAre(x, y);
+  // Changing x and y now shouldn't affect the meaning of the above matcher.
+  x = y = 0;
+  const int array1[] = {1, 2};
+  EXPECT_THAT(array1, polymorphic_matcher);
+  const int array2[] = {0, 0};
+  EXPECT_THAT(array2, Not(polymorphic_matcher));
+}
+
+// Tests for ElementsAreArray().  Since ElementsAreArray() shares most
+// of the implementation with ElementsAre(), we don't test it as
+// thoroughly here.
+
+TEST(ElementsAreArrayTest, CanBeCreatedWithValueArray) {
+  const int a[] = {1, 2, 3};
+
+  vector<int> test_vector(std::begin(a), std::end(a));
+  EXPECT_THAT(test_vector, ElementsAreArray(a));
+
+  test_vector[2] = 0;
+  EXPECT_THAT(test_vector, Not(ElementsAreArray(a)));
+}
+
+TEST(ElementsAreArrayTest, CanBeCreatedWithArraySize) {
+  std::array<const char*, 3> a = {{"one", "two", "three"}};
+
+  vector<std::string> test_vector(std::begin(a), std::end(a));
+  EXPECT_THAT(test_vector, ElementsAreArray(a.data(), a.size()));
+
+  const char** p = a.data();
+  test_vector[0] = "1";
+  EXPECT_THAT(test_vector, Not(ElementsAreArray(p, a.size())));
+}
+
+TEST(ElementsAreArrayTest, CanBeCreatedWithoutArraySize) {
+  const char* a[] = {"one", "two", "three"};
+
+  vector<std::string> test_vector(std::begin(a), std::end(a));
+  EXPECT_THAT(test_vector, ElementsAreArray(a));
+
+  test_vector[0] = "1";
+  EXPECT_THAT(test_vector, Not(ElementsAreArray(a)));
+}
+
+TEST(ElementsAreArrayTest, CanBeCreatedWithMatcherArray) {
+  const Matcher<std::string> kMatcherArray[] = {StrEq("one"), StrEq("two"),
+                                                StrEq("three")};
+
+  vector<std::string> test_vector;
+  test_vector.push_back("one");
+  test_vector.push_back("two");
+  test_vector.push_back("three");
+  EXPECT_THAT(test_vector, ElementsAreArray(kMatcherArray));
+
+  test_vector.push_back("three");
+  EXPECT_THAT(test_vector, Not(ElementsAreArray(kMatcherArray)));
+}
+
+TEST(ElementsAreArrayTest, CanBeCreatedWithVector) {
+  const int a[] = {1, 2, 3};
+  vector<int> test_vector(std::begin(a), std::end(a));
+  const vector<int> expected(std::begin(a), std::end(a));
+  EXPECT_THAT(test_vector, ElementsAreArray(expected));
+  test_vector.push_back(4);
+  EXPECT_THAT(test_vector, Not(ElementsAreArray(expected)));
+}
+
+TEST(ElementsAreArrayTest, TakesInitializerList) {
+  const int a[5] = {1, 2, 3, 4, 5};
+  EXPECT_THAT(a, ElementsAreArray({1, 2, 3, 4, 5}));
+  EXPECT_THAT(a, Not(ElementsAreArray({1, 2, 3, 5, 4})));
+  EXPECT_THAT(a, Not(ElementsAreArray({1, 2, 3, 4, 6})));
+}
+
+TEST(ElementsAreArrayTest, TakesInitializerListOfCStrings) {
+  const std::string a[5] = {"a", "b", "c", "d", "e"};
+  EXPECT_THAT(a, ElementsAreArray({"a", "b", "c", "d", "e"}));
+  EXPECT_THAT(a, Not(ElementsAreArray({"a", "b", "c", "e", "d"})));
+  EXPECT_THAT(a, Not(ElementsAreArray({"a", "b", "c", "d", "ef"})));
+}
+
+TEST(ElementsAreArrayTest, TakesInitializerListOfSameTypedMatchers) {
+  const int a[5] = {1, 2, 3, 4, 5};
+  EXPECT_THAT(a, ElementsAreArray({Eq(1), Eq(2), Eq(3), Eq(4), Eq(5)}));
+  EXPECT_THAT(a, Not(ElementsAreArray({Eq(1), Eq(2), Eq(3), Eq(4), Eq(6)})));
+}
+
+TEST(ElementsAreArrayTest, TakesInitializerListOfDifferentTypedMatchers) {
+  const int a[5] = {1, 2, 3, 4, 5};
+  // The compiler cannot infer the type of the initializer list if its
+  // elements have different types.  We must explicitly specify the
+  // unified element type in this case.
+  EXPECT_THAT(
+      a, ElementsAreArray<Matcher<int>>({Eq(1), Ne(-2), Ge(3), Le(4), Eq(5)}));
+  EXPECT_THAT(a, Not(ElementsAreArray<Matcher<int>>(
+                     {Eq(1), Ne(-2), Ge(3), Le(4), Eq(6)})));
+}
+
+TEST(ElementsAreArrayTest, CanBeCreatedWithMatcherVector) {
+  const int a[] = {1, 2, 3};
+  const Matcher<int> kMatchers[] = {Eq(1), Eq(2), Eq(3)};
+  vector<int> test_vector(std::begin(a), std::end(a));
+  const vector<Matcher<int>> expected(std::begin(kMatchers),
+                                      std::end(kMatchers));
+  EXPECT_THAT(test_vector, ElementsAreArray(expected));
+  test_vector.push_back(4);
+  EXPECT_THAT(test_vector, Not(ElementsAreArray(expected)));
+}
+
+TEST(ElementsAreArrayTest, CanBeCreatedWithIteratorRange) {
+  const int a[] = {1, 2, 3};
+  const vector<int> test_vector(std::begin(a), std::end(a));
+  const vector<int> expected(std::begin(a), std::end(a));
+  EXPECT_THAT(test_vector, ElementsAreArray(expected.begin(), expected.end()));
+  // Pointers are iterators, too.
+  EXPECT_THAT(test_vector, ElementsAreArray(std::begin(a), std::end(a)));
+  // The empty range of NULL pointers should also be okay.
+  int* const null_int = nullptr;
+  EXPECT_THAT(test_vector, Not(ElementsAreArray(null_int, null_int)));
+  EXPECT_THAT((vector<int>()), ElementsAreArray(null_int, null_int));
+}
+
+// Since ElementsAre() and ElementsAreArray() share much of the
+// implementation, we only do a test for native arrays here.
+TEST(ElementsAreArrayTest, WorksWithNativeArray) {
+  ::std::string a[] = {"hi", "ho"};
+  ::std::string b[] = {"hi", "ho"};
+
+  EXPECT_THAT(a, ElementsAreArray(b));
+  EXPECT_THAT(a, ElementsAreArray(b, 2));
+  EXPECT_THAT(a, Not(ElementsAreArray(b, 1)));
+}
+
+TEST(ElementsAreArrayTest, SourceLifeSpan) {
+  const int a[] = {1, 2, 3};
+  vector<int> test_vector(std::begin(a), std::end(a));
+  vector<int> expect(std::begin(a), std::end(a));
+  ElementsAreArrayMatcher<int> matcher_maker =
+      ElementsAreArray(expect.begin(), expect.end());
+  EXPECT_THAT(test_vector, matcher_maker);
+  // Changing in place the values that initialized matcher_maker should not
+  // affect matcher_maker anymore. It should have made its own copy of them.
+  for (int& i : expect) {
+    i += 10;
+  }
+  EXPECT_THAT(test_vector, matcher_maker);
+  test_vector.push_back(3);
+  EXPECT_THAT(test_vector, Not(matcher_maker));
+}
+
+// Tests Contains().
+
+INSTANTIATE_GTEST_MATCHER_TEST_P(ContainsTest);
+
+TEST(ContainsTest, ListMatchesWhenElementIsInContainer) {
+  list<int> some_list;
+  some_list.push_back(3);
+  some_list.push_back(1);
+  some_list.push_back(2);
+  some_list.push_back(3);
+  EXPECT_THAT(some_list, Contains(1));
+  EXPECT_THAT(some_list, Contains(Gt(2.5)));
+  EXPECT_THAT(some_list, Contains(Eq(2.0f)));
+
+  list<std::string> another_list;
+  another_list.push_back("fee");
+  another_list.push_back("fie");
+  another_list.push_back("foe");
+  another_list.push_back("fum");
+  EXPECT_THAT(another_list, Contains(std::string("fee")));
+}
+
+TEST(ContainsTest, ListDoesNotMatchWhenElementIsNotInContainer) {
+  list<int> some_list;
+  some_list.push_back(3);
+  some_list.push_back(1);
+  EXPECT_THAT(some_list, Not(Contains(4)));
+}
+
+TEST(ContainsTest, SetMatchesWhenElementIsInContainer) {
+  set<int> some_set;
+  some_set.insert(3);
+  some_set.insert(1);
+  some_set.insert(2);
+  EXPECT_THAT(some_set, Contains(Eq(1.0)));
+  EXPECT_THAT(some_set, Contains(Eq(3.0f)));
+  EXPECT_THAT(some_set, Contains(2));
+
+  set<std::string> another_set;
+  another_set.insert("fee");
+  another_set.insert("fie");
+  another_set.insert("foe");
+  another_set.insert("fum");
+  EXPECT_THAT(another_set, Contains(Eq(std::string("fum"))));
+}
+
+TEST(ContainsTest, SetDoesNotMatchWhenElementIsNotInContainer) {
+  set<int> some_set;
+  some_set.insert(3);
+  some_set.insert(1);
+  EXPECT_THAT(some_set, Not(Contains(4)));
+
+  set<std::string> c_string_set;
+  c_string_set.insert("hello");
+  EXPECT_THAT(c_string_set, Not(Contains(std::string("goodbye"))));
+}
+
+TEST_P(ContainsTestP, ExplainsMatchResultCorrectly) {
+  const int a[2] = {1, 2};
+  Matcher<const int(&)[2]> m = Contains(2);
+  EXPECT_EQ("whose element #1 matches", Explain(m, a));
+
+  m = Contains(3);
+  EXPECT_EQ("", Explain(m, a));
+
+  m = Contains(GreaterThan(0));
+  EXPECT_EQ("whose element #0 matches, which is 1 more than 0", Explain(m, a));
+
+  m = Contains(GreaterThan(10));
+  EXPECT_EQ("", Explain(m, a));
+}
+
+TEST(ContainsTest, DescribesItselfCorrectly) {
+  Matcher<vector<int>> m = Contains(1);
+  EXPECT_EQ("contains at least one element that is equal to 1", Describe(m));
+
+  Matcher<vector<int>> m2 = Not(m);
+  EXPECT_EQ("doesn't contain any element that is equal to 1", Describe(m2));
+}
+
+TEST(ContainsTest, MapMatchesWhenElementIsInContainer) {
+  map<std::string, int> my_map;
+  const char* bar = "a string";
+  my_map[bar] = 2;
+  EXPECT_THAT(my_map, Contains(pair<const char* const, int>(bar, 2)));
+
+  map<std::string, int> another_map;
+  another_map["fee"] = 1;
+  another_map["fie"] = 2;
+  another_map["foe"] = 3;
+  another_map["fum"] = 4;
+  EXPECT_THAT(another_map,
+              Contains(pair<const std::string, int>(std::string("fee"), 1)));
+  EXPECT_THAT(another_map, Contains(pair<const std::string, int>("fie", 2)));
+}
+
+TEST(ContainsTest, MapDoesNotMatchWhenElementIsNotInContainer) {
+  map<int, int> some_map;
+  some_map[1] = 11;
+  some_map[2] = 22;
+  EXPECT_THAT(some_map, Not(Contains(pair<const int, int>(2, 23))));
+}
+
+TEST(ContainsTest, ArrayMatchesWhenElementIsInContainer) {
+  const char* string_array[] = {"fee", "fie", "foe", "fum"};
+  EXPECT_THAT(string_array, Contains(Eq(std::string("fum"))));
+}
+
+TEST(ContainsTest, ArrayDoesNotMatchWhenElementIsNotInContainer) {
+  int int_array[] = {1, 2, 3, 4};
+  EXPECT_THAT(int_array, Not(Contains(5)));
+}
+
+TEST(ContainsTest, AcceptsMatcher) {
+  const int a[] = {1, 2, 3};
+  EXPECT_THAT(a, Contains(Gt(2)));
+  EXPECT_THAT(a, Not(Contains(Gt(4))));
+}
+
+TEST(ContainsTest, WorksForNativeArrayAsTuple) {
+  const int a[] = {1, 2};
+  const int* const pointer = a;
+  EXPECT_THAT(std::make_tuple(pointer, 2), Contains(1));
+  EXPECT_THAT(std::make_tuple(pointer, 2), Not(Contains(Gt(3))));
+}
+
+TEST(ContainsTest, WorksForTwoDimensionalNativeArray) {
+  int a[][3] = {{1, 2, 3}, {4, 5, 6}};
+  EXPECT_THAT(a, Contains(ElementsAre(4, 5, 6)));
+  EXPECT_THAT(a, Contains(Contains(5)));
+  EXPECT_THAT(a, Not(Contains(ElementsAre(3, 4, 5))));
+  EXPECT_THAT(a, Contains(Not(Contains(5))));
+}
+
+}  // namespace
+}  // namespace gmock_matchers_test
+}  // namespace testing
+
+GTEST_DISABLE_MSC_WARNINGS_POP_()  // 4244 4100

contrib/googletest/googlemock/test/gmock-matchers-misc_test.cc

@@ -0,0 +1,1823 @@
+// Copyright 2007, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+// Google Mock - a framework for writing C++ mock classes.
+//
+// This file tests some commonly used argument matchers.
+
+#include <array>
+#include <memory>
+#include <ostream>
+#include <string>
+#include <tuple>
+#include <utility>
+#include <vector>
+
+#include "gtest/gtest.h"
+
+// Silence warning C4244: 'initializing': conversion from 'int' to 'short',
+// possible loss of data and C4100, unreferenced local parameter
+GTEST_DISABLE_MSC_WARNINGS_PUSH_(4244 4100)
+
+#include "test/gmock-matchers_test.h"
+
+namespace testing {
+namespace gmock_matchers_test {
+namespace {
+
+TEST(AddressTest, NonConst) {
+  int n = 1;
+  const Matcher<int> m = Address(Eq(&n));
+
+  EXPECT_TRUE(m.Matches(n));
+
+  int other = 5;
+
+  EXPECT_FALSE(m.Matches(other));
+
+  int& n_ref = n;
+
+  EXPECT_TRUE(m.Matches(n_ref));
+}
+
+TEST(AddressTest, Const) {
+  const int n = 1;
+  const Matcher<int> m = Address(Eq(&n));
+
+  EXPECT_TRUE(m.Matches(n));
+
+  int other = 5;
+
+  EXPECT_FALSE(m.Matches(other));
+}
+
+TEST(AddressTest, MatcherDoesntCopy) {
+  std::unique_ptr<int> n(new int(1));
+  const Matcher<std::unique_ptr<int>> m = Address(Eq(&n));
+
+  EXPECT_TRUE(m.Matches(n));
+}
+
+TEST(AddressTest, Describe) {
+  Matcher<int> matcher = Address(_);
+  EXPECT_EQ("has address that is anything", Describe(matcher));
+  EXPECT_EQ("does not have address that is anything",
+            DescribeNegation(matcher));
+}
+
+// The following two tests verify that values without a public copy
+// ctor can be used as arguments to matchers like Eq(), Ge(), and etc
+// with the help of ByRef().
+
+class NotCopyable {
+ public:
+  explicit NotCopyable(int a_value) : value_(a_value) {}
+
+  int value() const { return value_; }
+
+  bool operator==(const NotCopyable& rhs) const {
+    return value() == rhs.value();
+  }
+
+  bool operator>=(const NotCopyable& rhs) const {
+    return value() >= rhs.value();
+  }
+
+ private:
+  int value_;
+
+  NotCopyable(const NotCopyable&) = delete;
+  NotCopyable& operator=(const NotCopyable&) = delete;
+};
+
+TEST(ByRefTest, AllowsNotCopyableConstValueInMatchers) {
+  const NotCopyable const_value1(1);
+  const Matcher<const NotCopyable&> m = Eq(ByRef(const_value1));
+
+  const NotCopyable n1(1), n2(2);
+  EXPECT_TRUE(m.Matches(n1));
+  EXPECT_FALSE(m.Matches(n2));
+}
+
+TEST(ByRefTest, AllowsNotCopyableValueInMatchers) {
+  NotCopyable value2(2);
+  const Matcher<NotCopyable&> m = Ge(ByRef(value2));
+
+  NotCopyable n1(1), n2(2);
+  EXPECT_FALSE(m.Matches(n1));
+  EXPECT_TRUE(m.Matches(n2));
+}
+
+TEST(IsEmptyTest, ImplementsIsEmpty) {
+  vector<int> container;
+  EXPECT_THAT(container, IsEmpty());
+  container.push_back(0);
+  EXPECT_THAT(container, Not(IsEmpty()));
+  container.push_back(1);
+  EXPECT_THAT(container, Not(IsEmpty()));
+}
+
+TEST(IsEmptyTest, WorksWithString) {
+  std::string text;
+  EXPECT_THAT(text, IsEmpty());
+  text = "foo";
+  EXPECT_THAT(text, Not(IsEmpty()));
+  text = std::string("\0", 1);
+  EXPECT_THAT(text, Not(IsEmpty()));
+}
+
+TEST(IsEmptyTest, CanDescribeSelf) {
+  Matcher<vector<int>> m = IsEmpty();
+  EXPECT_EQ("is empty", Describe(m));
+  EXPECT_EQ("isn't empty", DescribeNegation(m));
+}
+
+TEST(IsEmptyTest, ExplainsResult) {
+  Matcher<vector<int>> m = IsEmpty();
+  vector<int> container;
+  EXPECT_EQ("", Explain(m, container));
+  container.push_back(0);
+  EXPECT_EQ("whose size is 1", Explain(m, container));
+}
+
+TEST(IsEmptyTest, WorksWithMoveOnly) {
+  ContainerHelper helper;
+  EXPECT_CALL(helper, Call(IsEmpty()));
+  helper.Call({});
+}
+
+TEST(IsTrueTest, IsTrueIsFalse) {
+  EXPECT_THAT(true, IsTrue());
+  EXPECT_THAT(false, IsFalse());
+  EXPECT_THAT(true, Not(IsFalse()));
+  EXPECT_THAT(false, Not(IsTrue()));
+  EXPECT_THAT(0, Not(IsTrue()));
+  EXPECT_THAT(0, IsFalse());
+  EXPECT_THAT(nullptr, Not(IsTrue()));
+  EXPECT_THAT(nullptr, IsFalse());
+  EXPECT_THAT(-1, IsTrue());
+  EXPECT_THAT(-1, Not(IsFalse()));
+  EXPECT_THAT(1, IsTrue());
+  EXPECT_THAT(1, Not(IsFalse()));
+  EXPECT_THAT(2, IsTrue());
+  EXPECT_THAT(2, Not(IsFalse()));
+  int a = 42;
+  EXPECT_THAT(a, IsTrue());
+  EXPECT_THAT(a, Not(IsFalse()));
+  EXPECT_THAT(&a, IsTrue());
+  EXPECT_THAT(&a, Not(IsFalse()));
+  EXPECT_THAT(false, Not(IsTrue()));
+  EXPECT_THAT(true, Not(IsFalse()));
+  EXPECT_THAT(std::true_type(), IsTrue());
+  EXPECT_THAT(std::true_type(), Not(IsFalse()));
+  EXPECT_THAT(std::false_type(), IsFalse());
+  EXPECT_THAT(std::false_type(), Not(IsTrue()));
+  EXPECT_THAT(nullptr, Not(IsTrue()));
+  EXPECT_THAT(nullptr, IsFalse());
+  std::unique_ptr<int> null_unique;
+  std::unique_ptr<int> nonnull_unique(new int(0));
+  EXPECT_THAT(null_unique, Not(IsTrue()));
+  EXPECT_THAT(null_unique, IsFalse());
+  EXPECT_THAT(nonnull_unique, IsTrue());
+  EXPECT_THAT(nonnull_unique, Not(IsFalse()));
+}
+
+#ifdef GTEST_HAS_TYPED_TEST
+// Tests ContainerEq with different container types, and
+// different element types.
+
+template <typename T>
+class ContainerEqTest : public testing::Test {};
+
+typedef testing::Types<set<int>, vector<size_t>, multiset<size_t>, list<int>>
+    ContainerEqTestTypes;
+
+TYPED_TEST_SUITE(ContainerEqTest, ContainerEqTestTypes);
+
+// Tests that the filled container is equal to itself.
+TYPED_TEST(ContainerEqTest, EqualsSelf) {
+  static const int vals[] = {1, 1, 2, 3, 5, 8};
+  TypeParam my_set(vals, vals + 6);
+  const Matcher<TypeParam> m = ContainerEq(my_set);
+  EXPECT_TRUE(m.Matches(my_set));
+  EXPECT_EQ("", Explain(m, my_set));
+}
+
+// Tests that missing values are reported.
+TYPED_TEST(ContainerEqTest, ValueMissing) {
+  static const int vals[] = {1, 1, 2, 3, 5, 8};
+  static const int test_vals[] = {2, 1, 8, 5};
+  TypeParam my_set(vals, vals + 6);
+  TypeParam test_set(test_vals, test_vals + 4);
+  const Matcher<TypeParam> m = ContainerEq(my_set);
+  EXPECT_FALSE(m.Matches(test_set));
+  EXPECT_EQ("which doesn't have these expected elements: 3",
+            Explain(m, test_set));
+}
+
+// Tests that added values are reported.
+TYPED_TEST(ContainerEqTest, ValueAdded) {
+  static const int vals[] = {1, 1, 2, 3, 5, 8};
+  static const int test_vals[] = {1, 2, 3, 5, 8, 46};
+  TypeParam my_set(vals, vals + 6);
+  TypeParam test_set(test_vals, test_vals + 6);
+  const Matcher<const TypeParam&> m = ContainerEq(my_set);
+  EXPECT_FALSE(m.Matches(test_set));
+  EXPECT_EQ("which has these unexpected elements: 46", Explain(m, test_set));
+}
+
+// Tests that added and missing values are reported together.
+TYPED_TEST(ContainerEqTest, ValueAddedAndRemoved) {
+  static const int vals[] = {1, 1, 2, 3, 5, 8};
+  static const int test_vals[] = {1, 2, 3, 8, 46};
+  TypeParam my_set(vals, vals + 6);
+  TypeParam test_set(test_vals, test_vals + 5);
+  const Matcher<TypeParam> m = ContainerEq(my_set);
+  EXPECT_FALSE(m.Matches(test_set));
+  EXPECT_EQ(
+      "which has these unexpected elements: 46,\n"
+      "and doesn't have these expected elements: 5",
+      Explain(m, test_set));
+}
+
+// Tests duplicated value -- expect no explanation.
+TYPED_TEST(ContainerEqTest, DuplicateDifference) {
+  static const int vals[] = {1, 1, 2, 3, 5, 8};
+  static const int test_vals[] = {1, 2, 3, 5, 8};
+  TypeParam my_set(vals, vals + 6);
+  TypeParam test_set(test_vals, test_vals + 5);
+  const Matcher<const TypeParam&> m = ContainerEq(my_set);
+  // Depending on the container, match may be true or false
+  // But in any case there should be no explanation.
+  EXPECT_EQ("", Explain(m, test_set));
+}
+#endif  // GTEST_HAS_TYPED_TEST
+
+// Tests that multiple missing values are reported.
+// Using just vector here, so order is predictable.
+TEST(ContainerEqExtraTest, MultipleValuesMissing) {
+  static const int vals[] = {1, 1, 2, 3, 5, 8};
+  static const int test_vals[] = {2, 1, 5};
+  vector<int> my_set(vals, vals + 6);
+  vector<int> test_set(test_vals, test_vals + 3);
+  const Matcher<vector<int>> m = ContainerEq(my_set);
+  EXPECT_FALSE(m.Matches(test_set));
+  EXPECT_EQ("which doesn't have these expected elements: 3, 8",
+            Explain(m, test_set));
+}
+
+// Tests that added values are reported.
+// Using just vector here, so order is predictable.
+TEST(ContainerEqExtraTest, MultipleValuesAdded) {
+  static const int vals[] = {1, 1, 2, 3, 5, 8};
+  static const int test_vals[] = {1, 2, 92, 3, 5, 8, 46};
+  list<size_t> my_set(vals, vals + 6);
+  list<size_t> test_set(test_vals, test_vals + 7);
+  const Matcher<const list<size_t>&> m = ContainerEq(my_set);
+  EXPECT_FALSE(m.Matches(test_set));
+  EXPECT_EQ("which has these unexpected elements: 92, 46",
+            Explain(m, test_set));
+}
+
+// Tests that added and missing values are reported together.
+TEST(ContainerEqExtraTest, MultipleValuesAddedAndRemoved) {
+  static const int vals[] = {1, 1, 2, 3, 5, 8};
+  static const int test_vals[] = {1, 2, 3, 92, 46};
+  list<size_t> my_set(vals, vals + 6);
+  list<size_t> test_set(test_vals, test_vals + 5);
+  const Matcher<const list<size_t>> m = ContainerEq(my_set);
+  EXPECT_FALSE(m.Matches(test_set));
+  EXPECT_EQ(
+      "which has these unexpected elements: 92, 46,\n"
+      "and doesn't have these expected elements: 5, 8",
+      Explain(m, test_set));
+}
+
+// Tests to see that duplicate elements are detected,
+// but (as above) not reported in the explanation.
+TEST(ContainerEqExtraTest, MultiSetOfIntDuplicateDifference) {
+  static const int vals[] = {1, 1, 2, 3, 5, 8};
+  static const int test_vals[] = {1, 2, 3, 5, 8};
+  vector<int> my_set(vals, vals + 6);
+  vector<int> test_set(test_vals, test_vals + 5);
+  const Matcher<vector<int>> m = ContainerEq(my_set);
+  EXPECT_TRUE(m.Matches(my_set));
+  EXPECT_FALSE(m.Matches(test_set));
+  // There is nothing to report when both sets contain all the same values.
+  EXPECT_EQ("", Explain(m, test_set));
+}
+
+// Tests that ContainerEq works for non-trivial associative containers,
+// like maps.
+TEST(ContainerEqExtraTest, WorksForMaps) {
+  map<int, std::string> my_map;
+  my_map[0] = "a";
+  my_map[1] = "b";
+
+  map<int, std::string> test_map;
+  test_map[0] = "aa";
+  test_map[1] = "b";
+
+  const Matcher<const map<int, std::string>&> m = ContainerEq(my_map);
+  EXPECT_TRUE(m.Matches(my_map));
+  EXPECT_FALSE(m.Matches(test_map));
+
+  EXPECT_EQ(
+      "which has these unexpected elements: (0, \"aa\"),\n"
+      "and doesn't have these expected elements: (0, \"a\")",
+      Explain(m, test_map));
+}
+
+TEST(ContainerEqExtraTest, WorksForNativeArray) {
+  int a1[] = {1, 2, 3};
+  int a2[] = {1, 2, 3};
+  int b[] = {1, 2, 4};
+
+  EXPECT_THAT(a1, ContainerEq(a2));
+  EXPECT_THAT(a1, Not(ContainerEq(b)));
+}
+
+TEST(ContainerEqExtraTest, WorksForTwoDimensionalNativeArray) {
+  const char a1[][3] = {"hi", "lo"};
+  const char a2[][3] = {"hi", "lo"};
+  const char b[][3] = {"lo", "hi"};
+
+  // Tests using ContainerEq() in the first dimension.
+  EXPECT_THAT(a1, ContainerEq(a2));
+  EXPECT_THAT(a1, Not(ContainerEq(b)));
+
+  // Tests using ContainerEq() in the second dimension.
+  EXPECT_THAT(a1, ElementsAre(ContainerEq(a2[0]), ContainerEq(a2[1])));
+  EXPECT_THAT(a1, ElementsAre(Not(ContainerEq(b[0])), ContainerEq(a2[1])));
+}
+
+TEST(ContainerEqExtraTest, WorksForNativeArrayAsTuple) {
+  const int a1[] = {1, 2, 3};
+  const int a2[] = {1, 2, 3};
+  const int b[] = {1, 2, 3, 4};
+
+  const int* const p1 = a1;
+  EXPECT_THAT(std::make_tuple(p1, 3), ContainerEq(a2));
+  EXPECT_THAT(std::make_tuple(p1, 3), Not(ContainerEq(b)));
+
+  const int c[] = {1, 3, 2};
+  EXPECT_THAT(std::make_tuple(p1, 3), Not(ContainerEq(c)));
+}
+
+TEST(ContainerEqExtraTest, CopiesNativeArrayParameter) {
+  std::string a1[][3] = {{"hi", "hello", "ciao"}, {"bye", "see you", "ciao"}};
+
+  std::string a2[][3] = {{"hi", "hello", "ciao"}, {"bye", "see you", "ciao"}};
+
+  const Matcher<const std::string(&)[2][3]> m = ContainerEq(a2);
+  EXPECT_THAT(a1, m);
+
+  a2[0][0] = "ha";
+  EXPECT_THAT(a1, m);
+}
+
+namespace {
+
+// Used as a check on the more complex max flow method used in the
+// real testing::internal::FindMaxBipartiteMatching. This method is
+// compatible but runs in worst-case factorial time, so we only
+// use it in testing for small problem sizes.
+template <typename Graph>
+class BacktrackingMaxBPMState {
+ public:
+  // Does not take ownership of 'g'.
+  explicit BacktrackingMaxBPMState(const Graph* g) : graph_(g) {}
+
+  ElementMatcherPairs Compute() {
+    if (graph_->LhsSize() == 0 || graph_->RhsSize() == 0) {
+      return best_so_far_;
+    }
+    lhs_used_.assign(graph_->LhsSize(), kUnused);
+    rhs_used_.assign(graph_->RhsSize(), kUnused);
+    for (size_t irhs = 0; irhs < graph_->RhsSize(); ++irhs) {
+      matches_.clear();
+      RecurseInto(irhs);
+      if (best_so_far_.size() == graph_->RhsSize()) break;
+    }
+    return best_so_far_;
+  }
+
+ private:
+  static const size_t kUnused = static_cast<size_t>(-1);
+
+  void PushMatch(size_t lhs, size_t rhs) {
+    matches_.push_back(ElementMatcherPair(lhs, rhs));
+    lhs_used_[lhs] = rhs;
+    rhs_used_[rhs] = lhs;
+    if (matches_.size() > best_so_far_.size()) {
+      best_so_far_ = matches_;
+    }
+  }
+
+  void PopMatch() {
+    const ElementMatcherPair& back = matches_.back();
+    lhs_used_[back.first] = kUnused;
+    rhs_used_[back.second] = kUnused;
+    matches_.pop_back();
+  }
+
+  bool RecurseInto(size_t irhs) {
+    if (rhs_used_[irhs] != kUnused) {
+      return true;
+    }
+    for (size_t ilhs = 0; ilhs < graph_->LhsSize(); ++ilhs) {
+      if (lhs_used_[ilhs] != kUnused) {
+        continue;
+      }
+      if (!graph_->HasEdge(ilhs, irhs)) {
+        continue;
+      }
+      PushMatch(ilhs, irhs);
+      if (best_so_far_.size() == graph_->RhsSize()) {
+        return false;
+      }
+      for (size_t mi = irhs + 1; mi < graph_->RhsSize(); ++mi) {
+        if (!RecurseInto(mi)) return false;
+      }
+      PopMatch();
+    }
+    return true;
+  }
+
+  const Graph* graph_;  // not owned
+  std::vector<size_t> lhs_used_;
+  std::vector<size_t> rhs_used_;
+  ElementMatcherPairs matches_;
+  ElementMatcherPairs best_so_far_;
+};
+
+template <typename Graph>
+const size_t BacktrackingMaxBPMState<Graph>::kUnused;
+
+}  // namespace
+
+// Implement a simple backtracking algorithm to determine if it is possible
+// to find one element per matcher, without reusing elements.
+template <typename Graph>
+ElementMatcherPairs FindBacktrackingMaxBPM(const Graph& g) {
+  return BacktrackingMaxBPMState<Graph>(&g).Compute();
+}
+
+class BacktrackingBPMTest : public ::testing::Test {};
+
+// Tests the MaxBipartiteMatching algorithm with square matrices.
+// The single int param is the # of nodes on each of the left and right sides.
+class BipartiteTest : public ::testing::TestWithParam<size_t> {};
+
+// Verify all match graphs up to some moderate number of edges.
+TEST_P(BipartiteTest, Exhaustive) {
+  size_t nodes = GetParam();
+  MatchMatrix graph(nodes, nodes);
+  do {
+    ElementMatcherPairs matches = internal::FindMaxBipartiteMatching(graph);
+    EXPECT_EQ(FindBacktrackingMaxBPM(graph).size(), matches.size())
+        << "graph: " << graph.DebugString();
+    // Check that all elements of matches are in the graph.
+    // Check that elements of first and second are unique.
+    std::vector<bool> seen_element(graph.LhsSize());
+    std::vector<bool> seen_matcher(graph.RhsSize());
+    SCOPED_TRACE(PrintToString(matches));
+    for (size_t i = 0; i < matches.size(); ++i) {
+      size_t ilhs = matches[i].first;
+      size_t irhs = matches[i].second;
+      EXPECT_TRUE(graph.HasEdge(ilhs, irhs));
+      EXPECT_FALSE(seen_element[ilhs]);
+      EXPECT_FALSE(seen_matcher[irhs]);
+      seen_element[ilhs] = true;
+      seen_matcher[irhs] = true;
+    }
+  } while (graph.NextGraph());
+}
+
+INSTANTIATE_TEST_SUITE_P(AllGraphs, BipartiteTest,
+                         ::testing::Range(size_t{0}, size_t{5}));
+
+// Parameterized by a pair interpreted as (LhsSize, RhsSize).
+class BipartiteNonSquareTest
+    : public ::testing::TestWithParam<std::pair<size_t, size_t>> {};
+
+TEST_F(BipartiteNonSquareTest, SimpleBacktracking) {
+  //   .......
+  // 0:-----\ :
+  // 1:---\ | :
+  // 2:---\ | :
+  // 3:-\ | | :
+  //  :.......:
+  //    0 1 2
+  MatchMatrix g(4, 3);
+  constexpr std::array<std::array<size_t, 2>, 4> kEdges = {
+      {{{0, 2}}, {{1, 1}}, {{2, 1}}, {{3, 0}}}};
+  for (size_t i = 0; i < kEdges.size(); ++i) {
+    g.SetEdge(kEdges[i][0], kEdges[i][1], true);
+  }
+  EXPECT_THAT(FindBacktrackingMaxBPM(g),
+              ElementsAre(Pair(3, 0), Pair(AnyOf(1, 2), 1), Pair(0, 2)))
+      << g.DebugString();
+}
+
+// Verify a few nonsquare matrices.
+TEST_P(BipartiteNonSquareTest, Exhaustive) {
+  size_t nlhs = GetParam().first;
+  size_t nrhs = GetParam().second;
+  MatchMatrix graph(nlhs, nrhs);
+  do {
+    EXPECT_EQ(FindBacktrackingMaxBPM(graph).size(),
+              internal::FindMaxBipartiteMatching(graph).size())
+        << "graph: " << graph.DebugString()
+        << "\nbacktracking: " << PrintToString(FindBacktrackingMaxBPM(graph))
+        << "\nmax flow: "
+        << PrintToString(internal::FindMaxBipartiteMatching(graph));
+  } while (graph.NextGraph());
+}
+
+INSTANTIATE_TEST_SUITE_P(
+    AllGraphs, BipartiteNonSquareTest,
+    testing::Values(std::make_pair(1, 2), std::make_pair(2, 1),
+                    std::make_pair(3, 2), std::make_pair(2, 3),
+                    std::make_pair(4, 1), std::make_pair(1, 4),
+                    std::make_pair(4, 3), std::make_pair(3, 4)));
+
+class BipartiteRandomTest
+    : public ::testing::TestWithParam<std::pair<int, int>> {};
+
+// Verifies a large sample of larger graphs.
+TEST_P(BipartiteRandomTest, LargerNets) {
+  int nodes = GetParam().first;
+  int iters = GetParam().second;
+  MatchMatrix graph(static_cast<size_t>(nodes), static_cast<size_t>(nodes));
+
+  auto seed = static_cast<uint32_t>(GTEST_FLAG_GET(random_seed));
+  if (seed == 0) {
+    seed = static_cast<uint32_t>(time(nullptr));
+  }
+
+  for (; iters > 0; --iters, ++seed) {
+    srand(static_cast<unsigned int>(seed));
+    graph.Randomize();
+    EXPECT_EQ(FindBacktrackingMaxBPM(graph).size(),
+              internal::FindMaxBipartiteMatching(graph).size())
+        << " graph: " << graph.DebugString()
+        << "\nTo reproduce the failure, rerun the test with the flag"
+           " --"
+        << GTEST_FLAG_PREFIX_ << "random_seed=" << seed;
+  }
+}
+
+// Test argument is a std::pair<int, int> representing (nodes, iters).
+INSTANTIATE_TEST_SUITE_P(Samples, BipartiteRandomTest,
+                         testing::Values(std::make_pair(5, 10000),
+                                         std::make_pair(6, 5000),
+                                         std::make_pair(7, 2000),
+                                         std::make_pair(8, 500),
+                                         std::make_pair(9, 100)));
+
+// Tests IsReadableTypeName().
+
+TEST(IsReadableTypeNameTest, ReturnsTrueForShortNames) {
+  EXPECT_TRUE(IsReadableTypeName("int"));
+  EXPECT_TRUE(IsReadableTypeName("const unsigned char*"));
+  EXPECT_TRUE(IsReadableTypeName("MyMap<int, void*>"));
+  EXPECT_TRUE(IsReadableTypeName("void (*)(int, bool)"));
+}
+
+TEST(IsReadableTypeNameTest, ReturnsTrueForLongNonTemplateNonFunctionNames) {
+  EXPECT_TRUE(IsReadableTypeName("my_long_namespace::MyClassName"));
+  EXPECT_TRUE(IsReadableTypeName("int [5][6][7][8][9][10][11]"));
+  EXPECT_TRUE(IsReadableTypeName("my_namespace::MyOuterClass::MyInnerClass"));
+}
+
+TEST(IsReadableTypeNameTest, ReturnsFalseForLongTemplateNames) {
+  EXPECT_FALSE(
+      IsReadableTypeName("basic_string<char, std::char_traits<char> >"));
+  EXPECT_FALSE(IsReadableTypeName("std::vector<int, std::alloc_traits<int> >"));
+}
+
+TEST(IsReadableTypeNameTest, ReturnsFalseForLongFunctionTypeNames) {
+  EXPECT_FALSE(IsReadableTypeName("void (&)(int, bool, char, float)"));
+}
+
+// Tests FormatMatcherDescription().
+
+TEST(FormatMatcherDescriptionTest, WorksForEmptyDescription) {
+  EXPECT_EQ("is even",
+            FormatMatcherDescription(false, "IsEven", {}, Strings()));
+  EXPECT_EQ("not (is even)",
+            FormatMatcherDescription(true, "IsEven", {}, Strings()));
+
+  EXPECT_EQ("equals (a: 5)",
+            FormatMatcherDescription(false, "Equals", {"a"}, {"5"}));
+
+  EXPECT_EQ(
+      "is in range (a: 5, b: 8)",
+      FormatMatcherDescription(false, "IsInRange", {"a", "b"}, {"5", "8"}));
+}
+
+INSTANTIATE_GTEST_MATCHER_TEST_P(MatcherTupleTest);
+
+TEST_P(MatcherTupleTestP, ExplainsMatchFailure) {
+  stringstream ss1;
+  ExplainMatchFailureTupleTo(
+      std::make_tuple(Matcher<char>(Eq('a')), GreaterThan(5)),
+      std::make_tuple('a', 10), &ss1);
+  EXPECT_EQ("", ss1.str());  // Successful match.
+
+  stringstream ss2;
+  ExplainMatchFailureTupleTo(
+      std::make_tuple(GreaterThan(5), Matcher<char>(Eq('a'))),
+      std::make_tuple(2, 'b'), &ss2);
+  EXPECT_EQ(
+      "  Expected arg #0: is > 5\n"
+      "           Actual: 2, which is 3 less than 5\n"
+      "  Expected arg #1: is equal to 'a' (97, 0x61)\n"
+      "           Actual: 'b' (98, 0x62)\n",
+      ss2.str());  // Failed match where both arguments need explanation.
+
+  stringstream ss3;
+  ExplainMatchFailureTupleTo(
+      std::make_tuple(GreaterThan(5), Matcher<char>(Eq('a'))),
+      std::make_tuple(2, 'a'), &ss3);
+  EXPECT_EQ(
+      "  Expected arg #0: is > 5\n"
+      "           Actual: 2, which is 3 less than 5\n",
+      ss3.str());  // Failed match where only one argument needs
+                   // explanation.
+}
+
+// Sample optional type implementation with minimal requirements for use with
+// Optional matcher.
+template <typename T>
+class SampleOptional {
+ public:
+  using value_type = T;
+  explicit SampleOptional(T value)
+      : value_(std::move(value)), has_value_(true) {}
+  SampleOptional() : value_(), has_value_(false) {}
+  operator bool() const { return has_value_; }
+  const T& operator*() const { return value_; }
+
+ private:
+  T value_;
+  bool has_value_;
+};
+
+TEST(OptionalTest, DescribesSelf) {
+  const Matcher<SampleOptional<int>> m = Optional(Eq(1));
+  EXPECT_EQ("value is equal to 1", Describe(m));
+}
+
+TEST(OptionalTest, ExplainsSelf) {
+  const Matcher<SampleOptional<int>> m = Optional(Eq(1));
+  EXPECT_EQ("whose value 1 matches", Explain(m, SampleOptional<int>(1)));
+  EXPECT_EQ("whose value 2 doesn't match", Explain(m, SampleOptional<int>(2)));
+}
+
+TEST(OptionalTest, MatchesNonEmptyOptional) {
+  const Matcher<SampleOptional<int>> m1 = Optional(1);
+  const Matcher<SampleOptional<int>> m2 = Optional(Eq(2));
+  const Matcher<SampleOptional<int>> m3 = Optional(Lt(3));
+  SampleOptional<int> opt(1);
+  EXPECT_TRUE(m1.Matches(opt));
+  EXPECT_FALSE(m2.Matches(opt));
+  EXPECT_TRUE(m3.Matches(opt));
+}
+
+TEST(OptionalTest, DoesNotMatchNullopt) {
+  const Matcher<SampleOptional<int>> m = Optional(1);
+  SampleOptional<int> empty;
+  EXPECT_FALSE(m.Matches(empty));
+}
+
+TEST(OptionalTest, WorksWithMoveOnly) {
+  Matcher<SampleOptional<std::unique_ptr<int>>> m = Optional(Eq(nullptr));
+  EXPECT_TRUE(m.Matches(SampleOptional<std::unique_ptr<int>>(nullptr)));
+}
+
+class SampleVariantIntString {
+ public:
+  SampleVariantIntString(int i) : i_(i), has_int_(true) {}
+  SampleVariantIntString(const std::string& s) : s_(s), has_int_(false) {}
+
+  template <typename T>
+  friend bool holds_alternative(const SampleVariantIntString& value) {
+    return value.has_int_ == std::is_same<T, int>::value;
+  }
+
+  template <typename T>
+  friend const T& get(const SampleVariantIntString& value) {
+    return value.get_impl(static_cast<T*>(nullptr));
+  }
+
+ private:
+  const int& get_impl(int*) const { return i_; }
+  const std::string& get_impl(std::string*) const { return s_; }
+
+  int i_;
+  std::string s_;
+  bool has_int_;
+};
+
+TEST(VariantTest, DescribesSelf) {
+  const Matcher<SampleVariantIntString> m = VariantWith<int>(Eq(1));
+  EXPECT_THAT(Describe(m), ContainsRegex("is a variant<> with value of type "
+                                         "'.*' and the value is equal to 1"));
+}
+
+TEST(VariantTest, ExplainsSelf) {
+  const Matcher<SampleVariantIntString> m = VariantWith<int>(Eq(1));
+  EXPECT_THAT(Explain(m, SampleVariantIntString(1)),
+              ContainsRegex("whose value 1"));
+  EXPECT_THAT(Explain(m, SampleVariantIntString("A")),
+              HasSubstr("whose value is not of type '"));
+  EXPECT_THAT(Explain(m, SampleVariantIntString(2)),
+              "whose value 2 doesn't match");
+}
+
+TEST(VariantTest, FullMatch) {
+  Matcher<SampleVariantIntString> m = VariantWith<int>(Eq(1));
+  EXPECT_TRUE(m.Matches(SampleVariantIntString(1)));
+
+  m = VariantWith<std::string>(Eq("1"));
+  EXPECT_TRUE(m.Matches(SampleVariantIntString("1")));
+}
+
+TEST(VariantTest, TypeDoesNotMatch) {
+  Matcher<SampleVariantIntString> m = VariantWith<int>(Eq(1));
+  EXPECT_FALSE(m.Matches(SampleVariantIntString("1")));
+
+  m = VariantWith<std::string>(Eq("1"));
+  EXPECT_FALSE(m.Matches(SampleVariantIntString(1)));
+}
+
+TEST(VariantTest, InnerDoesNotMatch) {
+  Matcher<SampleVariantIntString> m = VariantWith<int>(Eq(1));
+  EXPECT_FALSE(m.Matches(SampleVariantIntString(2)));
+
+  m = VariantWith<std::string>(Eq("1"));
+  EXPECT_FALSE(m.Matches(SampleVariantIntString("2")));
+}
+
+class SampleAnyType {
+ public:
+  explicit SampleAnyType(int i) : index_(0), i_(i) {}
+  explicit SampleAnyType(const std::string& s) : index_(1), s_(s) {}
+
+  template <typename T>
+  friend const T* any_cast(const SampleAnyType* any) {
+    return any->get_impl(static_cast<T*>(nullptr));
+  }
+
+ private:
+  int index_;
+  int i_;
+  std::string s_;
+
+  const int* get_impl(int*) const { return index_ == 0 ? &i_ : nullptr; }
+  const std::string* get_impl(std::string*) const {
+    return index_ == 1 ? &s_ : nullptr;
+  }
+};
+
+TEST(AnyWithTest, FullMatch) {
+  Matcher<SampleAnyType> m = AnyWith<int>(Eq(1));
+  EXPECT_TRUE(m.Matches(SampleAnyType(1)));
+}
+
+TEST(AnyWithTest, TestBadCastType) {
+  Matcher<SampleAnyType> m = AnyWith<std::string>(Eq("fail"));
+  EXPECT_FALSE(m.Matches(SampleAnyType(1)));
+}
+
+TEST(AnyWithTest, TestUseInContainers) {
+  std::vector<SampleAnyType> a;
+  a.emplace_back(1);
+  a.emplace_back(2);
+  a.emplace_back(3);
+  EXPECT_THAT(
+      a, ElementsAreArray({AnyWith<int>(1), AnyWith<int>(2), AnyWith<int>(3)}));
+
+  std::vector<SampleAnyType> b;
+  b.emplace_back("hello");
+  b.emplace_back("merhaba");
+  b.emplace_back("salut");
+  EXPECT_THAT(b, ElementsAreArray({AnyWith<std::string>("hello"),
+                                   AnyWith<std::string>("merhaba"),
+                                   AnyWith<std::string>("salut")}));
+}
+TEST(AnyWithTest, TestCompare) {
+  EXPECT_THAT(SampleAnyType(1), AnyWith<int>(Gt(0)));
+}
+
+TEST(AnyWithTest, DescribesSelf) {
+  const Matcher<const SampleAnyType&> m = AnyWith<int>(Eq(1));
+  EXPECT_THAT(Describe(m), ContainsRegex("is an 'any' type with value of type "
+                                         "'.*' and the value is equal to 1"));
+}
+
+TEST(AnyWithTest, ExplainsSelf) {
+  const Matcher<const SampleAnyType&> m = AnyWith<int>(Eq(1));
+
+  EXPECT_THAT(Explain(m, SampleAnyType(1)), ContainsRegex("whose value 1"));
+  EXPECT_THAT(Explain(m, SampleAnyType("A")),
+              HasSubstr("whose value is not of type '"));
+  EXPECT_THAT(Explain(m, SampleAnyType(2)), "whose value 2 doesn't match");
+}
+
+// Tests Args<k0, ..., kn>(m).
+
+TEST(ArgsTest, AcceptsZeroTemplateArg) {
+  const std::tuple<int, bool> t(5, true);
+  EXPECT_THAT(t, Args<>(Eq(std::tuple<>())));
+  EXPECT_THAT(t, Not(Args<>(Ne(std::tuple<>()))));
+}
+
+TEST(ArgsTest, AcceptsOneTemplateArg) {
+  const std::tuple<int, bool> t(5, true);
+  EXPECT_THAT(t, Args<0>(Eq(std::make_tuple(5))));
+  EXPECT_THAT(t, Args<1>(Eq(std::make_tuple(true))));
+  EXPECT_THAT(t, Not(Args<1>(Eq(std::make_tuple(false)))));
+}
+
+TEST(ArgsTest, AcceptsTwoTemplateArgs) {
+  const std::tuple<short, int, long> t(short{4}, 5, 6L);  // NOLINT
+
+  EXPECT_THAT(t, (Args<0, 1>(Lt())));
+  EXPECT_THAT(t, (Args<1, 2>(Lt())));
+  EXPECT_THAT(t, Not(Args<0, 2>(Gt())));
+}
+
+TEST(ArgsTest, AcceptsRepeatedTemplateArgs) {
+  const std::tuple<short, int, long> t(short{4}, 5, 6L);  // NOLINT
+  EXPECT_THAT(t, (Args<0, 0>(Eq())));
+  EXPECT_THAT(t, Not(Args<1, 1>(Ne())));
+}
+
+TEST(ArgsTest, AcceptsDecreasingTemplateArgs) {
+  const std::tuple<short, int, long> t(short{4}, 5, 6L);  // NOLINT
+  EXPECT_THAT(t, (Args<2, 0>(Gt())));
+  EXPECT_THAT(t, Not(Args<2, 1>(Lt())));
+}
+
+MATCHER(SumIsZero, "") {
+  return std::get<0>(arg) + std::get<1>(arg) + std::get<2>(arg) == 0;
+}
+
+TEST(ArgsTest, AcceptsMoreTemplateArgsThanArityOfOriginalTuple) {
+  EXPECT_THAT(std::make_tuple(-1, 2), (Args<0, 0, 1>(SumIsZero())));
+  EXPECT_THAT(std::make_tuple(1, 2), Not(Args<0, 0, 1>(SumIsZero())));
+}
+
+TEST(ArgsTest, CanBeNested) {
+  const std::tuple<short, int, long, int> t(short{4}, 5, 6L, 6);  // NOLINT
+  EXPECT_THAT(t, (Args<1, 2, 3>(Args<1, 2>(Eq()))));
+  EXPECT_THAT(t, (Args<0, 1, 3>(Args<0, 2>(Lt()))));
+}
+
+TEST(ArgsTest, CanMatchTupleByValue) {
+  typedef std::tuple<char, int, int> Tuple3;
+  const Matcher<Tuple3> m = Args<1, 2>(Lt());
+  EXPECT_TRUE(m.Matches(Tuple3('a', 1, 2)));
+  EXPECT_FALSE(m.Matches(Tuple3('b', 2, 2)));
+}
+
+TEST(ArgsTest, CanMatchTupleByReference) {
+  typedef std::tuple<char, char, int> Tuple3;
+  const Matcher<const Tuple3&> m = Args<0, 1>(Lt());
+  EXPECT_TRUE(m.Matches(Tuple3('a', 'b', 2)));
+  EXPECT_FALSE(m.Matches(Tuple3('b', 'b', 2)));
+}
+
+// Validates that arg is printed as str.
+MATCHER_P(PrintsAs, str, "") { return testing::PrintToString(arg) == str; }
+
+TEST(ArgsTest, AcceptsTenTemplateArgs) {
+  EXPECT_THAT(std::make_tuple(0, 1L, 2, 3L, 4, 5, 6, 7, 8, 9),
+              (Args<9, 8, 7, 6, 5, 4, 3, 2, 1, 0>(
+                  PrintsAs("(9, 8, 7, 6, 5, 4, 3, 2, 1, 0)"))));
+  EXPECT_THAT(std::make_tuple(0, 1L, 2, 3L, 4, 5, 6, 7, 8, 9),
+              Not(Args<9, 8, 7, 6, 5, 4, 3, 2, 1, 0>(
+                  PrintsAs("(0, 8, 7, 6, 5, 4, 3, 2, 1, 0)"))));
+}
+
+TEST(ArgsTest, DescirbesSelfCorrectly) {
+  const Matcher<std::tuple<int, bool, char>> m = Args<2, 0>(Lt());
+  EXPECT_EQ(
+      "are a tuple whose fields (#2, #0) are a pair where "
+      "the first < the second",
+      Describe(m));
+}
+
+TEST(ArgsTest, DescirbesNestedArgsCorrectly) {
+  const Matcher<const std::tuple<int, bool, char, int>&> m =
+      Args<0, 2, 3>(Args<2, 0>(Lt()));
+  EXPECT_EQ(
+      "are a tuple whose fields (#0, #2, #3) are a tuple "
+      "whose fields (#2, #0) are a pair where the first < the second",
+      Describe(m));
+}
+
+TEST(ArgsTest, DescribesNegationCorrectly) {
+  const Matcher<std::tuple<int, char>> m = Args<1, 0>(Gt());
+  EXPECT_EQ(
+      "are a tuple whose fields (#1, #0) aren't a pair "
+      "where the first > the second",
+      DescribeNegation(m));
+}
+
+TEST(ArgsTest, ExplainsMatchResultWithoutInnerExplanation) {
+  const Matcher<std::tuple<bool, int, int>> m = Args<1, 2>(Eq());
+  EXPECT_EQ("whose fields (#1, #2) are (42, 42)",
+            Explain(m, std::make_tuple(false, 42, 42)));
+  EXPECT_EQ("whose fields (#1, #2) are (42, 43)",
+            Explain(m, std::make_tuple(false, 42, 43)));
+}
+
+// For testing Args<>'s explanation.
+class LessThanMatcher : public MatcherInterface<std::tuple<char, int>> {
+ public:
+  void DescribeTo(::std::ostream* /*os*/) const override {}
+
+  bool MatchAndExplain(std::tuple<char, int> value,
+                       MatchResultListener* listener) const override {
+    const int diff = std::get<0>(value) - std::get<1>(value);
+    if (diff > 0) {
+      *listener << "where the first value is " << diff
+                << " more than the second";
+    }
+    return diff < 0;
+  }
+};
+
+Matcher<std::tuple<char, int>> LessThan() {
+  return MakeMatcher(new LessThanMatcher);
+}
+
+TEST(ArgsTest, ExplainsMatchResultWithInnerExplanation) {
+  const Matcher<std::tuple<char, int, int>> m = Args<0, 2>(LessThan());
+  EXPECT_EQ(
+      "whose fields (#0, #2) are ('a' (97, 0x61), 42), "
+      "where the first value is 55 more than the second",
+      Explain(m, std::make_tuple('a', 42, 42)));
+  EXPECT_EQ("whose fields (#0, #2) are ('\\0', 43)",
+            Explain(m, std::make_tuple('\0', 42, 43)));
+}
+
+// Tests for the MATCHER*() macro family.
+
+// Tests that a simple MATCHER() definition works.
+
+MATCHER(IsEven, "") { return (arg % 2) == 0; }
+
+TEST(MatcherMacroTest, Works) {
+  const Matcher<int> m = IsEven();
+  EXPECT_TRUE(m.Matches(6));
+  EXPECT_FALSE(m.Matches(7));
+
+  EXPECT_EQ("is even", Describe(m));
+  EXPECT_EQ("not (is even)", DescribeNegation(m));
+  EXPECT_EQ("", Explain(m, 6));
+  EXPECT_EQ("", Explain(m, 7));
+}
+
+// This also tests that the description string can reference 'negation'.
+MATCHER(IsEven2, negation ? "is odd" : "is even") {
+  if ((arg % 2) == 0) {
+    // Verifies that we can stream to result_listener, a listener
+    // supplied by the MATCHER macro implicitly.
+    *result_listener << "OK";
+    return true;
+  } else {
+    *result_listener << "% 2 == " << (arg % 2);
+    return false;
+  }
+}
+
+// This also tests that the description string can reference matcher
+// parameters.
+MATCHER_P2(EqSumOf, x, y,
+           std::string(negation ? "doesn't equal" : "equals") + " the sum of " +
+               PrintToString(x) + " and " + PrintToString(y)) {
+  if (arg == (x + y)) {
+    *result_listener << "OK";
+    return true;
+  } else {
+    // Verifies that we can stream to the underlying stream of
+    // result_listener.
+    if (result_listener->stream() != nullptr) {
+      *result_listener->stream() << "diff == " << (x + y - arg);
+    }
+    return false;
+  }
+}
+
+// Tests that the matcher description can reference 'negation' and the
+// matcher parameters.
+TEST(MatcherMacroTest, DescriptionCanReferenceNegationAndParameters) {
+  const Matcher<int> m1 = IsEven2();
+  EXPECT_EQ("is even", Describe(m1));
+  EXPECT_EQ("is odd", DescribeNegation(m1));
+
+  const Matcher<int> m2 = EqSumOf(5, 9);
+  EXPECT_EQ("equals the sum of 5 and 9", Describe(m2));
+  EXPECT_EQ("doesn't equal the sum of 5 and 9", DescribeNegation(m2));
+}
+
+// Tests explaining match result in a MATCHER* macro.
+TEST(MatcherMacroTest, CanExplainMatchResult) {
+  const Matcher<int> m1 = IsEven2();
+  EXPECT_EQ("OK", Explain(m1, 4));
+  EXPECT_EQ("% 2 == 1", Explain(m1, 5));
+
+  const Matcher<int> m2 = EqSumOf(1, 2);
+  EXPECT_EQ("OK", Explain(m2, 3));
+  EXPECT_EQ("diff == -1", Explain(m2, 4));
+}
+
+// Tests that the body of MATCHER() can reference the type of the
+// value being matched.
+
+MATCHER(IsEmptyString, "") {
+  StaticAssertTypeEq<::std::string, arg_type>();
+  return arg.empty();
+}
+
+MATCHER(IsEmptyStringByRef, "") {
+  StaticAssertTypeEq<const ::std::string&, arg_type>();
+  return arg.empty();
+}
+
+TEST(MatcherMacroTest, CanReferenceArgType) {
+  const Matcher<::std::string> m1 = IsEmptyString();
+  EXPECT_TRUE(m1.Matches(""));
+
+  const Matcher<const ::std::string&> m2 = IsEmptyStringByRef();
+  EXPECT_TRUE(m2.Matches(""));
+}
+
+// Tests that MATCHER() can be used in a namespace.
+
+namespace matcher_test {
+MATCHER(IsOdd, "") { return (arg % 2) != 0; }
+}  // namespace matcher_test
+
+TEST(MatcherMacroTest, WorksInNamespace) {
+  Matcher<int> m = matcher_test::IsOdd();
+  EXPECT_FALSE(m.Matches(4));
+  EXPECT_TRUE(m.Matches(5));
+}
+
+// Tests that Value() can be used to compose matchers.
+MATCHER(IsPositiveOdd, "") {
+  return Value(arg, matcher_test::IsOdd()) && arg > 0;
+}
+
+TEST(MatcherMacroTest, CanBeComposedUsingValue) {
+  EXPECT_THAT(3, IsPositiveOdd());
+  EXPECT_THAT(4, Not(IsPositiveOdd()));
+  EXPECT_THAT(-1, Not(IsPositiveOdd()));
+}
+
+// Tests that a simple MATCHER_P() definition works.
+
+MATCHER_P(IsGreaterThan32And, n, "") { return arg > 32 && arg > n; }
+
+TEST(MatcherPMacroTest, Works) {
+  const Matcher<int> m = IsGreaterThan32And(5);
+  EXPECT_TRUE(m.Matches(36));
+  EXPECT_FALSE(m.Matches(5));
+
+  EXPECT_EQ("is greater than 32 and (n: 5)", Describe(m));
+  EXPECT_EQ("not (is greater than 32 and (n: 5))", DescribeNegation(m));
+  EXPECT_EQ("", Explain(m, 36));
+  EXPECT_EQ("", Explain(m, 5));
+}
+
+// Tests that the description is calculated correctly from the matcher name.
+MATCHER_P(_is_Greater_Than32and_, n, "") { return arg > 32 && arg > n; }
+
+TEST(MatcherPMacroTest, GeneratesCorrectDescription) {
+  const Matcher<int> m = _is_Greater_Than32and_(5);
+
+  EXPECT_EQ("is greater than 32 and (n: 5)", Describe(m));
+  EXPECT_EQ("not (is greater than 32 and (n: 5))", DescribeNegation(m));
+  EXPECT_EQ("", Explain(m, 36));
+  EXPECT_EQ("", Explain(m, 5));
+}
+
+// Tests that a MATCHER_P matcher can be explicitly instantiated with
+// a reference parameter type.
+
+class UncopyableFoo {
+ public:
+  explicit UncopyableFoo(char value) : value_(value) { (void)value_; }
+
+  UncopyableFoo(const UncopyableFoo&) = delete;
+  void operator=(const UncopyableFoo&) = delete;
+
+ private:
+  char value_;
+};
+
+MATCHER_P(ReferencesUncopyable, variable, "") { return &arg == &variable; }
+
+TEST(MatcherPMacroTest, WorksWhenExplicitlyInstantiatedWithReference) {
+  UncopyableFoo foo1('1'), foo2('2');
+  const Matcher<const UncopyableFoo&> m =
+      ReferencesUncopyable<const UncopyableFoo&>(foo1);
+
+  EXPECT_TRUE(m.Matches(foo1));
+  EXPECT_FALSE(m.Matches(foo2));
+
+  // We don't want the address of the parameter printed, as most
+  // likely it will just annoy the user.  If the address is
+  // interesting, the user should consider passing the parameter by
+  // pointer instead.
+  EXPECT_EQ("references uncopyable (variable: 1-byte object <31>)",
+            Describe(m));
+}
+
+// Tests that the body of MATCHER_Pn() can reference the parameter
+// types.
+
+MATCHER_P3(ParamTypesAreIntLongAndChar, foo, bar, baz, "") {
+  StaticAssertTypeEq<int, foo_type>();
+  StaticAssertTypeEq<long, bar_type>();  // NOLINT
+  StaticAssertTypeEq<char, baz_type>();
+  return arg == 0;
+}
+
+TEST(MatcherPnMacroTest, CanReferenceParamTypes) {
+  EXPECT_THAT(0, ParamTypesAreIntLongAndChar(10, 20L, 'a'));
+}
+
+// Tests that a MATCHER_Pn matcher can be explicitly instantiated with
+// reference parameter types.
+
+MATCHER_P2(ReferencesAnyOf, variable1, variable2, "") {
+  return &arg == &variable1 || &arg == &variable2;
+}
+
+TEST(MatcherPnMacroTest, WorksWhenExplicitlyInstantiatedWithReferences) {
+  UncopyableFoo foo1('1'), foo2('2'), foo3('3');
+  const Matcher<const UncopyableFoo&> const_m =
+      ReferencesAnyOf<const UncopyableFoo&, const UncopyableFoo&>(foo1, foo2);
+
+  EXPECT_TRUE(const_m.Matches(foo1));
+  EXPECT_TRUE(const_m.Matches(foo2));
+  EXPECT_FALSE(const_m.Matches(foo3));
+
+  const Matcher<UncopyableFoo&> m =
+      ReferencesAnyOf<UncopyableFoo&, UncopyableFoo&>(foo1, foo2);
+
+  EXPECT_TRUE(m.Matches(foo1));
+  EXPECT_TRUE(m.Matches(foo2));
+  EXPECT_FALSE(m.Matches(foo3));
+}
+
+TEST(MatcherPnMacroTest,
+     GeneratesCorretDescriptionWhenExplicitlyInstantiatedWithReferences) {
+  UncopyableFoo foo1('1'), foo2('2');
+  const Matcher<const UncopyableFoo&> m =
+      ReferencesAnyOf<const UncopyableFoo&, const UncopyableFoo&>(foo1, foo2);
+
+  // We don't want the addresses of the parameters printed, as most
+  // likely they will just annoy the user.  If the addresses are
+  // interesting, the user should consider passing the parameters by
+  // pointers instead.
+  EXPECT_EQ(
+      "references any of (variable1: 1-byte object <31>, variable2: 1-byte "
+      "object <32>)",
+      Describe(m));
+}
+
+// Tests that a simple MATCHER_P2() definition works.
+
+MATCHER_P2(IsNotInClosedRange, low, hi, "") { return arg < low || arg > hi; }
+
+TEST(MatcherPnMacroTest, Works) {
+  const Matcher<const long&> m = IsNotInClosedRange(10, 20);  // NOLINT
+  EXPECT_TRUE(m.Matches(36L));
+  EXPECT_FALSE(m.Matches(15L));
+
+  EXPECT_EQ("is not in closed range (low: 10, hi: 20)", Describe(m));
+  EXPECT_EQ("not (is not in closed range (low: 10, hi: 20))",
+            DescribeNegation(m));
+  EXPECT_EQ("", Explain(m, 36L));
+  EXPECT_EQ("", Explain(m, 15L));
+}
+
+// Tests that MATCHER*() definitions can be overloaded on the number
+// of parameters; also tests MATCHER_Pn() where n >= 3.
+
+MATCHER(EqualsSumOf, "") { return arg == 0; }
+MATCHER_P(EqualsSumOf, a, "") { return arg == a; }
+MATCHER_P2(EqualsSumOf, a, b, "") { return arg == a + b; }
+MATCHER_P3(EqualsSumOf, a, b, c, "") { return arg == a + b + c; }
+MATCHER_P4(EqualsSumOf, a, b, c, d, "") { return arg == a + b + c + d; }
+MATCHER_P5(EqualsSumOf, a, b, c, d, e, "") { return arg == a + b + c + d + e; }
+MATCHER_P6(EqualsSumOf, a, b, c, d, e, f, "") {
+  return arg == a + b + c + d + e + f;
+}
+MATCHER_P7(EqualsSumOf, a, b, c, d, e, f, g, "") {
+  return arg == a + b + c + d + e + f + g;
+}
+MATCHER_P8(EqualsSumOf, a, b, c, d, e, f, g, h, "") {
+  return arg == a + b + c + d + e + f + g + h;
+}
+MATCHER_P9(EqualsSumOf, a, b, c, d, e, f, g, h, i, "") {
+  return arg == a + b + c + d + e + f + g + h + i;
+}
+MATCHER_P10(EqualsSumOf, a, b, c, d, e, f, g, h, i, j, "") {
+  return arg == a + b + c + d + e + f + g + h + i + j;
+}
+
+TEST(MatcherPnMacroTest, CanBeOverloadedOnNumberOfParameters) {
+  EXPECT_THAT(0, EqualsSumOf());
+  EXPECT_THAT(1, EqualsSumOf(1));
+  EXPECT_THAT(12, EqualsSumOf(10, 2));
+  EXPECT_THAT(123, EqualsSumOf(100, 20, 3));
+  EXPECT_THAT(1234, EqualsSumOf(1000, 200, 30, 4));
+  EXPECT_THAT(12345, EqualsSumOf(10000, 2000, 300, 40, 5));
+  EXPECT_THAT("abcdef",
+              EqualsSumOf(::std::string("a"), 'b', 'c', "d", "e", 'f'));
+  EXPECT_THAT("abcdefg",
+              EqualsSumOf(::std::string("a"), 'b', 'c', "d", "e", 'f', 'g'));
+  EXPECT_THAT("abcdefgh", EqualsSumOf(::std::string("a"), 'b', 'c', "d", "e",
+                                      'f', 'g', "h"));
+  EXPECT_THAT("abcdefghi", EqualsSumOf(::std::string("a"), 'b', 'c', "d", "e",
+                                       'f', 'g', "h", 'i'));
+  EXPECT_THAT("abcdefghij",
+              EqualsSumOf(::std::string("a"), 'b', 'c', "d", "e", 'f', 'g', "h",
+                          'i', ::std::string("j")));
+
+  EXPECT_THAT(1, Not(EqualsSumOf()));
+  EXPECT_THAT(-1, Not(EqualsSumOf(1)));
+  EXPECT_THAT(-12, Not(EqualsSumOf(10, 2)));
+  EXPECT_THAT(-123, Not(EqualsSumOf(100, 20, 3)));
+  EXPECT_THAT(-1234, Not(EqualsSumOf(1000, 200, 30, 4)));
+  EXPECT_THAT(-12345, Not(EqualsSumOf(10000, 2000, 300, 40, 5)));
+  EXPECT_THAT("abcdef ",
+              Not(EqualsSumOf(::std::string("a"), 'b', 'c', "d", "e", 'f')));
+  EXPECT_THAT("abcdefg ", Not(EqualsSumOf(::std::string("a"), 'b', 'c', "d",
+                                          "e", 'f', 'g')));
+  EXPECT_THAT("abcdefgh ", Not(EqualsSumOf(::std::string("a"), 'b', 'c', "d",
+                                           "e", 'f', 'g', "h")));
+  EXPECT_THAT("abcdefghi ", Not(EqualsSumOf(::std::string("a"), 'b', 'c', "d",
+                                            "e", 'f', 'g', "h", 'i')));
+  EXPECT_THAT("abcdefghij ",
+              Not(EqualsSumOf(::std::string("a"), 'b', 'c', "d", "e", 'f', 'g',
+                              "h", 'i', ::std::string("j"))));
+}
+
+// Tests that a MATCHER_Pn() definition can be instantiated with any
+// compatible parameter types.
+TEST(MatcherPnMacroTest, WorksForDifferentParameterTypes) {
+  EXPECT_THAT(123, EqualsSumOf(100L, 20, static_cast<char>(3)));
+  EXPECT_THAT("abcd", EqualsSumOf(::std::string("a"), "b", 'c', "d"));
+
+  EXPECT_THAT(124, Not(EqualsSumOf(100L, 20, static_cast<char>(3))));
+  EXPECT_THAT("abcde", Not(EqualsSumOf(::std::string("a"), "b", 'c', "d")));
+}
+
+// Tests that the matcher body can promote the parameter types.
+
+MATCHER_P2(EqConcat, prefix, suffix, "") {
+  // The following lines promote the two parameters to desired types.
+  std::string prefix_str(prefix);
+  char suffix_char = static_cast<char>(suffix);
+  return arg == prefix_str + suffix_char;
+}
+
+TEST(MatcherPnMacroTest, SimpleTypePromotion) {
+  Matcher<std::string> no_promo = EqConcat(std::string("foo"), 't');
+  Matcher<const std::string&> promo = EqConcat("foo", static_cast<int>('t'));
+  EXPECT_FALSE(no_promo.Matches("fool"));
+  EXPECT_FALSE(promo.Matches("fool"));
+  EXPECT_TRUE(no_promo.Matches("foot"));
+  EXPECT_TRUE(promo.Matches("foot"));
+}
+
+// Verifies the type of a MATCHER*.
+
+TEST(MatcherPnMacroTest, TypesAreCorrect) {
+  // EqualsSumOf() must be assignable to a EqualsSumOfMatcher variable.
+  EqualsSumOfMatcher a0 = EqualsSumOf();
+
+  // EqualsSumOf(1) must be assignable to a EqualsSumOfMatcherP variable.
+  EqualsSumOfMatcherP<int> a1 = EqualsSumOf(1);
+
+  // EqualsSumOf(p1, ..., pk) must be assignable to a EqualsSumOfMatcherPk
+  // variable, and so on.
+  EqualsSumOfMatcherP2<int, char> a2 = EqualsSumOf(1, '2');
+  EqualsSumOfMatcherP3<int, int, char> a3 = EqualsSumOf(1, 2, '3');
+  EqualsSumOfMatcherP4<int, int, int, char> a4 = EqualsSumOf(1, 2, 3, '4');
+  EqualsSumOfMatcherP5<int, int, int, int, char> a5 =
+      EqualsSumOf(1, 2, 3, 4, '5');
+  EqualsSumOfMatcherP6<int, int, int, int, int, char> a6 =
+      EqualsSumOf(1, 2, 3, 4, 5, '6');
+  EqualsSumOfMatcherP7<int, int, int, int, int, int, char> a7 =
+      EqualsSumOf(1, 2, 3, 4, 5, 6, '7');
+  EqualsSumOfMatcherP8<int, int, int, int, int, int, int, char> a8 =
+      EqualsSumOf(1, 2, 3, 4, 5, 6, 7, '8');
+  EqualsSumOfMatcherP9<int, int, int, int, int, int, int, int, char> a9 =
+      EqualsSumOf(1, 2, 3, 4, 5, 6, 7, 8, '9');
+  EqualsSumOfMatcherP10<int, int, int, int, int, int, int, int, int, char> a10 =
+      EqualsSumOf(1, 2, 3, 4, 5, 6, 7, 8, 9, '0');
+
+  // Avoid "unused variable" warnings.
+  (void)a0;
+  (void)a1;
+  (void)a2;
+  (void)a3;
+  (void)a4;
+  (void)a5;
+  (void)a6;
+  (void)a7;
+  (void)a8;
+  (void)a9;
+  (void)a10;
+}
+
+// Tests that matcher-typed parameters can be used in Value() inside a
+// MATCHER_Pn definition.
+
+// Succeeds if arg matches exactly 2 of the 3 matchers.
+MATCHER_P3(TwoOf, m1, m2, m3, "") {
+  const int count = static_cast<int>(Value(arg, m1)) +
+                    static_cast<int>(Value(arg, m2)) +
+                    static_cast<int>(Value(arg, m3));
+  return count == 2;
+}
+
+TEST(MatcherPnMacroTest, CanUseMatcherTypedParameterInValue) {
+  EXPECT_THAT(42, TwoOf(Gt(0), Lt(50), Eq(10)));
+  EXPECT_THAT(0, Not(TwoOf(Gt(-1), Lt(1), Eq(0))));
+}
+
+// Tests Contains().Times().
+
+INSTANTIATE_GTEST_MATCHER_TEST_P(ContainsTimes);
+
+TEST(ContainsTimes, ListMatchesWhenElementQuantityMatches) {
+  list<int> some_list;
+  some_list.push_back(3);
+  some_list.push_back(1);
+  some_list.push_back(2);
+  some_list.push_back(3);
+  EXPECT_THAT(some_list, Contains(3).Times(2));
+  EXPECT_THAT(some_list, Contains(2).Times(1));
+  EXPECT_THAT(some_list, Contains(Ge(2)).Times(3));
+  EXPECT_THAT(some_list, Contains(Ge(2)).Times(Gt(2)));
+  EXPECT_THAT(some_list, Contains(4).Times(0));
+  EXPECT_THAT(some_list, Contains(_).Times(4));
+  EXPECT_THAT(some_list, Not(Contains(5).Times(1)));
+  EXPECT_THAT(some_list, Contains(5).Times(_));  // Times(_) always matches
+  EXPECT_THAT(some_list, Not(Contains(3).Times(1)));
+  EXPECT_THAT(some_list, Contains(3).Times(Not(1)));
+  EXPECT_THAT(list<int>{}, Not(Contains(_)));
+}
+
+TEST_P(ContainsTimesP, ExplainsMatchResultCorrectly) {
+  const int a[2] = {1, 2};
+  Matcher<const int(&)[2]> m = Contains(2).Times(3);
+  EXPECT_EQ(
+      "whose element #1 matches but whose match quantity of 1 does not match",
+      Explain(m, a));
+
+  m = Contains(3).Times(0);
+  EXPECT_EQ("has no element that matches and whose match quantity of 0 matches",
+            Explain(m, a));
+
+  m = Contains(3).Times(4);
+  EXPECT_EQ(
+      "has no element that matches and whose match quantity of 0 does not "
+      "match",
+      Explain(m, a));
+
+  m = Contains(2).Times(4);
+  EXPECT_EQ(
+      "whose element #1 matches but whose match quantity of 1 does not "
+      "match",
+      Explain(m, a));
+
+  m = Contains(GreaterThan(0)).Times(2);
+  EXPECT_EQ("whose elements (0, 1) match and whose match quantity of 2 matches",
+            Explain(m, a));
+
+  m = Contains(GreaterThan(10)).Times(Gt(1));
+  EXPECT_EQ(
+      "has no element that matches and whose match quantity of 0 does not "
+      "match",
+      Explain(m, a));
+
+  m = Contains(GreaterThan(0)).Times(GreaterThan<size_t>(5));
+  EXPECT_EQ(
+      "whose elements (0, 1) match but whose match quantity of 2 does not "
+      "match, which is 3 less than 5",
+      Explain(m, a));
+}
+
+TEST(ContainsTimes, DescribesItselfCorrectly) {
+  Matcher<vector<int>> m = Contains(1).Times(2);
+  EXPECT_EQ("quantity of elements that match is equal to 1 is equal to 2",
+            Describe(m));
+
+  Matcher<vector<int>> m2 = Not(m);
+  EXPECT_EQ("quantity of elements that match is equal to 1 isn't equal to 2",
+            Describe(m2));
+}
+
+// Tests AllOfArray()
+
+TEST(AllOfArrayTest, BasicForms) {
+  // Iterator
+  std::vector<int> v0{};
+  std::vector<int> v1{1};
+  std::vector<int> v2{2, 3};
+  std::vector<int> v3{4, 4, 4};
+  EXPECT_THAT(0, AllOfArray(v0.begin(), v0.end()));
+  EXPECT_THAT(1, AllOfArray(v1.begin(), v1.end()));
+  EXPECT_THAT(2, Not(AllOfArray(v1.begin(), v1.end())));
+  EXPECT_THAT(3, Not(AllOfArray(v2.begin(), v2.end())));
+  EXPECT_THAT(4, AllOfArray(v3.begin(), v3.end()));
+  // Pointer +  size
+  int ar[6] = {1, 2, 3, 4, 4, 4};
+  EXPECT_THAT(0, AllOfArray(ar, 0));
+  EXPECT_THAT(1, AllOfArray(ar, 1));
+  EXPECT_THAT(2, Not(AllOfArray(ar, 1)));
+  EXPECT_THAT(3, Not(AllOfArray(ar + 1, 3)));
+  EXPECT_THAT(4, AllOfArray(ar + 3, 3));
+  // Array
+  // int ar0[0];  Not usable
+  int ar1[1] = {1};
+  int ar2[2] = {2, 3};
+  int ar3[3] = {4, 4, 4};
+  // EXPECT_THAT(0, Not(AllOfArray(ar0)));  // Cannot work
+  EXPECT_THAT(1, AllOfArray(ar1));
+  EXPECT_THAT(2, Not(AllOfArray(ar1)));
+  EXPECT_THAT(3, Not(AllOfArray(ar2)));
+  EXPECT_THAT(4, AllOfArray(ar3));
+  // Container
+  EXPECT_THAT(0, AllOfArray(v0));
+  EXPECT_THAT(1, AllOfArray(v1));
+  EXPECT_THAT(2, Not(AllOfArray(v1)));
+  EXPECT_THAT(3, Not(AllOfArray(v2)));
+  EXPECT_THAT(4, AllOfArray(v3));
+  // Initializer
+  EXPECT_THAT(0, AllOfArray<int>({}));  // Requires template arg.
+  EXPECT_THAT(1, AllOfArray({1}));
+  EXPECT_THAT(2, Not(AllOfArray({1})));
+  EXPECT_THAT(3, Not(AllOfArray({2, 3})));
+  EXPECT_THAT(4, AllOfArray({4, 4, 4}));
+}
+
+TEST(AllOfArrayTest, Matchers) {
+  // vector
+  std::vector<Matcher<int>> matchers{Ge(1), Lt(2)};
+  EXPECT_THAT(0, Not(AllOfArray(matchers)));
+  EXPECT_THAT(1, AllOfArray(matchers));
+  EXPECT_THAT(2, Not(AllOfArray(matchers)));
+  // initializer_list
+  EXPECT_THAT(0, Not(AllOfArray({Ge(0), Ge(1)})));
+  EXPECT_THAT(1, AllOfArray({Ge(0), Ge(1)}));
+}
+
+INSTANTIATE_GTEST_MATCHER_TEST_P(AnyOfArrayTest);
+
+TEST(AnyOfArrayTest, BasicForms) {
+  // Iterator
+  std::vector<int> v0{};
+  std::vector<int> v1{1};
+  std::vector<int> v2{2, 3};
+  EXPECT_THAT(0, Not(AnyOfArray(v0.begin(), v0.end())));
+  EXPECT_THAT(1, AnyOfArray(v1.begin(), v1.end()));
+  EXPECT_THAT(2, Not(AnyOfArray(v1.begin(), v1.end())));
+  EXPECT_THAT(3, AnyOfArray(v2.begin(), v2.end()));
+  EXPECT_THAT(4, Not(AnyOfArray(v2.begin(), v2.end())));
+  // Pointer +  size
+  int ar[3] = {1, 2, 3};
+  EXPECT_THAT(0, Not(AnyOfArray(ar, 0)));
+  EXPECT_THAT(1, AnyOfArray(ar, 1));
+  EXPECT_THAT(2, Not(AnyOfArray(ar, 1)));
+  EXPECT_THAT(3, AnyOfArray(ar + 1, 2));
+  EXPECT_THAT(4, Not(AnyOfArray(ar + 1, 2)));
+  // Array
+  // int ar0[0];  Not usable
+  int ar1[1] = {1};
+  int ar2[2] = {2, 3};
+  // EXPECT_THAT(0, Not(AnyOfArray(ar0)));  // Cannot work
+  EXPECT_THAT(1, AnyOfArray(ar1));
+  EXPECT_THAT(2, Not(AnyOfArray(ar1)));
+  EXPECT_THAT(3, AnyOfArray(ar2));
+  EXPECT_THAT(4, Not(AnyOfArray(ar2)));
+  // Container
+  EXPECT_THAT(0, Not(AnyOfArray(v0)));
+  EXPECT_THAT(1, AnyOfArray(v1));
+  EXPECT_THAT(2, Not(AnyOfArray(v1)));
+  EXPECT_THAT(3, AnyOfArray(v2));
+  EXPECT_THAT(4, Not(AnyOfArray(v2)));
+  // Initializer
+  EXPECT_THAT(0, Not(AnyOfArray<int>({})));  // Requires template arg.
+  EXPECT_THAT(1, AnyOfArray({1}));
+  EXPECT_THAT(2, Not(AnyOfArray({1})));
+  EXPECT_THAT(3, AnyOfArray({2, 3}));
+  EXPECT_THAT(4, Not(AnyOfArray({2, 3})));
+}
+
+TEST(AnyOfArrayTest, Matchers) {
+  // We negate test AllOfArrayTest.Matchers.
+  // vector
+  std::vector<Matcher<int>> matchers{Lt(1), Ge(2)};
+  EXPECT_THAT(0, AnyOfArray(matchers));
+  EXPECT_THAT(1, Not(AnyOfArray(matchers)));
+  EXPECT_THAT(2, AnyOfArray(matchers));
+  // initializer_list
+  EXPECT_THAT(0, AnyOfArray({Lt(0), Lt(1)}));
+  EXPECT_THAT(1, Not(AllOfArray({Lt(0), Lt(1)})));
+}
+
+TEST_P(AnyOfArrayTestP, ExplainsMatchResultCorrectly) {
+  // AnyOfArray and AllOfArray use the same underlying template-template,
+  // thus it is sufficient to test one here.
+  const std::vector<int> v0{};
+  const std::vector<int> v1{1};
+  const std::vector<int> v2{2, 3};
+  const Matcher<int> m0 = AnyOfArray(v0);
+  const Matcher<int> m1 = AnyOfArray(v1);
+  const Matcher<int> m2 = AnyOfArray(v2);
+  EXPECT_EQ("", Explain(m0, 0));
+  EXPECT_EQ("", Explain(m1, 1));
+  EXPECT_EQ("", Explain(m1, 2));
+  EXPECT_EQ("", Explain(m2, 3));
+  EXPECT_EQ("", Explain(m2, 4));
+  EXPECT_EQ("()", Describe(m0));
+  EXPECT_EQ("(is equal to 1)", Describe(m1));
+  EXPECT_EQ("(is equal to 2) or (is equal to 3)", Describe(m2));
+  EXPECT_EQ("()", DescribeNegation(m0));
+  EXPECT_EQ("(isn't equal to 1)", DescribeNegation(m1));
+  EXPECT_EQ("(isn't equal to 2) and (isn't equal to 3)", DescribeNegation(m2));
+  // Explain with matchers
+  const Matcher<int> g1 = AnyOfArray({GreaterThan(1)});
+  const Matcher<int> g2 = AnyOfArray({GreaterThan(1), GreaterThan(2)});
+  // Explains the first positive match and all prior negative matches...
+  EXPECT_EQ("which is 1 less than 1", Explain(g1, 0));
+  EXPECT_EQ("which is the same as 1", Explain(g1, 1));
+  EXPECT_EQ("which is 1 more than 1", Explain(g1, 2));
+  EXPECT_EQ("which is 1 less than 1, and which is 2 less than 2",
+            Explain(g2, 0));
+  EXPECT_EQ("which is the same as 1, and which is 1 less than 2",
+            Explain(g2, 1));
+  EXPECT_EQ("which is 1 more than 1",  // Only the first
+            Explain(g2, 2));
+}
+
+MATCHER(IsNotNull, "") { return arg != nullptr; }
+
+// Verifies that a matcher defined using MATCHER() can work on
+// move-only types.
+TEST(MatcherMacroTest, WorksOnMoveOnlyType) {
+  std::unique_ptr<int> p(new int(3));
+  EXPECT_THAT(p, IsNotNull());
+  EXPECT_THAT(std::unique_ptr<int>(), Not(IsNotNull()));
+}
+
+MATCHER_P(UniquePointee, pointee, "") { return *arg == pointee; }
+
+// Verifies that a matcher defined using MATCHER_P*() can work on
+// move-only types.
+TEST(MatcherPMacroTest, WorksOnMoveOnlyType) {
+  std::unique_ptr<int> p(new int(3));
+  EXPECT_THAT(p, UniquePointee(3));
+  EXPECT_THAT(p, Not(UniquePointee(2)));
+}
+
+MATCHER(EnsureNoUnusedButMarkedUnusedWarning, "") { return (arg % 2) == 0; }
+
+TEST(MockMethodMockFunctionTest, EnsureNoUnusedButMarkedUnusedWarning) {
+#ifdef __clang__
+#pragma clang diagnostic push
+#pragma clang diagnostic error "-Wused-but-marked-unused"
+#endif
+  // https://github.com/google/googletest/issues/4055
+  EXPECT_THAT(0, EnsureNoUnusedButMarkedUnusedWarning());
+#ifdef __clang__
+#pragma clang diagnostic pop
+#endif
+}
+
+#if GTEST_HAS_EXCEPTIONS
+
+// std::function<void()> is used below for compatibility with older copies of
+// GCC. Normally, a raw lambda is all that is needed.
+
+// Test that examples from documentation compile
+TEST(ThrowsTest, Examples) {
+  EXPECT_THAT(
+      std::function<void()>([]() { throw std::runtime_error("message"); }),
+      Throws<std::runtime_error>());
+
+  EXPECT_THAT(
+      std::function<void()>([]() { throw std::runtime_error("message"); }),
+      ThrowsMessage<std::runtime_error>(HasSubstr("message")));
+}
+
+TEST(ThrowsTest, PrintsExceptionWhat) {
+  EXPECT_THAT(
+      std::function<void()>([]() { throw std::runtime_error("ABC123XYZ"); }),
+      ThrowsMessage<std::runtime_error>(HasSubstr("ABC123XYZ")));
+}
+
+TEST(ThrowsTest, DoesNotGenerateDuplicateCatchClauseWarning) {
+  EXPECT_THAT(std::function<void()>([]() { throw std::exception(); }),
+              Throws<std::exception>());
+}
+
+TEST(ThrowsTest, CallableExecutedExactlyOnce) {
+  size_t a = 0;
+
+  EXPECT_THAT(std::function<void()>([&a]() {
+                a++;
+                throw 10;
+              }),
+              Throws<int>());
+  EXPECT_EQ(a, 1u);
+
+  EXPECT_THAT(std::function<void()>([&a]() {
+                a++;
+                throw std::runtime_error("message");
+              }),
+              Throws<std::runtime_error>());
+  EXPECT_EQ(a, 2u);
+
+  EXPECT_THAT(std::function<void()>([&a]() {
+                a++;
+                throw std::runtime_error("message");
+              }),
+              ThrowsMessage<std::runtime_error>(HasSubstr("message")));
+  EXPECT_EQ(a, 3u);
+
+  EXPECT_THAT(std::function<void()>([&a]() {
+                a++;
+                throw std::runtime_error("message");
+              }),
+              Throws<std::runtime_error>(
+                  Property(&std::runtime_error::what, HasSubstr("message"))));
+  EXPECT_EQ(a, 4u);
+}
+
+TEST(ThrowsTest, Describe) {
+  Matcher<std::function<void()>> matcher = Throws<std::runtime_error>();
+  std::stringstream ss;
+  matcher.DescribeTo(&ss);
+  auto explanation = ss.str();
+  EXPECT_THAT(explanation, HasSubstr("std::runtime_error"));
+}
+
+TEST(ThrowsTest, Success) {
+  Matcher<std::function<void()>> matcher = Throws<std::runtime_error>();
+  StringMatchResultListener listener;
+  EXPECT_TRUE(matcher.MatchAndExplain(
+      []() { throw std::runtime_error("error message"); }, &listener));
+  EXPECT_THAT(listener.str(), HasSubstr("std::runtime_error"));
+}
+
+TEST(ThrowsTest, FailWrongType) {
+  Matcher<std::function<void()>> matcher = Throws<std::runtime_error>();
+  StringMatchResultListener listener;
+  EXPECT_FALSE(matcher.MatchAndExplain(
+      []() { throw std::logic_error("error message"); }, &listener));
+  EXPECT_THAT(listener.str(), HasSubstr("std::logic_error"));
+  EXPECT_THAT(listener.str(), HasSubstr("\"error message\""));
+}
+
+TEST(ThrowsTest, FailWrongTypeNonStd) {
+  Matcher<std::function<void()>> matcher = Throws<std::runtime_error>();
+  StringMatchResultListener listener;
+  EXPECT_FALSE(matcher.MatchAndExplain([]() { throw 10; }, &listener));
+  EXPECT_THAT(listener.str(),
+              HasSubstr("throws an exception of an unknown type"));
+}
+
+TEST(ThrowsTest, FailNoThrow) {
+  Matcher<std::function<void()>> matcher = Throws<std::runtime_error>();
+  StringMatchResultListener listener;
+  EXPECT_FALSE(matcher.MatchAndExplain([]() { (void)0; }, &listener));
+  EXPECT_THAT(listener.str(), HasSubstr("does not throw any exception"));
+}
+
+class ThrowsPredicateTest
+    : public TestWithParam<Matcher<std::function<void()>>> {};
+
+TEST_P(ThrowsPredicateTest, Describe) {
+  Matcher<std::function<void()>> matcher = GetParam();
+  std::stringstream ss;
+  matcher.DescribeTo(&ss);
+  auto explanation = ss.str();
+  EXPECT_THAT(explanation, HasSubstr("std::runtime_error"));
+  EXPECT_THAT(explanation, HasSubstr("error message"));
+}
+
+TEST_P(ThrowsPredicateTest, Success) {
+  Matcher<std::function<void()>> matcher = GetParam();
+  StringMatchResultListener listener;
+  EXPECT_TRUE(matcher.MatchAndExplain(
+      []() { throw std::runtime_error("error message"); }, &listener));
+  EXPECT_THAT(listener.str(), HasSubstr("std::runtime_error"));
+}
+
+TEST_P(ThrowsPredicateTest, FailWrongType) {
+  Matcher<std::function<void()>> matcher = GetParam();
+  StringMatchResultListener listener;
+  EXPECT_FALSE(matcher.MatchAndExplain(
+      []() { throw std::logic_error("error message"); }, &listener));
+  EXPECT_THAT(listener.str(), HasSubstr("std::logic_error"));
+  EXPECT_THAT(listener.str(), HasSubstr("\"error message\""));
+}
+
+TEST_P(ThrowsPredicateTest, FailWrongTypeNonStd) {
+  Matcher<std::function<void()>> matcher = GetParam();
+  StringMatchResultListener listener;
+  EXPECT_FALSE(matcher.MatchAndExplain([]() { throw 10; }, &listener));
+  EXPECT_THAT(listener.str(),
+              HasSubstr("throws an exception of an unknown type"));
+}
+
+TEST_P(ThrowsPredicateTest, FailNoThrow) {
+  Matcher<std::function<void()>> matcher = GetParam();
+  StringMatchResultListener listener;
+  EXPECT_FALSE(matcher.MatchAndExplain([]() {}, &listener));
+  EXPECT_THAT(listener.str(), HasSubstr("does not throw any exception"));
+}
+
+INSTANTIATE_TEST_SUITE_P(
+    AllMessagePredicates, ThrowsPredicateTest,
+    Values(Matcher<std::function<void()>>(
+        ThrowsMessage<std::runtime_error>(HasSubstr("error message")))));
+
+// Tests that Throws<E1>(Matcher<E2>{}) compiles even when E2 != const E1&.
+TEST(ThrowsPredicateCompilesTest, ExceptionMatcherAcceptsBroadType) {
+  {
+    Matcher<std::function<void()>> matcher =
+        ThrowsMessage<std::runtime_error>(HasSubstr("error message"));
+    EXPECT_TRUE(
+        matcher.Matches([]() { throw std::runtime_error("error message"); }));
+    EXPECT_FALSE(
+        matcher.Matches([]() { throw std::runtime_error("wrong message"); }));
+  }
+
+  {
+    Matcher<uint64_t> inner = Eq(10);
+    Matcher<std::function<void()>> matcher = Throws<uint32_t>(inner);
+    EXPECT_TRUE(matcher.Matches([]() { throw (uint32_t)10; }));
+    EXPECT_FALSE(matcher.Matches([]() { throw (uint32_t)11; }));
+  }
+}
+
+// Tests that ThrowsMessage("message") is equivalent
+// to ThrowsMessage(Eq<std::string>("message")).
+TEST(ThrowsPredicateCompilesTest, MessageMatcherAcceptsNonMatcher) {
+  Matcher<std::function<void()>> matcher =
+      ThrowsMessage<std::runtime_error>("error message");
+  EXPECT_TRUE(
+      matcher.Matches([]() { throw std::runtime_error("error message"); }));
+  EXPECT_FALSE(matcher.Matches(
+      []() { throw std::runtime_error("wrong error message"); }));
+}
+
+#endif  // GTEST_HAS_EXCEPTIONS
+
+}  // namespace
+}  // namespace gmock_matchers_test
+}  // namespace testing
+
+GTEST_DISABLE_MSC_WARNINGS_POP_()  // 4244 4100

contrib/googletest/googlemock/test/gmock-matchers_test.h

@@ -0,0 +1,192 @@
+// Copyright 2007, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+// Google Mock - a framework for writing C++ mock classes.
+//
+// This file tests some commonly used argument matchers.
+
+#ifndef GOOGLEMOCK_TEST_GMOCK_MATCHERS_TEST_H_
+#define GOOGLEMOCK_TEST_GMOCK_MATCHERS_TEST_H_
+
+#include <string.h>
+#include <time.h>
+
+#include <array>
+#include <cstdint>
+#include <deque>
+#include <forward_list>
+#include <functional>
+#include <iostream>
+#include <iterator>
+#include <limits>
+#include <list>
+#include <map>
+#include <memory>
+#include <set>
+#include <sstream>
+#include <string>
+#include <type_traits>
+#include <unordered_map>
+#include <unordered_set>
+#include <utility>
+#include <vector>
+
+#include "gmock/gmock-matchers.h"
+#include "gmock/gmock-more-matchers.h"
+#include "gmock/gmock.h"
+#include "gtest/gtest-spi.h"
+#include "gtest/gtest.h"
+
+namespace testing {
+namespace gmock_matchers_test {
+
+using std::greater;
+using std::less;
+using std::list;
+using std::make_pair;
+using std::map;
+using std::multimap;
+using std::multiset;
+using std::ostream;
+using std::pair;
+using std::set;
+using std::stringstream;
+using std::vector;
+using testing::internal::DummyMatchResultListener;
+using testing::internal::ElementMatcherPair;
+using testing::internal::ElementMatcherPairs;
+using testing::internal::ElementsAreArrayMatcher;
+using testing::internal::ExplainMatchFailureTupleTo;
+using testing::internal::FloatingEqMatcher;
+using testing::internal::FormatMatcherDescription;
+using testing::internal::IsReadableTypeName;
+using testing::internal::MatchMatrix;
+using testing::internal::PredicateFormatterFromMatcher;
+using testing::internal::RE;
+using testing::internal::StreamMatchResultListener;
+using testing::internal::Strings;
+
+// Helper for testing container-valued matchers in mock method context. It is
+// important to test matchers in this context, since it requires additional type
+// deduction beyond what EXPECT_THAT does, thus making it more restrictive.
+struct ContainerHelper {
+  MOCK_METHOD1(Call, void(std::vector<std::unique_ptr<int>>));
+};
+
+// For testing ExplainMatchResultTo().
+template <typename T>
+struct GtestGreaterThanMatcher {
+  using is_gtest_matcher = void;
+
+  void DescribeTo(ostream* os) const { *os << "is > " << rhs; }
+  void DescribeNegationTo(ostream* os) const { *os << "is <= " << rhs; }
+
+  bool MatchAndExplain(T lhs, MatchResultListener* listener) const {
+    if (lhs > rhs) {
+      *listener << "which is " << (lhs - rhs) << " more than " << rhs;
+    } else if (lhs == rhs) {
+      *listener << "which is the same as " << rhs;
+    } else {
+      *listener << "which is " << (rhs - lhs) << " less than " << rhs;
+    }
+
+    return lhs > rhs;
+  }
+
+  T rhs;
+};
+
+template <typename T>
+GtestGreaterThanMatcher<typename std::decay<T>::type> GtestGreaterThan(
+    T&& rhs) {
+  return {rhs};
+}
+
+// As the matcher above, but using the base class with virtual functions.
+template <typename T>
+class GreaterThanMatcher : public MatcherInterface<T> {
+ public:
+  explicit GreaterThanMatcher(T rhs) : impl_{rhs} {}
+
+  void DescribeTo(ostream* os) const override { impl_.DescribeTo(os); }
+  void DescribeNegationTo(ostream* os) const override {
+    impl_.DescribeNegationTo(os);
+  }
+
+  bool MatchAndExplain(T lhs, MatchResultListener* listener) const override {
+    return impl_.MatchAndExplain(lhs, listener);
+  }
+
+ private:
+  const GtestGreaterThanMatcher<T> impl_;
+};
+
+// Names and instantiates a new instance of GTestMatcherTestP.
+#define INSTANTIATE_GTEST_MATCHER_TEST_P(TestSuite)                        \
+  using TestSuite##P = GTestMatcherTestP;                                  \
+  INSTANTIATE_TEST_SUITE_P(MatcherInterface, TestSuite##P, Values(false)); \
+  INSTANTIATE_TEST_SUITE_P(GtestMatcher, TestSuite##P, Values(true))
+
+class GTestMatcherTestP : public testing::TestWithParam<bool> {
+ public:
+  template <typename T>
+  Matcher<T> GreaterThan(T n) {
+    if (use_gtest_matcher_) {
+      return GtestGreaterThan(n);
+    } else {
+      return MakeMatcher(new GreaterThanMatcher<T>(n));
+    }
+  }
+  const bool use_gtest_matcher_ = GetParam();
+};
+
+// Returns the description of the given matcher.
+template <typename T>
+std::string Describe(const Matcher<T>& m) {
+  return DescribeMatcher<T>(m);
+}
+
+// Returns the description of the negation of the given matcher.
+template <typename T>
+std::string DescribeNegation(const Matcher<T>& m) {
+  return DescribeMatcher<T>(m, true);
+}
+
+// Returns the reason why x matches, or doesn't match, m.
+template <typename MatcherType, typename Value>
+std::string Explain(const MatcherType& m, const Value& x) {
+  StringMatchResultListener listener;
+  ExplainMatchResult(m, x, &listener);
+  return listener.str();
+}
+
+}  // namespace gmock_matchers_test
+}  // namespace testing
+
+#endif  // GOOGLEMOCK_TEST_GMOCK_MATCHERS_TEST_H_

contrib/googletest/googlemock/test/gmock-more-actions_test.cc

@@ -0,0 +1,1550 @@
+// Copyright 2007, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+// Google Mock - a framework for writing C++ mock classes.
+//
+// This file tests the built-in actions in gmock-actions.h.
+
+#include "gmock/gmock-more-actions.h"
+
+#include <algorithm>
+#include <functional>
+#include <iterator>
+#include <memory>
+#include <sstream>
+#include <string>
+#include <tuple>
+#include <vector>
+
+#include "gmock/gmock.h"
+#include "gtest/gtest-spi.h"
+#include "gtest/gtest.h"
+
+GTEST_DISABLE_MSC_WARNINGS_PUSH_(4577)
+
+namespace testing {
+namespace gmock_more_actions_test {
+
+using ::std::plus;
+using ::std::string;
+using testing::Action;
+using testing::DeleteArg;
+using testing::Invoke;
+using testing::ReturnArg;
+using testing::ReturnPointee;
+using testing::SaveArg;
+using testing::SaveArgPointee;
+using testing::SetArgReferee;
+using testing::Unused;
+using testing::WithArg;
+using testing::WithoutArgs;
+
+// For suppressing compiler warnings on conversion possibly losing precision.
+inline short Short(short n) { return n; }  // NOLINT
+inline char Char(char ch) { return ch; }
+
+// Sample functions and functors for testing Invoke() and etc.
+int Nullary() { return 1; }
+
+bool g_done = false;
+
+bool Unary(int x) { return x < 0; }
+
+bool ByConstRef(const std::string& s) { return s == "Hi"; }
+
+const double g_double = 0;
+bool ReferencesGlobalDouble(const double& x) { return &x == &g_double; }
+
+struct UnaryFunctor {
+  int operator()(bool x) { return x ? 1 : -1; }
+};
+
+const char* Binary(const char* input, short n) { return input + n; }  // NOLINT
+
+int Ternary(int x, char y, short z) { return x + y + z; }  // NOLINT
+
+int SumOf4(int a, int b, int c, int d) { return a + b + c + d; }
+
+int SumOfFirst2(int a, int b, Unused, Unused) { return a + b; }
+
+int SumOf5(int a, int b, int c, int d, int e) { return a + b + c + d + e; }
+
+struct SumOf5Functor {
+  int operator()(int a, int b, int c, int d, int e) {
+    return a + b + c + d + e;
+  }
+};
+
+int SumOf6(int a, int b, int c, int d, int e, int f) {
+  return a + b + c + d + e + f;
+}
+
+struct SumOf6Functor {
+  int operator()(int a, int b, int c, int d, int e, int f) {
+    return a + b + c + d + e + f;
+  }
+};
+
+std::string Concat7(const char* s1, const char* s2, const char* s3,
+                    const char* s4, const char* s5, const char* s6,
+                    const char* s7) {
+  return std::string(s1) + s2 + s3 + s4 + s5 + s6 + s7;
+}
+
+std::string Concat8(const char* s1, const char* s2, const char* s3,
+                    const char* s4, const char* s5, const char* s6,
+                    const char* s7, const char* s8) {
+  return std::string(s1) + s2 + s3 + s4 + s5 + s6 + s7 + s8;
+}
+
+std::string Concat9(const char* s1, const char* s2, const char* s3,
+                    const char* s4, const char* s5, const char* s6,
+                    const char* s7, const char* s8, const char* s9) {
+  return std::string(s1) + s2 + s3 + s4 + s5 + s6 + s7 + s8 + s9;
+}
+
+std::string Concat10(const char* s1, const char* s2, const char* s3,
+                     const char* s4, const char* s5, const char* s6,
+                     const char* s7, const char* s8, const char* s9,
+                     const char* s10) {
+  return std::string(s1) + s2 + s3 + s4 + s5 + s6 + s7 + s8 + s9 + s10;
+}
+
+class Foo {
+ public:
+  Foo() : value_(123) {}
+
+  int Nullary() const { return value_; }
+
+  short Unary(long x) { return static_cast<short>(value_ + x); }  // NOLINT
+
+  std::string Binary(const std::string& str, char c) const { return str + c; }
+
+  int Ternary(int x, bool y, char z) { return value_ + x + y * z; }
+
+  int SumOf4(int a, int b, int c, int d) const {
+    return a + b + c + d + value_;
+  }
+
+  int SumOfLast2(Unused, Unused, int a, int b) const { return a + b; }
+
+  int SumOf5(int a, int b, int c, int d, int e) { return a + b + c + d + e; }
+
+  int SumOf6(int a, int b, int c, int d, int e, int f) {
+    return a + b + c + d + e + f;
+  }
+
+  std::string Concat7(const char* s1, const char* s2, const char* s3,
+                      const char* s4, const char* s5, const char* s6,
+                      const char* s7) {
+    return std::string(s1) + s2 + s3 + s4 + s5 + s6 + s7;
+  }
+
+  std::string Concat8(const char* s1, const char* s2, const char* s3,
+                      const char* s4, const char* s5, const char* s6,
+                      const char* s7, const char* s8) {
+    return std::string(s1) + s2 + s3 + s4 + s5 + s6 + s7 + s8;
+  }
+
+  std::string Concat9(const char* s1, const char* s2, const char* s3,
+                      const char* s4, const char* s5, const char* s6,
+                      const char* s7, const char* s8, const char* s9) {
+    return std::string(s1) + s2 + s3 + s4 + s5 + s6 + s7 + s8 + s9;
+  }
+
+  std::string Concat10(const char* s1, const char* s2, const char* s3,
+                       const char* s4, const char* s5, const char* s6,
+                       const char* s7, const char* s8, const char* s9,
+                       const char* s10) {
+    return std::string(s1) + s2 + s3 + s4 + s5 + s6 + s7 + s8 + s9 + s10;
+  }
+
+ private:
+  int value_;
+};
+
+// Tests using Invoke() with a nullary function.
+TEST(InvokeTest, Nullary) {
+  Action<int()> a = Invoke(Nullary);  // NOLINT
+  EXPECT_EQ(1, a.Perform(std::make_tuple()));
+}
+
+// Tests using Invoke() with a unary function.
+TEST(InvokeTest, Unary) {
+  Action<bool(int)> a = Invoke(Unary);  // NOLINT
+  EXPECT_FALSE(a.Perform(std::make_tuple(1)));
+  EXPECT_TRUE(a.Perform(std::make_tuple(-1)));
+}
+
+// Tests using Invoke() with a binary function.
+TEST(InvokeTest, Binary) {
+  Action<const char*(const char*, short)> a = Invoke(Binary);  // NOLINT
+  const char* p = "Hello";
+  EXPECT_EQ(p + 2, a.Perform(std::make_tuple(p, Short(2))));
+}
+
+// Tests using Invoke() with a ternary function.
+TEST(InvokeTest, Ternary) {
+  Action<int(int, char, short)> a = Invoke(Ternary);  // NOLINT
+  EXPECT_EQ(6, a.Perform(std::make_tuple(1, '\2', Short(3))));
+}
+
+// Tests using Invoke() with a 4-argument function.
+TEST(InvokeTest, FunctionThatTakes4Arguments) {
+  Action<int(int, int, int, int)> a = Invoke(SumOf4);  // NOLINT
+  EXPECT_EQ(1234, a.Perform(std::make_tuple(1000, 200, 30, 4)));
+}
+
+// Tests using Invoke() with a 5-argument function.
+TEST(InvokeTest, FunctionThatTakes5Arguments) {
+  Action<int(int, int, int, int, int)> a = Invoke(SumOf5);  // NOLINT
+  EXPECT_EQ(12345, a.Perform(std::make_tuple(10000, 2000, 300, 40, 5)));
+}
+
+// Tests using Invoke() with a 6-argument function.
+TEST(InvokeTest, FunctionThatTakes6Arguments) {
+  Action<int(int, int, int, int, int, int)> a = Invoke(SumOf6);  // NOLINT
+  EXPECT_EQ(123456,
+            a.Perform(std::make_tuple(100000, 20000, 3000, 400, 50, 6)));
+}
+
+// A helper that turns the type of a C-string literal from const
+// char[N] to const char*.
+inline const char* CharPtr(const char* s) { return s; }
+
+// Tests using Invoke() with a 7-argument function.
+TEST(InvokeTest, FunctionThatTakes7Arguments) {
+  Action<std::string(const char*, const char*, const char*, const char*,
+                     const char*, const char*, const char*)>
+      a = Invoke(Concat7);
+  EXPECT_EQ("1234567",
+            a.Perform(std::make_tuple(CharPtr("1"), CharPtr("2"), CharPtr("3"),
+                                      CharPtr("4"), CharPtr("5"), CharPtr("6"),
+                                      CharPtr("7"))));
+}
+
+// Tests using Invoke() with a 8-argument function.
+TEST(InvokeTest, FunctionThatTakes8Arguments) {
+  Action<std::string(const char*, const char*, const char*, const char*,
+                     const char*, const char*, const char*, const char*)>
+      a = Invoke(Concat8);
+  EXPECT_EQ("12345678",
+            a.Perform(std::make_tuple(CharPtr("1"), CharPtr("2"), CharPtr("3"),
+                                      CharPtr("4"), CharPtr("5"), CharPtr("6"),
+                                      CharPtr("7"), CharPtr("8"))));
+}
+
+// Tests using Invoke() with a 9-argument function.
+TEST(InvokeTest, FunctionThatTakes9Arguments) {
+  Action<std::string(const char*, const char*, const char*, const char*,
+                     const char*, const char*, const char*, const char*,
+                     const char*)>
+      a = Invoke(Concat9);
+  EXPECT_EQ("123456789", a.Perform(std::make_tuple(
+                             CharPtr("1"), CharPtr("2"), CharPtr("3"),
+                             CharPtr("4"), CharPtr("5"), CharPtr("6"),
+                             CharPtr("7"), CharPtr("8"), CharPtr("9"))));
+}
+
+// Tests using Invoke() with a 10-argument function.
+TEST(InvokeTest, FunctionThatTakes10Arguments) {
+  Action<std::string(const char*, const char*, const char*, const char*,
+                     const char*, const char*, const char*, const char*,
+                     const char*, const char*)>
+      a = Invoke(Concat10);
+  EXPECT_EQ("1234567890",
+            a.Perform(std::make_tuple(CharPtr("1"), CharPtr("2"), CharPtr("3"),
+                                      CharPtr("4"), CharPtr("5"), CharPtr("6"),
+                                      CharPtr("7"), CharPtr("8"), CharPtr("9"),
+                                      CharPtr("0"))));
+}
+
+// Tests using Invoke() with functions with parameters declared as Unused.
+TEST(InvokeTest, FunctionWithUnusedParameters) {
+  Action<int(int, int, double, const std::string&)> a1 = Invoke(SumOfFirst2);
+  std::tuple<int, int, double, std::string> dummy =
+      std::make_tuple(10, 2, 5.6, std::string("hi"));
+  EXPECT_EQ(12, a1.Perform(dummy));
+
+  Action<int(int, int, bool, int*)> a2 = Invoke(SumOfFirst2);
+  EXPECT_EQ(
+      23, a2.Perform(std::make_tuple(20, 3, true, static_cast<int*>(nullptr))));
+}
+
+// Tests using Invoke() with methods with parameters declared as Unused.
+TEST(InvokeTest, MethodWithUnusedParameters) {
+  Foo foo;
+  Action<int(std::string, bool, int, int)> a1 = Invoke(&foo, &Foo::SumOfLast2);
+  EXPECT_EQ(12, a1.Perform(std::make_tuple(CharPtr("hi"), true, 10, 2)));
+
+  Action<int(char, double, int, int)> a2 = Invoke(&foo, &Foo::SumOfLast2);
+  EXPECT_EQ(23, a2.Perform(std::make_tuple('a', 2.5, 20, 3)));
+}
+
+// Tests using Invoke() with a functor.
+TEST(InvokeTest, Functor) {
+  Action<long(long, int)> a = Invoke(plus<long>());  // NOLINT
+  EXPECT_EQ(3L, a.Perform(std::make_tuple(1, 2)));
+}
+
+// Tests using Invoke(f) as an action of a compatible type.
+TEST(InvokeTest, FunctionWithCompatibleType) {
+  Action<long(int, short, char, bool)> a = Invoke(SumOf4);  // NOLINT
+  EXPECT_EQ(4321, a.Perform(std::make_tuple(4000, Short(300), Char(20), true)));
+}
+
+// Tests using Invoke() with an object pointer and a method pointer.
+
+// Tests using Invoke() with a nullary method.
+TEST(InvokeMethodTest, Nullary) {
+  Foo foo;
+  Action<int()> a = Invoke(&foo, &Foo::Nullary);  // NOLINT
+  EXPECT_EQ(123, a.Perform(std::make_tuple()));
+}
+
+// Tests using Invoke() with a unary method.
+TEST(InvokeMethodTest, Unary) {
+  Foo foo;
+  Action<short(long)> a = Invoke(&foo, &Foo::Unary);  // NOLINT
+  EXPECT_EQ(4123, a.Perform(std::make_tuple(4000)));
+}
+
+// Tests using Invoke() with a binary method.
+TEST(InvokeMethodTest, Binary) {
+  Foo foo;
+  Action<std::string(const std::string&, char)> a = Invoke(&foo, &Foo::Binary);
+  std::string s("Hell");
+  std::tuple<std::string, char> dummy = std::make_tuple(s, 'o');
+  EXPECT_EQ("Hello", a.Perform(dummy));
+}
+
+// Tests using Invoke() with a ternary method.
+TEST(InvokeMethodTest, Ternary) {
+  Foo foo;
+  Action<int(int, bool, char)> a = Invoke(&foo, &Foo::Ternary);  // NOLINT
+  EXPECT_EQ(1124, a.Perform(std::make_tuple(1000, true, Char(1))));
+}
+
+// Tests using Invoke() with a 4-argument method.
+TEST(InvokeMethodTest, MethodThatTakes4Arguments) {
+  Foo foo;
+  Action<int(int, int, int, int)> a = Invoke(&foo, &Foo::SumOf4);  // NOLINT
+  EXPECT_EQ(1357, a.Perform(std::make_tuple(1000, 200, 30, 4)));
+}
+
+// Tests using Invoke() with a 5-argument method.
+TEST(InvokeMethodTest, MethodThatTakes5Arguments) {
+  Foo foo;
+  Action<int(int, int, int, int, int)> a =
+      Invoke(&foo, &Foo::SumOf5);  // NOLINT
+  EXPECT_EQ(12345, a.Perform(std::make_tuple(10000, 2000, 300, 40, 5)));
+}
+
+// Tests using Invoke() with a 6-argument method.
+TEST(InvokeMethodTest, MethodThatTakes6Arguments) {
+  Foo foo;
+  Action<int(int, int, int, int, int, int)> a =  // NOLINT
+      Invoke(&foo, &Foo::SumOf6);
+  EXPECT_EQ(123456,
+            a.Perform(std::make_tuple(100000, 20000, 3000, 400, 50, 6)));
+}
+
+// Tests using Invoke() with a 7-argument method.
+TEST(InvokeMethodTest, MethodThatTakes7Arguments) {
+  Foo foo;
+  Action<std::string(const char*, const char*, const char*, const char*,
+                     const char*, const char*, const char*)>
+      a = Invoke(&foo, &Foo::Concat7);
+  EXPECT_EQ("1234567",
+            a.Perform(std::make_tuple(CharPtr("1"), CharPtr("2"), CharPtr("3"),
+                                      CharPtr("4"), CharPtr("5"), CharPtr("6"),
+                                      CharPtr("7"))));
+}
+
+// Tests using Invoke() with a 8-argument method.
+TEST(InvokeMethodTest, MethodThatTakes8Arguments) {
+  Foo foo;
+  Action<std::string(const char*, const char*, const char*, const char*,
+                     const char*, const char*, const char*, const char*)>
+      a = Invoke(&foo, &Foo::Concat8);
+  EXPECT_EQ("12345678",
+            a.Perform(std::make_tuple(CharPtr("1"), CharPtr("2"), CharPtr("3"),
+                                      CharPtr("4"), CharPtr("5"), CharPtr("6"),
+                                      CharPtr("7"), CharPtr("8"))));
+}
+
+// Tests using Invoke() with a 9-argument method.
+TEST(InvokeMethodTest, MethodThatTakes9Arguments) {
+  Foo foo;
+  Action<std::string(const char*, const char*, const char*, const char*,
+                     const char*, const char*, const char*, const char*,
+                     const char*)>
+      a = Invoke(&foo, &Foo::Concat9);
+  EXPECT_EQ("123456789", a.Perform(std::make_tuple(
+                             CharPtr("1"), CharPtr("2"), CharPtr("3"),
+                             CharPtr("4"), CharPtr("5"), CharPtr("6"),
+                             CharPtr("7"), CharPtr("8"), CharPtr("9"))));
+}
+
+// Tests using Invoke() with a 10-argument method.
+TEST(InvokeMethodTest, MethodThatTakes10Arguments) {
+  Foo foo;
+  Action<std::string(const char*, const char*, const char*, const char*,
+                     const char*, const char*, const char*, const char*,
+                     const char*, const char*)>
+      a = Invoke(&foo, &Foo::Concat10);
+  EXPECT_EQ("1234567890",
+            a.Perform(std::make_tuple(CharPtr("1"), CharPtr("2"), CharPtr("3"),
+                                      CharPtr("4"), CharPtr("5"), CharPtr("6"),
+                                      CharPtr("7"), CharPtr("8"), CharPtr("9"),
+                                      CharPtr("0"))));
+}
+
+// Tests using Invoke(f) as an action of a compatible type.
+TEST(InvokeMethodTest, MethodWithCompatibleType) {
+  Foo foo;
+  Action<long(int, short, char, bool)> a =  // NOLINT
+      Invoke(&foo, &Foo::SumOf4);
+  EXPECT_EQ(4444, a.Perform(std::make_tuple(4000, Short(300), Char(20), true)));
+}
+
+// Tests using WithoutArgs with an action that takes no argument.
+TEST(WithoutArgsTest, NoArg) {
+  Action<int(int n)> a = WithoutArgs(Invoke(Nullary));  // NOLINT
+  EXPECT_EQ(1, a.Perform(std::make_tuple(2)));
+}
+
+// Tests using WithArg with an action that takes 1 argument.
+TEST(WithArgTest, OneArg) {
+  Action<bool(double x, int n)> b = WithArg<1>(Invoke(Unary));  // NOLINT
+  EXPECT_TRUE(b.Perform(std::make_tuple(1.5, -1)));
+  EXPECT_FALSE(b.Perform(std::make_tuple(1.5, 1)));
+}
+
+TEST(ReturnArgActionTest, WorksForOneArgIntArg0) {
+  const Action<int(int)> a = ReturnArg<0>();
+  EXPECT_EQ(5, a.Perform(std::make_tuple(5)));
+}
+
+TEST(ReturnArgActionTest, WorksForMultiArgBoolArg0) {
+  const Action<bool(bool, bool, bool)> a = ReturnArg<0>();
+  EXPECT_TRUE(a.Perform(std::make_tuple(true, false, false)));
+}
+
+TEST(ReturnArgActionTest, WorksForMultiArgStringArg2) {
+  const Action<std::string(int, int, std::string, int)> a = ReturnArg<2>();
+  EXPECT_EQ("seven", a.Perform(std::make_tuple(5, 6, std::string("seven"), 8)));
+}
+
+TEST(ReturnArgActionTest, WorksForNonConstRefArg0) {
+  const Action<std::string&(std::string&)> a = ReturnArg<0>();
+  std::string s = "12345";
+  EXPECT_EQ(&s, &a.Perform(std::forward_as_tuple(s)));
+}
+
+TEST(SaveArgActionTest, WorksForSameType) {
+  int result = 0;
+  const Action<void(int n)> a1 = SaveArg<0>(&result);
+  a1.Perform(std::make_tuple(5));
+  EXPECT_EQ(5, result);
+}
+
+TEST(SaveArgActionTest, WorksForCompatibleType) {
+  int result = 0;
+  const Action<void(bool, char)> a1 = SaveArg<1>(&result);
+  a1.Perform(std::make_tuple(true, 'a'));
+  EXPECT_EQ('a', result);
+}
+
+TEST(SaveArgPointeeActionTest, WorksForSameType) {
+  int result = 0;
+  const int value = 5;
+  const Action<void(const int*)> a1 = SaveArgPointee<0>(&result);
+  a1.Perform(std::make_tuple(&value));
+  EXPECT_EQ(5, result);
+}
+
+TEST(SaveArgPointeeActionTest, WorksForCompatibleType) {
+  int result = 0;
+  char value = 'a';
+  const Action<void(bool, char*)> a1 = SaveArgPointee<1>(&result);
+  a1.Perform(std::make_tuple(true, &value));
+  EXPECT_EQ('a', result);
+}
+
+TEST(SetArgRefereeActionTest, WorksForSameType) {
+  int value = 0;
+  const Action<void(int&)> a1 = SetArgReferee<0>(1);
+  a1.Perform(std::tuple<int&>(value));
+  EXPECT_EQ(1, value);
+}
+
+TEST(SetArgRefereeActionTest, WorksForCompatibleType) {
+  int value = 0;
+  const Action<void(int, int&)> a1 = SetArgReferee<1>('a');
+  a1.Perform(std::tuple<int, int&>(0, value));
+  EXPECT_EQ('a', value);
+}
+
+TEST(SetArgRefereeActionTest, WorksWithExtraArguments) {
+  int value = 0;
+  const Action<void(bool, int, int&, const char*)> a1 = SetArgReferee<2>('a');
+  a1.Perform(std::tuple<bool, int, int&, const char*>(true, 0, value, "hi"));
+  EXPECT_EQ('a', value);
+}
+
+// A class that can be used to verify that its destructor is called: it will set
+// the bool provided to the constructor to true when destroyed.
+class DeletionTester {
+ public:
+  explicit DeletionTester(bool* is_deleted) : is_deleted_(is_deleted) {
+    // Make sure the bit is set to false.
+    *is_deleted_ = false;
+  }
+
+  ~DeletionTester() { *is_deleted_ = true; }
+
+ private:
+  bool* is_deleted_;
+};
+
+TEST(DeleteArgActionTest, OneArg) {
+  bool is_deleted = false;
+  DeletionTester* t = new DeletionTester(&is_deleted);
+  const Action<void(DeletionTester*)> a1 = DeleteArg<0>();  // NOLINT
+  EXPECT_FALSE(is_deleted);
+  a1.Perform(std::make_tuple(t));
+  EXPECT_TRUE(is_deleted);
+}
+
+TEST(DeleteArgActionTest, TenArgs) {
+  bool is_deleted = false;
+  DeletionTester* t = new DeletionTester(&is_deleted);
+  const Action<void(bool, int, int, const char*, bool, int, int, int, int,
+                    DeletionTester*)>
+      a1 = DeleteArg<9>();
+  EXPECT_FALSE(is_deleted);
+  a1.Perform(std::make_tuple(true, 5, 6, CharPtr("hi"), false, 7, 8, 9, 10, t));
+  EXPECT_TRUE(is_deleted);
+}
+
+#if GTEST_HAS_EXCEPTIONS
+
+TEST(ThrowActionTest, ThrowsGivenExceptionInVoidFunction) {
+  const Action<void(int n)> a = Throw('a');
+  EXPECT_THROW(a.Perform(std::make_tuple(0)), char);
+}
+
+class MyException {};
+
+TEST(ThrowActionTest, ThrowsGivenExceptionInNonVoidFunction) {
+  const Action<double(char ch)> a = Throw(MyException());
+  EXPECT_THROW(a.Perform(std::make_tuple('0')), MyException);
+}
+
+TEST(ThrowActionTest, ThrowsGivenExceptionInNullaryFunction) {
+  const Action<double()> a = Throw(MyException());
+  EXPECT_THROW(a.Perform(std::make_tuple()), MyException);
+}
+
+class Object {
+ public:
+  virtual ~Object() {}
+  virtual void Func() {}
+};
+
+class MockObject : public Object {
+ public:
+  ~MockObject() override {}
+  MOCK_METHOD(void, Func, (), (override));
+};
+
+TEST(ThrowActionTest, Times0) {
+  EXPECT_NONFATAL_FAILURE(
+      [] {
+        try {
+          MockObject m;
+          ON_CALL(m, Func()).WillByDefault([] { throw "something"; });
+          EXPECT_CALL(m, Func()).Times(0);
+          m.Func();
+        } catch (...) {
+          // Exception is caught but Times(0) still triggers a failure.
+        }
+      }(),
+      "");
+}
+
+#endif  // GTEST_HAS_EXCEPTIONS
+
+// Tests that SetArrayArgument<N>(first, last) sets the elements of the array
+// pointed to by the N-th (0-based) argument to values in range [first, last).
+TEST(SetArrayArgumentTest, SetsTheNthArray) {
+  using MyFunction = void(bool, int*, char*);
+  int numbers[] = {1, 2, 3};
+  Action<MyFunction> a = SetArrayArgument<1>(numbers, numbers + 3);
+
+  int n[4] = {};
+  int* pn = n;
+  char ch[4] = {};
+  char* pch = ch;
+  a.Perform(std::make_tuple(true, pn, pch));
+  EXPECT_EQ(1, n[0]);
+  EXPECT_EQ(2, n[1]);
+  EXPECT_EQ(3, n[2]);
+  EXPECT_EQ(0, n[3]);
+  EXPECT_EQ('\0', ch[0]);
+  EXPECT_EQ('\0', ch[1]);
+  EXPECT_EQ('\0', ch[2]);
+  EXPECT_EQ('\0', ch[3]);
+
+  // Tests first and last are iterators.
+  std::string letters = "abc";
+  a = SetArrayArgument<2>(letters.begin(), letters.end());
+  std::fill_n(n, 4, 0);
+  std::fill_n(ch, 4, '\0');
+  a.Perform(std::make_tuple(true, pn, pch));
+  EXPECT_EQ(0, n[0]);
+  EXPECT_EQ(0, n[1]);
+  EXPECT_EQ(0, n[2]);
+  EXPECT_EQ(0, n[3]);
+  EXPECT_EQ('a', ch[0]);
+  EXPECT_EQ('b', ch[1]);
+  EXPECT_EQ('c', ch[2]);
+  EXPECT_EQ('\0', ch[3]);
+}
+
+// Tests SetArrayArgument<N>(first, last) where first == last.
+TEST(SetArrayArgumentTest, SetsTheNthArrayWithEmptyRange) {
+  using MyFunction = void(bool, int*);
+  int numbers[] = {1, 2, 3};
+  Action<MyFunction> a = SetArrayArgument<1>(numbers, numbers);
+
+  int n[4] = {};
+  int* pn = n;
+  a.Perform(std::make_tuple(true, pn));
+  EXPECT_EQ(0, n[0]);
+  EXPECT_EQ(0, n[1]);
+  EXPECT_EQ(0, n[2]);
+  EXPECT_EQ(0, n[3]);
+}
+
+// Tests SetArrayArgument<N>(first, last) where *first is convertible
+// (but not equal) to the argument type.
+TEST(SetArrayArgumentTest, SetsTheNthArrayWithConvertibleType) {
+  using MyFunction = void(bool, int*);
+  char chars[] = {97, 98, 99};
+  Action<MyFunction> a = SetArrayArgument<1>(chars, chars + 3);
+
+  int codes[4] = {111, 222, 333, 444};
+  int* pcodes = codes;
+  a.Perform(std::make_tuple(true, pcodes));
+  EXPECT_EQ(97, codes[0]);
+  EXPECT_EQ(98, codes[1]);
+  EXPECT_EQ(99, codes[2]);
+  EXPECT_EQ(444, codes[3]);
+}
+
+// Test SetArrayArgument<N>(first, last) with iterator as argument.
+TEST(SetArrayArgumentTest, SetsTheNthArrayWithIteratorArgument) {
+  using MyFunction = void(bool, std::back_insert_iterator<std::string>);
+  std::string letters = "abc";
+  Action<MyFunction> a = SetArrayArgument<1>(letters.begin(), letters.end());
+
+  std::string s;
+  a.Perform(std::make_tuple(true, std::back_inserter(s)));
+  EXPECT_EQ(letters, s);
+}
+
+TEST(ReturnPointeeTest, Works) {
+  int n = 42;
+  const Action<int()> a = ReturnPointee(&n);
+  EXPECT_EQ(42, a.Perform(std::make_tuple()));
+
+  n = 43;
+  EXPECT_EQ(43, a.Perform(std::make_tuple()));
+}
+
+// Tests InvokeArgument<N>(...).
+
+// Tests using InvokeArgument with a nullary function.
+TEST(InvokeArgumentTest, Function0) {
+  Action<int(int, int (*)())> a = InvokeArgument<1>();  // NOLINT
+  EXPECT_EQ(1, a.Perform(std::make_tuple(2, &Nullary)));
+}
+
+// Tests using InvokeArgument with a unary function.
+TEST(InvokeArgumentTest, Functor1) {
+  Action<int(UnaryFunctor)> a = InvokeArgument<0>(true);  // NOLINT
+  EXPECT_EQ(1, a.Perform(std::make_tuple(UnaryFunctor())));
+}
+
+// Tests using InvokeArgument with a 5-ary function.
+TEST(InvokeArgumentTest, Function5) {
+  Action<int(int (*)(int, int, int, int, int))> a =  // NOLINT
+      InvokeArgument<0>(10000, 2000, 300, 40, 5);
+  EXPECT_EQ(12345, a.Perform(std::make_tuple(&SumOf5)));
+}
+
+// Tests using InvokeArgument with a 5-ary functor.
+TEST(InvokeArgumentTest, Functor5) {
+  Action<int(SumOf5Functor)> a =  // NOLINT
+      InvokeArgument<0>(10000, 2000, 300, 40, 5);
+  EXPECT_EQ(12345, a.Perform(std::make_tuple(SumOf5Functor())));
+}
+
+// Tests using InvokeArgument with a 6-ary function.
+TEST(InvokeArgumentTest, Function6) {
+  Action<int(int (*)(int, int, int, int, int, int))> a =  // NOLINT
+      InvokeArgument<0>(100000, 20000, 3000, 400, 50, 6);
+  EXPECT_EQ(123456, a.Perform(std::make_tuple(&SumOf6)));
+}
+
+// Tests using InvokeArgument with a 6-ary functor.
+TEST(InvokeArgumentTest, Functor6) {
+  Action<int(SumOf6Functor)> a =  // NOLINT
+      InvokeArgument<0>(100000, 20000, 3000, 400, 50, 6);
+  EXPECT_EQ(123456, a.Perform(std::make_tuple(SumOf6Functor())));
+}
+
+// Tests using InvokeArgument with a 7-ary function.
+TEST(InvokeArgumentTest, Function7) {
+  Action<std::string(std::string(*)(const char*, const char*, const char*,
+                                    const char*, const char*, const char*,
+                                    const char*))>
+      a = InvokeArgument<0>("1", "2", "3", "4", "5", "6", "7");
+  EXPECT_EQ("1234567", a.Perform(std::make_tuple(&Concat7)));
+}
+
+// Tests using InvokeArgument with a 8-ary function.
+TEST(InvokeArgumentTest, Function8) {
+  Action<std::string(std::string(*)(const char*, const char*, const char*,
+                                    const char*, const char*, const char*,
+                                    const char*, const char*))>
+      a = InvokeArgument<0>("1", "2", "3", "4", "5", "6", "7", "8");
+  EXPECT_EQ("12345678", a.Perform(std::make_tuple(&Concat8)));
+}
+
+// Tests using InvokeArgument with a 9-ary function.
+TEST(InvokeArgumentTest, Function9) {
+  Action<std::string(std::string(*)(const char*, const char*, const char*,
+                                    const char*, const char*, const char*,
+                                    const char*, const char*, const char*))>
+      a = InvokeArgument<0>("1", "2", "3", "4", "5", "6", "7", "8", "9");
+  EXPECT_EQ("123456789", a.Perform(std::make_tuple(&Concat9)));
+}
+
+// Tests using InvokeArgument with a 10-ary function.
+TEST(InvokeArgumentTest, Function10) {
+  Action<std::string(std::string(*)(
+      const char*, const char*, const char*, const char*, const char*,
+      const char*, const char*, const char*, const char*, const char*))>
+      a = InvokeArgument<0>("1", "2", "3", "4", "5", "6", "7", "8", "9", "0");
+  EXPECT_EQ("1234567890", a.Perform(std::make_tuple(&Concat10)));
+}
+
+// Tests using InvokeArgument with a function that takes a pointer argument.
+TEST(InvokeArgumentTest, ByPointerFunction) {
+  Action<const char*(const char* (*)(const char* input, short n))>  // NOLINT
+      a = InvokeArgument<0>(static_cast<const char*>("Hi"), Short(1));
+  EXPECT_STREQ("i", a.Perform(std::make_tuple(&Binary)));
+}
+
+// Tests using InvokeArgument with a function that takes a const char*
+// by passing it a C-string literal.
+TEST(InvokeArgumentTest, FunctionWithCStringLiteral) {
+  Action<const char*(const char* (*)(const char* input, short n))>  // NOLINT
+      a = InvokeArgument<0>("Hi", Short(1));
+  EXPECT_STREQ("i", a.Perform(std::make_tuple(&Binary)));
+}
+
+// Tests using InvokeArgument with a function that takes a const reference.
+TEST(InvokeArgumentTest, ByConstReferenceFunction) {
+  Action<bool(bool (*function)(const std::string& s))> a =  // NOLINT
+      InvokeArgument<0>(std::string("Hi"));
+  // When action 'a' is constructed, it makes a copy of the temporary
+  // string object passed to it, so it's OK to use 'a' later, when the
+  // temporary object has already died.
+  EXPECT_TRUE(a.Perform(std::make_tuple(&ByConstRef)));
+}
+
+// Tests using InvokeArgument with ByRef() and a function that takes a
+// const reference.
+TEST(InvokeArgumentTest, ByExplicitConstReferenceFunction) {
+  Action<bool(bool (*)(const double& x))> a =  // NOLINT
+      InvokeArgument<0>(ByRef(g_double));
+  // The above line calls ByRef() on a const value.
+  EXPECT_TRUE(a.Perform(std::make_tuple(&ReferencesGlobalDouble)));
+
+  double x = 0;
+  a = InvokeArgument<0>(ByRef(x));  // This calls ByRef() on a non-const.
+  EXPECT_FALSE(a.Perform(std::make_tuple(&ReferencesGlobalDouble)));
+}
+
+// Tests DoAll(a1, a2).
+TEST(DoAllTest, TwoActions) {
+  int n = 0;
+  Action<int(int*)> a = DoAll(SetArgPointee<0>(1),  // NOLINT
+                              Return(2));
+  EXPECT_EQ(2, a.Perform(std::make_tuple(&n)));
+  EXPECT_EQ(1, n);
+}
+
+// Tests DoAll(a1, a2, a3).
+TEST(DoAllTest, ThreeActions) {
+  int m = 0, n = 0;
+  Action<int(int*, int*)> a = DoAll(SetArgPointee<0>(1),  // NOLINT
+                                    SetArgPointee<1>(2), Return(3));
+  EXPECT_EQ(3, a.Perform(std::make_tuple(&m, &n)));
+  EXPECT_EQ(1, m);
+  EXPECT_EQ(2, n);
+}
+
+// Tests DoAll(a1, a2, a3, a4).
+TEST(DoAllTest, FourActions) {
+  int m = 0, n = 0;
+  char ch = '\0';
+  Action<int(int*, int*, char*)> a =  // NOLINT
+      DoAll(SetArgPointee<0>(1), SetArgPointee<1>(2), SetArgPointee<2>('a'),
+            Return(3));
+  EXPECT_EQ(3, a.Perform(std::make_tuple(&m, &n, &ch)));
+  EXPECT_EQ(1, m);
+  EXPECT_EQ(2, n);
+  EXPECT_EQ('a', ch);
+}
+
+// Tests DoAll(a1, a2, a3, a4, a5).
+TEST(DoAllTest, FiveActions) {
+  int m = 0, n = 0;
+  char a = '\0', b = '\0';
+  Action<int(int*, int*, char*, char*)> action =  // NOLINT
+      DoAll(SetArgPointee<0>(1), SetArgPointee<1>(2), SetArgPointee<2>('a'),
+            SetArgPointee<3>('b'), Return(3));
+  EXPECT_EQ(3, action.Perform(std::make_tuple(&m, &n, &a, &b)));
+  EXPECT_EQ(1, m);
+  EXPECT_EQ(2, n);
+  EXPECT_EQ('a', a);
+  EXPECT_EQ('b', b);
+}
+
+// Tests DoAll(a1, a2, ..., a6).
+TEST(DoAllTest, SixActions) {
+  int m = 0, n = 0;
+  char a = '\0', b = '\0', c = '\0';
+  Action<int(int*, int*, char*, char*, char*)> action =  // NOLINT
+      DoAll(SetArgPointee<0>(1), SetArgPointee<1>(2), SetArgPointee<2>('a'),
+            SetArgPointee<3>('b'), SetArgPointee<4>('c'), Return(3));
+  EXPECT_EQ(3, action.Perform(std::make_tuple(&m, &n, &a, &b, &c)));
+  EXPECT_EQ(1, m);
+  EXPECT_EQ(2, n);
+  EXPECT_EQ('a', a);
+  EXPECT_EQ('b', b);
+  EXPECT_EQ('c', c);
+}
+
+// Tests DoAll(a1, a2, ..., a7).
+TEST(DoAllTest, SevenActions) {
+  int m = 0, n = 0;
+  char a = '\0', b = '\0', c = '\0', d = '\0';
+  Action<int(int*, int*, char*, char*, char*, char*)> action =  // NOLINT
+      DoAll(SetArgPointee<0>(1), SetArgPointee<1>(2), SetArgPointee<2>('a'),
+            SetArgPointee<3>('b'), SetArgPointee<4>('c'), SetArgPointee<5>('d'),
+            Return(3));
+  EXPECT_EQ(3, action.Perform(std::make_tuple(&m, &n, &a, &b, &c, &d)));
+  EXPECT_EQ(1, m);
+  EXPECT_EQ(2, n);
+  EXPECT_EQ('a', a);
+  EXPECT_EQ('b', b);
+  EXPECT_EQ('c', c);
+  EXPECT_EQ('d', d);
+}
+
+// Tests DoAll(a1, a2, ..., a8).
+TEST(DoAllTest, EightActions) {
+  int m = 0, n = 0;
+  char a = '\0', b = '\0', c = '\0', d = '\0', e = '\0';
+  Action<int(int*, int*, char*, char*, char*, char*,  // NOLINT
+             char*)>
+      action =
+          DoAll(SetArgPointee<0>(1), SetArgPointee<1>(2), SetArgPointee<2>('a'),
+                SetArgPointee<3>('b'), SetArgPointee<4>('c'),
+                SetArgPointee<5>('d'), SetArgPointee<6>('e'), Return(3));
+  EXPECT_EQ(3, action.Perform(std::make_tuple(&m, &n, &a, &b, &c, &d, &e)));
+  EXPECT_EQ(1, m);
+  EXPECT_EQ(2, n);
+  EXPECT_EQ('a', a);
+  EXPECT_EQ('b', b);
+  EXPECT_EQ('c', c);
+  EXPECT_EQ('d', d);
+  EXPECT_EQ('e', e);
+}
+
+// Tests DoAll(a1, a2, ..., a9).
+TEST(DoAllTest, NineActions) {
+  int m = 0, n = 0;
+  char a = '\0', b = '\0', c = '\0', d = '\0', e = '\0', f = '\0';
+  Action<int(int*, int*, char*, char*, char*, char*,  // NOLINT
+             char*, char*)>
+      action = DoAll(SetArgPointee<0>(1), SetArgPointee<1>(2),
+                     SetArgPointee<2>('a'), SetArgPointee<3>('b'),
+                     SetArgPointee<4>('c'), SetArgPointee<5>('d'),
+                     SetArgPointee<6>('e'), SetArgPointee<7>('f'), Return(3));
+  EXPECT_EQ(3, action.Perform(std::make_tuple(&m, &n, &a, &b, &c, &d, &e, &f)));
+  EXPECT_EQ(1, m);
+  EXPECT_EQ(2, n);
+  EXPECT_EQ('a', a);
+  EXPECT_EQ('b', b);
+  EXPECT_EQ('c', c);
+  EXPECT_EQ('d', d);
+  EXPECT_EQ('e', e);
+  EXPECT_EQ('f', f);
+}
+
+// Tests DoAll(a1, a2, ..., a10).
+TEST(DoAllTest, TenActions) {
+  int m = 0, n = 0;
+  char a = '\0', b = '\0', c = '\0', d = '\0';
+  char e = '\0', f = '\0', g = '\0';
+  Action<int(int*, int*, char*, char*, char*, char*,  // NOLINT
+             char*, char*, char*)>
+      action =
+          DoAll(SetArgPointee<0>(1), SetArgPointee<1>(2), SetArgPointee<2>('a'),
+                SetArgPointee<3>('b'), SetArgPointee<4>('c'),
+                SetArgPointee<5>('d'), SetArgPointee<6>('e'),
+                SetArgPointee<7>('f'), SetArgPointee<8>('g'), Return(3));
+  EXPECT_EQ(
+      3, action.Perform(std::make_tuple(&m, &n, &a, &b, &c, &d, &e, &f, &g)));
+  EXPECT_EQ(1, m);
+  EXPECT_EQ(2, n);
+  EXPECT_EQ('a', a);
+  EXPECT_EQ('b', b);
+  EXPECT_EQ('c', c);
+  EXPECT_EQ('d', d);
+  EXPECT_EQ('e', e);
+  EXPECT_EQ('f', f);
+  EXPECT_EQ('g', g);
+}
+
+TEST(DoAllTest, NoArgs) {
+  bool ran_first = false;
+  Action<bool()> a =
+      DoAll([&] { ran_first = true; }, [&] { return ran_first; });
+  EXPECT_TRUE(a.Perform({}));
+}
+
+TEST(DoAllTest, MoveOnlyArgs) {
+  bool ran_first = false;
+  Action<int(std::unique_ptr<int>)> a =
+      DoAll(InvokeWithoutArgs([&] { ran_first = true; }),
+            [](std::unique_ptr<int> p) { return *p; });
+  EXPECT_EQ(7, a.Perform(std::make_tuple(std::unique_ptr<int>(new int(7)))));
+  EXPECT_TRUE(ran_first);
+}
+
+TEST(DoAllTest, ImplicitlyConvertsActionArguments) {
+  bool ran_first = false;
+  // Action<void(std::vector<int>)> isn't an
+  // Action<void(const std::vector<int>&) but can be converted.
+  Action<void(std::vector<int>)> first = [&] { ran_first = true; };
+  Action<int(std::vector<int>)> a =
+      DoAll(first, [](std::vector<int> arg) { return arg.front(); });
+  EXPECT_EQ(7, a.Perform(std::make_tuple(std::vector<int>{7})));
+  EXPECT_TRUE(ran_first);
+}
+
+// The ACTION*() macros trigger warning C4100 (unreferenced formal
+// parameter) in MSVC with -W4.  Unfortunately they cannot be fixed in
+// the macro definition, as the warnings are generated when the macro
+// is expanded and macro expansion cannot contain #pragma.  Therefore
+// we suppress them here.
+// Also suppress C4503 decorated name length exceeded, name was truncated
+GTEST_DISABLE_MSC_WARNINGS_PUSH_(4100 4503)
+// Tests the ACTION*() macro family.
+
+// Tests that ACTION() can define an action that doesn't reference the
+// mock function arguments.
+ACTION(Return5) { return 5; }
+
+TEST(ActionMacroTest, WorksWhenNotReferencingArguments) {
+  Action<double()> a1 = Return5();
+  EXPECT_DOUBLE_EQ(5, a1.Perform(std::make_tuple()));
+
+  Action<int(double, bool)> a2 = Return5();
+  EXPECT_EQ(5, a2.Perform(std::make_tuple(1, true)));
+}
+
+// Tests that ACTION() can define an action that returns void.
+ACTION(IncrementArg1) { (*arg1)++; }
+
+TEST(ActionMacroTest, WorksWhenReturningVoid) {
+  Action<void(int, int*)> a1 = IncrementArg1();
+  int n = 0;
+  a1.Perform(std::make_tuple(5, &n));
+  EXPECT_EQ(1, n);
+}
+
+// Tests that the body of ACTION() can reference the type of the
+// argument.
+ACTION(IncrementArg2) {
+  StaticAssertTypeEq<int*, arg2_type>();
+  arg2_type temp = arg2;
+  (*temp)++;
+}
+
+TEST(ActionMacroTest, CanReferenceArgumentType) {
+  Action<void(int, bool, int*)> a1 = IncrementArg2();
+  int n = 0;
+  a1.Perform(std::make_tuple(5, false, &n));
+  EXPECT_EQ(1, n);
+}
+
+// Tests that the body of ACTION() can reference the argument tuple
+// via args_type and args.
+ACTION(Sum2) {
+  StaticAssertTypeEq<std::tuple<int, char, int*>, args_type>();
+  args_type args_copy = args;
+  return std::get<0>(args_copy) + std::get<1>(args_copy);
+}
+
+TEST(ActionMacroTest, CanReferenceArgumentTuple) {
+  Action<int(int, char, int*)> a1 = Sum2();
+  int dummy = 0;
+  EXPECT_EQ(11, a1.Perform(std::make_tuple(5, Char(6), &dummy)));
+}
+
+namespace {
+
+// Tests that the body of ACTION() can reference the mock function
+// type.
+int Dummy(bool flag) { return flag ? 1 : 0; }
+
+}  // namespace
+
+ACTION(InvokeDummy) {
+  StaticAssertTypeEq<int(bool), function_type>();
+  function_type* fp = &Dummy;
+  return (*fp)(true);
+}
+
+TEST(ActionMacroTest, CanReferenceMockFunctionType) {
+  Action<int(bool)> a1 = InvokeDummy();
+  EXPECT_EQ(1, a1.Perform(std::make_tuple(true)));
+  EXPECT_EQ(1, a1.Perform(std::make_tuple(false)));
+}
+
+// Tests that the body of ACTION() can reference the mock function's
+// return type.
+ACTION(InvokeDummy2) {
+  StaticAssertTypeEq<int, return_type>();
+  return_type result = Dummy(true);
+  return result;
+}
+
+TEST(ActionMacroTest, CanReferenceMockFunctionReturnType) {
+  Action<int(bool)> a1 = InvokeDummy2();
+  EXPECT_EQ(1, a1.Perform(std::make_tuple(true)));
+  EXPECT_EQ(1, a1.Perform(std::make_tuple(false)));
+}
+
+// Tests that ACTION() works for arguments passed by const reference.
+ACTION(ReturnAddrOfConstBoolReferenceArg) {
+  StaticAssertTypeEq<const bool&, arg1_type>();
+  return &arg1;
+}
+
+TEST(ActionMacroTest, WorksForConstReferenceArg) {
+  Action<const bool*(int, const bool&)> a = ReturnAddrOfConstBoolReferenceArg();
+  const bool b = false;
+  EXPECT_EQ(&b, a.Perform(std::tuple<int, const bool&>(0, b)));
+}
+
+// Tests that ACTION() works for arguments passed by non-const reference.
+ACTION(ReturnAddrOfIntReferenceArg) {
+  StaticAssertTypeEq<int&, arg0_type>();
+  return &arg0;
+}
+
+TEST(ActionMacroTest, WorksForNonConstReferenceArg) {
+  Action<int*(int&, bool, int)> a = ReturnAddrOfIntReferenceArg();
+  int n = 0;
+  EXPECT_EQ(&n, a.Perform(std::tuple<int&, bool, int>(n, true, 1)));
+}
+
+// Tests that ACTION() can be used in a namespace.
+namespace action_test {
+ACTION(Sum) { return arg0 + arg1; }
+}  // namespace action_test
+
+TEST(ActionMacroTest, WorksInNamespace) {
+  Action<int(int, int)> a1 = action_test::Sum();
+  EXPECT_EQ(3, a1.Perform(std::make_tuple(1, 2)));
+}
+
+// Tests that the same ACTION definition works for mock functions with
+// different argument numbers.
+ACTION(PlusTwo) { return arg0 + 2; }
+
+TEST(ActionMacroTest, WorksForDifferentArgumentNumbers) {
+  Action<int(int)> a1 = PlusTwo();
+  EXPECT_EQ(4, a1.Perform(std::make_tuple(2)));
+
+  Action<double(float, void*)> a2 = PlusTwo();
+  int dummy;
+  EXPECT_DOUBLE_EQ(6, a2.Perform(std::make_tuple(4.0f, &dummy)));
+}
+
+// Tests that ACTION_P can define a parameterized action.
+ACTION_P(Plus, n) { return arg0 + n; }
+
+TEST(ActionPMacroTest, DefinesParameterizedAction) {
+  Action<int(int m, bool t)> a1 = Plus(9);
+  EXPECT_EQ(10, a1.Perform(std::make_tuple(1, true)));
+}
+
+// Tests that the body of ACTION_P can reference the argument types
+// and the parameter type.
+ACTION_P(TypedPlus, n) {
+  arg0_type t1 = arg0;
+  n_type t2 = n;
+  return t1 + t2;
+}
+
+TEST(ActionPMacroTest, CanReferenceArgumentAndParameterTypes) {
+  Action<int(char m, bool t)> a1 = TypedPlus(9);
+  EXPECT_EQ(10, a1.Perform(std::make_tuple(Char(1), true)));
+}
+
+// Tests that a parameterized action can be used in any mock function
+// whose type is compatible.
+TEST(ActionPMacroTest, WorksInCompatibleMockFunction) {
+  Action<std::string(const std::string& s)> a1 = Plus("tail");
+  const std::string re = "re";
+  std::tuple<const std::string> dummy = std::make_tuple(re);
+  EXPECT_EQ("retail", a1.Perform(dummy));
+}
+
+// Tests that we can use ACTION*() to define actions overloaded on the
+// number of parameters.
+
+ACTION(OverloadedAction) { return arg0 ? arg1 : "hello"; }
+
+ACTION_P(OverloadedAction, default_value) {
+  return arg0 ? arg1 : default_value;
+}
+
+ACTION_P2(OverloadedAction, true_value, false_value) {
+  return arg0 ? true_value : false_value;
+}
+
+TEST(ActionMacroTest, CanDefineOverloadedActions) {
+  using MyAction = Action<const char*(bool, const char*)>;
+
+  const MyAction a1 = OverloadedAction();
+  EXPECT_STREQ("hello", a1.Perform(std::make_tuple(false, CharPtr("world"))));
+  EXPECT_STREQ("world", a1.Perform(std::make_tuple(true, CharPtr("world"))));
+
+  const MyAction a2 = OverloadedAction("hi");
+  EXPECT_STREQ("hi", a2.Perform(std::make_tuple(false, CharPtr("world"))));
+  EXPECT_STREQ("world", a2.Perform(std::make_tuple(true, CharPtr("world"))));
+
+  const MyAction a3 = OverloadedAction("hi", "you");
+  EXPECT_STREQ("hi", a3.Perform(std::make_tuple(true, CharPtr("world"))));
+  EXPECT_STREQ("you", a3.Perform(std::make_tuple(false, CharPtr("world"))));
+}
+
+// Tests ACTION_Pn where n >= 3.
+
+ACTION_P3(Plus, m, n, k) { return arg0 + m + n + k; }
+
+TEST(ActionPnMacroTest, WorksFor3Parameters) {
+  Action<double(int m, bool t)> a1 = Plus(100, 20, 3.4);
+  EXPECT_DOUBLE_EQ(3123.4, a1.Perform(std::make_tuple(3000, true)));
+
+  Action<std::string(const std::string& s)> a2 = Plus("tail", "-", ">");
+  const std::string re = "re";
+  std::tuple<const std::string> dummy = std::make_tuple(re);
+  EXPECT_EQ("retail->", a2.Perform(dummy));
+}
+
+ACTION_P4(Plus, p0, p1, p2, p3) { return arg0 + p0 + p1 + p2 + p3; }
+
+TEST(ActionPnMacroTest, WorksFor4Parameters) {
+  Action<int(int)> a1 = Plus(1, 2, 3, 4);
+  EXPECT_EQ(10 + 1 + 2 + 3 + 4, a1.Perform(std::make_tuple(10)));
+}
+
+ACTION_P5(Plus, p0, p1, p2, p3, p4) { return arg0 + p0 + p1 + p2 + p3 + p4; }
+
+TEST(ActionPnMacroTest, WorksFor5Parameters) {
+  Action<int(int)> a1 = Plus(1, 2, 3, 4, 5);
+  EXPECT_EQ(10 + 1 + 2 + 3 + 4 + 5, a1.Perform(std::make_tuple(10)));
+}
+
+ACTION_P6(Plus, p0, p1, p2, p3, p4, p5) {
+  return arg0 + p0 + p1 + p2 + p3 + p4 + p5;
+}
+
+TEST(ActionPnMacroTest, WorksFor6Parameters) {
+  Action<int(int)> a1 = Plus(1, 2, 3, 4, 5, 6);
+  EXPECT_EQ(10 + 1 + 2 + 3 + 4 + 5 + 6, a1.Perform(std::make_tuple(10)));
+}
+
+ACTION_P7(Plus, p0, p1, p2, p3, p4, p5, p6) {
+  return arg0 + p0 + p1 + p2 + p3 + p4 + p5 + p6;
+}
+
+TEST(ActionPnMacroTest, WorksFor7Parameters) {
+  Action<int(int)> a1 = Plus(1, 2, 3, 4, 5, 6, 7);
+  EXPECT_EQ(10 + 1 + 2 + 3 + 4 + 5 + 6 + 7, a1.Perform(std::make_tuple(10)));
+}
+
+ACTION_P8(Plus, p0, p1, p2, p3, p4, p5, p6, p7) {
+  return arg0 + p0 + p1 + p2 + p3 + p4 + p5 + p6 + p7;
+}
+
+TEST(ActionPnMacroTest, WorksFor8Parameters) {
+  Action<int(int)> a1 = Plus(1, 2, 3, 4, 5, 6, 7, 8);
+  EXPECT_EQ(10 + 1 + 2 + 3 + 4 + 5 + 6 + 7 + 8,
+            a1.Perform(std::make_tuple(10)));
+}
+
+ACTION_P9(Plus, p0, p1, p2, p3, p4, p5, p6, p7, p8) {
+  return arg0 + p0 + p1 + p2 + p3 + p4 + p5 + p6 + p7 + p8;
+}
+
+TEST(ActionPnMacroTest, WorksFor9Parameters) {
+  Action<int(int)> a1 = Plus(1, 2, 3, 4, 5, 6, 7, 8, 9);
+  EXPECT_EQ(10 + 1 + 2 + 3 + 4 + 5 + 6 + 7 + 8 + 9,
+            a1.Perform(std::make_tuple(10)));
+}
+
+ACTION_P10(Plus, p0, p1, p2, p3, p4, p5, p6, p7, p8, last_param) {
+  arg0_type t0 = arg0;
+  last_param_type t9 = last_param;
+  return t0 + p0 + p1 + p2 + p3 + p4 + p5 + p6 + p7 + p8 + t9;
+}
+
+TEST(ActionPnMacroTest, WorksFor10Parameters) {
+  Action<int(int)> a1 = Plus(1, 2, 3, 4, 5, 6, 7, 8, 9, 10);
+  EXPECT_EQ(10 + 1 + 2 + 3 + 4 + 5 + 6 + 7 + 8 + 9 + 10,
+            a1.Perform(std::make_tuple(10)));
+}
+
+// Tests that the action body can promote the parameter types.
+
+ACTION_P2(PadArgument, prefix, suffix) {
+  // The following lines promote the two parameters to desired types.
+  std::string prefix_str(prefix);
+  char suffix_char = static_cast<char>(suffix);
+  return prefix_str + arg0 + suffix_char;
+}
+
+TEST(ActionPnMacroTest, SimpleTypePromotion) {
+  Action<std::string(const char*)> no_promo =
+      PadArgument(std::string("foo"), 'r');
+  Action<std::string(const char*)> promo =
+      PadArgument("foo", static_cast<int>('r'));
+  EXPECT_EQ("foobar", no_promo.Perform(std::make_tuple(CharPtr("ba"))));
+  EXPECT_EQ("foobar", promo.Perform(std::make_tuple(CharPtr("ba"))));
+}
+
+// Tests that we can partially restrict parameter types using a
+// straight-forward pattern.
+
+// Defines a generic action that doesn't restrict the types of its
+// parameters.
+ACTION_P3(ConcatImpl, a, b, c) {
+  std::stringstream ss;
+  ss << a << b << c;
+  return ss.str();
+}
+
+// Next, we try to restrict that either the first parameter is a
+// string, or the second parameter is an int.
+
+// Defines a partially specialized wrapper that restricts the first
+// parameter to std::string.
+template <typename T1, typename T2>
+// ConcatImplActionP3 is the class template ACTION_P3 uses to
+// implement ConcatImpl.  We shouldn't change the name as this
+// pattern requires the user to use it directly.
+ConcatImplActionP3<std::string, T1, T2> Concat(const std::string& a, T1 b,
+                                               T2 c) {
+  GTEST_INTENTIONAL_CONST_COND_PUSH_()
+  if (true) {
+    GTEST_INTENTIONAL_CONST_COND_POP_()
+    // This branch verifies that ConcatImpl() can be invoked without
+    // explicit template arguments.
+    return ConcatImpl(a, b, c);
+  } else {
+    // This branch verifies that ConcatImpl() can also be invoked with
+    // explicit template arguments.  It doesn't really need to be
+    // executed as this is a compile-time verification.
+    return ConcatImpl<std::string, T1, T2>(a, b, c);
+  }
+}
+
+// Defines another partially specialized wrapper that restricts the
+// second parameter to int.
+template <typename T1, typename T2>
+ConcatImplActionP3<T1, int, T2> Concat(T1 a, int b, T2 c) {
+  return ConcatImpl(a, b, c);
+}
+
+TEST(ActionPnMacroTest, CanPartiallyRestrictParameterTypes) {
+  Action<const std::string()> a1 = Concat("Hello", "1", 2);
+  EXPECT_EQ("Hello12", a1.Perform(std::make_tuple()));
+
+  a1 = Concat(1, 2, 3);
+  EXPECT_EQ("123", a1.Perform(std::make_tuple()));
+}
+
+// Verifies the type of an ACTION*.
+
+ACTION(DoFoo) {}
+ACTION_P(DoFoo, p) {}
+ACTION_P2(DoFoo, p0, p1) {}
+
+TEST(ActionPnMacroTest, TypesAreCorrect) {
+  // DoFoo() must be assignable to a DoFooAction variable.
+  DoFooAction a0 = DoFoo();
+
+  // DoFoo(1) must be assignable to a DoFooActionP variable.
+  DoFooActionP<int> a1 = DoFoo(1);
+
+  // DoFoo(p1, ..., pk) must be assignable to a DoFooActionPk
+  // variable, and so on.
+  DoFooActionP2<int, char> a2 = DoFoo(1, '2');
+  PlusActionP3<int, int, char> a3 = Plus(1, 2, '3');
+  PlusActionP4<int, int, int, char> a4 = Plus(1, 2, 3, '4');
+  PlusActionP5<int, int, int, int, char> a5 = Plus(1, 2, 3, 4, '5');
+  PlusActionP6<int, int, int, int, int, char> a6 = Plus(1, 2, 3, 4, 5, '6');
+  PlusActionP7<int, int, int, int, int, int, char> a7 =
+      Plus(1, 2, 3, 4, 5, 6, '7');
+  PlusActionP8<int, int, int, int, int, int, int, char> a8 =
+      Plus(1, 2, 3, 4, 5, 6, 7, '8');
+  PlusActionP9<int, int, int, int, int, int, int, int, char> a9 =
+      Plus(1, 2, 3, 4, 5, 6, 7, 8, '9');
+  PlusActionP10<int, int, int, int, int, int, int, int, int, char> a10 =
+      Plus(1, 2, 3, 4, 5, 6, 7, 8, 9, '0');
+
+  // Avoid "unused variable" warnings.
+  (void)a0;
+  (void)a1;
+  (void)a2;
+  (void)a3;
+  (void)a4;
+  (void)a5;
+  (void)a6;
+  (void)a7;
+  (void)a8;
+  (void)a9;
+  (void)a10;
+}
+
+// Tests that an ACTION_P*() action can be explicitly instantiated
+// with reference-typed parameters.
+
+ACTION_P(Plus1, x) { return x; }
+ACTION_P2(Plus2, x, y) { return x + y; }
+ACTION_P3(Plus3, x, y, z) { return x + y + z; }
+ACTION_P10(Plus10, a0, a1, a2, a3, a4, a5, a6, a7, a8, a9) {
+  return a0 + a1 + a2 + a3 + a4 + a5 + a6 + a7 + a8 + a9;
+}
+
+TEST(ActionPnMacroTest, CanExplicitlyInstantiateWithReferenceTypes) {
+  int x = 1, y = 2, z = 3;
+  const std::tuple<> empty = std::make_tuple();
+
+  Action<int()> a = Plus1<int&>(x);
+  EXPECT_EQ(1, a.Perform(empty));
+
+  a = Plus2<const int&, int&>(x, y);
+  EXPECT_EQ(3, a.Perform(empty));
+
+  a = Plus3<int&, const int&, int&>(x, y, z);
+  EXPECT_EQ(6, a.Perform(empty));
+
+  int n[10] = {1, 2, 3, 4, 5, 6, 7, 8, 9, 10};
+  a = Plus10<const int&, int&, const int&, int&, const int&, int&, const int&,
+             int&, const int&, int&>(n[0], n[1], n[2], n[3], n[4], n[5], n[6],
+                                     n[7], n[8], n[9]);
+  EXPECT_EQ(55, a.Perform(empty));
+}
+
+class TenArgConstructorClass {
+ public:
+  TenArgConstructorClass(int a1, int a2, int a3, int a4, int a5, int a6, int a7,
+                         int a8, int a9, int a10)
+      : value_(a1 + a2 + a3 + a4 + a5 + a6 + a7 + a8 + a9 + a10) {}
+  int value_;
+};
+
+// Tests that ACTION_TEMPLATE works when there is no value parameter.
+ACTION_TEMPLATE(CreateNew, HAS_1_TEMPLATE_PARAMS(typename, T),
+                AND_0_VALUE_PARAMS()) {
+  return new T;
+}
+
+TEST(ActionTemplateTest, WorksWithoutValueParam) {
+  const Action<int*()> a = CreateNew<int>();
+  int* p = a.Perform(std::make_tuple());
+  delete p;
+}
+
+// Tests that ACTION_TEMPLATE works when there are value parameters.
+ACTION_TEMPLATE(CreateNew, HAS_1_TEMPLATE_PARAMS(typename, T),
+                AND_1_VALUE_PARAMS(a0)) {
+  return new T(a0);
+}
+
+TEST(ActionTemplateTest, WorksWithValueParams) {
+  const Action<int*()> a = CreateNew<int>(42);
+  int* p = a.Perform(std::make_tuple());
+  EXPECT_EQ(42, *p);
+  delete p;
+}
+
+// Tests that ACTION_TEMPLATE works for integral template parameters.
+ACTION_TEMPLATE(MyDeleteArg, HAS_1_TEMPLATE_PARAMS(int, k),
+                AND_0_VALUE_PARAMS()) {
+  delete std::get<k>(args);
+}
+
+// Resets a bool variable in the destructor.
+class BoolResetter {
+ public:
+  explicit BoolResetter(bool* value) : value_(value) {}
+  ~BoolResetter() { *value_ = false; }
+
+ private:
+  bool* value_;
+};
+
+TEST(ActionTemplateTest, WorksForIntegralTemplateParams) {
+  const Action<void(int*, BoolResetter*)> a = MyDeleteArg<1>();
+  int n = 0;
+  bool b = true;
+  auto* resetter = new BoolResetter(&b);
+  a.Perform(std::make_tuple(&n, resetter));
+  EXPECT_FALSE(b);  // Verifies that resetter is deleted.
+}
+
+// Tests that ACTION_TEMPLATES works for template template parameters.
+ACTION_TEMPLATE(ReturnSmartPointer,
+                HAS_1_TEMPLATE_PARAMS(template <typename Pointee> class,
+                                      Pointer),
+                AND_1_VALUE_PARAMS(pointee)) {
+  return Pointer<pointee_type>(new pointee_type(pointee));
+}
+
+TEST(ActionTemplateTest, WorksForTemplateTemplateParameters) {
+  const Action<std::shared_ptr<int>()> a =
+      ReturnSmartPointer<std::shared_ptr>(42);
+  std::shared_ptr<int> p = a.Perform(std::make_tuple());
+  EXPECT_EQ(42, *p);
+}
+
+// Tests that ACTION_TEMPLATE works for 10 template parameters.
+template <typename T1, typename T2, typename T3, int k4, bool k5,
+          unsigned int k6, typename T7, typename T8, typename T9>
+struct GiantTemplate {
+ public:
+  explicit GiantTemplate(int a_value) : value(a_value) {}
+  int value;
+};
+
+ACTION_TEMPLATE(ReturnGiant,
+                HAS_10_TEMPLATE_PARAMS(typename, T1, typename, T2, typename, T3,
+                                       int, k4, bool, k5, unsigned int, k6,
+                                       class, T7, class, T8, class, T9,
+                                       template <typename T> class, T10),
+                AND_1_VALUE_PARAMS(value)) {
+  return GiantTemplate<T10<T1>, T2, T3, k4, k5, k6, T7, T8, T9>(value);
+}
+
+TEST(ActionTemplateTest, WorksFor10TemplateParameters) {
+  using Giant = GiantTemplate<std::shared_ptr<int>, bool, double, 5, true, 6,
+                              char, unsigned, int>;
+  const Action<Giant()> a = ReturnGiant<int, bool, double, 5, true, 6, char,
+                                        unsigned, int, std::shared_ptr>(42);
+  Giant giant = a.Perform(std::make_tuple());
+  EXPECT_EQ(42, giant.value);
+}
+
+// Tests that ACTION_TEMPLATE works for 10 value parameters.
+ACTION_TEMPLATE(ReturnSum, HAS_1_TEMPLATE_PARAMS(typename, Number),
+                AND_10_VALUE_PARAMS(v1, v2, v3, v4, v5, v6, v7, v8, v9, v10)) {
+  return static_cast<Number>(v1) + v2 + v3 + v4 + v5 + v6 + v7 + v8 + v9 + v10;
+}
+
+TEST(ActionTemplateTest, WorksFor10ValueParameters) {
+  const Action<int()> a = ReturnSum<int>(1, 2, 3, 4, 5, 6, 7, 8, 9, 10);
+  EXPECT_EQ(55, a.Perform(std::make_tuple()));
+}
+
+// Tests that ACTION_TEMPLATE and ACTION/ACTION_P* can be overloaded
+// on the number of value parameters.
+
+ACTION(ReturnSum) { return 0; }
+
+ACTION_P(ReturnSum, x) { return x; }
+
+ACTION_TEMPLATE(ReturnSum, HAS_1_TEMPLATE_PARAMS(typename, Number),
+                AND_2_VALUE_PARAMS(v1, v2)) {
+  return static_cast<Number>(v1) + v2;
+}
+
+ACTION_TEMPLATE(ReturnSum, HAS_1_TEMPLATE_PARAMS(typename, Number),
+                AND_3_VALUE_PARAMS(v1, v2, v3)) {
+  return static_cast<Number>(v1) + v2 + v3;
+}
+
+ACTION_TEMPLATE(ReturnSum, HAS_2_TEMPLATE_PARAMS(typename, Number, int, k),
+                AND_4_VALUE_PARAMS(v1, v2, v3, v4)) {
+  return static_cast<Number>(v1) + v2 + v3 + v4 + k;
+}
+
+TEST(ActionTemplateTest, CanBeOverloadedOnNumberOfValueParameters) {
+  const Action<int()> a0 = ReturnSum();
+  const Action<int()> a1 = ReturnSum(1);
+  const Action<int()> a2 = ReturnSum<int>(1, 2);
+  const Action<int()> a3 = ReturnSum<int>(1, 2, 3);
+  const Action<int()> a4 = ReturnSum<int, 10000>(2000, 300, 40, 5);
+  EXPECT_EQ(0, a0.Perform(std::make_tuple()));
+  EXPECT_EQ(1, a1.Perform(std::make_tuple()));
+  EXPECT_EQ(3, a2.Perform(std::make_tuple()));
+  EXPECT_EQ(6, a3.Perform(std::make_tuple()));
+  EXPECT_EQ(12345, a4.Perform(std::make_tuple()));
+}
+
+}  // namespace gmock_more_actions_test
+}  // namespace testing
+
+GTEST_DISABLE_MSC_WARNINGS_POP_()  // 4100 4503
+GTEST_DISABLE_MSC_WARNINGS_POP_()  // 4577

contrib/googletest/googlemock/test/gmock-nice-strict_test.cc

@@ -0,0 +1,541 @@
+// Copyright 2008, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+#include "gmock/gmock-nice-strict.h"
+
+#include <string>
+#include <utility>
+
+#include "gmock/gmock.h"
+#include "gtest/gtest-spi.h"
+#include "gtest/gtest.h"
+
+// This must not be defined inside the ::testing namespace, or it will
+// clash with ::testing::Mock.
+class Mock {
+ public:
+  Mock() = default;
+
+  MOCK_METHOD0(DoThis, void());
+
+ private:
+  Mock(const Mock&) = delete;
+  Mock& operator=(const Mock&) = delete;
+};
+
+namespace testing {
+namespace gmock_nice_strict_test {
+
+using testing::HasSubstr;
+using testing::NaggyMock;
+using testing::NiceMock;
+using testing::StrictMock;
+
+#if GTEST_HAS_STREAM_REDIRECTION
+using testing::internal::CaptureStdout;
+using testing::internal::GetCapturedStdout;
+#endif
+
+// Class without default constructor.
+class NotDefaultConstructible {
+ public:
+  explicit NotDefaultConstructible(int) {}
+};
+
+class CallsMockMethodInDestructor {
+ public:
+  ~CallsMockMethodInDestructor() { OnDestroy(); }
+  MOCK_METHOD(void, OnDestroy, ());
+};
+
+// Defines some mock classes needed by the tests.
+
+class Foo {
+ public:
+  virtual ~Foo() = default;
+
+  virtual void DoThis() = 0;
+  virtual int DoThat(bool flag) = 0;
+};
+
+class MockFoo : public Foo {
+ public:
+  MockFoo() = default;
+  void Delete() { delete this; }
+
+  MOCK_METHOD0(DoThis, void());
+  MOCK_METHOD1(DoThat, int(bool flag));
+  MOCK_METHOD0(ReturnNonDefaultConstructible, NotDefaultConstructible());
+
+ private:
+  MockFoo(const MockFoo&) = delete;
+  MockFoo& operator=(const MockFoo&) = delete;
+};
+
+class MockBar {
+ public:
+  explicit MockBar(const std::string& s) : str_(s) {}
+
+  MockBar(char a1, char a2, std::string a3, std::string a4, int a5, int a6,
+          const std::string& a7, const std::string& a8, bool a9, bool a10) {
+    str_ = std::string() + a1 + a2 + a3 + a4 + static_cast<char>(a5) +
+           static_cast<char>(a6) + a7 + a8 + (a9 ? 'T' : 'F') +
+           (a10 ? 'T' : 'F');
+  }
+
+  virtual ~MockBar() = default;
+
+  const std::string& str() const { return str_; }
+
+  MOCK_METHOD0(This, int());
+  MOCK_METHOD2(That, std::string(int, bool));
+
+ private:
+  std::string str_;
+
+  MockBar(const MockBar&) = delete;
+  MockBar& operator=(const MockBar&) = delete;
+};
+
+class MockBaz {
+ public:
+  class MoveOnly {
+   public:
+    MoveOnly() = default;
+
+    MoveOnly(const MoveOnly&) = delete;
+    MoveOnly& operator=(const MoveOnly&) = delete;
+
+    MoveOnly(MoveOnly&&) = default;
+    MoveOnly& operator=(MoveOnly&&) = default;
+  };
+
+  MockBaz(MoveOnly) {}
+};
+
+#if GTEST_HAS_STREAM_REDIRECTION
+
+// Tests that a raw mock generates warnings for uninteresting calls.
+TEST(RawMockTest, WarningForUninterestingCall) {
+  const std::string saved_flag = GMOCK_FLAG_GET(verbose);
+  GMOCK_FLAG_SET(verbose, "warning");
+
+  MockFoo raw_foo;
+
+  CaptureStdout();
+  raw_foo.DoThis();
+  raw_foo.DoThat(true);
+  EXPECT_THAT(GetCapturedStdout(),
+              HasSubstr("Uninteresting mock function call"));
+
+  GMOCK_FLAG_SET(verbose, saved_flag);
+}
+
+// Tests that a raw mock generates warnings for uninteresting calls
+// that delete the mock object.
+TEST(RawMockTest, WarningForUninterestingCallAfterDeath) {
+  const std::string saved_flag = GMOCK_FLAG_GET(verbose);
+  GMOCK_FLAG_SET(verbose, "warning");
+
+  MockFoo* const raw_foo = new MockFoo;
+
+  ON_CALL(*raw_foo, DoThis()).WillByDefault(Invoke(raw_foo, &MockFoo::Delete));
+
+  CaptureStdout();
+  raw_foo->DoThis();
+  EXPECT_THAT(GetCapturedStdout(),
+              HasSubstr("Uninteresting mock function call"));
+
+  GMOCK_FLAG_SET(verbose, saved_flag);
+}
+
+// Tests that a raw mock generates informational logs for
+// uninteresting calls.
+TEST(RawMockTest, InfoForUninterestingCall) {
+  MockFoo raw_foo;
+
+  const std::string saved_flag = GMOCK_FLAG_GET(verbose);
+  GMOCK_FLAG_SET(verbose, "info");
+  CaptureStdout();
+  raw_foo.DoThis();
+  EXPECT_THAT(GetCapturedStdout(),
+              HasSubstr("Uninteresting mock function call"));
+
+  GMOCK_FLAG_SET(verbose, saved_flag);
+}
+
+TEST(RawMockTest, IsNaggy_IsNice_IsStrict) {
+  MockFoo raw_foo;
+  EXPECT_TRUE(Mock::IsNaggy(&raw_foo));
+  EXPECT_FALSE(Mock::IsNice(&raw_foo));
+  EXPECT_FALSE(Mock::IsStrict(&raw_foo));
+}
+
+// Tests that a nice mock generates no warning for uninteresting calls.
+TEST(NiceMockTest, NoWarningForUninterestingCall) {
+  NiceMock<MockFoo> nice_foo;
+
+  CaptureStdout();
+  nice_foo.DoThis();
+  nice_foo.DoThat(true);
+  EXPECT_EQ("", GetCapturedStdout());
+}
+
+// Tests that a nice mock generates no warning for uninteresting calls
+// that delete the mock object.
+TEST(NiceMockTest, NoWarningForUninterestingCallAfterDeath) {
+  NiceMock<MockFoo>* const nice_foo = new NiceMock<MockFoo>;
+
+  ON_CALL(*nice_foo, DoThis())
+      .WillByDefault(Invoke(nice_foo, &MockFoo::Delete));
+
+  CaptureStdout();
+  nice_foo->DoThis();
+  EXPECT_EQ("", GetCapturedStdout());
+}
+
+// Tests that a nice mock generates informational logs for
+// uninteresting calls.
+TEST(NiceMockTest, InfoForUninterestingCall) {
+  NiceMock<MockFoo> nice_foo;
+
+  const std::string saved_flag = GMOCK_FLAG_GET(verbose);
+  GMOCK_FLAG_SET(verbose, "info");
+  CaptureStdout();
+  nice_foo.DoThis();
+  EXPECT_THAT(GetCapturedStdout(),
+              HasSubstr("Uninteresting mock function call"));
+
+  GMOCK_FLAG_SET(verbose, saved_flag);
+}
+
+#endif  // GTEST_HAS_STREAM_REDIRECTION
+
+// Tests that a nice mock allows expected calls.
+TEST(NiceMockTest, AllowsExpectedCall) {
+  NiceMock<MockFoo> nice_foo;
+
+  EXPECT_CALL(nice_foo, DoThis());
+  nice_foo.DoThis();
+}
+
+// Tests that an unexpected call on a nice mock which returns a
+// not-default-constructible type throws an exception and the exception contains
+// the method's name.
+TEST(NiceMockTest, ThrowsExceptionForUnknownReturnTypes) {
+  NiceMock<MockFoo> nice_foo;
+#if GTEST_HAS_EXCEPTIONS
+  try {
+    nice_foo.ReturnNonDefaultConstructible();
+    FAIL();
+  } catch (const std::runtime_error& ex) {
+    EXPECT_THAT(ex.what(), HasSubstr("ReturnNonDefaultConstructible"));
+  }
+#else
+  EXPECT_DEATH_IF_SUPPORTED({ nice_foo.ReturnNonDefaultConstructible(); }, "");
+#endif
+}
+
+// Tests that an unexpected call on a nice mock fails.
+TEST(NiceMockTest, UnexpectedCallFails) {
+  NiceMock<MockFoo> nice_foo;
+
+  EXPECT_CALL(nice_foo, DoThis()).Times(0);
+  EXPECT_NONFATAL_FAILURE(nice_foo.DoThis(), "called more times than expected");
+}
+
+// Tests that NiceMock works with a mock class that has a non-default
+// constructor.
+TEST(NiceMockTest, NonDefaultConstructor) {
+  NiceMock<MockBar> nice_bar("hi");
+  EXPECT_EQ("hi", nice_bar.str());
+
+  nice_bar.This();
+  nice_bar.That(5, true);
+}
+
+// Tests that NiceMock works with a mock class that has a 10-ary
+// non-default constructor.
+TEST(NiceMockTest, NonDefaultConstructor10) {
+  NiceMock<MockBar> nice_bar('a', 'b', "c", "d", 'e', 'f', "g", "h", true,
+                             false);
+  EXPECT_EQ("abcdefghTF", nice_bar.str());
+
+  nice_bar.This();
+  nice_bar.That(5, true);
+}
+
+TEST(NiceMockTest, AllowLeak) {
+  NiceMock<MockFoo>* leaked = new NiceMock<MockFoo>;
+  Mock::AllowLeak(leaked);
+  EXPECT_CALL(*leaked, DoThis());
+  leaked->DoThis();
+}
+
+TEST(NiceMockTest, MoveOnlyConstructor) {
+  NiceMock<MockBaz> nice_baz(MockBaz::MoveOnly{});
+}
+
+// Tests that NiceMock<Mock> compiles where Mock is a user-defined
+// class (as opposed to ::testing::Mock).
+TEST(NiceMockTest, AcceptsClassNamedMock) {
+  NiceMock< ::Mock> nice;
+  EXPECT_CALL(nice, DoThis());
+  nice.DoThis();
+}
+
+TEST(NiceMockTest, IsNiceInDestructor) {
+  {
+    NiceMock<CallsMockMethodInDestructor> nice_on_destroy;
+    // Don't add an expectation for the call before the mock goes out of scope.
+  }
+}
+
+TEST(NiceMockTest, IsNaggy_IsNice_IsStrict) {
+  NiceMock<MockFoo> nice_foo;
+  EXPECT_FALSE(Mock::IsNaggy(&nice_foo));
+  EXPECT_TRUE(Mock::IsNice(&nice_foo));
+  EXPECT_FALSE(Mock::IsStrict(&nice_foo));
+}
+
+#if GTEST_HAS_STREAM_REDIRECTION
+
+// Tests that a naggy mock generates warnings for uninteresting calls.
+TEST(NaggyMockTest, WarningForUninterestingCall) {
+  const std::string saved_flag = GMOCK_FLAG_GET(verbose);
+  GMOCK_FLAG_SET(verbose, "warning");
+
+  NaggyMock<MockFoo> naggy_foo;
+
+  CaptureStdout();
+  naggy_foo.DoThis();
+  naggy_foo.DoThat(true);
+  EXPECT_THAT(GetCapturedStdout(),
+              HasSubstr("Uninteresting mock function call"));
+
+  GMOCK_FLAG_SET(verbose, saved_flag);
+}
+
+// Tests that a naggy mock generates a warning for an uninteresting call
+// that deletes the mock object.
+TEST(NaggyMockTest, WarningForUninterestingCallAfterDeath) {
+  const std::string saved_flag = GMOCK_FLAG_GET(verbose);
+  GMOCK_FLAG_SET(verbose, "warning");
+
+  NaggyMock<MockFoo>* const naggy_foo = new NaggyMock<MockFoo>;
+
+  ON_CALL(*naggy_foo, DoThis())
+      .WillByDefault(Invoke(naggy_foo, &MockFoo::Delete));
+
+  CaptureStdout();
+  naggy_foo->DoThis();
+  EXPECT_THAT(GetCapturedStdout(),
+              HasSubstr("Uninteresting mock function call"));
+
+  GMOCK_FLAG_SET(verbose, saved_flag);
+}
+
+#endif  // GTEST_HAS_STREAM_REDIRECTION
+
+// Tests that a naggy mock allows expected calls.
+TEST(NaggyMockTest, AllowsExpectedCall) {
+  NaggyMock<MockFoo> naggy_foo;
+
+  EXPECT_CALL(naggy_foo, DoThis());
+  naggy_foo.DoThis();
+}
+
+// Tests that an unexpected call on a naggy mock fails.
+TEST(NaggyMockTest, UnexpectedCallFails) {
+  NaggyMock<MockFoo> naggy_foo;
+
+  EXPECT_CALL(naggy_foo, DoThis()).Times(0);
+  EXPECT_NONFATAL_FAILURE(naggy_foo.DoThis(),
+                          "called more times than expected");
+}
+
+// Tests that NaggyMock works with a mock class that has a non-default
+// constructor.
+TEST(NaggyMockTest, NonDefaultConstructor) {
+  NaggyMock<MockBar> naggy_bar("hi");
+  EXPECT_EQ("hi", naggy_bar.str());
+
+  naggy_bar.This();
+  naggy_bar.That(5, true);
+}
+
+// Tests that NaggyMock works with a mock class that has a 10-ary
+// non-default constructor.
+TEST(NaggyMockTest, NonDefaultConstructor10) {
+  NaggyMock<MockBar> naggy_bar('0', '1', "2", "3", '4', '5', "6", "7", true,
+                               false);
+  EXPECT_EQ("01234567TF", naggy_bar.str());
+
+  naggy_bar.This();
+  naggy_bar.That(5, true);
+}
+
+TEST(NaggyMockTest, AllowLeak) {
+  NaggyMock<MockFoo>* leaked = new NaggyMock<MockFoo>;
+  Mock::AllowLeak(leaked);
+  EXPECT_CALL(*leaked, DoThis());
+  leaked->DoThis();
+}
+
+TEST(NaggyMockTest, MoveOnlyConstructor) {
+  NaggyMock<MockBaz> naggy_baz(MockBaz::MoveOnly{});
+}
+
+// Tests that NaggyMock<Mock> compiles where Mock is a user-defined
+// class (as opposed to ::testing::Mock).
+TEST(NaggyMockTest, AcceptsClassNamedMock) {
+  NaggyMock< ::Mock> naggy;
+  EXPECT_CALL(naggy, DoThis());
+  naggy.DoThis();
+}
+
+TEST(NaggyMockTest, IsNaggyInDestructor) {
+  const std::string saved_flag = GMOCK_FLAG_GET(verbose);
+  GMOCK_FLAG_SET(verbose, "warning");
+  CaptureStdout();
+
+  {
+    NaggyMock<CallsMockMethodInDestructor> naggy_on_destroy;
+    // Don't add an expectation for the call before the mock goes out of scope.
+  }
+
+  EXPECT_THAT(GetCapturedStdout(),
+              HasSubstr("Uninteresting mock function call"));
+
+  GMOCK_FLAG_SET(verbose, saved_flag);
+}
+
+TEST(NaggyMockTest, IsNaggy_IsNice_IsStrict) {
+  NaggyMock<MockFoo> naggy_foo;
+  EXPECT_TRUE(Mock::IsNaggy(&naggy_foo));
+  EXPECT_FALSE(Mock::IsNice(&naggy_foo));
+  EXPECT_FALSE(Mock::IsStrict(&naggy_foo));
+}
+
+// Tests that a strict mock allows expected calls.
+TEST(StrictMockTest, AllowsExpectedCall) {
+  StrictMock<MockFoo> strict_foo;
+
+  EXPECT_CALL(strict_foo, DoThis());
+  strict_foo.DoThis();
+}
+
+// Tests that an unexpected call on a strict mock fails.
+TEST(StrictMockTest, UnexpectedCallFails) {
+  StrictMock<MockFoo> strict_foo;
+
+  EXPECT_CALL(strict_foo, DoThis()).Times(0);
+  EXPECT_NONFATAL_FAILURE(strict_foo.DoThis(),
+                          "called more times than expected");
+}
+
+// Tests that an uninteresting call on a strict mock fails.
+TEST(StrictMockTest, UninterestingCallFails) {
+  StrictMock<MockFoo> strict_foo;
+
+  EXPECT_NONFATAL_FAILURE(strict_foo.DoThis(),
+                          "Uninteresting mock function call");
+}
+
+// Tests that an uninteresting call on a strict mock fails, even if
+// the call deletes the mock object.
+TEST(StrictMockTest, UninterestingCallFailsAfterDeath) {
+  StrictMock<MockFoo>* const strict_foo = new StrictMock<MockFoo>;
+
+  ON_CALL(*strict_foo, DoThis())
+      .WillByDefault(Invoke(strict_foo, &MockFoo::Delete));
+
+  EXPECT_NONFATAL_FAILURE(strict_foo->DoThis(),
+                          "Uninteresting mock function call");
+}
+
+// Tests that StrictMock works with a mock class that has a
+// non-default constructor.
+TEST(StrictMockTest, NonDefaultConstructor) {
+  StrictMock<MockBar> strict_bar("hi");
+  EXPECT_EQ("hi", strict_bar.str());
+
+  EXPECT_NONFATAL_FAILURE(strict_bar.That(5, true),
+                          "Uninteresting mock function call");
+}
+
+// Tests that StrictMock works with a mock class that has a 10-ary
+// non-default constructor.
+TEST(StrictMockTest, NonDefaultConstructor10) {
+  StrictMock<MockBar> strict_bar('a', 'b', "c", "d", 'e', 'f', "g", "h", true,
+                                 false);
+  EXPECT_EQ("abcdefghTF", strict_bar.str());
+
+  EXPECT_NONFATAL_FAILURE(strict_bar.That(5, true),
+                          "Uninteresting mock function call");
+}
+
+TEST(StrictMockTest, AllowLeak) {
+  StrictMock<MockFoo>* leaked = new StrictMock<MockFoo>;
+  Mock::AllowLeak(leaked);
+  EXPECT_CALL(*leaked, DoThis());
+  leaked->DoThis();
+}
+
+TEST(StrictMockTest, MoveOnlyConstructor) {
+  StrictMock<MockBaz> strict_baz(MockBaz::MoveOnly{});
+}
+
+// Tests that StrictMock<Mock> compiles where Mock is a user-defined
+// class (as opposed to ::testing::Mock).
+TEST(StrictMockTest, AcceptsClassNamedMock) {
+  StrictMock< ::Mock> strict;
+  EXPECT_CALL(strict, DoThis());
+  strict.DoThis();
+}
+
+TEST(StrictMockTest, IsStrictInDestructor) {
+  EXPECT_NONFATAL_FAILURE(
+      {
+        StrictMock<CallsMockMethodInDestructor> strict_on_destroy;
+        // Don't add an expectation for the call before the mock goes out of
+        // scope.
+      },
+      "Uninteresting mock function call");
+}
+
+TEST(StrictMockTest, IsNaggy_IsNice_IsStrict) {
+  StrictMock<MockFoo> strict_foo;
+  EXPECT_FALSE(Mock::IsNaggy(&strict_foo));
+  EXPECT_FALSE(Mock::IsNice(&strict_foo));
+  EXPECT_TRUE(Mock::IsStrict(&strict_foo));
+}
+
+}  // namespace gmock_nice_strict_test
+}  // namespace testing

contrib/googletest/googlemock/test/gmock-port_test.cc

@@ -0,0 +1,42 @@
+// Copyright 2008, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+// Google Mock - a framework for writing C++ mock classes.
+//
+// This file tests the internal cross-platform support utilities.
+
+#include "gmock/internal/gmock-port.h"
+
+#include "gtest/gtest.h"
+
+// NOTE: if this file is left without tests for some reason, put a dummy
+// test here to make references to symbols in the gtest library and avoid
+// 'undefined symbol' linker errors in gmock_main:
+
+TEST(DummyTest, Dummy) {}

contrib/googletest/googlemock/test/gmock-pp-string_test.cc

@@ -0,0 +1,205 @@
+// Copyright 2018, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+// Google Mock - a framework for writing C++ mock classes.
+//
+// This file tests the internal preprocessor macro library.
+#include <string>
+
+#include "gmock/gmock.h"
+#include "gmock/internal/gmock-pp.h"
+
+namespace testing {
+namespace {
+
+// Matcher to verify that to strings are identical up to whitespace
+// Not 100% correct, because it treats "AB" as equal to "A B".
+::testing::Matcher<const std::string&> SameExceptSpaces(const std::string& s) {
+  auto remove_spaces = [](std::string to_split) {
+    to_split.erase(std::remove(to_split.begin(), to_split.end(), ' '),
+                   to_split.end());
+    return to_split;
+  };
+  return ::testing::ResultOf(remove_spaces, remove_spaces(s));
+}
+
+// Verify that a macro expands to a given text. Ignores whitespace difference.
+// In MSVC, GMOCK_PP_STRINGIZE() returns nothing, rather than "". So concatenate
+// with an empty string.
+#define EXPECT_EXPANSION(Result, Macro) \
+  EXPECT_THAT("" GMOCK_PP_STRINGIZE(Macro), SameExceptSpaces(Result))
+
+TEST(Macros, Cat) {
+  EXPECT_EXPANSION("14", GMOCK_PP_CAT(1, 4));
+  EXPECT_EXPANSION("+=", GMOCK_PP_CAT(+, =));
+}
+
+TEST(Macros, Narg) {
+  EXPECT_EXPANSION("1", GMOCK_PP_NARG());
+  EXPECT_EXPANSION("1", GMOCK_PP_NARG(x));
+  EXPECT_EXPANSION("2", GMOCK_PP_NARG(x, y));
+  EXPECT_EXPANSION("3", GMOCK_PP_NARG(x, y, z));
+  EXPECT_EXPANSION("4", GMOCK_PP_NARG(x, y, z, w));
+
+  EXPECT_EXPANSION("0", GMOCK_PP_NARG0());
+  EXPECT_EXPANSION("1", GMOCK_PP_NARG0(x));
+  EXPECT_EXPANSION("2", GMOCK_PP_NARG0(x, y));
+}
+
+TEST(Macros, Comma) {
+  EXPECT_EXPANSION("0", GMOCK_PP_HAS_COMMA());
+  EXPECT_EXPANSION("1", GMOCK_PP_HAS_COMMA(, ));
+  EXPECT_EXPANSION("0", GMOCK_PP_HAS_COMMA((, )));
+}
+
+TEST(Macros, IsEmpty) {
+  EXPECT_EXPANSION("1", GMOCK_PP_IS_EMPTY());
+  EXPECT_EXPANSION("0", GMOCK_PP_IS_EMPTY(, ));
+  EXPECT_EXPANSION("0", GMOCK_PP_IS_EMPTY(a));
+  EXPECT_EXPANSION("0", GMOCK_PP_IS_EMPTY(()));
+
+#define GMOCK_PP_INTERNAL_IS_EMPTY_TEST_1
+  EXPECT_EXPANSION("1", GMOCK_PP_IS_EMPTY(GMOCK_PP_INTERNAL_IS_EMPTY_TEST_1));
+}
+
+TEST(Macros, If) {
+  EXPECT_EXPANSION("1", GMOCK_PP_IF(1, 1, 2));
+  EXPECT_EXPANSION("2", GMOCK_PP_IF(0, 1, 2));
+}
+
+TEST(Macros, HeadTail) {
+  EXPECT_EXPANSION("1", GMOCK_PP_HEAD(1));
+  EXPECT_EXPANSION("1", GMOCK_PP_HEAD(1, 2));
+  EXPECT_EXPANSION("1", GMOCK_PP_HEAD(1, 2, 3));
+
+  EXPECT_EXPANSION("", GMOCK_PP_TAIL(1));
+  EXPECT_EXPANSION("2", GMOCK_PP_TAIL(1, 2));
+  EXPECT_EXPANSION("2", GMOCK_PP_HEAD(GMOCK_PP_TAIL(1, 2, 3)));
+}
+
+TEST(Macros, Parentheses) {
+  EXPECT_EXPANSION("0", GMOCK_PP_IS_BEGIN_PARENS(sss));
+  EXPECT_EXPANSION("0", GMOCK_PP_IS_BEGIN_PARENS(sss()));
+  EXPECT_EXPANSION("0", GMOCK_PP_IS_BEGIN_PARENS(sss() sss));
+  EXPECT_EXPANSION("1", GMOCK_PP_IS_BEGIN_PARENS((sss)));
+  EXPECT_EXPANSION("1", GMOCK_PP_IS_BEGIN_PARENS((sss)ss));
+
+  EXPECT_EXPANSION("0", GMOCK_PP_IS_ENCLOSED_PARENS(sss));
+  EXPECT_EXPANSION("0", GMOCK_PP_IS_ENCLOSED_PARENS(sss()));
+  EXPECT_EXPANSION("0", GMOCK_PP_IS_ENCLOSED_PARENS(sss() sss));
+  EXPECT_EXPANSION("1", GMOCK_PP_IS_ENCLOSED_PARENS((sss)));
+  EXPECT_EXPANSION("0", GMOCK_PP_IS_ENCLOSED_PARENS((sss)ss));
+
+  EXPECT_EXPANSION("1 + 1", GMOCK_PP_REMOVE_PARENS((1 + 1)));
+}
+
+TEST(Macros, Increment) {
+  EXPECT_EXPANSION("1", GMOCK_PP_INC(0));
+  EXPECT_EXPANSION("2", GMOCK_PP_INC(1));
+  EXPECT_EXPANSION("3", GMOCK_PP_INC(2));
+  EXPECT_EXPANSION("4", GMOCK_PP_INC(3));
+  EXPECT_EXPANSION("5", GMOCK_PP_INC(4));
+
+  EXPECT_EXPANSION("16", GMOCK_PP_INC(15));
+}
+
+#define JOINER_CAT(a, b) a##b
+#define JOINER(_N, _Data, _Elem) JOINER_CAT(_Data, _N) = _Elem
+
+TEST(Macros, Repeat) {
+  EXPECT_EXPANSION("", GMOCK_PP_REPEAT(JOINER, X, 0));
+  EXPECT_EXPANSION("X0=", GMOCK_PP_REPEAT(JOINER, X, 1));
+  EXPECT_EXPANSION("X0= X1=", GMOCK_PP_REPEAT(JOINER, X, 2));
+  EXPECT_EXPANSION("X0= X1= X2=", GMOCK_PP_REPEAT(JOINER, X, 3));
+  EXPECT_EXPANSION("X0= X1= X2= X3=", GMOCK_PP_REPEAT(JOINER, X, 4));
+  EXPECT_EXPANSION("X0= X1= X2= X3= X4=", GMOCK_PP_REPEAT(JOINER, X, 5));
+  EXPECT_EXPANSION("X0= X1= X2= X3= X4= X5=", GMOCK_PP_REPEAT(JOINER, X, 6));
+  EXPECT_EXPANSION("X0= X1= X2= X3= X4= X5= X6=",
+                   GMOCK_PP_REPEAT(JOINER, X, 7));
+  EXPECT_EXPANSION("X0= X1= X2= X3= X4= X5= X6= X7=",
+                   GMOCK_PP_REPEAT(JOINER, X, 8));
+  EXPECT_EXPANSION("X0= X1= X2= X3= X4= X5= X6= X7= X8=",
+                   GMOCK_PP_REPEAT(JOINER, X, 9));
+  EXPECT_EXPANSION("X0= X1= X2= X3= X4= X5= X6= X7= X8= X9=",
+                   GMOCK_PP_REPEAT(JOINER, X, 10));
+  EXPECT_EXPANSION("X0= X1= X2= X3= X4= X5= X6= X7= X8= X9= X10=",
+                   GMOCK_PP_REPEAT(JOINER, X, 11));
+  EXPECT_EXPANSION("X0= X1= X2= X3= X4= X5= X6= X7= X8= X9= X10= X11=",
+                   GMOCK_PP_REPEAT(JOINER, X, 12));
+  EXPECT_EXPANSION("X0= X1= X2= X3= X4= X5= X6= X7= X8= X9= X10= X11= X12=",
+                   GMOCK_PP_REPEAT(JOINER, X, 13));
+  EXPECT_EXPANSION(
+      "X0= X1= X2= X3= X4= X5= X6= X7= X8= X9= X10= X11= X12= X13=",
+      GMOCK_PP_REPEAT(JOINER, X, 14));
+  EXPECT_EXPANSION(
+      "X0= X1= X2= X3= X4= X5= X6= X7= X8= X9= X10= X11= X12= X13= X14=",
+      GMOCK_PP_REPEAT(JOINER, X, 15));
+}
+TEST(Macros, ForEach) {
+  EXPECT_EXPANSION("", GMOCK_PP_FOR_EACH(JOINER, X, ()));
+  EXPECT_EXPANSION("X0=a", GMOCK_PP_FOR_EACH(JOINER, X, (a)));
+  EXPECT_EXPANSION("X0=a X1=b", GMOCK_PP_FOR_EACH(JOINER, X, (a, b)));
+  EXPECT_EXPANSION("X0=a X1=b X2=c", GMOCK_PP_FOR_EACH(JOINER, X, (a, b, c)));
+  EXPECT_EXPANSION("X0=a X1=b X2=c X3=d",
+                   GMOCK_PP_FOR_EACH(JOINER, X, (a, b, c, d)));
+  EXPECT_EXPANSION("X0=a X1=b X2=c X3=d X4=e",
+                   GMOCK_PP_FOR_EACH(JOINER, X, (a, b, c, d, e)));
+  EXPECT_EXPANSION("X0=a X1=b X2=c X3=d X4=e X5=f",
+                   GMOCK_PP_FOR_EACH(JOINER, X, (a, b, c, d, e, f)));
+  EXPECT_EXPANSION("X0=a X1=b X2=c X3=d X4=e X5=f X6=g",
+                   GMOCK_PP_FOR_EACH(JOINER, X, (a, b, c, d, e, f, g)));
+  EXPECT_EXPANSION("X0=a X1=b X2=c X3=d X4=e X5=f X6=g X7=h",
+                   GMOCK_PP_FOR_EACH(JOINER, X, (a, b, c, d, e, f, g, h)));
+  EXPECT_EXPANSION("X0=a X1=b X2=c X3=d X4=e X5=f X6=g X7=h X8=i",
+                   GMOCK_PP_FOR_EACH(JOINER, X, (a, b, c, d, e, f, g, h, i)));
+  EXPECT_EXPANSION(
+      "X0=a X1=b X2=c X3=d X4=e X5=f X6=g X7=h X8=i X9=j",
+      GMOCK_PP_FOR_EACH(JOINER, X, (a, b, c, d, e, f, g, h, i, j)));
+  EXPECT_EXPANSION(
+      "X0=a X1=b X2=c X3=d X4=e X5=f X6=g X7=h X8=i X9=j X10=k",
+      GMOCK_PP_FOR_EACH(JOINER, X, (a, b, c, d, e, f, g, h, i, j, k)));
+  EXPECT_EXPANSION(
+      "X0=a X1=b X2=c X3=d X4=e X5=f X6=g X7=h X8=i X9=j X10=k X11=l",
+      GMOCK_PP_FOR_EACH(JOINER, X, (a, b, c, d, e, f, g, h, i, j, k, l)));
+  EXPECT_EXPANSION(
+      "X0=a X1=b X2=c X3=d X4=e X5=f X6=g X7=h X8=i X9=j X10=k X11=l X12=m",
+      GMOCK_PP_FOR_EACH(JOINER, X, (a, b, c, d, e, f, g, h, i, j, k, l, m)));
+  EXPECT_EXPANSION(
+      "X0=a X1=b X2=c X3=d X4=e X5=f X6=g X7=h X8=i X9=j X10=k X11=l X12=m "
+      "X13=n",
+      GMOCK_PP_FOR_EACH(JOINER, X, (a, b, c, d, e, f, g, h, i, j, k, l, m, n)));
+  EXPECT_EXPANSION(
+      "X0=a X1=b X2=c X3=d X4=e X5=f X6=g X7=h X8=i X9=j X10=k X11=l X12=m "
+      "X13=n X14=o",
+      GMOCK_PP_FOR_EACH(JOINER, X,
+                        (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o)));
+}
+
+}  // namespace
+}  // namespace testing

contrib/googletest/googlemock/test/gmock-pp_test.cc

@@ -0,0 +1,83 @@
+#include "gmock/internal/gmock-pp.h"
+
+// Used to test MSVC treating __VA_ARGS__ with a comma in it as one value
+#define GMOCK_TEST_REPLACE_comma_WITH_COMMA_I_comma ,
+#define GMOCK_TEST_REPLACE_comma_WITH_COMMA(x) \
+  GMOCK_PP_CAT(GMOCK_TEST_REPLACE_comma_WITH_COMMA_I_, x)
+
+// Static assertions.
+namespace testing {
+namespace internal {
+namespace gmockpp {
+
+static_assert(GMOCK_PP_CAT(1, 4) == 14, "");
+static_assert(GMOCK_PP_INTERNAL_INTERNAL_16TH(1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11,
+                                              12, 13, 14, 15, 16, 17, 18) == 16,
+              "");
+static_assert(GMOCK_PP_NARG() == 1, "");
+static_assert(GMOCK_PP_NARG(x) == 1, "");
+static_assert(GMOCK_PP_NARG(x, y) == 2, "");
+static_assert(GMOCK_PP_NARG(x, y, z) == 3, "");
+static_assert(GMOCK_PP_NARG(x, y, z, w) == 4, "");
+static_assert(!GMOCK_PP_HAS_COMMA(), "");
+static_assert(GMOCK_PP_HAS_COMMA(b, ), "");
+static_assert(!GMOCK_PP_HAS_COMMA((, )), "");
+static_assert(GMOCK_PP_HAS_COMMA(GMOCK_TEST_REPLACE_comma_WITH_COMMA(comma)),
+              "");
+static_assert(
+    GMOCK_PP_HAS_COMMA(GMOCK_TEST_REPLACE_comma_WITH_COMMA(comma(unrelated))),
+    "");
+static_assert(!GMOCK_PP_IS_EMPTY(, ), "");
+static_assert(!GMOCK_PP_IS_EMPTY(a), "");
+static_assert(!GMOCK_PP_IS_EMPTY(()), "");
+static_assert(GMOCK_PP_IF(1, 1, 2) == 1, "");
+static_assert(GMOCK_PP_IF(0, 1, 2) == 2, "");
+static_assert(GMOCK_PP_NARG0(x) == 1, "");
+static_assert(GMOCK_PP_NARG0(x, y) == 2, "");
+static_assert(GMOCK_PP_HEAD(1) == 1, "");
+static_assert(GMOCK_PP_HEAD(1, 2) == 1, "");
+static_assert(GMOCK_PP_HEAD(1, 2, 3) == 1, "");
+static_assert(GMOCK_PP_TAIL(1, 2) == 2, "");
+static_assert(GMOCK_PP_HEAD(GMOCK_PP_TAIL(1, 2, 3)) == 2, "");
+static_assert(!GMOCK_PP_IS_BEGIN_PARENS(sss), "");
+static_assert(!GMOCK_PP_IS_BEGIN_PARENS(sss()), "");
+static_assert(!GMOCK_PP_IS_BEGIN_PARENS(sss() sss), "");
+static_assert(GMOCK_PP_IS_BEGIN_PARENS((sss)), "");
+static_assert(GMOCK_PP_IS_BEGIN_PARENS((sss)ss), "");
+static_assert(!GMOCK_PP_IS_ENCLOSED_PARENS(sss), "");
+static_assert(!GMOCK_PP_IS_ENCLOSED_PARENS(sss()), "");
+static_assert(!GMOCK_PP_IS_ENCLOSED_PARENS(sss() sss), "");
+static_assert(!GMOCK_PP_IS_ENCLOSED_PARENS((sss)ss), "");
+static_assert(GMOCK_PP_REMOVE_PARENS((1 + 1)) * 2 == 3, "");
+static_assert(GMOCK_PP_INC(4) == 5, "");
+
+template <class... Args>
+struct Test {
+  static constexpr int kArgs = sizeof...(Args);
+};
+#define GMOCK_PP_INTERNAL_TYPE_TEST(_i, _Data, _element) \
+  GMOCK_PP_COMMA_IF(_i) _element
+static_assert(Test<GMOCK_PP_FOR_EACH(GMOCK_PP_INTERNAL_TYPE_TEST, ~,
+                                     (int, float, double, char))>::kArgs == 4,
+              "");
+#define GMOCK_PP_INTERNAL_VAR_TEST_1(_x) 1
+#define GMOCK_PP_INTERNAL_VAR_TEST_2(_x, _y) 2
+#define GMOCK_PP_INTERNAL_VAR_TEST_3(_x, _y, _z) 3
+
+#define GMOCK_PP_INTERNAL_VAR_TEST(...) \
+  GMOCK_PP_VARIADIC_CALL(GMOCK_PP_INTERNAL_VAR_TEST_, __VA_ARGS__)
+static_assert(GMOCK_PP_INTERNAL_VAR_TEST(x, y) == 2, "");
+static_assert(GMOCK_PP_INTERNAL_VAR_TEST(silly) == 1, "");
+static_assert(GMOCK_PP_INTERNAL_VAR_TEST(x, y, z) == 3, "");
+
+// TODO(iserna): The following asserts fail in --config=lexan.
+#define GMOCK_PP_INTERNAL_IS_EMPTY_TEST_1
+static_assert(GMOCK_PP_IS_EMPTY(GMOCK_PP_INTERNAL_IS_EMPTY_TEST_1), "");
+static_assert(GMOCK_PP_IS_EMPTY(), "");
+static_assert(GMOCK_PP_IS_ENCLOSED_PARENS((sss)), "");
+static_assert(GMOCK_PP_IS_EMPTY(GMOCK_PP_TAIL(1)), "");
+static_assert(GMOCK_PP_NARG0() == 0, "");
+
+}  // namespace gmockpp
+}  // namespace internal
+}  // namespace testing

contrib/googletest/googlemock/test/gmock-spec-builders_test.cc

@@ -0,0 +1,2600 @@
+// Copyright 2007, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+// Google Mock - a framework for writing C++ mock classes.
+//
+// This file tests the spec builder syntax.
+
+#include "gmock/gmock-spec-builders.h"
+
+#include <memory>
+#include <ostream>  // NOLINT
+#include <sstream>
+#include <string>
+#include <type_traits>
+
+#include "gmock/gmock.h"
+#include "gmock/internal/gmock-port.h"
+#include "gtest/gtest-spi.h"
+#include "gtest/gtest.h"
+#include "gtest/internal/gtest-port.h"
+
+namespace testing {
+namespace {
+
+using ::testing::internal::FormatFileLocation;
+using ::testing::internal::kAllow;
+using ::testing::internal::kErrorVerbosity;
+using ::testing::internal::kFail;
+using ::testing::internal::kInfoVerbosity;
+using ::testing::internal::kWarn;
+using ::testing::internal::kWarningVerbosity;
+
+#if GTEST_HAS_STREAM_REDIRECTION
+using ::testing::internal::CaptureStdout;
+using ::testing::internal::GetCapturedStdout;
+#endif
+
+class Incomplete;
+
+class MockIncomplete {
+ public:
+  // This line verifies that a mock method can take a by-reference
+  // argument of an incomplete type.
+  MOCK_METHOD1(ByRefFunc, void(const Incomplete& x));
+};
+
+// Tells Google Mock how to print a value of type Incomplete.
+void PrintTo(const Incomplete& x, ::std::ostream* os);
+
+TEST(MockMethodTest, CanInstantiateWithIncompleteArgType) {
+  // Even though this mock class contains a mock method that takes
+  // by-reference an argument whose type is incomplete, we can still
+  // use the mock, as long as Google Mock knows how to print the
+  // argument.
+  MockIncomplete incomplete;
+  EXPECT_CALL(incomplete, ByRefFunc(_)).Times(AnyNumber());
+}
+
+// The definition of the printer for the argument type doesn't have to
+// be visible where the mock is used.
+void PrintTo(const Incomplete& /* x */, ::std::ostream* os) {
+  *os << "incomplete";
+}
+
+class Result {};
+
+// A type that's not default constructible.
+class NonDefaultConstructible {
+ public:
+  explicit NonDefaultConstructible(int /* dummy */) {}
+};
+
+class MockA {
+ public:
+  MockA() = default;
+
+  MOCK_METHOD1(DoA, void(int n));
+  MOCK_METHOD1(ReturnResult, Result(int n));
+  MOCK_METHOD0(ReturnNonDefaultConstructible, NonDefaultConstructible());
+  MOCK_METHOD2(Binary, bool(int x, int y));
+  MOCK_METHOD2(ReturnInt, int(int x, int y));
+
+ private:
+  MockA(const MockA&) = delete;
+  MockA& operator=(const MockA&) = delete;
+};
+
+class MockB {
+ public:
+  MockB() = default;
+
+  MOCK_CONST_METHOD0(DoB, int());  // NOLINT
+  MOCK_METHOD1(DoB, int(int n));   // NOLINT
+
+ private:
+  MockB(const MockB&) = delete;
+  MockB& operator=(const MockB&) = delete;
+};
+
+class ReferenceHoldingMock {
+ public:
+  ReferenceHoldingMock() = default;
+
+  MOCK_METHOD1(AcceptReference, void(std::shared_ptr<MockA>*));
+
+ private:
+  ReferenceHoldingMock(const ReferenceHoldingMock&) = delete;
+  ReferenceHoldingMock& operator=(const ReferenceHoldingMock&) = delete;
+};
+
+// Tests that EXPECT_CALL and ON_CALL compile in a presence of macro
+// redefining a mock method name. This could happen, for example, when
+// the tested code #includes Win32 API headers which define many APIs
+// as macros, e.g. #define TextOut TextOutW.
+
+#define Method MethodW
+
+class CC {
+ public:
+  virtual ~CC() = default;
+  virtual int Method() = 0;
+};
+class MockCC : public CC {
+ public:
+  MockCC() = default;
+
+  MOCK_METHOD0(Method, int());
+
+ private:
+  MockCC(const MockCC&) = delete;
+  MockCC& operator=(const MockCC&) = delete;
+};
+
+// Tests that a method with expanded name compiles.
+TEST(OnCallSyntaxTest, CompilesWithMethodNameExpandedFromMacro) {
+  MockCC cc;
+  ON_CALL(cc, Method());
+}
+
+// Tests that the method with expanded name not only compiles but runs
+// and returns a correct value, too.
+TEST(OnCallSyntaxTest, WorksWithMethodNameExpandedFromMacro) {
+  MockCC cc;
+  ON_CALL(cc, Method()).WillByDefault(Return(42));
+  EXPECT_EQ(42, cc.Method());
+}
+
+// Tests that a method with expanded name compiles.
+TEST(ExpectCallSyntaxTest, CompilesWithMethodNameExpandedFromMacro) {
+  MockCC cc;
+  EXPECT_CALL(cc, Method());
+  cc.Method();
+}
+
+// Tests that it works, too.
+TEST(ExpectCallSyntaxTest, WorksWithMethodNameExpandedFromMacro) {
+  MockCC cc;
+  EXPECT_CALL(cc, Method()).WillOnce(Return(42));
+  EXPECT_EQ(42, cc.Method());
+}
+
+#undef Method  // Done with macro redefinition tests.
+
+// Tests that ON_CALL evaluates its arguments exactly once as promised
+// by Google Mock.
+TEST(OnCallSyntaxTest, EvaluatesFirstArgumentOnce) {
+  MockA a;
+  MockA* pa = &a;
+
+  ON_CALL(*pa++, DoA(_));
+  EXPECT_EQ(&a + 1, pa);
+}
+
+TEST(OnCallSyntaxTest, EvaluatesSecondArgumentOnce) {
+  MockA a;
+  int n = 0;
+
+  ON_CALL(a, DoA(n++));
+  EXPECT_EQ(1, n);
+}
+
+// Tests that the syntax of ON_CALL() is enforced at run time.
+
+TEST(OnCallSyntaxTest, WithIsOptional) {
+  MockA a;
+
+  ON_CALL(a, DoA(5)).WillByDefault(Return());
+  ON_CALL(a, DoA(_)).With(_).WillByDefault(Return());
+}
+
+TEST(OnCallSyntaxTest, WithCanAppearAtMostOnce) {
+  MockA a;
+
+  EXPECT_NONFATAL_FAILURE(
+      {  // NOLINT
+        ON_CALL(a, ReturnResult(_))
+            .With(_)
+            .With(_)
+            .WillByDefault(Return(Result()));
+      },
+      ".With() cannot appear more than once in an ON_CALL()");
+}
+
+TEST(OnCallSyntaxTest, WillByDefaultIsMandatory) {
+  MockA a;
+
+  EXPECT_DEATH_IF_SUPPORTED(
+      {
+        ON_CALL(a, DoA(5));
+        a.DoA(5);
+      },
+      "");
+}
+
+TEST(OnCallSyntaxTest, WillByDefaultCanAppearAtMostOnce) {
+  MockA a;
+
+  EXPECT_NONFATAL_FAILURE(
+      {  // NOLINT
+        ON_CALL(a, DoA(5)).WillByDefault(Return()).WillByDefault(Return());
+      },
+      ".WillByDefault() must appear exactly once in an ON_CALL()");
+}
+
+// Tests that EXPECT_CALL evaluates its arguments exactly once as
+// promised by Google Mock.
+TEST(ExpectCallSyntaxTest, EvaluatesFirstArgumentOnce) {
+  MockA a;
+  MockA* pa = &a;
+
+  EXPECT_CALL(*pa++, DoA(_));
+  a.DoA(0);
+  EXPECT_EQ(&a + 1, pa);
+}
+
+TEST(ExpectCallSyntaxTest, EvaluatesSecondArgumentOnce) {
+  MockA a;
+  int n = 0;
+
+  EXPECT_CALL(a, DoA(n++));
+  a.DoA(0);
+  EXPECT_EQ(1, n);
+}
+
+// Tests that the syntax of EXPECT_CALL() is enforced at run time.
+
+TEST(ExpectCallSyntaxTest, WithIsOptional) {
+  MockA a;
+
+  EXPECT_CALL(a, DoA(5)).Times(0);
+  EXPECT_CALL(a, DoA(6)).With(_).Times(0);
+}
+
+TEST(ExpectCallSyntaxTest, WithCanAppearAtMostOnce) {
+  MockA a;
+
+  EXPECT_NONFATAL_FAILURE(
+      {  // NOLINT
+        EXPECT_CALL(a, DoA(6)).With(_).With(_);
+      },
+      ".With() cannot appear more than once in an EXPECT_CALL()");
+
+  a.DoA(6);
+}
+
+TEST(ExpectCallSyntaxTest, WithMustBeFirstClause) {
+  MockA a;
+
+  EXPECT_NONFATAL_FAILURE(
+      {  // NOLINT
+        EXPECT_CALL(a, DoA(1)).Times(1).With(_);
+      },
+      ".With() must be the first clause in an EXPECT_CALL()");
+
+  a.DoA(1);
+
+  EXPECT_NONFATAL_FAILURE(
+      {  // NOLINT
+        EXPECT_CALL(a, DoA(2)).WillOnce(Return()).With(_);
+      },
+      ".With() must be the first clause in an EXPECT_CALL()");
+
+  a.DoA(2);
+}
+
+TEST(ExpectCallSyntaxTest, TimesCanBeInferred) {
+  MockA a;
+
+  EXPECT_CALL(a, DoA(1)).WillOnce(Return());
+
+  EXPECT_CALL(a, DoA(2)).WillOnce(Return()).WillRepeatedly(Return());
+
+  a.DoA(1);
+  a.DoA(2);
+  a.DoA(2);
+}
+
+TEST(ExpectCallSyntaxTest, TimesCanAppearAtMostOnce) {
+  MockA a;
+
+  EXPECT_NONFATAL_FAILURE(
+      {  // NOLINT
+        EXPECT_CALL(a, DoA(1)).Times(1).Times(2);
+      },
+      ".Times() cannot appear more than once in an EXPECT_CALL()");
+
+  a.DoA(1);
+  a.DoA(1);
+}
+
+TEST(ExpectCallSyntaxTest, TimesMustBeBeforeInSequence) {
+  MockA a;
+  Sequence s;
+
+  EXPECT_NONFATAL_FAILURE(
+      {  // NOLINT
+        EXPECT_CALL(a, DoA(1)).InSequence(s).Times(1);
+      },
+      ".Times() may only appear *before* ");
+
+  a.DoA(1);
+}
+
+TEST(ExpectCallSyntaxTest, InSequenceIsOptional) {
+  MockA a;
+  Sequence s;
+
+  EXPECT_CALL(a, DoA(1));
+  EXPECT_CALL(a, DoA(2)).InSequence(s);
+
+  a.DoA(1);
+  a.DoA(2);
+}
+
+TEST(ExpectCallSyntaxTest, InSequenceCanAppearMultipleTimes) {
+  MockA a;
+  Sequence s1, s2;
+
+  EXPECT_CALL(a, DoA(1)).InSequence(s1, s2).InSequence(s1);
+
+  a.DoA(1);
+}
+
+TEST(ExpectCallSyntaxTest, InSequenceMustBeBeforeAfter) {
+  MockA a;
+  Sequence s;
+
+  Expectation e = EXPECT_CALL(a, DoA(1)).Times(AnyNumber());
+  EXPECT_NONFATAL_FAILURE(
+      {  // NOLINT
+        EXPECT_CALL(a, DoA(2)).After(e).InSequence(s);
+      },
+      ".InSequence() cannot appear after ");
+
+  a.DoA(2);
+}
+
+TEST(ExpectCallSyntaxTest, InSequenceMustBeBeforeWillOnce) {
+  MockA a;
+  Sequence s;
+
+  EXPECT_NONFATAL_FAILURE(
+      {  // NOLINT
+        EXPECT_CALL(a, DoA(1)).WillOnce(Return()).InSequence(s);
+      },
+      ".InSequence() cannot appear after ");
+
+  a.DoA(1);
+}
+
+TEST(ExpectCallSyntaxTest, AfterMustBeBeforeWillOnce) {
+  MockA a;
+
+  Expectation e = EXPECT_CALL(a, DoA(1));
+  EXPECT_NONFATAL_FAILURE(
+      { EXPECT_CALL(a, DoA(2)).WillOnce(Return()).After(e); },
+      ".After() cannot appear after ");
+
+  a.DoA(1);
+  a.DoA(2);
+}
+
+TEST(ExpectCallSyntaxTest, WillIsOptional) {
+  MockA a;
+
+  EXPECT_CALL(a, DoA(1));
+  EXPECT_CALL(a, DoA(2)).WillOnce(Return());
+
+  a.DoA(1);
+  a.DoA(2);
+}
+
+TEST(ExpectCallSyntaxTest, WillCanAppearMultipleTimes) {
+  MockA a;
+
+  EXPECT_CALL(a, DoA(1))
+      .Times(AnyNumber())
+      .WillOnce(Return())
+      .WillOnce(Return())
+      .WillOnce(Return());
+}
+
+TEST(ExpectCallSyntaxTest, WillMustBeBeforeWillRepeatedly) {
+  MockA a;
+
+  EXPECT_NONFATAL_FAILURE(
+      {  // NOLINT
+        EXPECT_CALL(a, DoA(1)).WillRepeatedly(Return()).WillOnce(Return());
+      },
+      ".WillOnce() cannot appear after ");
+
+  a.DoA(1);
+}
+
+TEST(ExpectCallSyntaxTest, WillRepeatedlyIsOptional) {
+  MockA a;
+
+  EXPECT_CALL(a, DoA(1)).WillOnce(Return());
+  EXPECT_CALL(a, DoA(2)).WillOnce(Return()).WillRepeatedly(Return());
+
+  a.DoA(1);
+  a.DoA(2);
+  a.DoA(2);
+}
+
+TEST(ExpectCallSyntaxTest, WillRepeatedlyCannotAppearMultipleTimes) {
+  MockA a;
+
+  EXPECT_NONFATAL_FAILURE(
+      {  // NOLINT
+        EXPECT_CALL(a, DoA(1)).WillRepeatedly(Return()).WillRepeatedly(
+            Return());
+      },
+      ".WillRepeatedly() cannot appear more than once in an "
+      "EXPECT_CALL()");
+}
+
+TEST(ExpectCallSyntaxTest, WillRepeatedlyMustBeBeforeRetiresOnSaturation) {
+  MockA a;
+
+  EXPECT_NONFATAL_FAILURE(
+      {  // NOLINT
+        EXPECT_CALL(a, DoA(1)).RetiresOnSaturation().WillRepeatedly(Return());
+      },
+      ".WillRepeatedly() cannot appear after ");
+}
+
+TEST(ExpectCallSyntaxTest, RetiresOnSaturationIsOptional) {
+  MockA a;
+
+  EXPECT_CALL(a, DoA(1));
+  EXPECT_CALL(a, DoA(1)).RetiresOnSaturation();
+
+  a.DoA(1);
+  a.DoA(1);
+}
+
+TEST(ExpectCallSyntaxTest, RetiresOnSaturationCannotAppearMultipleTimes) {
+  MockA a;
+
+  EXPECT_NONFATAL_FAILURE(
+      {  // NOLINT
+        EXPECT_CALL(a, DoA(1)).RetiresOnSaturation().RetiresOnSaturation();
+      },
+      ".RetiresOnSaturation() cannot appear more than once");
+
+  a.DoA(1);
+}
+
+TEST(ExpectCallSyntaxTest, DefaultCardinalityIsOnce) {
+  {
+    MockA a;
+    EXPECT_CALL(a, DoA(1));
+    a.DoA(1);
+  }
+  EXPECT_NONFATAL_FAILURE(
+      {  // NOLINT
+        MockA a;
+        EXPECT_CALL(a, DoA(1));
+      },
+      "to be called once");
+  EXPECT_NONFATAL_FAILURE(
+      {  // NOLINT
+        MockA a;
+        EXPECT_CALL(a, DoA(1));
+        a.DoA(1);
+        a.DoA(1);
+      },
+      "to be called once");
+}
+
+#if GTEST_HAS_STREAM_REDIRECTION
+
+// Tests that Google Mock doesn't print a warning when the number of
+// WillOnce() is adequate.
+TEST(ExpectCallSyntaxTest, DoesNotWarnOnAdequateActionCount) {
+  CaptureStdout();
+  {
+    MockB b;
+
+    // It's always fine to omit WillOnce() entirely.
+    EXPECT_CALL(b, DoB()).Times(0);
+    EXPECT_CALL(b, DoB(1)).Times(AtMost(1));
+    EXPECT_CALL(b, DoB(2)).Times(1).WillRepeatedly(Return(1));
+
+    // It's fine for the number of WillOnce()s to equal the upper bound.
+    EXPECT_CALL(b, DoB(3))
+        .Times(Between(1, 2))
+        .WillOnce(Return(1))
+        .WillOnce(Return(2));
+
+    // It's fine for the number of WillOnce()s to be smaller than the
+    // upper bound when there is a WillRepeatedly().
+    EXPECT_CALL(b, DoB(4)).Times(AtMost(3)).WillOnce(Return(1)).WillRepeatedly(
+        Return(2));
+
+    // Satisfies the above expectations.
+    b.DoB(2);
+    b.DoB(3);
+  }
+  EXPECT_STREQ("", GetCapturedStdout().c_str());
+}
+
+// Tests that Google Mock warns on having too many actions in an
+// expectation compared to its cardinality.
+TEST(ExpectCallSyntaxTest, WarnsOnTooManyActions) {
+  CaptureStdout();
+  {
+    MockB b;
+
+    // Warns when the number of WillOnce()s is larger than the upper bound.
+    EXPECT_CALL(b, DoB()).Times(0).WillOnce(Return(1));  // #1
+    EXPECT_CALL(b, DoB()).Times(AtMost(1)).WillOnce(Return(1)).WillOnce(
+        Return(2));  // #2
+    EXPECT_CALL(b, DoB(1))
+        .Times(1)
+        .WillOnce(Return(1))
+        .WillOnce(Return(2))
+        .RetiresOnSaturation();  // #3
+
+    // Warns when the number of WillOnce()s equals the upper bound and
+    // there is a WillRepeatedly().
+    EXPECT_CALL(b, DoB()).Times(0).WillRepeatedly(Return(1));  // #4
+    EXPECT_CALL(b, DoB(2)).Times(1).WillOnce(Return(1)).WillRepeatedly(
+        Return(2));  // #5
+
+    // Satisfies the above expectations.
+    b.DoB(1);
+    b.DoB(2);
+  }
+  const std::string output = GetCapturedStdout();
+  EXPECT_PRED_FORMAT2(IsSubstring,
+                      "Too many actions specified in EXPECT_CALL(b, DoB())...\n"
+                      "Expected to be never called, but has 1 WillOnce().",
+                      output);  // #1
+  EXPECT_PRED_FORMAT2(IsSubstring,
+                      "Too many actions specified in EXPECT_CALL(b, DoB())...\n"
+                      "Expected to be called at most once, "
+                      "but has 2 WillOnce()s.",
+                      output);  // #2
+  EXPECT_PRED_FORMAT2(
+      IsSubstring,
+      "Too many actions specified in EXPECT_CALL(b, DoB(1))...\n"
+      "Expected to be called once, but has 2 WillOnce()s.",
+      output);  // #3
+  EXPECT_PRED_FORMAT2(IsSubstring,
+                      "Too many actions specified in EXPECT_CALL(b, DoB())...\n"
+                      "Expected to be never called, but has 0 WillOnce()s "
+                      "and a WillRepeatedly().",
+                      output);  // #4
+  EXPECT_PRED_FORMAT2(
+      IsSubstring,
+      "Too many actions specified in EXPECT_CALL(b, DoB(2))...\n"
+      "Expected to be called once, but has 1 WillOnce() "
+      "and a WillRepeatedly().",
+      output);  // #5
+}
+
+// Tests that Google Mock warns on having too few actions in an
+// expectation compared to its cardinality.
+TEST(ExpectCallSyntaxTest, WarnsOnTooFewActions) {
+  MockB b;
+
+  EXPECT_CALL(b, DoB()).Times(Between(2, 3)).WillOnce(Return(1));
+
+  CaptureStdout();
+  b.DoB();
+  const std::string output = GetCapturedStdout();
+  EXPECT_PRED_FORMAT2(IsSubstring,
+                      "Too few actions specified in EXPECT_CALL(b, DoB())...\n"
+                      "Expected to be called between 2 and 3 times, "
+                      "but has only 1 WillOnce().",
+                      output);
+  b.DoB();
+}
+
+TEST(ExpectCallSyntaxTest, WarningIsErrorWithFlag) {
+  int original_behavior = GMOCK_FLAG_GET(default_mock_behavior);
+
+  GMOCK_FLAG_SET(default_mock_behavior, kAllow);
+  CaptureStdout();
+  {
+    MockA a;
+    a.DoA(0);
+  }
+  std::string output = GetCapturedStdout();
+  EXPECT_TRUE(output.empty()) << output;
+
+  GMOCK_FLAG_SET(default_mock_behavior, kWarn);
+  CaptureStdout();
+  {
+    MockA a;
+    a.DoA(0);
+  }
+  std::string warning_output = GetCapturedStdout();
+  EXPECT_PRED_FORMAT2(IsSubstring, "GMOCK WARNING", warning_output);
+  EXPECT_PRED_FORMAT2(IsSubstring, "Uninteresting mock function call",
+                      warning_output);
+
+  GMOCK_FLAG_SET(default_mock_behavior, kFail);
+  EXPECT_NONFATAL_FAILURE(
+      {
+        MockA a;
+        a.DoA(0);
+      },
+      "Uninteresting mock function call");
+
+  // Out of bounds values are converted to kWarn
+  GMOCK_FLAG_SET(default_mock_behavior, -1);
+  CaptureStdout();
+  {
+    MockA a;
+    a.DoA(0);
+  }
+  warning_output = GetCapturedStdout();
+  EXPECT_PRED_FORMAT2(IsSubstring, "GMOCK WARNING", warning_output);
+  EXPECT_PRED_FORMAT2(IsSubstring, "Uninteresting mock function call",
+                      warning_output);
+  GMOCK_FLAG_SET(default_mock_behavior, 3);
+  CaptureStdout();
+  {
+    MockA a;
+    a.DoA(0);
+  }
+  warning_output = GetCapturedStdout();
+  EXPECT_PRED_FORMAT2(IsSubstring, "GMOCK WARNING", warning_output);
+  EXPECT_PRED_FORMAT2(IsSubstring, "Uninteresting mock function call",
+                      warning_output);
+
+  GMOCK_FLAG_SET(default_mock_behavior, original_behavior);
+}
+
+#endif  // GTEST_HAS_STREAM_REDIRECTION
+
+// Tests the semantics of ON_CALL().
+
+// Tests that the built-in default action is taken when no ON_CALL()
+// is specified.
+TEST(OnCallTest, TakesBuiltInDefaultActionWhenNoOnCall) {
+  MockB b;
+  EXPECT_CALL(b, DoB());
+
+  EXPECT_EQ(0, b.DoB());
+}
+
+// Tests that the built-in default action is taken when no ON_CALL()
+// matches the invocation.
+TEST(OnCallTest, TakesBuiltInDefaultActionWhenNoOnCallMatches) {
+  MockB b;
+  ON_CALL(b, DoB(1)).WillByDefault(Return(1));
+  EXPECT_CALL(b, DoB(_));
+
+  EXPECT_EQ(0, b.DoB(2));
+}
+
+// Tests that the last matching ON_CALL() action is taken.
+TEST(OnCallTest, PicksLastMatchingOnCall) {
+  MockB b;
+  ON_CALL(b, DoB(_)).WillByDefault(Return(3));
+  ON_CALL(b, DoB(2)).WillByDefault(Return(2));
+  ON_CALL(b, DoB(1)).WillByDefault(Return(1));
+  EXPECT_CALL(b, DoB(_));
+
+  EXPECT_EQ(2, b.DoB(2));
+}
+
+// Tests the semantics of EXPECT_CALL().
+
+// Tests that any call is allowed when no EXPECT_CALL() is specified.
+TEST(ExpectCallTest, AllowsAnyCallWhenNoSpec) {
+  MockB b;
+  EXPECT_CALL(b, DoB());
+  // There is no expectation on DoB(int).
+
+  b.DoB();
+
+  // DoB(int) can be called any number of times.
+  b.DoB(1);
+  b.DoB(2);
+}
+
+// Tests that the last matching EXPECT_CALL() fires.
+TEST(ExpectCallTest, PicksLastMatchingExpectCall) {
+  MockB b;
+  EXPECT_CALL(b, DoB(_)).WillRepeatedly(Return(2));
+  EXPECT_CALL(b, DoB(1)).WillRepeatedly(Return(1));
+
+  EXPECT_EQ(1, b.DoB(1));
+}
+
+// Tests lower-bound violation.
+TEST(ExpectCallTest, CatchesTooFewCalls) {
+  EXPECT_NONFATAL_FAILURE(
+      {  // NOLINT
+        MockB b;
+        EXPECT_CALL(b, DoB(5)).Description("DoB Method").Times(AtLeast(2));
+
+        b.DoB(5);
+      },
+      "Actual function \"DoB Method\" call count "
+      "doesn't match EXPECT_CALL(b, DoB(5))...\n"
+      "         Expected: to be called at least twice\n"
+      "           Actual: called once - unsatisfied and active");
+}
+
+// Tests that the cardinality can be inferred when no Times(...) is
+// specified.
+TEST(ExpectCallTest, InfersCardinalityWhenThereIsNoWillRepeatedly) {
+  {
+    MockB b;
+    EXPECT_CALL(b, DoB()).WillOnce(Return(1)).WillOnce(Return(2));
+
+    EXPECT_EQ(1, b.DoB());
+    EXPECT_EQ(2, b.DoB());
+  }
+
+  EXPECT_NONFATAL_FAILURE(
+      {  // NOLINT
+        MockB b;
+        EXPECT_CALL(b, DoB()).WillOnce(Return(1)).WillOnce(Return(2));
+
+        EXPECT_EQ(1, b.DoB());
+      },
+      "to be called twice");
+
+  {  // NOLINT
+    MockB b;
+    EXPECT_CALL(b, DoB()).WillOnce(Return(1)).WillOnce(Return(2));
+
+    EXPECT_EQ(1, b.DoB());
+    EXPECT_EQ(2, b.DoB());
+    EXPECT_NONFATAL_FAILURE(b.DoB(), "to be called twice");
+  }
+}
+
+TEST(ExpectCallTest, InfersCardinality1WhenThereIsWillRepeatedly) {
+  {
+    MockB b;
+    EXPECT_CALL(b, DoB()).WillOnce(Return(1)).WillRepeatedly(Return(2));
+
+    EXPECT_EQ(1, b.DoB());
+  }
+
+  {  // NOLINT
+    MockB b;
+    EXPECT_CALL(b, DoB()).WillOnce(Return(1)).WillRepeatedly(Return(2));
+
+    EXPECT_EQ(1, b.DoB());
+    EXPECT_EQ(2, b.DoB());
+    EXPECT_EQ(2, b.DoB());
+  }
+
+  EXPECT_NONFATAL_FAILURE(
+      {  // NOLINT
+        MockB b;
+        EXPECT_CALL(b, DoB()).WillOnce(Return(1)).WillRepeatedly(Return(2));
+      },
+      "to be called at least once");
+}
+
+#if defined(GTEST_INTERNAL_CPLUSPLUS_LANG) && \
+    GTEST_INTERNAL_CPLUSPLUS_LANG >= 201703L
+
+// It should be possible to return a non-moveable type from a mock action in
+// C++17 and above, where it's guaranteed that such a type can be initialized
+// from a prvalue returned from a function.
+TEST(ExpectCallTest, NonMoveableType) {
+  // Define a non-moveable result type.
+  struct NonMoveableStruct {
+    explicit NonMoveableStruct(int x_in) : x(x_in) {}
+    NonMoveableStruct(NonMoveableStruct&&) = delete;
+
+    int x;
+  };
+
+  static_assert(!std::is_move_constructible_v<NonMoveableStruct>);
+  static_assert(!std::is_copy_constructible_v<NonMoveableStruct>);
+
+  static_assert(!std::is_move_assignable_v<NonMoveableStruct>);
+  static_assert(!std::is_copy_assignable_v<NonMoveableStruct>);
+
+  // We should be able to use a callable that returns that result as both a
+  // OnceAction and an Action, whether the callable ignores arguments or not.
+  const auto return_17 = [] { return NonMoveableStruct(17); };
+
+  static_cast<void>(OnceAction<NonMoveableStruct()>{return_17});
+  static_cast<void>(Action<NonMoveableStruct()>{return_17});
+
+  static_cast<void>(OnceAction<NonMoveableStruct(int)>{return_17});
+  static_cast<void>(Action<NonMoveableStruct(int)>{return_17});
+
+  // It should be possible to return the result end to end through an
+  // EXPECT_CALL statement, with both WillOnce and WillRepeatedly.
+  MockFunction<NonMoveableStruct()> mock;
+  EXPECT_CALL(mock, Call)   //
+      .WillOnce(return_17)  //
+      .WillRepeatedly(return_17);
+
+  EXPECT_EQ(17, mock.AsStdFunction()().x);
+  EXPECT_EQ(17, mock.AsStdFunction()().x);
+  EXPECT_EQ(17, mock.AsStdFunction()().x);
+}
+
+#endif  // C++17 and above
+
+// Tests that the n-th action is taken for the n-th matching
+// invocation.
+TEST(ExpectCallTest, NthMatchTakesNthAction) {
+  MockB b;
+  EXPECT_CALL(b, DoB()).WillOnce(Return(1)).WillOnce(Return(2)).WillOnce(
+      Return(3));
+
+  EXPECT_EQ(1, b.DoB());
+  EXPECT_EQ(2, b.DoB());
+  EXPECT_EQ(3, b.DoB());
+}
+
+// Tests that the WillRepeatedly() action is taken when the WillOnce(...)
+// list is exhausted.
+TEST(ExpectCallTest, TakesRepeatedActionWhenWillListIsExhausted) {
+  MockB b;
+  EXPECT_CALL(b, DoB()).WillOnce(Return(1)).WillRepeatedly(Return(2));
+
+  EXPECT_EQ(1, b.DoB());
+  EXPECT_EQ(2, b.DoB());
+  EXPECT_EQ(2, b.DoB());
+}
+
+#if GTEST_HAS_STREAM_REDIRECTION
+
+// Tests that the default action is taken when the WillOnce(...) list is
+// exhausted and there is no WillRepeatedly().
+TEST(ExpectCallTest, TakesDefaultActionWhenWillListIsExhausted) {
+  MockB b;
+  EXPECT_CALL(b, DoB(_)).Times(1);
+  EXPECT_CALL(b, DoB())
+      .Times(AnyNumber())
+      .WillOnce(Return(1))
+      .WillOnce(Return(2));
+
+  CaptureStdout();
+  EXPECT_EQ(0, b.DoB(1));  // Shouldn't generate a warning as the
+                           // expectation has no action clause at all.
+  EXPECT_EQ(1, b.DoB());
+  EXPECT_EQ(2, b.DoB());
+  const std::string output1 = GetCapturedStdout();
+  EXPECT_STREQ("", output1.c_str());
+
+  CaptureStdout();
+  EXPECT_EQ(0, b.DoB());
+  EXPECT_EQ(0, b.DoB());
+  const std::string output2 = GetCapturedStdout();
+  EXPECT_THAT(output2.c_str(),
+              HasSubstr("Actions ran out in EXPECT_CALL(b, DoB())...\n"
+                        "Called 3 times, but only 2 WillOnce()s are specified"
+                        " - returning default value."));
+  EXPECT_THAT(output2.c_str(),
+              HasSubstr("Actions ran out in EXPECT_CALL(b, DoB())...\n"
+                        "Called 4 times, but only 2 WillOnce()s are specified"
+                        " - returning default value."));
+}
+
+TEST(FunctionMockerMessageTest, ReportsExpectCallLocationForExhausedActions) {
+  MockB b;
+  std::string expect_call_location = FormatFileLocation(__FILE__, __LINE__ + 1);
+  EXPECT_CALL(b, DoB()).Times(AnyNumber()).WillOnce(Return(1));
+
+  EXPECT_EQ(1, b.DoB());
+
+  CaptureStdout();
+  EXPECT_EQ(0, b.DoB());
+  const std::string output = GetCapturedStdout();
+  // The warning message should contain the call location.
+  EXPECT_PRED_FORMAT2(IsSubstring, expect_call_location, output);
+}
+
+TEST(FunctionMockerMessageTest,
+     ReportsDefaultActionLocationOfUninterestingCallsForNaggyMock) {
+  std::string on_call_location;
+  CaptureStdout();
+  {
+    NaggyMock<MockB> b;
+    on_call_location = FormatFileLocation(__FILE__, __LINE__ + 1);
+    ON_CALL(b, DoB(_)).WillByDefault(Return(0));
+    b.DoB(0);
+  }
+  EXPECT_PRED_FORMAT2(IsSubstring, on_call_location, GetCapturedStdout());
+}
+
+#endif  // GTEST_HAS_STREAM_REDIRECTION
+
+// Tests that an uninteresting call performs the default action.
+TEST(UninterestingCallTest, DoesDefaultAction) {
+  // When there is an ON_CALL() statement, the action specified by it
+  // should be taken.
+  MockA a;
+  ON_CALL(a, Binary(_, _)).WillByDefault(Return(true));
+  EXPECT_TRUE(a.Binary(1, 2));
+
+  // When there is no ON_CALL(), the default value for the return type
+  // should be returned.
+  MockB b;
+  EXPECT_EQ(0, b.DoB());
+}
+
+// Tests that an unexpected call performs the default action.
+TEST(UnexpectedCallTest, DoesDefaultAction) {
+  // When there is an ON_CALL() statement, the action specified by it
+  // should be taken.
+  MockA a;
+  ON_CALL(a, Binary(_, _)).WillByDefault(Return(true));
+  EXPECT_CALL(a, Binary(0, 0));
+  a.Binary(0, 0);
+  bool result = false;
+  EXPECT_NONFATAL_FAILURE(result = a.Binary(1, 2),
+                          "Unexpected mock function call");
+  EXPECT_TRUE(result);
+
+  // When there is no ON_CALL(), the default value for the return type
+  // should be returned.
+  MockB b;
+  EXPECT_CALL(b, DoB(0)).Times(0);
+  int n = -1;
+  EXPECT_NONFATAL_FAILURE(n = b.DoB(1), "Unexpected mock function call");
+  EXPECT_EQ(0, n);
+}
+
+// Tests that when an unexpected void function generates the right
+// failure message.
+TEST(UnexpectedCallTest, GeneratesFailureForVoidFunction) {
+  // First, tests the message when there is only one EXPECT_CALL().
+  MockA a1;
+  EXPECT_CALL(a1, DoA(1));
+  a1.DoA(1);
+  // Ideally we should match the failure message against a regex, but
+  // EXPECT_NONFATAL_FAILURE doesn't support that, so we test for
+  // multiple sub-strings instead.
+  EXPECT_NONFATAL_FAILURE(
+      a1.DoA(9),
+      "Unexpected mock function call - returning directly.\n"
+      "    Function call: DoA(9)\n"
+      "Google Mock tried the following 1 expectation, but it didn't match:");
+  EXPECT_NONFATAL_FAILURE(
+      a1.DoA(9),
+      "  Expected arg #0: is equal to 1\n"
+      "           Actual: 9\n"
+      "         Expected: to be called once\n"
+      "           Actual: called once - saturated and active");
+
+  // Next, tests the message when there are more than one EXPECT_CALL().
+  MockA a2;
+  EXPECT_CALL(a2, DoA(1));
+  EXPECT_CALL(a2, DoA(3));
+  a2.DoA(1);
+  EXPECT_NONFATAL_FAILURE(
+      a2.DoA(2),
+      "Unexpected mock function call - returning directly.\n"
+      "    Function call: DoA(2)\n"
+      "Google Mock tried the following 2 expectations, but none matched:");
+  EXPECT_NONFATAL_FAILURE(
+      a2.DoA(2),
+      "tried expectation #0: EXPECT_CALL(a2, DoA(1))...\n"
+      "  Expected arg #0: is equal to 1\n"
+      "           Actual: 2\n"
+      "         Expected: to be called once\n"
+      "           Actual: called once - saturated and active");
+  EXPECT_NONFATAL_FAILURE(
+      a2.DoA(2),
+      "tried expectation #1: EXPECT_CALL(a2, DoA(3))...\n"
+      "  Expected arg #0: is equal to 3\n"
+      "           Actual: 2\n"
+      "         Expected: to be called once\n"
+      "           Actual: never called - unsatisfied and active");
+  a2.DoA(3);
+}
+
+// Tests that an unexpected non-void function generates the right
+// failure message.
+TEST(UnexpectedCallTest, GeneartesFailureForNonVoidFunction) {
+  MockB b1;
+  EXPECT_CALL(b1, DoB(1));
+  b1.DoB(1);
+  EXPECT_NONFATAL_FAILURE(
+      b1.DoB(2),
+      "Unexpected mock function call - returning default value.\n"
+      "    Function call: DoB(2)\n"
+      "          Returns: 0\n"
+      "Google Mock tried the following 1 expectation, but it didn't match:");
+  EXPECT_NONFATAL_FAILURE(
+      b1.DoB(2),
+      "  Expected arg #0: is equal to 1\n"
+      "           Actual: 2\n"
+      "         Expected: to be called once\n"
+      "           Actual: called once - saturated and active");
+}
+
+// Tests that Google Mock explains that an retired expectation doesn't
+// match the call.
+TEST(UnexpectedCallTest, RetiredExpectation) {
+  MockB b;
+  EXPECT_CALL(b, DoB(1)).RetiresOnSaturation();
+
+  b.DoB(1);
+  EXPECT_NONFATAL_FAILURE(b.DoB(1),
+                          "         Expected: the expectation is active\n"
+                          "           Actual: it is retired");
+}
+
+// Tests that Google Mock explains that an expectation that doesn't
+// match the arguments doesn't match the call.
+TEST(UnexpectedCallTest, UnmatchedArguments) {
+  MockB b;
+  EXPECT_CALL(b, DoB(1));
+
+  EXPECT_NONFATAL_FAILURE(b.DoB(2),
+                          "  Expected arg #0: is equal to 1\n"
+                          "           Actual: 2\n");
+  b.DoB(1);
+}
+
+// Tests that Google Mock explains that an expectation with
+// unsatisfied pre-requisites doesn't match the call.
+TEST(UnexpectedCallTest, UnsatisfiedPrerequisites) {
+  Sequence s1, s2;
+  MockB b;
+  EXPECT_CALL(b, DoB(1)).InSequence(s1);
+  EXPECT_CALL(b, DoB(2)).Times(AnyNumber()).InSequence(s1);
+  EXPECT_CALL(b, DoB(3)).InSequence(s2);
+  EXPECT_CALL(b, DoB(4)).InSequence(s1, s2);
+
+  ::testing::TestPartResultArray failures;
+  {
+    ::testing::ScopedFakeTestPartResultReporter reporter(&failures);
+    b.DoB(4);
+    // Now 'failures' contains the Google Test failures generated by
+    // the above statement.
+  }
+
+  // There should be one non-fatal failure.
+  ASSERT_EQ(1, failures.size());
+  const ::testing::TestPartResult& r = failures.GetTestPartResult(0);
+  EXPECT_EQ(::testing::TestPartResult::kNonFatalFailure, r.type());
+
+  // Verifies that the failure message contains the two unsatisfied
+  // pre-requisites but not the satisfied one.
+#ifdef GTEST_USES_POSIX_RE
+  EXPECT_THAT(r.message(),
+              ContainsRegex(
+                  // POSIX RE doesn't understand the (?s) prefix, but has no
+                  // trouble with (.|\n).
+                  "the following immediate pre-requisites are not satisfied:\n"
+                  "(.|\n)*: pre-requisite #0\n"
+                  "(.|\n)*: pre-requisite #1"));
+#else
+  // We can only use Google Test's own simple regex.
+  EXPECT_THAT(r.message(),
+              ContainsRegex(
+                  "the following immediate pre-requisites are not satisfied:"));
+  EXPECT_THAT(r.message(), ContainsRegex(": pre-requisite #0"));
+  EXPECT_THAT(r.message(), ContainsRegex(": pre-requisite #1"));
+#endif  // GTEST_USES_POSIX_RE
+
+  b.DoB(1);
+  b.DoB(3);
+  b.DoB(4);
+}
+
+TEST(UndefinedReturnValueTest,
+     ReturnValueIsMandatoryWhenNotDefaultConstructible) {
+  MockA a;
+  // FIXME: We should really verify the output message,
+  // but we cannot yet due to that EXPECT_DEATH only captures stderr
+  // while Google Mock logs to stdout.
+#if GTEST_HAS_EXCEPTIONS
+  EXPECT_ANY_THROW(a.ReturnNonDefaultConstructible());
+#else
+  EXPECT_DEATH_IF_SUPPORTED(a.ReturnNonDefaultConstructible(), "");
+#endif
+}
+
+// Tests that an excessive call (one whose arguments match the
+// matchers but is called too many times) performs the default action.
+TEST(ExcessiveCallTest, DoesDefaultAction) {
+  // When there is an ON_CALL() statement, the action specified by it
+  // should be taken.
+  MockA a;
+  ON_CALL(a, Binary(_, _)).WillByDefault(Return(true));
+  EXPECT_CALL(a, Binary(0, 0));
+  a.Binary(0, 0);
+  bool result = false;
+  EXPECT_NONFATAL_FAILURE(result = a.Binary(0, 0),
+                          "Mock function called more times than expected");
+  EXPECT_TRUE(result);
+
+  // When there is no ON_CALL(), the default value for the return type
+  // should be returned.
+  MockB b;
+  EXPECT_CALL(b, DoB(0)).Description("DoB Method").Times(0);
+  int n = -1;
+  EXPECT_NONFATAL_FAILURE(
+      n = b.DoB(0),
+      "Mock function \"DoB Method\" called more times than expected");
+  EXPECT_EQ(0, n);
+}
+
+// Tests that when a void function is called too many times,
+// the failure message contains the argument values.
+TEST(ExcessiveCallTest, GeneratesFailureForVoidFunction) {
+  MockA a;
+  EXPECT_CALL(a, DoA(_)).Description("DoA Method").Times(0);
+  EXPECT_NONFATAL_FAILURE(
+      a.DoA(9),
+      "Mock function \"DoA Method\" called more times than expected - "
+      "returning directly.\n"
+      "    Function call: DoA(9)\n"
+      "         Expected: to be never called\n"
+      "           Actual: called once - over-saturated and active");
+}
+
+// Tests that when a non-void function is called too many times, the
+// failure message contains the argument values and the return value.
+TEST(ExcessiveCallTest, GeneratesFailureForNonVoidFunction) {
+  MockB b;
+  EXPECT_CALL(b, DoB(_));
+  b.DoB(1);
+  EXPECT_NONFATAL_FAILURE(
+      b.DoB(2),
+      "Mock function called more times than expected - "
+      "returning default value.\n"
+      "    Function call: DoB(2)\n"
+      "          Returns: 0\n"
+      "         Expected: to be called once\n"
+      "           Actual: called twice - over-saturated and active");
+}
+
+// Tests using sequences.
+
+TEST(InSequenceTest, AllExpectationInScopeAreInSequence) {
+  MockA a;
+  {
+    InSequence dummy;
+
+    EXPECT_CALL(a, DoA(1));
+    EXPECT_CALL(a, DoA(2));
+  }
+
+  EXPECT_NONFATAL_FAILURE(
+      {  // NOLINT
+        a.DoA(2);
+      },
+      "Unexpected mock function call");
+
+  a.DoA(1);
+  a.DoA(2);
+}
+
+TEST(InSequenceTest, NestedInSequence) {
+  MockA a;
+  {
+    InSequence dummy;
+
+    EXPECT_CALL(a, DoA(1));
+    {
+      InSequence dummy2;
+
+      EXPECT_CALL(a, DoA(2));
+      EXPECT_CALL(a, DoA(3));
+    }
+  }
+
+  EXPECT_NONFATAL_FAILURE(
+      {  // NOLINT
+        a.DoA(1);
+        a.DoA(3);
+      },
+      "Unexpected mock function call");
+
+  a.DoA(2);
+  a.DoA(3);
+}
+
+TEST(InSequenceTest, ExpectationsOutOfScopeAreNotAffected) {
+  MockA a;
+  {
+    InSequence dummy;
+
+    EXPECT_CALL(a, DoA(1));
+    EXPECT_CALL(a, DoA(2));
+  }
+  EXPECT_CALL(a, DoA(3));
+
+  EXPECT_NONFATAL_FAILURE(
+      {  // NOLINT
+        a.DoA(2);
+      },
+      "Unexpected mock function call");
+
+  a.DoA(3);
+  a.DoA(1);
+  a.DoA(2);
+}
+
+// Tests that any order is allowed when no sequence is used.
+TEST(SequenceTest, AnyOrderIsOkByDefault) {
+  {
+    MockA a;
+    MockB b;
+
+    EXPECT_CALL(a, DoA(1));
+    EXPECT_CALL(b, DoB()).Times(AnyNumber());
+
+    a.DoA(1);
+    b.DoB();
+  }
+
+  {  // NOLINT
+    MockA a;
+    MockB b;
+
+    EXPECT_CALL(a, DoA(1));
+    EXPECT_CALL(b, DoB()).Times(AnyNumber());
+
+    b.DoB();
+    a.DoA(1);
+  }
+}
+
+// Tests that the calls must be in strict order when a complete order
+// is specified.
+TEST(SequenceTest, CallsMustBeInStrictOrderWhenSaidSo1) {
+  MockA a;
+  ON_CALL(a, ReturnResult(_)).WillByDefault(Return(Result()));
+
+  Sequence s;
+  EXPECT_CALL(a, ReturnResult(1)).InSequence(s);
+  EXPECT_CALL(a, ReturnResult(2)).InSequence(s);
+  EXPECT_CALL(a, ReturnResult(3)).InSequence(s);
+
+  a.ReturnResult(1);
+
+  // May only be called after a.ReturnResult(2).
+  EXPECT_NONFATAL_FAILURE(a.ReturnResult(3), "Unexpected mock function call");
+
+  a.ReturnResult(2);
+  a.ReturnResult(3);
+}
+
+// Tests that the calls must be in strict order when a complete order
+// is specified.
+TEST(SequenceTest, CallsMustBeInStrictOrderWhenSaidSo2) {
+  MockA a;
+  ON_CALL(a, ReturnResult(_)).WillByDefault(Return(Result()));
+
+  Sequence s;
+  EXPECT_CALL(a, ReturnResult(1)).InSequence(s);
+  EXPECT_CALL(a, ReturnResult(2)).InSequence(s);
+
+  // May only be called after a.ReturnResult(1).
+  EXPECT_NONFATAL_FAILURE(a.ReturnResult(2), "Unexpected mock function call");
+
+  a.ReturnResult(1);
+  a.ReturnResult(2);
+}
+
+// Tests specifying a DAG using multiple sequences.
+class PartialOrderTest : public testing::Test {
+ protected:
+  PartialOrderTest() {
+    ON_CALL(a_, ReturnResult(_)).WillByDefault(Return(Result()));
+
+    // Specifies this partial ordering:
+    //
+    // a.ReturnResult(1) ==>
+    //                       a.ReturnResult(2) * n  ==>  a.ReturnResult(3)
+    // b.DoB() * 2       ==>
+    Sequence x, y;
+    EXPECT_CALL(a_, ReturnResult(1)).InSequence(x);
+    EXPECT_CALL(b_, DoB()).Times(2).InSequence(y);
+    EXPECT_CALL(a_, ReturnResult(2)).Times(AnyNumber()).InSequence(x, y);
+    EXPECT_CALL(a_, ReturnResult(3)).InSequence(x);
+  }
+
+  MockA a_;
+  MockB b_;
+};
+
+TEST_F(PartialOrderTest, CallsMustConformToSpecifiedDag1) {
+  a_.ReturnResult(1);
+  b_.DoB();
+
+  // May only be called after the second DoB().
+  EXPECT_NONFATAL_FAILURE(a_.ReturnResult(2), "Unexpected mock function call");
+
+  b_.DoB();
+  a_.ReturnResult(3);
+}
+
+TEST_F(PartialOrderTest, CallsMustConformToSpecifiedDag2) {
+  // May only be called after ReturnResult(1).
+  EXPECT_NONFATAL_FAILURE(a_.ReturnResult(2), "Unexpected mock function call");
+
+  a_.ReturnResult(1);
+  b_.DoB();
+  b_.DoB();
+  a_.ReturnResult(3);
+}
+
+TEST_F(PartialOrderTest, CallsMustConformToSpecifiedDag3) {
+  // May only be called last.
+  EXPECT_NONFATAL_FAILURE(a_.ReturnResult(3), "Unexpected mock function call");
+
+  a_.ReturnResult(1);
+  b_.DoB();
+  b_.DoB();
+  a_.ReturnResult(3);
+}
+
+TEST_F(PartialOrderTest, CallsMustConformToSpecifiedDag4) {
+  a_.ReturnResult(1);
+  b_.DoB();
+  b_.DoB();
+  a_.ReturnResult(3);
+
+  // May only be called before ReturnResult(3).
+  EXPECT_NONFATAL_FAILURE(a_.ReturnResult(2), "Unexpected mock function call");
+}
+
+TEST(SequenceTest, Retirement) {
+  MockA a;
+  Sequence s;
+
+  EXPECT_CALL(a, DoA(1)).InSequence(s);
+  EXPECT_CALL(a, DoA(_)).InSequence(s).RetiresOnSaturation();
+  EXPECT_CALL(a, DoA(1)).InSequence(s);
+
+  a.DoA(1);
+  a.DoA(2);
+  a.DoA(1);
+}
+
+// Tests Expectation.
+
+TEST(ExpectationTest, ConstrutorsWork) {
+  MockA a;
+  Expectation e1;  // Default ctor.
+
+  // Ctor from various forms of EXPECT_CALL.
+  Expectation e2 = EXPECT_CALL(a, DoA(2));
+  Expectation e3 = EXPECT_CALL(a, DoA(3)).With(_);
+  {
+    Sequence s;
+    Expectation e4 = EXPECT_CALL(a, DoA(4)).Times(1);
+    Expectation e5 = EXPECT_CALL(a, DoA(5)).InSequence(s);
+  }
+  Expectation e6 = EXPECT_CALL(a, DoA(6)).After(e2);
+  Expectation e7 = EXPECT_CALL(a, DoA(7)).WillOnce(Return());
+  Expectation e8 = EXPECT_CALL(a, DoA(8)).WillRepeatedly(Return());
+  Expectation e9 = EXPECT_CALL(a, DoA(9)).RetiresOnSaturation();
+
+  Expectation e10 = e2;  // Copy ctor.
+
+  EXPECT_THAT(e1, Ne(e2));
+  EXPECT_THAT(e2, Eq(e10));
+
+  a.DoA(2);
+  a.DoA(3);
+  a.DoA(4);
+  a.DoA(5);
+  a.DoA(6);
+  a.DoA(7);
+  a.DoA(8);
+  a.DoA(9);
+}
+
+TEST(ExpectationTest, AssignmentWorks) {
+  MockA a;
+  Expectation e1;
+  Expectation e2 = EXPECT_CALL(a, DoA(1));
+
+  EXPECT_THAT(e1, Ne(e2));
+
+  e1 = e2;
+  EXPECT_THAT(e1, Eq(e2));
+
+  a.DoA(1);
+}
+
+// Tests ExpectationSet.
+
+TEST(ExpectationSetTest, MemberTypesAreCorrect) {
+  ::testing::StaticAssertTypeEq<Expectation, ExpectationSet::value_type>();
+}
+
+TEST(ExpectationSetTest, ConstructorsWork) {
+  MockA a;
+
+  Expectation e1;
+  const Expectation e2;
+  ExpectationSet es1;                           // Default ctor.
+  ExpectationSet es2 = EXPECT_CALL(a, DoA(1));  // Ctor from EXPECT_CALL.
+  ExpectationSet es3 = e1;                      // Ctor from Expectation.
+  ExpectationSet es4(e1);    // Ctor from Expectation; alternative syntax.
+  ExpectationSet es5 = e2;   // Ctor from const Expectation.
+  ExpectationSet es6(e2);    // Ctor from const Expectation; alternative syntax.
+  ExpectationSet es7 = es2;  // Copy ctor.
+
+  EXPECT_EQ(0, es1.size());
+  EXPECT_EQ(1, es2.size());
+  EXPECT_EQ(1, es3.size());
+  EXPECT_EQ(1, es4.size());
+  EXPECT_EQ(1, es5.size());
+  EXPECT_EQ(1, es6.size());
+  EXPECT_EQ(1, es7.size());
+
+  EXPECT_THAT(es3, Ne(es2));
+  EXPECT_THAT(es4, Eq(es3));
+  EXPECT_THAT(es5, Eq(es4));
+  EXPECT_THAT(es6, Eq(es5));
+  EXPECT_THAT(es7, Eq(es2));
+  a.DoA(1);
+}
+
+TEST(ExpectationSetTest, AssignmentWorks) {
+  ExpectationSet es1;
+  ExpectationSet es2 = Expectation();
+
+  es1 = es2;
+  EXPECT_EQ(1, es1.size());
+  EXPECT_THAT(*(es1.begin()), Eq(Expectation()));
+  EXPECT_THAT(es1, Eq(es2));
+}
+
+TEST(ExpectationSetTest, InsertionWorks) {
+  ExpectationSet es1;
+  Expectation e1;
+  es1 += e1;
+  EXPECT_EQ(1, es1.size());
+  EXPECT_THAT(*(es1.begin()), Eq(e1));
+
+  MockA a;
+  Expectation e2 = EXPECT_CALL(a, DoA(1));
+  es1 += e2;
+  EXPECT_EQ(2, es1.size());
+
+  ExpectationSet::const_iterator it1 = es1.begin();
+  ExpectationSet::const_iterator it2 = it1;
+  ++it2;
+  EXPECT_TRUE(*it1 == e1 || *it2 == e1);  // e1 must be in the set.
+  EXPECT_TRUE(*it1 == e2 || *it2 == e2);  // e2 must be in the set too.
+  a.DoA(1);
+}
+
+TEST(ExpectationSetTest, SizeWorks) {
+  ExpectationSet es;
+  EXPECT_EQ(0, es.size());
+
+  es += Expectation();
+  EXPECT_EQ(1, es.size());
+
+  MockA a;
+  es += EXPECT_CALL(a, DoA(1));
+  EXPECT_EQ(2, es.size());
+
+  a.DoA(1);
+}
+
+TEST(ExpectationSetTest, IsEnumerable) {
+  ExpectationSet es;
+  EXPECT_TRUE(es.begin() == es.end());
+
+  es += Expectation();
+  ExpectationSet::const_iterator it = es.begin();
+  EXPECT_TRUE(it != es.end());
+  EXPECT_THAT(*it, Eq(Expectation()));
+  ++it;
+  EXPECT_TRUE(it == es.end());
+}
+
+// Tests the .After() clause.
+
+TEST(AfterTest, SucceedsWhenPartialOrderIsSatisfied) {
+  MockA a;
+  ExpectationSet es;
+  es += EXPECT_CALL(a, DoA(1));
+  es += EXPECT_CALL(a, DoA(2));
+  EXPECT_CALL(a, DoA(3)).After(es);
+
+  a.DoA(1);
+  a.DoA(2);
+  a.DoA(3);
+}
+
+TEST(AfterTest, SucceedsWhenTotalOrderIsSatisfied) {
+  MockA a;
+  MockB b;
+  // The following also verifies that const Expectation objects work
+  // too.  Do not remove the const modifiers.
+  const Expectation e1 = EXPECT_CALL(a, DoA(1));
+  const Expectation e2 = EXPECT_CALL(b, DoB()).Times(2).After(e1);
+  EXPECT_CALL(a, DoA(2)).After(e2);
+
+  a.DoA(1);
+  b.DoB();
+  b.DoB();
+  a.DoA(2);
+}
+
+// Calls must be in strict order when specified so using .After().
+TEST(AfterTest, CallsMustBeInStrictOrderWhenSpecifiedSo1) {
+  MockA a;
+  MockB b;
+
+  // Define ordering:
+  //   a.DoA(1) ==> b.DoB() ==> a.DoA(2)
+  Expectation e1 = EXPECT_CALL(a, DoA(1));
+  Expectation e2 = EXPECT_CALL(b, DoB()).After(e1);
+  EXPECT_CALL(a, DoA(2)).After(e2);
+
+  a.DoA(1);
+
+  // May only be called after DoB().
+  EXPECT_NONFATAL_FAILURE(a.DoA(2), "Unexpected mock function call");
+
+  b.DoB();
+  a.DoA(2);
+}
+
+// Calls must be in strict order when specified so using .After().
+TEST(AfterTest, CallsMustBeInStrictOrderWhenSpecifiedSo2) {
+  MockA a;
+  MockB b;
+
+  // Define ordering:
+  //   a.DoA(1) ==> b.DoB() * 2 ==> a.DoA(2)
+  Expectation e1 = EXPECT_CALL(a, DoA(1));
+  Expectation e2 = EXPECT_CALL(b, DoB()).Times(2).After(e1);
+  EXPECT_CALL(a, DoA(2)).After(e2);
+
+  a.DoA(1);
+  b.DoB();
+
+  // May only be called after the second DoB().
+  EXPECT_NONFATAL_FAILURE(a.DoA(2), "Unexpected mock function call");
+
+  b.DoB();
+  a.DoA(2);
+}
+
+// Calls must satisfy the partial order when specified so.
+TEST(AfterTest, CallsMustSatisfyPartialOrderWhenSpecifiedSo) {
+  MockA a;
+  ON_CALL(a, ReturnResult(_)).WillByDefault(Return(Result()));
+
+  // Define ordering:
+  //   a.DoA(1) ==>
+  //   a.DoA(2) ==> a.ReturnResult(3)
+  Expectation e = EXPECT_CALL(a, DoA(1));
+  const ExpectationSet es = EXPECT_CALL(a, DoA(2));
+  EXPECT_CALL(a, ReturnResult(3)).After(e, es);
+
+  // May only be called last.
+  EXPECT_NONFATAL_FAILURE(a.ReturnResult(3), "Unexpected mock function call");
+
+  a.DoA(2);
+  a.DoA(1);
+  a.ReturnResult(3);
+}
+
+// Calls must satisfy the partial order when specified so.
+TEST(AfterTest, CallsMustSatisfyPartialOrderWhenSpecifiedSo2) {
+  MockA a;
+
+  // Define ordering:
+  //   a.DoA(1) ==>
+  //   a.DoA(2) ==> a.DoA(3)
+  Expectation e = EXPECT_CALL(a, DoA(1));
+  const ExpectationSet es = EXPECT_CALL(a, DoA(2));
+  EXPECT_CALL(a, DoA(3)).After(e, es);
+
+  a.DoA(2);
+
+  // May only be called last.
+  EXPECT_NONFATAL_FAILURE(a.DoA(3), "Unexpected mock function call");
+
+  a.DoA(1);
+  a.DoA(3);
+}
+
+// .After() can be combined with .InSequence().
+TEST(AfterTest, CanBeUsedWithInSequence) {
+  MockA a;
+  Sequence s;
+  Expectation e = EXPECT_CALL(a, DoA(1));
+  EXPECT_CALL(a, DoA(2)).InSequence(s);
+  EXPECT_CALL(a, DoA(3)).InSequence(s).After(e);
+
+  a.DoA(1);
+
+  // May only be after DoA(2).
+  EXPECT_NONFATAL_FAILURE(a.DoA(3), "Unexpected mock function call");
+
+  a.DoA(2);
+  a.DoA(3);
+}
+
+// .After() can be called multiple times.
+TEST(AfterTest, CanBeCalledManyTimes) {
+  MockA a;
+  Expectation e1 = EXPECT_CALL(a, DoA(1));
+  Expectation e2 = EXPECT_CALL(a, DoA(2));
+  Expectation e3 = EXPECT_CALL(a, DoA(3));
+  EXPECT_CALL(a, DoA(4)).After(e1).After(e2).After(e3);
+
+  a.DoA(3);
+  a.DoA(1);
+  a.DoA(2);
+  a.DoA(4);
+}
+
+// .After() accepts up to 5 arguments.
+TEST(AfterTest, AcceptsUpToFiveArguments) {
+  MockA a;
+  Expectation e1 = EXPECT_CALL(a, DoA(1));
+  Expectation e2 = EXPECT_CALL(a, DoA(2));
+  Expectation e3 = EXPECT_CALL(a, DoA(3));
+  ExpectationSet es1 = EXPECT_CALL(a, DoA(4));
+  ExpectationSet es2 = EXPECT_CALL(a, DoA(5));
+  EXPECT_CALL(a, DoA(6)).After(e1, e2, e3, es1, es2);
+
+  a.DoA(5);
+  a.DoA(2);
+  a.DoA(4);
+  a.DoA(1);
+  a.DoA(3);
+  a.DoA(6);
+}
+
+// .After() allows input to contain duplicated Expectations.
+TEST(AfterTest, AcceptsDuplicatedInput) {
+  MockA a;
+  ON_CALL(a, ReturnResult(_)).WillByDefault(Return(Result()));
+
+  // Define ordering:
+  //   DoA(1) ==>
+  //   DoA(2) ==> ReturnResult(3)
+  Expectation e1 = EXPECT_CALL(a, DoA(1));
+  Expectation e2 = EXPECT_CALL(a, DoA(2));
+  ExpectationSet es;
+  es += e1;
+  es += e2;
+  EXPECT_CALL(a, ReturnResult(3)).After(e1, e2, es, e1);
+
+  a.DoA(1);
+
+  // May only be after DoA(2).
+  EXPECT_NONFATAL_FAILURE(a.ReturnResult(3), "Unexpected mock function call");
+
+  a.DoA(2);
+  a.ReturnResult(3);
+}
+
+// An Expectation added to an ExpectationSet after it has been used in
+// an .After() has no effect.
+TEST(AfterTest, ChangesToExpectationSetHaveNoEffectAfterwards) {
+  MockA a;
+  ExpectationSet es1 = EXPECT_CALL(a, DoA(1));
+  Expectation e2 = EXPECT_CALL(a, DoA(2));
+  EXPECT_CALL(a, DoA(3)).After(es1);
+  es1 += e2;
+
+  a.DoA(1);
+  a.DoA(3);
+  a.DoA(2);
+}
+
+// Tests that Google Mock correctly handles calls to mock functions
+// after a mock object owning one of their pre-requisites has died.
+
+// Tests that calls that satisfy the original spec are successful.
+TEST(DeletingMockEarlyTest, Success1) {
+  MockB* const b1 = new MockB;
+  MockA* const a = new MockA;
+  MockB* const b2 = new MockB;
+
+  {
+    InSequence dummy;
+    EXPECT_CALL(*b1, DoB(_)).WillOnce(Return(1));
+    EXPECT_CALL(*a, Binary(_, _))
+        .Times(AnyNumber())
+        .WillRepeatedly(Return(true));
+    EXPECT_CALL(*b2, DoB(_)).Times(AnyNumber()).WillRepeatedly(Return(2));
+  }
+
+  EXPECT_EQ(1, b1->DoB(1));
+  delete b1;
+  // a's pre-requisite has died.
+  EXPECT_TRUE(a->Binary(0, 1));
+  delete b2;
+  // a's successor has died.
+  EXPECT_TRUE(a->Binary(1, 2));
+  delete a;
+}
+
+// Tests that calls that satisfy the original spec are successful.
+TEST(DeletingMockEarlyTest, Success2) {
+  MockB* const b1 = new MockB;
+  MockA* const a = new MockA;
+  MockB* const b2 = new MockB;
+
+  {
+    InSequence dummy;
+    EXPECT_CALL(*b1, DoB(_)).WillOnce(Return(1));
+    EXPECT_CALL(*a, Binary(_, _)).Times(AnyNumber());
+    EXPECT_CALL(*b2, DoB(_)).Times(AnyNumber()).WillRepeatedly(Return(2));
+  }
+
+  delete a;  // a is trivially satisfied.
+  EXPECT_EQ(1, b1->DoB(1));
+  EXPECT_EQ(2, b2->DoB(2));
+  delete b1;
+  delete b2;
+}
+
+// Tests that it's OK to delete a mock object itself in its action.
+
+// Suppresses warning on unreferenced formal parameter in MSVC with
+// -W4.
+GTEST_DISABLE_MSC_WARNINGS_PUSH_(4100)
+
+ACTION_P(Delete, ptr) { delete ptr; }
+
+GTEST_DISABLE_MSC_WARNINGS_POP_()  // 4100
+
+TEST(DeletingMockEarlyTest, CanDeleteSelfInActionReturningVoid) {
+  MockA* const a = new MockA;
+  EXPECT_CALL(*a, DoA(_)).WillOnce(Delete(a));
+  a->DoA(42);  // This will cause a to be deleted.
+}
+
+TEST(DeletingMockEarlyTest, CanDeleteSelfInActionReturningValue) {
+  MockA* const a = new MockA;
+  EXPECT_CALL(*a, ReturnResult(_)).WillOnce(DoAll(Delete(a), Return(Result())));
+  a->ReturnResult(42);  // This will cause a to be deleted.
+}
+
+// Tests that calls that violate the original spec yield failures.
+TEST(DeletingMockEarlyTest, Failure1) {
+  MockB* const b1 = new MockB;
+  MockA* const a = new MockA;
+  MockB* const b2 = new MockB;
+
+  {
+    InSequence dummy;
+    EXPECT_CALL(*b1, DoB(_)).WillOnce(Return(1));
+    EXPECT_CALL(*a, Binary(_, _)).Times(AnyNumber());
+    EXPECT_CALL(*b2, DoB(_)).Times(AnyNumber()).WillRepeatedly(Return(2));
+  }
+
+  delete a;  // a is trivially satisfied.
+  EXPECT_NONFATAL_FAILURE({ b2->DoB(2); }, "Unexpected mock function call");
+  EXPECT_EQ(1, b1->DoB(1));
+  delete b1;
+  delete b2;
+}
+
+// Tests that calls that violate the original spec yield failures.
+TEST(DeletingMockEarlyTest, Failure2) {
+  MockB* const b1 = new MockB;
+  MockA* const a = new MockA;
+  MockB* const b2 = new MockB;
+
+  {
+    InSequence dummy;
+    EXPECT_CALL(*b1, DoB(_));
+    EXPECT_CALL(*a, Binary(_, _)).Times(AnyNumber());
+    EXPECT_CALL(*b2, DoB(_)).Times(AnyNumber());
+  }
+
+  EXPECT_NONFATAL_FAILURE(delete b1, "Actual: never called");
+  EXPECT_NONFATAL_FAILURE(a->Binary(0, 1), "Unexpected mock function call");
+  EXPECT_NONFATAL_FAILURE(b2->DoB(1), "Unexpected mock function call");
+  delete a;
+  delete b2;
+}
+
+class EvenNumberCardinality : public CardinalityInterface {
+ public:
+  // Returns true if and only if call_count calls will satisfy this
+  // cardinality.
+  bool IsSatisfiedByCallCount(int call_count) const override {
+    return call_count % 2 == 0;
+  }
+
+  // Returns true if and only if call_count calls will saturate this
+  // cardinality.
+  bool IsSaturatedByCallCount(int /* call_count */) const override {
+    return false;
+  }
+
+  // Describes self to an ostream.
+  void DescribeTo(::std::ostream* os) const override {
+    *os << "called even number of times";
+  }
+};
+
+Cardinality EvenNumber() { return Cardinality(new EvenNumberCardinality); }
+
+TEST(ExpectationBaseTest,
+     AllPrerequisitesAreSatisfiedWorksForNonMonotonicCardinality) {
+  MockA* a = new MockA;
+  Sequence s;
+
+  EXPECT_CALL(*a, DoA(1)).Times(EvenNumber()).InSequence(s);
+  EXPECT_CALL(*a, DoA(2)).Times(AnyNumber()).InSequence(s);
+  EXPECT_CALL(*a, DoA(3)).Times(AnyNumber());
+
+  a->DoA(3);
+  a->DoA(1);
+  EXPECT_NONFATAL_FAILURE(a->DoA(2), "Unexpected mock function call");
+  EXPECT_NONFATAL_FAILURE(delete a, "to be called even number of times");
+}
+
+// The following tests verify the message generated when a mock
+// function is called.
+
+struct Printable {};
+
+inline void operator<<(::std::ostream& os, const Printable&) {
+  os << "Printable";
+}
+
+struct Unprintable {
+  Unprintable() : value(0) {}
+  int value;
+};
+
+class MockC {
+ public:
+  MockC() = default;
+
+  MOCK_METHOD6(VoidMethod, void(bool cond, int n, std::string s, void* p,
+                                const Printable& x, Unprintable y));
+  MOCK_METHOD0(NonVoidMethod, int());  // NOLINT
+
+ private:
+  MockC(const MockC&) = delete;
+  MockC& operator=(const MockC&) = delete;
+};
+
+class VerboseFlagPreservingFixture : public testing::Test {
+ protected:
+  VerboseFlagPreservingFixture()
+      : saved_verbose_flag_(GMOCK_FLAG_GET(verbose)) {}
+
+  ~VerboseFlagPreservingFixture() override {
+    GMOCK_FLAG_SET(verbose, saved_verbose_flag_);
+  }
+
+ private:
+  const std::string saved_verbose_flag_;
+
+  VerboseFlagPreservingFixture(const VerboseFlagPreservingFixture&) = delete;
+  VerboseFlagPreservingFixture& operator=(const VerboseFlagPreservingFixture&) =
+      delete;
+};
+
+#if GTEST_HAS_STREAM_REDIRECTION
+
+// Tests that an uninteresting mock function call on a naggy mock
+// generates a warning without the stack trace when
+// --gmock_verbose=warning is specified.
+TEST(FunctionCallMessageTest,
+     UninterestingCallOnNaggyMockGeneratesNoStackTraceWhenVerboseWarning) {
+  GMOCK_FLAG_SET(verbose, kWarningVerbosity);
+  NaggyMock<MockC> c;
+  CaptureStdout();
+  c.VoidMethod(false, 5, "Hi", nullptr, Printable(), Unprintable());
+  const std::string output = GetCapturedStdout();
+  EXPECT_PRED_FORMAT2(IsSubstring, "GMOCK WARNING", output);
+  EXPECT_PRED_FORMAT2(IsNotSubstring, "Stack trace:", output);
+}
+
+// Tests that an uninteresting mock function call on a naggy mock
+// generates a warning containing the stack trace when
+// --gmock_verbose=info is specified.
+TEST(FunctionCallMessageTest,
+     UninterestingCallOnNaggyMockGeneratesFyiWithStackTraceWhenVerboseInfo) {
+  GMOCK_FLAG_SET(verbose, kInfoVerbosity);
+  NaggyMock<MockC> c;
+  CaptureStdout();
+  c.VoidMethod(false, 5, "Hi", nullptr, Printable(), Unprintable());
+  const std::string output = GetCapturedStdout();
+  EXPECT_PRED_FORMAT2(IsSubstring, "GMOCK WARNING", output);
+  EXPECT_PRED_FORMAT2(IsSubstring, "Stack trace:", output);
+
+#ifndef NDEBUG
+
+  // We check the stack trace content in dbg-mode only, as opt-mode
+  // may inline the call we are interested in seeing.
+
+  // Verifies that a void mock function's name appears in the stack
+  // trace.
+  EXPECT_PRED_FORMAT2(IsSubstring, "VoidMethod(", output);
+
+  // Verifies that a non-void mock function's name appears in the
+  // stack trace.
+  CaptureStdout();
+  c.NonVoidMethod();
+  const std::string output2 = GetCapturedStdout();
+  EXPECT_PRED_FORMAT2(IsSubstring, "NonVoidMethod(", output2);
+
+#endif  // NDEBUG
+}
+
+// Tests that an uninteresting mock function call on a naggy mock
+// causes the function arguments and return value to be printed.
+TEST(FunctionCallMessageTest,
+     UninterestingCallOnNaggyMockPrintsArgumentsAndReturnValue) {
+  // A non-void mock function.
+  NaggyMock<MockB> b;
+  CaptureStdout();
+  b.DoB();
+  const std::string output1 = GetCapturedStdout();
+  EXPECT_PRED_FORMAT2(
+      IsSubstring,
+      "Uninteresting mock function call - returning default value.\n"
+      "    Function call: DoB()\n"
+      "          Returns: 0\n",
+      output1.c_str());
+  // Makes sure the return value is printed.
+
+  // A void mock function.
+  NaggyMock<MockC> c;
+  CaptureStdout();
+  c.VoidMethod(false, 5, "Hi", nullptr, Printable(), Unprintable());
+  const std::string output2 = GetCapturedStdout();
+  EXPECT_THAT(
+      output2.c_str(),
+      ContainsRegex("Uninteresting mock function call - returning directly\\.\n"
+                    "    Function call: VoidMethod"
+                    "\\(false, 5, \"Hi\", NULL, @.+ "
+                    "Printable, 4-byte object <00-00 00-00>\\)"));
+  // A void function has no return value to print.
+}
+
+// Tests how the --gmock_verbose flag affects Google Mock's output.
+
+class GMockVerboseFlagTest : public VerboseFlagPreservingFixture {
+ public:
+  // Verifies that the given Google Mock output is correct.  (When
+  // should_print is true, the output should match the given regex and
+  // contain the given function name in the stack trace.  When it's
+  // false, the output should be empty.)
+  void VerifyOutput(const std::string& output, bool should_print,
+                    const std::string& expected_substring,
+                    const std::string& function_name) {
+    if (should_print) {
+      EXPECT_THAT(output.c_str(), HasSubstr(expected_substring));
+#ifndef NDEBUG
+      // We check the stack trace content in dbg-mode only, as opt-mode
+      // may inline the call we are interested in seeing.
+      EXPECT_THAT(output.c_str(), HasSubstr(function_name));
+#else
+      // Suppresses 'unused function parameter' warnings.
+      static_cast<void>(function_name);
+#endif  // NDEBUG
+    } else {
+      EXPECT_STREQ("", output.c_str());
+    }
+  }
+
+  // Tests how the flag affects expected calls.
+  void TestExpectedCall(bool should_print) {
+    MockA a;
+    EXPECT_CALL(a, DoA(5));
+    EXPECT_CALL(a, Binary(_, 1)).WillOnce(Return(true));
+
+    // A void-returning function.
+    CaptureStdout();
+    a.DoA(5);
+    VerifyOutput(GetCapturedStdout(), should_print,
+                 "Mock function call matches EXPECT_CALL(a, DoA(5))...\n"
+                 "    Function call: DoA(5)\n"
+                 "Stack trace:\n",
+                 "DoA");
+
+    // A non-void-returning function.
+    CaptureStdout();
+    a.Binary(2, 1);
+    VerifyOutput(GetCapturedStdout(), should_print,
+                 "Mock function call matches EXPECT_CALL(a, Binary(_, 1))...\n"
+                 "    Function call: Binary(2, 1)\n"
+                 "          Returns: true\n"
+                 "Stack trace:\n",
+                 "Binary");
+  }
+
+  // Tests how the flag affects uninteresting calls on a naggy mock.
+  void TestUninterestingCallOnNaggyMock(bool should_print) {
+    NaggyMock<MockA> a;
+    const std::string note =
+        "NOTE: You can safely ignore the above warning unless this "
+        "call should not happen.  Do not suppress it by blindly adding "
+        "an EXPECT_CALL() if you don't mean to enforce the call.  "
+        "See "
+        "https://github.com/google/googletest/blob/main/docs/"
+        "gmock_cook_book.md#"
+        "knowing-when-to-expect-useoncall for details.";
+
+    // A void-returning function.
+    CaptureStdout();
+    a.DoA(5);
+    VerifyOutput(GetCapturedStdout(), should_print,
+                 "\nGMOCK WARNING:\n"
+                 "Uninteresting mock function call - returning directly.\n"
+                 "    Function call: DoA(5)\n" +
+                     note,
+                 "DoA");
+
+    // A non-void-returning function.
+    CaptureStdout();
+    a.Binary(2, 1);
+    VerifyOutput(GetCapturedStdout(), should_print,
+                 "\nGMOCK WARNING:\n"
+                 "Uninteresting mock function call - returning default value.\n"
+                 "    Function call: Binary(2, 1)\n"
+                 "          Returns: false\n" +
+                     note,
+                 "Binary");
+  }
+};
+
+// Tests that --gmock_verbose=info causes both expected and
+// uninteresting calls to be reported.
+TEST_F(GMockVerboseFlagTest, Info) {
+  GMOCK_FLAG_SET(verbose, kInfoVerbosity);
+  TestExpectedCall(true);
+  TestUninterestingCallOnNaggyMock(true);
+}
+
+// Tests that --gmock_verbose=warning causes uninteresting calls to be
+// reported.
+TEST_F(GMockVerboseFlagTest, Warning) {
+  GMOCK_FLAG_SET(verbose, kWarningVerbosity);
+  TestExpectedCall(false);
+  TestUninterestingCallOnNaggyMock(true);
+}
+
+// Tests that --gmock_verbose=warning causes neither expected nor
+// uninteresting calls to be reported.
+TEST_F(GMockVerboseFlagTest, Error) {
+  GMOCK_FLAG_SET(verbose, kErrorVerbosity);
+  TestExpectedCall(false);
+  TestUninterestingCallOnNaggyMock(false);
+}
+
+// Tests that --gmock_verbose=SOME_INVALID_VALUE has the same effect
+// as --gmock_verbose=warning.
+TEST_F(GMockVerboseFlagTest, InvalidFlagIsTreatedAsWarning) {
+  GMOCK_FLAG_SET(verbose, "invalid");  // Treated as "warning".
+  TestExpectedCall(false);
+  TestUninterestingCallOnNaggyMock(true);
+}
+
+#endif  // GTEST_HAS_STREAM_REDIRECTION
+
+// A helper class that generates a failure when printed.  We use it to
+// ensure that Google Mock doesn't print a value (even to an internal
+// buffer) when it is not supposed to do so.
+class PrintMeNot {};
+
+void PrintTo(PrintMeNot /* dummy */, ::std::ostream* /* os */) {
+  ADD_FAILURE() << "Google Mock is printing a value that shouldn't be "
+                << "printed even to an internal buffer.";
+}
+
+class LogTestHelper {
+ public:
+  LogTestHelper() = default;
+
+  MOCK_METHOD1(Foo, PrintMeNot(PrintMeNot));
+
+ private:
+  LogTestHelper(const LogTestHelper&) = delete;
+  LogTestHelper& operator=(const LogTestHelper&) = delete;
+};
+
+class GMockLogTest : public VerboseFlagPreservingFixture {
+ protected:
+  LogTestHelper helper_;
+};
+
+TEST_F(GMockLogTest, DoesNotPrintGoodCallInternallyIfVerbosityIsWarning) {
+  GMOCK_FLAG_SET(verbose, kWarningVerbosity);
+  EXPECT_CALL(helper_, Foo(_)).WillOnce(Return(PrintMeNot()));
+  helper_.Foo(PrintMeNot());  // This is an expected call.
+}
+
+TEST_F(GMockLogTest, DoesNotPrintGoodCallInternallyIfVerbosityIsError) {
+  GMOCK_FLAG_SET(verbose, kErrorVerbosity);
+  EXPECT_CALL(helper_, Foo(_)).WillOnce(Return(PrintMeNot()));
+  helper_.Foo(PrintMeNot());  // This is an expected call.
+}
+
+TEST_F(GMockLogTest, DoesNotPrintWarningInternallyIfVerbosityIsError) {
+  GMOCK_FLAG_SET(verbose, kErrorVerbosity);
+  ON_CALL(helper_, Foo(_)).WillByDefault(Return(PrintMeNot()));
+  helper_.Foo(PrintMeNot());  // This should generate a warning.
+}
+
+// Tests Mock::AllowLeak().
+
+TEST(AllowLeakTest, AllowsLeakingUnusedMockObject) {
+  MockA* a = new MockA;
+  Mock::AllowLeak(a);
+}
+
+TEST(AllowLeakTest, CanBeCalledBeforeOnCall) {
+  MockA* a = new MockA;
+  Mock::AllowLeak(a);
+  ON_CALL(*a, DoA(_)).WillByDefault(Return());
+  a->DoA(0);
+}
+
+TEST(AllowLeakTest, CanBeCalledAfterOnCall) {
+  MockA* a = new MockA;
+  ON_CALL(*a, DoA(_)).WillByDefault(Return());
+  Mock::AllowLeak(a);
+}
+
+TEST(AllowLeakTest, CanBeCalledBeforeExpectCall) {
+  MockA* a = new MockA;
+  Mock::AllowLeak(a);
+  EXPECT_CALL(*a, DoA(_));
+  a->DoA(0);
+}
+
+TEST(AllowLeakTest, CanBeCalledAfterExpectCall) {
+  MockA* a = new MockA;
+  EXPECT_CALL(*a, DoA(_)).Times(AnyNumber());
+  Mock::AllowLeak(a);
+}
+
+TEST(AllowLeakTest, WorksWhenBothOnCallAndExpectCallArePresent) {
+  MockA* a = new MockA;
+  ON_CALL(*a, DoA(_)).WillByDefault(Return());
+  EXPECT_CALL(*a, DoA(_)).Times(AnyNumber());
+  Mock::AllowLeak(a);
+}
+
+// Tests that we can verify and clear a mock object's expectations
+// when none of its methods has expectations.
+TEST(VerifyAndClearExpectationsTest, NoMethodHasExpectations) {
+  MockB b;
+  ASSERT_TRUE(Mock::VerifyAndClearExpectations(&b));
+
+  // There should be no expectations on the methods now, so we can
+  // freely call them.
+  EXPECT_EQ(0, b.DoB());
+  EXPECT_EQ(0, b.DoB(1));
+}
+
+// Tests that we can verify and clear a mock object's expectations
+// when some, but not all, of its methods have expectations *and* the
+// verification succeeds.
+TEST(VerifyAndClearExpectationsTest, SomeMethodsHaveExpectationsAndSucceed) {
+  MockB b;
+  EXPECT_CALL(b, DoB()).WillOnce(Return(1));
+  b.DoB();
+  ASSERT_TRUE(Mock::VerifyAndClearExpectations(&b));
+
+  // There should be no expectations on the methods now, so we can
+  // freely call them.
+  EXPECT_EQ(0, b.DoB());
+  EXPECT_EQ(0, b.DoB(1));
+}
+
+// Tests that we can verify and clear a mock object's expectations
+// when some, but not all, of its methods have expectations *and* the
+// verification fails.
+TEST(VerifyAndClearExpectationsTest, SomeMethodsHaveExpectationsAndFail) {
+  MockB b;
+  EXPECT_CALL(b, DoB()).WillOnce(Return(1));
+  bool result = true;
+  EXPECT_NONFATAL_FAILURE(result = Mock::VerifyAndClearExpectations(&b),
+                          "Actual: never called");
+  ASSERT_FALSE(result);
+
+  // There should be no expectations on the methods now, so we can
+  // freely call them.
+  EXPECT_EQ(0, b.DoB());
+  EXPECT_EQ(0, b.DoB(1));
+}
+
+// Tests that we can verify and clear a mock object's expectations
+// when all of its methods have expectations.
+TEST(VerifyAndClearExpectationsTest, AllMethodsHaveExpectations) {
+  MockB b;
+  EXPECT_CALL(b, DoB()).WillOnce(Return(1));
+  EXPECT_CALL(b, DoB(_)).WillOnce(Return(2));
+  b.DoB();
+  b.DoB(1);
+  ASSERT_TRUE(Mock::VerifyAndClearExpectations(&b));
+
+  // There should be no expectations on the methods now, so we can
+  // freely call them.
+  EXPECT_EQ(0, b.DoB());
+  EXPECT_EQ(0, b.DoB(1));
+}
+
+// Tests that we can verify and clear a mock object's expectations
+// when a method has more than one expectation.
+TEST(VerifyAndClearExpectationsTest, AMethodHasManyExpectations) {
+  MockB b;
+  EXPECT_CALL(b, DoB(0)).WillOnce(Return(1));
+  EXPECT_CALL(b, DoB(_)).WillOnce(Return(2));
+  b.DoB(1);
+  bool result = true;
+  EXPECT_NONFATAL_FAILURE(result = Mock::VerifyAndClearExpectations(&b),
+                          "Actual: never called");
+  ASSERT_FALSE(result);
+
+  // There should be no expectations on the methods now, so we can
+  // freely call them.
+  EXPECT_EQ(0, b.DoB());
+  EXPECT_EQ(0, b.DoB(1));
+}
+
+// Tests that we can call VerifyAndClearExpectations() on the same
+// mock object multiple times.
+TEST(VerifyAndClearExpectationsTest, CanCallManyTimes) {
+  MockB b;
+  EXPECT_CALL(b, DoB());
+  b.DoB();
+  Mock::VerifyAndClearExpectations(&b);
+
+  EXPECT_CALL(b, DoB(_)).WillOnce(Return(1));
+  b.DoB(1);
+  Mock::VerifyAndClearExpectations(&b);
+  Mock::VerifyAndClearExpectations(&b);
+
+  // There should be no expectations on the methods now, so we can
+  // freely call them.
+  EXPECT_EQ(0, b.DoB());
+  EXPECT_EQ(0, b.DoB(1));
+}
+
+// Tests that we can clear a mock object's default actions when none
+// of its methods has default actions.
+TEST(VerifyAndClearTest, NoMethodHasDefaultActions) {
+  MockB b;
+  // If this crashes or generates a failure, the test will catch it.
+  Mock::VerifyAndClear(&b);
+  EXPECT_EQ(0, b.DoB());
+}
+
+// Tests that we can clear a mock object's default actions when some,
+// but not all of its methods have default actions.
+TEST(VerifyAndClearTest, SomeMethodsHaveDefaultActions) {
+  MockB b;
+  ON_CALL(b, DoB()).WillByDefault(Return(1));
+
+  Mock::VerifyAndClear(&b);
+
+  // Verifies that the default action of int DoB() was removed.
+  EXPECT_EQ(0, b.DoB());
+}
+
+// Tests that we can clear a mock object's default actions when all of
+// its methods have default actions.
+TEST(VerifyAndClearTest, AllMethodsHaveDefaultActions) {
+  MockB b;
+  ON_CALL(b, DoB()).WillByDefault(Return(1));
+  ON_CALL(b, DoB(_)).WillByDefault(Return(2));
+
+  Mock::VerifyAndClear(&b);
+
+  // Verifies that the default action of int DoB() was removed.
+  EXPECT_EQ(0, b.DoB());
+
+  // Verifies that the default action of int DoB(int) was removed.
+  EXPECT_EQ(0, b.DoB(0));
+}
+
+// Tests that we can clear a mock object's default actions when a
+// method has more than one ON_CALL() set on it.
+TEST(VerifyAndClearTest, AMethodHasManyDefaultActions) {
+  MockB b;
+  ON_CALL(b, DoB(0)).WillByDefault(Return(1));
+  ON_CALL(b, DoB(_)).WillByDefault(Return(2));
+
+  Mock::VerifyAndClear(&b);
+
+  // Verifies that the default actions (there are two) of int DoB(int)
+  // were removed.
+  EXPECT_EQ(0, b.DoB(0));
+  EXPECT_EQ(0, b.DoB(1));
+}
+
+// Tests that we can call VerifyAndClear() on a mock object multiple
+// times.
+TEST(VerifyAndClearTest, CanCallManyTimes) {
+  MockB b;
+  ON_CALL(b, DoB()).WillByDefault(Return(1));
+  Mock::VerifyAndClear(&b);
+  Mock::VerifyAndClear(&b);
+
+  ON_CALL(b, DoB(_)).WillByDefault(Return(1));
+  Mock::VerifyAndClear(&b);
+
+  EXPECT_EQ(0, b.DoB());
+  EXPECT_EQ(0, b.DoB(1));
+}
+
+// Tests that VerifyAndClear() works when the verification succeeds.
+TEST(VerifyAndClearTest, Success) {
+  MockB b;
+  ON_CALL(b, DoB()).WillByDefault(Return(1));
+  EXPECT_CALL(b, DoB(1)).WillOnce(Return(2));
+
+  b.DoB();
+  b.DoB(1);
+  ASSERT_TRUE(Mock::VerifyAndClear(&b));
+
+  // There should be no expectations on the methods now, so we can
+  // freely call them.
+  EXPECT_EQ(0, b.DoB());
+  EXPECT_EQ(0, b.DoB(1));
+}
+
+// Tests that VerifyAndClear() works when the verification fails.
+TEST(VerifyAndClearTest, Failure) {
+  MockB b;
+  ON_CALL(b, DoB(_)).WillByDefault(Return(1));
+  EXPECT_CALL(b, DoB()).WillOnce(Return(2));
+
+  b.DoB(1);
+  bool result = true;
+  EXPECT_NONFATAL_FAILURE(result = Mock::VerifyAndClear(&b),
+                          "Actual: never called");
+  ASSERT_FALSE(result);
+
+  // There should be no expectations on the methods now, so we can
+  // freely call them.
+  EXPECT_EQ(0, b.DoB());
+  EXPECT_EQ(0, b.DoB(1));
+}
+
+// Tests that VerifyAndClear() works when the default actions and
+// expectations are set on a const mock object.
+TEST(VerifyAndClearTest, Const) {
+  MockB b;
+  ON_CALL(Const(b), DoB()).WillByDefault(Return(1));
+
+  EXPECT_CALL(Const(b), DoB()).WillOnce(DoDefault()).WillOnce(Return(2));
+
+  b.DoB();
+  b.DoB();
+  ASSERT_TRUE(Mock::VerifyAndClear(&b));
+
+  // There should be no expectations on the methods now, so we can
+  // freely call them.
+  EXPECT_EQ(0, b.DoB());
+  EXPECT_EQ(0, b.DoB(1));
+}
+
+// Tests that we can set default actions and expectations on a mock
+// object after VerifyAndClear() has been called on it.
+TEST(VerifyAndClearTest, CanSetDefaultActionsAndExpectationsAfterwards) {
+  MockB b;
+  ON_CALL(b, DoB()).WillByDefault(Return(1));
+  EXPECT_CALL(b, DoB(_)).WillOnce(Return(2));
+  b.DoB(1);
+
+  Mock::VerifyAndClear(&b);
+
+  EXPECT_CALL(b, DoB()).WillOnce(Return(3));
+  ON_CALL(b, DoB(_)).WillByDefault(Return(4));
+
+  EXPECT_EQ(3, b.DoB());
+  EXPECT_EQ(4, b.DoB(1));
+}
+
+// Tests that calling VerifyAndClear() on one mock object does not
+// affect other mock objects (either of the same type or not).
+TEST(VerifyAndClearTest, DoesNotAffectOtherMockObjects) {
+  MockA a;
+  MockB b1;
+  MockB b2;
+
+  ON_CALL(a, Binary(_, _)).WillByDefault(Return(true));
+  EXPECT_CALL(a, Binary(_, _)).WillOnce(DoDefault()).WillOnce(Return(false));
+
+  ON_CALL(b1, DoB()).WillByDefault(Return(1));
+  EXPECT_CALL(b1, DoB(_)).WillOnce(Return(2));
+
+  ON_CALL(b2, DoB()).WillByDefault(Return(3));
+  EXPECT_CALL(b2, DoB(_));
+
+  b2.DoB(0);
+  Mock::VerifyAndClear(&b2);
+
+  // Verifies that the default actions and expectations of a and b1
+  // are still in effect.
+  EXPECT_TRUE(a.Binary(0, 0));
+  EXPECT_FALSE(a.Binary(0, 0));
+
+  EXPECT_EQ(1, b1.DoB());
+  EXPECT_EQ(2, b1.DoB(0));
+}
+
+TEST(VerifyAndClearTest,
+     DestroyingChainedMocksDoesNotDeadlockThroughExpectations) {
+  std::shared_ptr<MockA> a(new MockA);
+  ReferenceHoldingMock test_mock;
+
+  // EXPECT_CALL stores a reference to a inside test_mock.
+  EXPECT_CALL(test_mock, AcceptReference(_))
+      .WillRepeatedly(SetArgPointee<0>(a));
+
+  // Throw away the reference to the mock that we have in a. After this, the
+  // only reference to it is stored by test_mock.
+  a.reset();
+
+  // When test_mock goes out of scope, it destroys the last remaining reference
+  // to the mock object originally pointed to by a. This will cause the MockA
+  // destructor to be called from inside the ReferenceHoldingMock destructor.
+  // The state of all mocks is protected by a single global lock, but there
+  // should be no deadlock.
+}
+
+TEST(VerifyAndClearTest,
+     DestroyingChainedMocksDoesNotDeadlockThroughDefaultAction) {
+  std::shared_ptr<MockA> a(new MockA);
+  ReferenceHoldingMock test_mock;
+
+  // ON_CALL stores a reference to a inside test_mock.
+  ON_CALL(test_mock, AcceptReference(_)).WillByDefault(SetArgPointee<0>(a));
+
+  // Throw away the reference to the mock that we have in a. After this, the
+  // only reference to it is stored by test_mock.
+  a.reset();
+
+  // When test_mock goes out of scope, it destroys the last remaining reference
+  // to the mock object originally pointed to by a. This will cause the MockA
+  // destructor to be called from inside the ReferenceHoldingMock destructor.
+  // The state of all mocks is protected by a single global lock, but there
+  // should be no deadlock.
+}
+
+// Tests that a mock function's action can call a mock function
+// (either the same function or a different one) either as an explicit
+// action or as a default action without causing a dead lock.  It
+// verifies that the action is not performed inside the critical
+// section.
+TEST(SynchronizationTest, CanCallMockMethodInAction) {
+  MockA a;
+  MockC c;
+  ON_CALL(a, DoA(_)).WillByDefault(
+      IgnoreResult(InvokeWithoutArgs(&c, &MockC::NonVoidMethod)));
+  EXPECT_CALL(a, DoA(1));
+  EXPECT_CALL(a, DoA(1))
+      .WillOnce(Invoke(&a, &MockA::DoA))
+      .RetiresOnSaturation();
+  EXPECT_CALL(c, NonVoidMethod());
+
+  a.DoA(1);
+  // This will match the second EXPECT_CALL() and trigger another a.DoA(1),
+  // which will in turn match the first EXPECT_CALL() and trigger a call to
+  // c.NonVoidMethod() that was specified by the ON_CALL() since the first
+  // EXPECT_CALL() did not specify an action.
+}
+
+TEST(ParameterlessExpectationsTest, CanSetExpectationsWithoutMatchers) {
+  MockA a;
+  int do_a_arg0 = 0;
+  ON_CALL(a, DoA).WillByDefault(SaveArg<0>(&do_a_arg0));
+  int do_a_47_arg0 = 0;
+  ON_CALL(a, DoA(47)).WillByDefault(SaveArg<0>(&do_a_47_arg0));
+
+  a.DoA(17);
+  EXPECT_THAT(do_a_arg0, 17);
+  EXPECT_THAT(do_a_47_arg0, 0);
+  a.DoA(47);
+  EXPECT_THAT(do_a_arg0, 17);
+  EXPECT_THAT(do_a_47_arg0, 47);
+
+  ON_CALL(a, Binary).WillByDefault(Return(true));
+  ON_CALL(a, Binary(_, 14)).WillByDefault(Return(false));
+  EXPECT_THAT(a.Binary(14, 17), true);
+  EXPECT_THAT(a.Binary(17, 14), false);
+}
+
+TEST(ParameterlessExpectationsTest, CanSetExpectationsForOverloadedMethods) {
+  MockB b;
+  ON_CALL(b, DoB()).WillByDefault(Return(9));
+  ON_CALL(b, DoB(5)).WillByDefault(Return(11));
+
+  EXPECT_THAT(b.DoB(), 9);
+  EXPECT_THAT(b.DoB(1), 0);  // default value
+  EXPECT_THAT(b.DoB(5), 11);
+}
+
+struct MockWithConstMethods {
+ public:
+  MOCK_CONST_METHOD1(Foo, int(int));
+  MOCK_CONST_METHOD2(Bar, int(int, const char*));
+};
+
+TEST(ParameterlessExpectationsTest, CanSetExpectationsForConstMethods) {
+  MockWithConstMethods mock;
+  ON_CALL(mock, Foo).WillByDefault(Return(7));
+  ON_CALL(mock, Bar).WillByDefault(Return(33));
+
+  EXPECT_THAT(mock.Foo(17), 7);
+  EXPECT_THAT(mock.Bar(27, "purple"), 33);
+}
+
+class MockConstOverload {
+ public:
+  MOCK_METHOD1(Overloaded, int(int));
+  MOCK_CONST_METHOD1(Overloaded, int(int));
+};
+
+TEST(ParameterlessExpectationsTest,
+     CanSetExpectationsForConstOverloadedMethods) {
+  MockConstOverload mock;
+  ON_CALL(mock, Overloaded(_)).WillByDefault(Return(7));
+  ON_CALL(mock, Overloaded(5)).WillByDefault(Return(9));
+  ON_CALL(Const(mock), Overloaded(5)).WillByDefault(Return(11));
+  ON_CALL(Const(mock), Overloaded(7)).WillByDefault(Return(13));
+
+  EXPECT_THAT(mock.Overloaded(1), 7);
+  EXPECT_THAT(mock.Overloaded(5), 9);
+  EXPECT_THAT(mock.Overloaded(7), 7);
+
+  const MockConstOverload& const_mock = mock;
+  EXPECT_THAT(const_mock.Overloaded(1), 0);
+  EXPECT_THAT(const_mock.Overloaded(5), 11);
+  EXPECT_THAT(const_mock.Overloaded(7), 13);
+}
+
+}  // namespace
+}  // namespace testing
+
+int main(int argc, char** argv) {
+  testing::InitGoogleMock(&argc, argv);
+  // Ensures that the tests pass no matter what value of
+  // --gmock_catch_leaked_mocks and --gmock_verbose the user specifies.
+  GMOCK_FLAG_SET(catch_leaked_mocks, true);
+  GMOCK_FLAG_SET(verbose, testing::internal::kWarningVerbosity);
+
+  return RUN_ALL_TESTS();
+}

contrib/googletest/googlemock/test/gmock_all_test.cc

@@ -0,0 +1,49 @@
+// Copyright 2009, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+//
+// Tests for Google C++ Mocking Framework (Google Mock)
+//
+// Some users use a build system that Google Mock doesn't support directly,
+// yet they still want to build and run Google Mock's own tests.  This file
+// includes most such tests, making it easier for these users to maintain
+// their build scripts (they just need to build this file, even though the
+// below list of actual *_test.cc files might change).
+#include "test/gmock-actions_test.cc"
+#include "test/gmock-cardinalities_test.cc"
+#include "test/gmock-internal-utils_test.cc"
+#include "test/gmock-matchers-arithmetic_test.cc"
+#include "test/gmock-matchers-comparisons_test.cc"
+#include "test/gmock-matchers-containers_test.cc"
+#include "test/gmock-matchers-misc_test.cc"
+#include "test/gmock-more-actions_test.cc"
+#include "test/gmock-nice-strict_test.cc"
+#include "test/gmock-port_test.cc"
+#include "test/gmock-spec-builders_test.cc"
+#include "test/gmock_test.cc"

contrib/googletest/googlemock/test/gmock_ex_test.cc

@@ -0,0 +1,80 @@
+// Copyright 2013, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+// Tests Google Mock's functionality that depends on exceptions.
+
+#include <exception>
+
+#include "gmock/gmock.h"
+#include "gtest/gtest.h"
+
+#if GTEST_HAS_EXCEPTIONS
+namespace {
+
+using testing::HasSubstr;
+
+using testing::internal::GoogleTestFailureException;
+
+// A type that cannot be default constructed.
+class NonDefaultConstructible {
+ public:
+  explicit NonDefaultConstructible(int /* dummy */) {}
+};
+
+class MockFoo {
+ public:
+  // A mock method that returns a user-defined type.  Google Mock
+  // doesn't know what the default value for this type is.
+  MOCK_METHOD0(GetNonDefaultConstructible, NonDefaultConstructible());
+};
+
+TEST(DefaultValueTest, ThrowsRuntimeErrorWhenNoDefaultValue) {
+  MockFoo mock;
+  try {
+    // No expectation is set on this method, so Google Mock must
+    // return the default value.  However, since Google Mock knows
+    // nothing about the return type, it doesn't know what to return,
+    // and has to throw (when exceptions are enabled) or abort
+    // (otherwise).
+    mock.GetNonDefaultConstructible();
+    FAIL() << "GetNonDefaultConstructible()'s return type has no default "
+           << "value, so Google Mock should have thrown.";
+  } catch (const GoogleTestFailureException& /* unused */) {
+    FAIL() << "Google Test does not try to catch an exception of type "
+           << "GoogleTestFailureException, which is used for reporting "
+           << "a failure to other testing frameworks.  Google Mock should "
+           << "not throw a GoogleTestFailureException as it will kill the "
+           << "entire test program instead of just the current TEST.";
+  } catch (const std::exception& ex) {
+    EXPECT_THAT(ex.what(), HasSubstr("has no default value"));
+  }
+}
+
+}  // unnamed namespace
+#endif

contrib/googletest/googlemock/test/gmock_leak_test.py

@@ -0,0 +1,113 @@
+#!/usr/bin/env python
+#
+# Copyright 2009, Google Inc.
+# All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are
+# met:
+#
+#     * Redistributions of source code must retain the above copyright
+# notice, this list of conditions and the following disclaimer.
+#     * Redistributions in binary form must reproduce the above
+# copyright notice, this list of conditions and the following disclaimer
+# in the documentation and/or other materials provided with the
+# distribution.
+#     * Neither the name of Google Inc. nor the names of its
+# contributors may be used to endorse or promote products derived from
+# this software without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+"""Tests that leaked mock objects can be caught be Google Mock."""
+
+from googlemock.test import gmock_test_utils
+
+PROGRAM_PATH = gmock_test_utils.GetTestExecutablePath('gmock_leak_test_')
+TEST_WITH_EXPECT_CALL = [PROGRAM_PATH, '--gtest_filter=*ExpectCall*']
+TEST_WITH_ON_CALL = [PROGRAM_PATH, '--gtest_filter=*OnCall*']
+TEST_MULTIPLE_LEAKS = [PROGRAM_PATH, '--gtest_filter=*MultipleLeaked*']
+
+environ = gmock_test_utils.environ
+SetEnvVar = gmock_test_utils.SetEnvVar
+
+# Tests in this file run a Google-Test-based test program and expect it
+# to terminate prematurely.  Therefore they are incompatible with
+# the premature-exit-file protocol by design.  Unset the
+# premature-exit filepath to prevent Google Test from creating
+# the file.
+SetEnvVar(gmock_test_utils.PREMATURE_EXIT_FILE_ENV_VAR, None)
+
+
+class GMockLeakTest(gmock_test_utils.TestCase):
+
+  def testCatchesLeakedMockByDefault(self):
+    self.assertNotEqual(
+        0,
+        gmock_test_utils.Subprocess(
+            TEST_WITH_EXPECT_CALL, env=environ
+        ).exit_code,
+    )
+    self.assertNotEqual(
+        0, gmock_test_utils.Subprocess(TEST_WITH_ON_CALL, env=environ).exit_code
+    )
+
+  def testDoesNotCatchLeakedMockWhenDisabled(self):
+    self.assertEqual(
+        0,
+        gmock_test_utils.Subprocess(
+            TEST_WITH_EXPECT_CALL + ['--gmock_catch_leaked_mocks=0'],
+            env=environ,
+        ).exit_code,
+    )
+    self.assertEqual(
+        0,
+        gmock_test_utils.Subprocess(
+            TEST_WITH_ON_CALL + ['--gmock_catch_leaked_mocks=0'], env=environ
+        ).exit_code,
+    )
+
+  def testCatchesLeakedMockWhenEnabled(self):
+    self.assertNotEqual(
+        0,
+        gmock_test_utils.Subprocess(
+            TEST_WITH_EXPECT_CALL + ['--gmock_catch_leaked_mocks'], env=environ
+        ).exit_code,
+    )
+    self.assertNotEqual(
+        0,
+        gmock_test_utils.Subprocess(
+            TEST_WITH_ON_CALL + ['--gmock_catch_leaked_mocks'], env=environ
+        ).exit_code,
+    )
+
+  def testCatchesLeakedMockWhenEnabledWithExplictFlagValue(self):
+    self.assertNotEqual(
+        0,
+        gmock_test_utils.Subprocess(
+            TEST_WITH_EXPECT_CALL + ['--gmock_catch_leaked_mocks=1'],
+            env=environ,
+        ).exit_code,
+    )
+
+  def testCatchesMultipleLeakedMocks(self):
+    self.assertNotEqual(
+        0,
+        gmock_test_utils.Subprocess(
+            TEST_MULTIPLE_LEAKS + ['--gmock_catch_leaked_mocks'], env=environ
+        ).exit_code,
+    )
+
+
+if __name__ == '__main__':
+  gmock_test_utils.Main()

contrib/googletest/googlemock/test/gmock_leak_test_.cc

@@ -0,0 +1,99 @@
+// Copyright 2009, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+// Google Mock - a framework for writing C++ mock classes.
+//
+// This program is for verifying that a leaked mock object can be
+// caught by Google Mock's leak detector.
+
+#include "gmock/gmock.h"
+
+namespace {
+
+using ::testing::Return;
+
+class FooInterface {
+ public:
+  virtual ~FooInterface() = default;
+  virtual void DoThis() = 0;
+};
+
+class MockFoo : public FooInterface {
+ public:
+  MockFoo() = default;
+
+  MOCK_METHOD0(DoThis, void());
+
+ private:
+  MockFoo(const MockFoo&) = delete;
+  MockFoo& operator=(const MockFoo&) = delete;
+};
+
+TEST(LeakTest, LeakedMockWithExpectCallCausesFailureWhenLeakCheckingIsEnabled) {
+  MockFoo* foo = new MockFoo;
+
+  EXPECT_CALL(*foo, DoThis());
+  foo->DoThis();
+
+  // In order to test the leak detector, we deliberately leak foo.
+
+  // Makes sure Google Mock's leak detector can change the exit code
+  // to 1 even when the code is already exiting with 0.
+  exit(0);
+}
+
+TEST(LeakTest, LeakedMockWithOnCallCausesFailureWhenLeakCheckingIsEnabled) {
+  MockFoo* foo = new MockFoo;
+
+  ON_CALL(*foo, DoThis()).WillByDefault(Return());
+
+  // In order to test the leak detector, we deliberately leak foo.
+
+  // Makes sure Google Mock's leak detector can change the exit code
+  // to 1 even when the code is already exiting with 0.
+  exit(0);
+}
+
+TEST(LeakTest, CatchesMultipleLeakedMockObjects) {
+  MockFoo* foo1 = new MockFoo;
+  MockFoo* foo2 = new MockFoo;
+
+  ON_CALL(*foo1, DoThis()).WillByDefault(Return());
+  EXPECT_CALL(*foo2, DoThis());
+  foo2->DoThis();
+
+  // In order to test the leak detector, we deliberately leak foo1 and
+  // foo2.
+
+  // Makes sure Google Mock's leak detector can change the exit code
+  // to 1 even when the code is already exiting with 0.
+  exit(0);
+}
+
+}  // namespace

contrib/googletest/googlemock/test/gmock_link2_test.cc

@@ -0,0 +1,38 @@
+// Copyright 2008, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+// Google Mock - a framework for writing C++ mock classes.
+//
+// This file is for verifying that various Google Mock constructs do not
+// produce linker errors when instantiated in different translation units.
+// Please see gmock_link_test.h for details.
+
+#define LinkTest LinkTest2
+
+#include "test/gmock_link_test.h"

contrib/googletest/googlemock/test/gmock_link_test.cc

@@ -0,0 +1,38 @@
+// Copyright 2008, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+// Google Mock - a framework for writing C++ mock classes.
+//
+// This file is for verifying that various Google Mock constructs do not
+// produce linker errors when instantiated in different translation units.
+// Please see gmock_link_test.h for details.
+
+#define LinkTest LinkTest1
+
+#include "test/gmock_link_test.h"

contrib/googletest/googlemock/test/gmock_link_test.h

@@ -0,0 +1,684 @@
+// Copyright 2009, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+// Google Mock - a framework for writing C++ mock classes.
+//
+// This file tests that:
+// a. A header file defining a mock class can be included in multiple
+//    translation units without causing a link error.
+// b. Actions and matchers can be instantiated with identical template
+//    arguments in different translation units without causing link
+//    errors.
+//    The following constructs are currently tested:
+//    Actions:
+//      Return()
+//      Return(value)
+//      ReturnNull
+//      ReturnRef
+//      Assign
+//      SetArgPointee
+//      SetArrayArgument
+//      SetErrnoAndReturn
+//      Invoke(function)
+//      Invoke(object, method)
+//      InvokeWithoutArgs(function)
+//      InvokeWithoutArgs(object, method)
+//      InvokeArgument
+//      WithArg
+//      WithArgs
+//      WithoutArgs
+//      DoAll
+//      DoDefault
+//      IgnoreResult
+//      Throw
+//      ACTION()-generated
+//      ACTION_P()-generated
+//      ACTION_P2()-generated
+//    Matchers:
+//      _
+//      A
+//      An
+//      Eq
+//      Gt, Lt, Ge, Le, Ne
+//      NotNull
+//      Ref
+//      TypedEq
+//      DoubleEq
+//      FloatEq
+//      NanSensitiveDoubleEq
+//      NanSensitiveFloatEq
+//      ContainsRegex
+//      MatchesRegex
+//      EndsWith
+//      HasSubstr
+//      StartsWith
+//      StrCaseEq
+//      StrCaseNe
+//      StrEq
+//      StrNe
+//      ElementsAre
+//      ElementsAreArray
+//      ContainerEq
+//      Field
+//      Property
+//      ResultOf(function)
+//      ResultOf(callback)
+//      Pointee
+//      Truly(predicate)
+//      AddressSatisfies
+//      AllOf
+//      AnyOf
+//      Not
+//      MatcherCast<T>
+//
+//  Please note: this test does not verify the functioning of these
+//  constructs, only that the programs using them will link successfully.
+//
+// Implementation note:
+// This test requires identical definitions of Interface and Mock to be
+// included in different translation units.  We achieve this by writing
+// them in this header and #including it in gmock_link_test.cc and
+// gmock_link2_test.cc.  Because the symbols generated by the compiler for
+// those constructs must be identical in both translation units,
+// definitions of Interface and Mock tests MUST be kept in the SAME
+// NON-ANONYMOUS namespace in this file.  The test fixture class LinkTest
+// is defined as LinkTest1 in gmock_link_test.cc and as LinkTest2 in
+// gmock_link2_test.cc to avoid producing linker errors.
+
+#ifndef GOOGLEMOCK_TEST_GMOCK_LINK_TEST_H_
+#define GOOGLEMOCK_TEST_GMOCK_LINK_TEST_H_
+
+#include "gmock/gmock.h"
+
+#ifndef GTEST_OS_WINDOWS_MOBILE
+#include <errno.h>
+#endif
+
+#include <iostream>
+#include <vector>
+
+#include "gtest/gtest.h"
+#include "gtest/internal/gtest-port.h"
+
+using testing::_;
+using testing::A;
+using testing::Action;
+using testing::AllOf;
+using testing::AnyOf;
+using testing::Assign;
+using testing::ContainerEq;
+using testing::DoAll;
+using testing::DoDefault;
+using testing::DoubleEq;
+using testing::ElementsAre;
+using testing::ElementsAreArray;
+using testing::EndsWith;
+using testing::Eq;
+using testing::Field;
+using testing::FloatEq;
+using testing::Ge;
+using testing::Gt;
+using testing::HasSubstr;
+using testing::IgnoreResult;
+using testing::Invoke;
+using testing::InvokeArgument;
+using testing::InvokeWithoutArgs;
+using testing::IsNull;
+using testing::IsSubsetOf;
+using testing::IsSupersetOf;
+using testing::Le;
+using testing::Lt;
+using testing::Matcher;
+using testing::MatcherCast;
+using testing::NanSensitiveDoubleEq;
+using testing::NanSensitiveFloatEq;
+using testing::Ne;
+using testing::Not;
+using testing::NotNull;
+using testing::Pointee;
+using testing::Property;
+using testing::Ref;
+using testing::ResultOf;
+using testing::Return;
+using testing::ReturnNull;
+using testing::ReturnRef;
+using testing::SetArgPointee;
+using testing::SetArrayArgument;
+using testing::StartsWith;
+using testing::StrCaseEq;
+using testing::StrCaseNe;
+using testing::StrEq;
+using testing::StrNe;
+using testing::Truly;
+using testing::TypedEq;
+using testing::WithArg;
+using testing::WithArgs;
+using testing::WithoutArgs;
+
+#ifndef GTEST_OS_WINDOWS_MOBILE
+using testing::SetErrnoAndReturn;
+#endif
+
+#if GTEST_HAS_EXCEPTIONS
+using testing::Throw;
+#endif
+
+using testing::ContainsRegex;
+using testing::MatchesRegex;
+
+class Interface {
+ public:
+  virtual ~Interface() = default;
+  virtual void VoidFromString(char* str) = 0;
+  virtual char* StringFromString(char* str) = 0;
+  virtual int IntFromString(char* str) = 0;
+  virtual int& IntRefFromString(char* str) = 0;
+  virtual void VoidFromFunc(void (*func)(char* str)) = 0;
+  virtual void VoidFromIntRef(int& n) = 0;  // NOLINT
+  virtual void VoidFromFloat(float n) = 0;
+  virtual void VoidFromDouble(double n) = 0;
+  virtual void VoidFromVector(const std::vector<int>& v) = 0;
+};
+
+class Mock : public Interface {
+ public:
+  Mock() = default;
+
+  MOCK_METHOD1(VoidFromString, void(char* str));
+  MOCK_METHOD1(StringFromString, char*(char* str));
+  MOCK_METHOD1(IntFromString, int(char* str));
+  MOCK_METHOD1(IntRefFromString, int&(char* str));
+  MOCK_METHOD1(VoidFromFunc, void(void (*func)(char* str)));
+  MOCK_METHOD1(VoidFromIntRef, void(int& n));  // NOLINT
+  MOCK_METHOD1(VoidFromFloat, void(float n));
+  MOCK_METHOD1(VoidFromDouble, void(double n));
+  MOCK_METHOD1(VoidFromVector, void(const std::vector<int>& v));
+
+ private:
+  Mock(const Mock&) = delete;
+  Mock& operator=(const Mock&) = delete;
+};
+
+class InvokeHelper {
+ public:
+  static void StaticVoidFromVoid() {}
+  void VoidFromVoid() {}
+  static void StaticVoidFromString(char* /* str */) {}
+  void VoidFromString(char* /* str */) {}
+  static int StaticIntFromString(char* /* str */) { return 1; }
+  static bool StaticBoolFromString(const char* /* str */) { return true; }
+};
+
+class FieldHelper {
+ public:
+  explicit FieldHelper(int a_field) : field_(a_field) {}
+  int field() const { return field_; }
+  int field_;  // NOLINT -- need external access to field_ to test
+               //           the Field matcher.
+};
+
+// Tests the linkage of the ReturnVoid action.
+TEST(LinkTest, TestReturnVoid) {
+  Mock mock;
+
+  EXPECT_CALL(mock, VoidFromString(_)).WillOnce(Return());
+  mock.VoidFromString(nullptr);
+}
+
+// Tests the linkage of the Return action.
+TEST(LinkTest, TestReturn) {
+  Mock mock;
+  char ch = 'x';
+
+  EXPECT_CALL(mock, StringFromString(_)).WillOnce(Return(&ch));
+  mock.StringFromString(nullptr);
+}
+
+// Tests the linkage of the ReturnNull action.
+TEST(LinkTest, TestReturnNull) {
+  Mock mock;
+
+  EXPECT_CALL(mock, VoidFromString(_)).WillOnce(Return());
+  mock.VoidFromString(nullptr);
+}
+
+// Tests the linkage of the ReturnRef action.
+TEST(LinkTest, TestReturnRef) {
+  Mock mock;
+  int n = 42;
+
+  EXPECT_CALL(mock, IntRefFromString(_)).WillOnce(ReturnRef(n));
+  mock.IntRefFromString(nullptr);
+}
+
+// Tests the linkage of the Assign action.
+TEST(LinkTest, TestAssign) {
+  Mock mock;
+  char ch = 'x';
+
+  EXPECT_CALL(mock, VoidFromString(_)).WillOnce(Assign(&ch, 'y'));
+  mock.VoidFromString(nullptr);
+}
+
+// Tests the linkage of the SetArgPointee action.
+TEST(LinkTest, TestSetArgPointee) {
+  Mock mock;
+  char ch = 'x';
+
+  EXPECT_CALL(mock, VoidFromString(_)).WillOnce(SetArgPointee<0>('y'));
+  mock.VoidFromString(&ch);
+}
+
+// Tests the linkage of the SetArrayArgument action.
+TEST(LinkTest, TestSetArrayArgument) {
+  Mock mock;
+  char ch = 'x';
+  char ch2 = 'y';
+
+  EXPECT_CALL(mock, VoidFromString(_))
+      .WillOnce(SetArrayArgument<0>(&ch2, &ch2 + 1));
+  mock.VoidFromString(&ch);
+}
+
+#ifndef GTEST_OS_WINDOWS_MOBILE
+
+// Tests the linkage of the SetErrnoAndReturn action.
+TEST(LinkTest, TestSetErrnoAndReturn) {
+  Mock mock;
+
+  int saved_errno = errno;
+  EXPECT_CALL(mock, IntFromString(_)).WillOnce(SetErrnoAndReturn(1, -1));
+  mock.IntFromString(nullptr);
+  errno = saved_errno;
+}
+
+#endif  // !GTEST_OS_WINDOWS_MOBILE
+
+// Tests the linkage of the Invoke(function) and Invoke(object, method) actions.
+TEST(LinkTest, TestInvoke) {
+  Mock mock;
+  InvokeHelper test_invoke_helper;
+
+  EXPECT_CALL(mock, VoidFromString(_))
+      .WillOnce(Invoke(&InvokeHelper::StaticVoidFromString))
+      .WillOnce(Invoke(&test_invoke_helper, &InvokeHelper::VoidFromString));
+  mock.VoidFromString(nullptr);
+  mock.VoidFromString(nullptr);
+}
+
+// Tests the linkage of the InvokeWithoutArgs action.
+TEST(LinkTest, TestInvokeWithoutArgs) {
+  Mock mock;
+  InvokeHelper test_invoke_helper;
+
+  EXPECT_CALL(mock, VoidFromString(_))
+      .WillOnce(InvokeWithoutArgs(&InvokeHelper::StaticVoidFromVoid))
+      .WillOnce(
+          InvokeWithoutArgs(&test_invoke_helper, &InvokeHelper::VoidFromVoid));
+  mock.VoidFromString(nullptr);
+  mock.VoidFromString(nullptr);
+}
+
+// Tests the linkage of the InvokeArgument action.
+TEST(LinkTest, TestInvokeArgument) {
+  Mock mock;
+  char ch = 'x';
+
+  EXPECT_CALL(mock, VoidFromFunc(_)).WillOnce(InvokeArgument<0>(&ch));
+  mock.VoidFromFunc(InvokeHelper::StaticVoidFromString);
+}
+
+// Tests the linkage of the WithArg action.
+TEST(LinkTest, TestWithArg) {
+  Mock mock;
+
+  EXPECT_CALL(mock, VoidFromString(_))
+      .WillOnce(WithArg<0>(Invoke(&InvokeHelper::StaticVoidFromString)));
+  mock.VoidFromString(nullptr);
+}
+
+// Tests the linkage of the WithArgs action.
+TEST(LinkTest, TestWithArgs) {
+  Mock mock;
+
+  EXPECT_CALL(mock, VoidFromString(_))
+      .WillOnce(WithArgs<0>(Invoke(&InvokeHelper::StaticVoidFromString)));
+  mock.VoidFromString(nullptr);
+}
+
+// Tests the linkage of the WithoutArgs action.
+TEST(LinkTest, TestWithoutArgs) {
+  Mock mock;
+
+  EXPECT_CALL(mock, VoidFromString(_)).WillOnce(WithoutArgs(Return()));
+  mock.VoidFromString(nullptr);
+}
+
+// Tests the linkage of the DoAll action.
+TEST(LinkTest, TestDoAll) {
+  Mock mock;
+  char ch = 'x';
+
+  EXPECT_CALL(mock, VoidFromString(_))
+      .WillOnce(DoAll(SetArgPointee<0>('y'), Return()));
+  mock.VoidFromString(&ch);
+}
+
+// Tests the linkage of the DoDefault action.
+TEST(LinkTest, TestDoDefault) {
+  Mock mock;
+  char ch = 'x';
+
+  ON_CALL(mock, VoidFromString(_)).WillByDefault(Return());
+  EXPECT_CALL(mock, VoidFromString(_)).WillOnce(DoDefault());
+  mock.VoidFromString(&ch);
+}
+
+// Tests the linkage of the IgnoreResult action.
+TEST(LinkTest, TestIgnoreResult) {
+  Mock mock;
+
+  EXPECT_CALL(mock, VoidFromString(_)).WillOnce(IgnoreResult(Return(42)));
+  mock.VoidFromString(nullptr);
+}
+
+#if GTEST_HAS_EXCEPTIONS
+// Tests the linkage of the Throw action.
+TEST(LinkTest, TestThrow) {
+  Mock mock;
+
+  EXPECT_CALL(mock, VoidFromString(_)).WillOnce(Throw(42));
+  EXPECT_THROW(mock.VoidFromString(nullptr), int);
+}
+#endif  // GTEST_HAS_EXCEPTIONS
+
+// The ACTION*() macros trigger warning C4100 (unreferenced formal
+// parameter) in MSVC with -W4.  Unfortunately they cannot be fixed in
+// the macro definition, as the warnings are generated when the macro
+// is expanded and macro expansion cannot contain #pragma.  Therefore
+// we suppress them here.
+GTEST_DISABLE_MSC_WARNINGS_PUSH_(4100)
+
+// Tests the linkage of actions created using ACTION macro.
+namespace {
+ACTION(Return1) { return 1; }
+}  // namespace
+
+TEST(LinkTest, TestActionMacro) {
+  Mock mock;
+
+  EXPECT_CALL(mock, IntFromString(_)).WillOnce(Return1());
+  mock.IntFromString(nullptr);
+}
+
+// Tests the linkage of actions created using ACTION_P macro.
+namespace {
+ACTION_P(ReturnArgument, ret_value) { return ret_value; }
+}  // namespace
+
+TEST(LinkTest, TestActionPMacro) {
+  Mock mock;
+
+  EXPECT_CALL(mock, IntFromString(_)).WillOnce(ReturnArgument(42));
+  mock.IntFromString(nullptr);
+}
+
+// Tests the linkage of actions created using ACTION_P2 macro.
+namespace {
+ACTION_P2(ReturnEqualsEitherOf, first, second) {
+  return arg0 == first || arg0 == second;
+}
+}  // namespace
+
+GTEST_DISABLE_MSC_WARNINGS_POP_()  // 4100
+
+TEST(LinkTest, TestActionP2Macro) {
+  Mock mock;
+  char ch = 'x';
+
+  EXPECT_CALL(mock, IntFromString(_))
+      .WillOnce(ReturnEqualsEitherOf("one", "two"));
+  mock.IntFromString(&ch);
+}
+
+// Tests the linkage of the "_" matcher.
+TEST(LinkTest, TestMatcherAnything) {
+  Mock mock;
+
+  ON_CALL(mock, VoidFromString(_)).WillByDefault(Return());
+}
+
+// Tests the linkage of the A matcher.
+TEST(LinkTest, TestMatcherA) {
+  Mock mock;
+
+  ON_CALL(mock, VoidFromString(A<char*>())).WillByDefault(Return());
+}
+
+// Tests the linkage of the Eq and the "bare value" matcher.
+TEST(LinkTest, TestMatchersEq) {
+  Mock mock;
+  const char* p = "x";
+
+  ON_CALL(mock, VoidFromString(Eq(p))).WillByDefault(Return());
+  ON_CALL(mock, VoidFromString(const_cast<char*>("y"))).WillByDefault(Return());
+}
+
+// Tests the linkage of the Lt, Gt, Le, Ge, and Ne matchers.
+TEST(LinkTest, TestMatchersRelations) {
+  Mock mock;
+
+  ON_CALL(mock, VoidFromFloat(Lt(1.0f))).WillByDefault(Return());
+  ON_CALL(mock, VoidFromFloat(Gt(1.0f))).WillByDefault(Return());
+  ON_CALL(mock, VoidFromFloat(Le(1.0f))).WillByDefault(Return());
+  ON_CALL(mock, VoidFromFloat(Ge(1.0f))).WillByDefault(Return());
+  ON_CALL(mock, VoidFromFloat(Ne(1.0f))).WillByDefault(Return());
+}
+
+// Tests the linkage of the NotNull matcher.
+TEST(LinkTest, TestMatcherNotNull) {
+  Mock mock;
+
+  ON_CALL(mock, VoidFromString(NotNull())).WillByDefault(Return());
+}
+
+// Tests the linkage of the IsNull matcher.
+TEST(LinkTest, TestMatcherIsNull) {
+  Mock mock;
+
+  ON_CALL(mock, VoidFromString(IsNull())).WillByDefault(Return());
+}
+
+// Tests the linkage of the Ref matcher.
+TEST(LinkTest, TestMatcherRef) {
+  Mock mock;
+  int a = 0;
+
+  ON_CALL(mock, VoidFromIntRef(Ref(a))).WillByDefault(Return());
+}
+
+// Tests the linkage of the TypedEq matcher.
+TEST(LinkTest, TestMatcherTypedEq) {
+  Mock mock;
+  long a = 0;
+
+  ON_CALL(mock, VoidFromIntRef(TypedEq<int&>(a))).WillByDefault(Return());
+}
+
+// Tests the linkage of the FloatEq, DoubleEq, NanSensitiveFloatEq and
+// NanSensitiveDoubleEq matchers.
+TEST(LinkTest, TestMatchersFloatingPoint) {
+  Mock mock;
+  float a = 0;
+
+  ON_CALL(mock, VoidFromFloat(FloatEq(a))).WillByDefault(Return());
+  ON_CALL(mock, VoidFromDouble(DoubleEq(a))).WillByDefault(Return());
+  ON_CALL(mock, VoidFromFloat(NanSensitiveFloatEq(a))).WillByDefault(Return());
+  ON_CALL(mock, VoidFromDouble(NanSensitiveDoubleEq(a)))
+      .WillByDefault(Return());
+}
+
+// Tests the linkage of the ContainsRegex matcher.
+TEST(LinkTest, TestMatcherContainsRegex) {
+  Mock mock;
+
+  ON_CALL(mock, VoidFromString(ContainsRegex(".*"))).WillByDefault(Return());
+}
+
+// Tests the linkage of the MatchesRegex matcher.
+TEST(LinkTest, TestMatcherMatchesRegex) {
+  Mock mock;
+
+  ON_CALL(mock, VoidFromString(MatchesRegex(".*"))).WillByDefault(Return());
+}
+
+// Tests the linkage of the StartsWith, EndsWith, and HasSubstr matchers.
+TEST(LinkTest, TestMatchersSubstrings) {
+  Mock mock;
+
+  ON_CALL(mock, VoidFromString(StartsWith("a"))).WillByDefault(Return());
+  ON_CALL(mock, VoidFromString(EndsWith("c"))).WillByDefault(Return());
+  ON_CALL(mock, VoidFromString(HasSubstr("b"))).WillByDefault(Return());
+}
+
+// Tests the linkage of the StrEq, StrNe, StrCaseEq, and StrCaseNe matchers.
+TEST(LinkTest, TestMatchersStringEquality) {
+  Mock mock;
+  ON_CALL(mock, VoidFromString(StrEq("a"))).WillByDefault(Return());
+  ON_CALL(mock, VoidFromString(StrNe("a"))).WillByDefault(Return());
+  ON_CALL(mock, VoidFromString(StrCaseEq("a"))).WillByDefault(Return());
+  ON_CALL(mock, VoidFromString(StrCaseNe("a"))).WillByDefault(Return());
+}
+
+// Tests the linkage of the ElementsAre matcher.
+TEST(LinkTest, TestMatcherElementsAre) {
+  Mock mock;
+
+  ON_CALL(mock, VoidFromVector(ElementsAre('a', _))).WillByDefault(Return());
+}
+
+// Tests the linkage of the ElementsAreArray matcher.
+TEST(LinkTest, TestMatcherElementsAreArray) {
+  Mock mock;
+  char arr[] = {'a', 'b'};
+
+  ON_CALL(mock, VoidFromVector(ElementsAreArray(arr))).WillByDefault(Return());
+}
+
+// Tests the linkage of the IsSubsetOf matcher.
+TEST(LinkTest, TestMatcherIsSubsetOf) {
+  Mock mock;
+  char arr[] = {'a', 'b'};
+
+  ON_CALL(mock, VoidFromVector(IsSubsetOf(arr))).WillByDefault(Return());
+}
+
+// Tests the linkage of the IsSupersetOf matcher.
+TEST(LinkTest, TestMatcherIsSupersetOf) {
+  Mock mock;
+  char arr[] = {'a', 'b'};
+
+  ON_CALL(mock, VoidFromVector(IsSupersetOf(arr))).WillByDefault(Return());
+}
+
+// Tests the linkage of the ContainerEq matcher.
+TEST(LinkTest, TestMatcherContainerEq) {
+  Mock mock;
+  std::vector<int> v;
+
+  ON_CALL(mock, VoidFromVector(ContainerEq(v))).WillByDefault(Return());
+}
+
+// Tests the linkage of the Field matcher.
+TEST(LinkTest, TestMatcherField) {
+  FieldHelper helper(0);
+
+  Matcher<const FieldHelper&> m = Field(&FieldHelper::field_, Eq(0));
+  EXPECT_TRUE(m.Matches(helper));
+
+  Matcher<const FieldHelper*> m2 = Field(&FieldHelper::field_, Eq(0));
+  EXPECT_TRUE(m2.Matches(&helper));
+}
+
+// Tests the linkage of the Property matcher.
+TEST(LinkTest, TestMatcherProperty) {
+  FieldHelper helper(0);
+
+  Matcher<const FieldHelper&> m = Property(&FieldHelper::field, Eq(0));
+  EXPECT_TRUE(m.Matches(helper));
+
+  Matcher<const FieldHelper*> m2 = Property(&FieldHelper::field, Eq(0));
+  EXPECT_TRUE(m2.Matches(&helper));
+}
+
+// Tests the linkage of the ResultOf matcher.
+TEST(LinkTest, TestMatcherResultOf) {
+  Matcher<char*> m = ResultOf(&InvokeHelper::StaticIntFromString, Eq(1));
+  EXPECT_TRUE(m.Matches(nullptr));
+}
+
+// Tests the linkage of the ResultOf matcher.
+TEST(LinkTest, TestMatcherPointee) {
+  int n = 1;
+
+  Matcher<int*> m = Pointee(Eq(1));
+  EXPECT_TRUE(m.Matches(&n));
+}
+
+// Tests the linkage of the Truly matcher.
+TEST(LinkTest, TestMatcherTruly) {
+  Matcher<const char*> m = Truly(&InvokeHelper::StaticBoolFromString);
+  EXPECT_TRUE(m.Matches(nullptr));
+}
+
+// Tests the linkage of the AllOf matcher.
+TEST(LinkTest, TestMatcherAllOf) {
+  Matcher<int> m = AllOf(_, Eq(1));
+  EXPECT_TRUE(m.Matches(1));
+}
+
+// Tests the linkage of the AnyOf matcher.
+TEST(LinkTest, TestMatcherAnyOf) {
+  Matcher<int> m = AnyOf(_, Eq(1));
+  EXPECT_TRUE(m.Matches(1));
+}
+
+// Tests the linkage of the Not matcher.
+TEST(LinkTest, TestMatcherNot) {
+  Matcher<int> m = Not(_);
+  EXPECT_FALSE(m.Matches(1));
+}
+
+// Tests the linkage of the MatcherCast<T>() function.
+TEST(LinkTest, TestMatcherCast) {
+  Matcher<const char*> m = MatcherCast<const char*>(_);
+  EXPECT_TRUE(m.Matches(nullptr));
+}
+
+#endif  // GOOGLEMOCK_TEST_GMOCK_LINK_TEST_H_

contrib/googletest/googlemock/test/gmock_output_test.py

@@ -0,0 +1,190 @@
+#!/usr/bin/env python
+#
+# Copyright 2008, Google Inc.
+# All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are
+# met:
+#
+#     * Redistributions of source code must retain the above copyright
+# notice, this list of conditions and the following disclaimer.
+#     * Redistributions in binary form must reproduce the above
+# copyright notice, this list of conditions and the following disclaimer
+# in the documentation and/or other materials provided with the
+# distribution.
+#     * Neither the name of Google Inc. nor the names of its
+# contributors may be used to endorse or promote products derived from
+# this software without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+r"""Tests the text output of Google C++ Mocking Framework.
+
+To update the golden file:
+gmock_output_test.py --build_dir=BUILD/DIR --gengolden
+where BUILD/DIR contains the built gmock_output_test_ file.
+gmock_output_test.py --gengolden
+gmock_output_test.py
+
+"""
+
+from io import open  # pylint: disable=redefined-builtin, g-importing-member
+import os
+import re
+import sys
+from googlemock.test import gmock_test_utils
+
+
+# The flag for generating the golden file
+GENGOLDEN_FLAG = '--gengolden'
+
+PROGRAM_PATH = gmock_test_utils.GetTestExecutablePath('gmock_output_test_')
+COMMAND = [PROGRAM_PATH, '--gtest_stack_trace_depth=0', '--gtest_print_time=0']
+GOLDEN_NAME = 'gmock_output_test_golden.txt'
+GOLDEN_PATH = os.path.join(gmock_test_utils.GetSourceDir(), GOLDEN_NAME)
+
+
+def ToUnixLineEnding(s):
+  """Changes all Windows/Mac line endings in s to UNIX line endings."""
+
+  return s.replace('\r\n', '\n').replace('\r', '\n')
+
+
+def RemoveReportHeaderAndFooter(output):
+  """Removes Google Test result report's header and footer from the output."""
+
+  output = re.sub(r'.*gtest_main.*\n', '', output)
+  output = re.sub(r'\[.*\d+ tests.*\n', '', output)
+  output = re.sub(r'\[.* test environment .*\n', '', output)
+  output = re.sub(r'\[=+\] \d+ tests .* ran.*', '', output)
+  output = re.sub(r'.* FAILED TESTS\n', '', output)
+  return output
+
+
+def RemoveLocations(output):
+  """Removes all file location info from a Google Test program's output.
+
+  Args:
+       output:  the output of a Google Test program.
+
+  Returns:
+       output with all file location info (in the form of
+       'DIRECTORY/FILE_NAME:LINE_NUMBER: 'or
+       'DIRECTORY\\FILE_NAME(LINE_NUMBER): ') replaced by
+       'FILE:#: '.
+  """
+
+  return re.sub(r'.*[/\\](.+)(\:\d+|\(\d+\))\:', 'FILE:#:', output)
+
+
+def NormalizeErrorMarker(output):
+  """Normalizes the error marker, which is different on Windows vs on Linux."""
+
+  return re.sub(r' error: ', ' Failure\n', output)
+
+
+def RemoveMemoryAddresses(output):
+  """Removes memory addresses from the test output."""
+
+  return re.sub(r'@\w+', '@0x#', output)
+
+
+def RemoveTestNamesOfLeakedMocks(output):
+  """Removes the test names of leaked mock objects from the test output."""
+
+  return re.sub(r'\(used in test .+\) ', '', output)
+
+
+def GetLeakyTests(output):
+  """Returns a list of test names that leak mock objects."""
+
+  # findall() returns a list of all matches of the regex in output.
+  # For example, if '(used in test FooTest.Bar)' is in output, the
+  # list will contain 'FooTest.Bar'.
+  return re.findall(r'\(used in test (.+)\)', output)
+
+
+def GetNormalizedOutputAndLeakyTests(output):
+  """Normalizes the output of gmock_output_test_.
+
+  Args:
+    output: The test output.
+
+  Returns:
+    A tuple (the normalized test output, the list of test names that have
+    leaked mocks).
+  """
+
+  output = ToUnixLineEnding(output)
+  output = RemoveReportHeaderAndFooter(output)
+  output = NormalizeErrorMarker(output)
+  output = RemoveLocations(output)
+  output = RemoveMemoryAddresses(output)
+  return (RemoveTestNamesOfLeakedMocks(output), GetLeakyTests(output))
+
+
+def GetShellCommandOutput(cmd):
+  """Runs a command in a sub-process, and returns its STDOUT in a string."""
+
+  return gmock_test_utils.Subprocess(cmd, capture_stderr=False).output
+
+
+def GetNormalizedCommandOutputAndLeakyTests(cmd):
+  """Runs a command and returns its normalized output and a list of leaky tests.
+
+  Args:
+    cmd:  the shell command.
+  """
+
+  # Disables exception pop-ups on Windows.
+  os.environ['GTEST_CATCH_EXCEPTIONS'] = '1'
+  return GetNormalizedOutputAndLeakyTests(GetShellCommandOutput(cmd))
+
+
+class GMockOutputTest(gmock_test_utils.TestCase):
+
+  def testOutput(self):
+    (output, leaky_tests) = GetNormalizedCommandOutputAndLeakyTests(COMMAND)
+    golden_file = open(GOLDEN_PATH, 'rb')
+    golden = golden_file.read().decode('utf-8')
+    golden_file.close()
+    # On Windows the repository might have been checked out with \r\n line
+    # endings, so normalize it here.
+    golden = ToUnixLineEnding(golden)
+
+    # The normalized output should match the golden file.
+    self.assertEqual(golden, output)
+
+    # The raw output should contain 2 leaked mock object errors for
+    # test GMockOutputTest.CatchesLeakedMocks.
+    self.assertEqual(
+        [
+            'GMockOutputTest.CatchesLeakedMocks',
+            'GMockOutputTest.CatchesLeakedMocks',
+        ],
+        leaky_tests,
+    )
+
+
+if __name__ == '__main__':
+  if sys.argv[1:] == [GENGOLDEN_FLAG]:
+    (output, _) = GetNormalizedCommandOutputAndLeakyTests(COMMAND)
+    golden_file = open(GOLDEN_PATH, 'wb')
+    golden_file.write(output)
+    golden_file.close()
+    # Suppress the error "googletest was imported but a call to its main()
+    # was never detected."
+    os._exit(0)
+  else:
+    gmock_test_utils.Main()

contrib/googletest/googlemock/test/gmock_output_test_.cc

@@ -0,0 +1,286 @@
+// Copyright 2008, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+// Tests Google Mock's output in various scenarios.  This ensures that
+// Google Mock's messages are readable and useful.
+
+#include <stdio.h>
+
+#include <string>
+
+#include "gmock/gmock.h"
+#include "gtest/gtest.h"
+
+// Silence C4100 (unreferenced formal parameter)
+GTEST_DISABLE_MSC_WARNINGS_PUSH_(4100)
+
+using testing::_;
+using testing::AnyNumber;
+using testing::Ge;
+using testing::InSequence;
+using testing::NaggyMock;
+using testing::Ref;
+using testing::Return;
+using testing::Sequence;
+using testing::Value;
+
+class MockFoo {
+ public:
+  MockFoo() = default;
+
+  MOCK_METHOD3(Bar, char(const std::string& s, int i, double x));
+  MOCK_METHOD2(Bar2, bool(int x, int y));
+  MOCK_METHOD2(Bar3, void(int x, int y));
+
+ private:
+  MockFoo(const MockFoo&) = delete;
+  MockFoo& operator=(const MockFoo&) = delete;
+};
+
+class GMockOutputTest : public testing::Test {
+ protected:
+  NaggyMock<MockFoo> foo_;
+};
+
+TEST_F(GMockOutputTest, ExpectedCall) {
+  GMOCK_FLAG_SET(verbose, "info");
+
+  EXPECT_CALL(foo_, Bar2(0, _));
+  foo_.Bar2(0, 0);  // Expected call
+
+  GMOCK_FLAG_SET(verbose, "warning");
+}
+
+TEST_F(GMockOutputTest, ExpectedCallToVoidFunction) {
+  GMOCK_FLAG_SET(verbose, "info");
+
+  EXPECT_CALL(foo_, Bar3(0, _));
+  foo_.Bar3(0, 0);  // Expected call
+
+  GMOCK_FLAG_SET(verbose, "warning");
+}
+
+TEST_F(GMockOutputTest, ExplicitActionsRunOut) {
+  EXPECT_CALL(foo_, Bar2(_, _)).Times(2).WillOnce(Return(false));
+  foo_.Bar2(2, 2);
+  foo_.Bar2(1, 1);  // Explicit actions in EXPECT_CALL run out.
+}
+
+TEST_F(GMockOutputTest, UnexpectedCall) {
+  EXPECT_CALL(foo_, Bar2(0, _));
+
+  foo_.Bar2(1, 0);  // Unexpected call
+  foo_.Bar2(0, 0);  // Expected call
+}
+
+TEST_F(GMockOutputTest, UnexpectedCallToVoidFunction) {
+  EXPECT_CALL(foo_, Bar3(0, _));
+
+  foo_.Bar3(1, 0);  // Unexpected call
+  foo_.Bar3(0, 0);  // Expected call
+}
+
+TEST_F(GMockOutputTest, ExcessiveCall) {
+  EXPECT_CALL(foo_, Bar2(0, _));
+
+  foo_.Bar2(0, 0);  // Expected call
+  foo_.Bar2(0, 1);  // Excessive call
+}
+
+TEST_F(GMockOutputTest, ExcessiveCallToVoidFunction) {
+  EXPECT_CALL(foo_, Bar3(0, _));
+
+  foo_.Bar3(0, 0);  // Expected call
+  foo_.Bar3(0, 1);  // Excessive call
+}
+
+TEST_F(GMockOutputTest, UninterestingCall) {
+  foo_.Bar2(0, 1);  // Uninteresting call
+}
+
+TEST_F(GMockOutputTest, UninterestingCallToVoidFunction) {
+  foo_.Bar3(0, 1);  // Uninteresting call
+}
+
+TEST_F(GMockOutputTest, RetiredExpectation) {
+  EXPECT_CALL(foo_, Bar2(_, _)).RetiresOnSaturation();
+  EXPECT_CALL(foo_, Bar2(0, 0));
+
+  foo_.Bar2(1, 1);
+  foo_.Bar2(1, 1);  // Matches a retired expectation
+  foo_.Bar2(0, 0);
+}
+
+TEST_F(GMockOutputTest, UnsatisfiedPrerequisite) {
+  {
+    InSequence s;
+    EXPECT_CALL(foo_, Bar(_, 0, _));
+    EXPECT_CALL(foo_, Bar2(0, 0));
+    EXPECT_CALL(foo_, Bar2(1, _));
+  }
+
+  foo_.Bar2(1, 0);  // Has one immediate unsatisfied pre-requisite
+  foo_.Bar("Hi", 0, 0);
+  foo_.Bar2(0, 0);
+  foo_.Bar2(1, 0);
+}
+
+TEST_F(GMockOutputTest, UnsatisfiedPrerequisites) {
+  Sequence s1, s2;
+
+  EXPECT_CALL(foo_, Bar(_, 0, _)).InSequence(s1);
+  EXPECT_CALL(foo_, Bar2(0, 0)).InSequence(s2);
+  EXPECT_CALL(foo_, Bar2(1, _)).InSequence(s1, s2);
+
+  foo_.Bar2(1, 0);  // Has two immediate unsatisfied pre-requisites
+  foo_.Bar("Hi", 0, 0);
+  foo_.Bar2(0, 0);
+  foo_.Bar2(1, 0);
+}
+
+TEST_F(GMockOutputTest, UnsatisfiedWith) {
+  EXPECT_CALL(foo_, Bar2(_, _)).With(Ge());
+}
+
+TEST_F(GMockOutputTest, UnsatisfiedExpectation) {
+  EXPECT_CALL(foo_, Bar(_, _, _));
+  EXPECT_CALL(foo_, Bar2(0, _)).Times(2);
+
+  foo_.Bar2(0, 1);
+}
+
+TEST_F(GMockOutputTest, MismatchArguments) {
+  const std::string s = "Hi";
+  EXPECT_CALL(foo_, Bar(Ref(s), _, Ge(0)));
+
+  foo_.Bar("Ho", 0, -0.1);  // Mismatch arguments
+  foo_.Bar(s, 0, 0);
+}
+
+TEST_F(GMockOutputTest, MismatchWith) {
+  EXPECT_CALL(foo_, Bar2(Ge(2), Ge(1))).With(Ge());
+
+  foo_.Bar2(2, 3);  // Mismatch With()
+  foo_.Bar2(2, 1);
+}
+
+TEST_F(GMockOutputTest, MismatchArgumentsAndWith) {
+  EXPECT_CALL(foo_, Bar2(Ge(2), Ge(1))).With(Ge());
+
+  foo_.Bar2(1, 3);  // Mismatch arguments and mismatch With()
+  foo_.Bar2(2, 1);
+}
+
+TEST_F(GMockOutputTest, UnexpectedCallWithDefaultAction) {
+  ON_CALL(foo_, Bar2(_, _)).WillByDefault(Return(true));   // Default action #1
+  ON_CALL(foo_, Bar2(1, _)).WillByDefault(Return(false));  // Default action #2
+
+  EXPECT_CALL(foo_, Bar2(2, 2));
+  foo_.Bar2(1, 0);  // Unexpected call, takes default action #2.
+  foo_.Bar2(0, 0);  // Unexpected call, takes default action #1.
+  foo_.Bar2(2, 2);  // Expected call.
+}
+
+TEST_F(GMockOutputTest, ExcessiveCallWithDefaultAction) {
+  ON_CALL(foo_, Bar2(_, _)).WillByDefault(Return(true));   // Default action #1
+  ON_CALL(foo_, Bar2(1, _)).WillByDefault(Return(false));  // Default action #2
+
+  EXPECT_CALL(foo_, Bar2(2, 2));
+  EXPECT_CALL(foo_, Bar2(1, 1));
+
+  foo_.Bar2(2, 2);  // Expected call.
+  foo_.Bar2(2, 2);  // Excessive call, takes default action #1.
+  foo_.Bar2(1, 1);  // Expected call.
+  foo_.Bar2(1, 1);  // Excessive call, takes default action #2.
+}
+
+TEST_F(GMockOutputTest, UninterestingCallWithDefaultAction) {
+  ON_CALL(foo_, Bar2(_, _)).WillByDefault(Return(true));   // Default action #1
+  ON_CALL(foo_, Bar2(1, _)).WillByDefault(Return(false));  // Default action #2
+
+  foo_.Bar2(2, 2);  // Uninteresting call, takes default action #1.
+  foo_.Bar2(1, 1);  // Uninteresting call, takes default action #2.
+}
+
+TEST_F(GMockOutputTest, ExplicitActionsRunOutWithDefaultAction) {
+  ON_CALL(foo_, Bar2(_, _)).WillByDefault(Return(true));  // Default action #1
+
+  EXPECT_CALL(foo_, Bar2(_, _)).Times(2).WillOnce(Return(false));
+  foo_.Bar2(2, 2);
+  foo_.Bar2(1, 1);  // Explicit actions in EXPECT_CALL run out.
+}
+
+TEST_F(GMockOutputTest, CatchesLeakedMocks) {
+  MockFoo* foo1 = new MockFoo;
+  MockFoo* foo2 = new MockFoo;
+
+  // Invokes ON_CALL on foo1.
+  ON_CALL(*foo1, Bar(_, _, _)).WillByDefault(Return('a'));
+
+  // Invokes EXPECT_CALL on foo2.
+  EXPECT_CALL(*foo2, Bar2(_, _));
+  EXPECT_CALL(*foo2, Bar2(1, _));
+  EXPECT_CALL(*foo2, Bar3(_, _)).Times(AnyNumber());
+  foo2->Bar2(2, 1);
+  foo2->Bar2(1, 1);
+
+  // Both foo1 and foo2 are deliberately leaked.
+}
+
+MATCHER_P2(IsPair, first, second, "") {
+  return Value(arg.first, first) && Value(arg.second, second);
+}
+
+TEST_F(GMockOutputTest, PrintsMatcher) {
+  const testing::Matcher<int> m1 = Ge(48);
+  EXPECT_THAT((std::pair<int, bool>(42, true)), IsPair(m1, true));
+}
+
+void TestCatchesLeakedMocksInAdHocTests() {
+  MockFoo* foo = new MockFoo;
+
+  // Invokes EXPECT_CALL on foo.
+  EXPECT_CALL(*foo, Bar2(_, _));
+  foo->Bar2(2, 1);
+
+  // foo is deliberately leaked.
+}
+
+int main(int argc, char** argv) {
+  testing::InitGoogleMock(&argc, argv);
+  // Ensures that the tests pass no matter what value of
+  // --gmock_catch_leaked_mocks and --gmock_verbose the user specifies.
+  GMOCK_FLAG_SET(catch_leaked_mocks, true);
+  GMOCK_FLAG_SET(verbose, "warning");
+
+  TestCatchesLeakedMocksInAdHocTests();
+  return RUN_ALL_TESTS();
+}
+
+GTEST_DISABLE_MSC_WARNINGS_POP_()  // 4100

contrib/googletest/googlemock/test/gmock_output_test_golden.txt

@@ -0,0 +1,335 @@
+[ RUN      ] GMockOutputTest.ExpectedCall
+
+FILE:#: EXPECT_CALL(foo_, Bar2(0, _)) invoked
+Stack trace:
+
+FILE:#: Mock function call matches EXPECT_CALL(foo_, Bar2(0, _))...
+    Function call: Bar2(0, 0)
+          Returns: false
+Stack trace:
+[       OK ] GMockOutputTest.ExpectedCall
+[ RUN      ] GMockOutputTest.ExpectedCallToVoidFunction
+
+FILE:#: EXPECT_CALL(foo_, Bar3(0, _)) invoked
+Stack trace:
+
+FILE:#: Mock function call matches EXPECT_CALL(foo_, Bar3(0, _))...
+    Function call: Bar3(0, 0)
+Stack trace:
+[       OK ] GMockOutputTest.ExpectedCallToVoidFunction
+[ RUN      ] GMockOutputTest.ExplicitActionsRunOut
+
+GMOCK WARNING:
+FILE:#: Too few actions specified in EXPECT_CALL(foo_, Bar2(_, _))...
+Expected to be called twice, but has only 1 WillOnce().
+GMOCK WARNING:
+FILE:#: Actions ran out in EXPECT_CALL(foo_, Bar2(_, _))...
+Called 2 times, but only 1 WillOnce() is specified - returning default value.
+Stack trace:
+[       OK ] GMockOutputTest.ExplicitActionsRunOut
+[ RUN      ] GMockOutputTest.UnexpectedCall
+unknown file: Failure
+
+Unexpected mock function call - returning default value.
+    Function call: Bar2(1, 0)
+          Returns: false
+Google Mock tried the following 1 expectation, but it didn't match:
+
+FILE:#: EXPECT_CALL(foo_, Bar2(0, _))...
+  Expected arg #0: is equal to 0
+           Actual: 1
+         Expected: to be called once
+           Actual: never called - unsatisfied and active
+
+[  FAILED  ] GMockOutputTest.UnexpectedCall
+[ RUN      ] GMockOutputTest.UnexpectedCallToVoidFunction
+unknown file: Failure
+
+Unexpected mock function call - returning directly.
+    Function call: Bar3(1, 0)
+Google Mock tried the following 1 expectation, but it didn't match:
+
+FILE:#: EXPECT_CALL(foo_, Bar3(0, _))...
+  Expected arg #0: is equal to 0
+           Actual: 1
+         Expected: to be called once
+           Actual: never called - unsatisfied and active
+
+[  FAILED  ] GMockOutputTest.UnexpectedCallToVoidFunction
+[ RUN      ] GMockOutputTest.ExcessiveCall
+FILE:#: Failure
+Mock function called more times than expected - returning default value.
+    Function call: Bar2(0, 1)
+          Returns: false
+         Expected: to be called once
+           Actual: called twice - over-saturated and active
+
+[  FAILED  ] GMockOutputTest.ExcessiveCall
+[ RUN      ] GMockOutputTest.ExcessiveCallToVoidFunction
+FILE:#: Failure
+Mock function called more times than expected - returning directly.
+    Function call: Bar3(0, 1)
+         Expected: to be called once
+           Actual: called twice - over-saturated and active
+
+[  FAILED  ] GMockOutputTest.ExcessiveCallToVoidFunction
+[ RUN      ] GMockOutputTest.UninterestingCall
+
+GMOCK WARNING:
+Uninteresting mock function call - returning default value.
+    Function call: Bar2(0, 1)
+          Returns: false
+NOTE: You can safely ignore the above warning unless this call should not happen.  Do not suppress it by blindly adding an EXPECT_CALL() if you don't mean to enforce the call.  See https://github.com/google/googletest/blob/main/docs/gmock_cook_book.md#knowing-when-to-expect-useoncall for details.
+[       OK ] GMockOutputTest.UninterestingCall
+[ RUN      ] GMockOutputTest.UninterestingCallToVoidFunction
+
+GMOCK WARNING:
+Uninteresting mock function call - returning directly.
+    Function call: Bar3(0, 1)
+NOTE: You can safely ignore the above warning unless this call should not happen.  Do not suppress it by blindly adding an EXPECT_CALL() if you don't mean to enforce the call.  See https://github.com/google/googletest/blob/main/docs/gmock_cook_book.md#knowing-when-to-expect-useoncall for details.
+[       OK ] GMockOutputTest.UninterestingCallToVoidFunction
+[ RUN      ] GMockOutputTest.RetiredExpectation
+unknown file: Failure
+
+Unexpected mock function call - returning default value.
+    Function call: Bar2(1, 1)
+          Returns: false
+Google Mock tried the following 2 expectations, but none matched:
+
+FILE:#: tried expectation #0: EXPECT_CALL(foo_, Bar2(_, _))...
+         Expected: the expectation is active
+           Actual: it is retired
+         Expected: to be called once
+           Actual: called once - saturated and retired
+FILE:#: tried expectation #1: EXPECT_CALL(foo_, Bar2(0, 0))...
+  Expected arg #0: is equal to 0
+           Actual: 1
+  Expected arg #1: is equal to 0
+           Actual: 1
+         Expected: to be called once
+           Actual: never called - unsatisfied and active
+
+[  FAILED  ] GMockOutputTest.RetiredExpectation
+[ RUN      ] GMockOutputTest.UnsatisfiedPrerequisite
+unknown file: Failure
+
+Unexpected mock function call - returning default value.
+    Function call: Bar2(1, 0)
+          Returns: false
+Google Mock tried the following 2 expectations, but none matched:
+
+FILE:#: tried expectation #0: EXPECT_CALL(foo_, Bar2(0, 0))...
+  Expected arg #0: is equal to 0
+           Actual: 1
+         Expected: to be called once
+           Actual: never called - unsatisfied and active
+FILE:#: tried expectation #1: EXPECT_CALL(foo_, Bar2(1, _))...
+         Expected: all pre-requisites are satisfied
+           Actual: the following immediate pre-requisites are not satisfied:
+FILE:#: pre-requisite #0
+                   (end of pre-requisites)
+         Expected: to be called once
+           Actual: never called - unsatisfied and active
+
+[  FAILED  ] GMockOutputTest.UnsatisfiedPrerequisite
+[ RUN      ] GMockOutputTest.UnsatisfiedPrerequisites
+unknown file: Failure
+
+Unexpected mock function call - returning default value.
+    Function call: Bar2(1, 0)
+          Returns: false
+Google Mock tried the following 2 expectations, but none matched:
+
+FILE:#: tried expectation #0: EXPECT_CALL(foo_, Bar2(0, 0))...
+  Expected arg #0: is equal to 0
+           Actual: 1
+         Expected: to be called once
+           Actual: never called - unsatisfied and active
+FILE:#: tried expectation #1: EXPECT_CALL(foo_, Bar2(1, _))...
+         Expected: all pre-requisites are satisfied
+           Actual: the following immediate pre-requisites are not satisfied:
+FILE:#: pre-requisite #0
+FILE:#: pre-requisite #1
+                   (end of pre-requisites)
+         Expected: to be called once
+           Actual: never called - unsatisfied and active
+
+[  FAILED  ] GMockOutputTest.UnsatisfiedPrerequisites
+[ RUN      ] GMockOutputTest.UnsatisfiedWith
+FILE:#: Failure
+Actual function call count doesn't match EXPECT_CALL(foo_, Bar2(_, _))...
+    Expected args: are a pair where the first >= the second
+         Expected: to be called once
+           Actual: never called - unsatisfied and active
+
+[  FAILED  ] GMockOutputTest.UnsatisfiedWith
+[ RUN      ] GMockOutputTest.UnsatisfiedExpectation
+FILE:#: Failure
+Actual function call count doesn't match EXPECT_CALL(foo_, Bar2(0, _))...
+         Expected: to be called twice
+           Actual: called once - unsatisfied and active
+
+FILE:#: Failure
+Actual function call count doesn't match EXPECT_CALL(foo_, Bar(_, _, _))...
+         Expected: to be called once
+           Actual: never called - unsatisfied and active
+
+[  FAILED  ] GMockOutputTest.UnsatisfiedExpectation
+[ RUN      ] GMockOutputTest.MismatchArguments
+unknown file: Failure
+
+Unexpected mock function call - returning default value.
+    Function call: Bar(@0x# "Ho", 0, -0.1)
+          Returns: '\0'
+Google Mock tried the following 1 expectation, but it didn't match:
+
+FILE:#: EXPECT_CALL(foo_, Bar(Ref(s), _, Ge(0)))...
+  Expected arg #0: references the variable @0x# "Hi"
+           Actual: "Ho", which is located @0x#
+  Expected arg #2: is >= 0
+           Actual: -0.1
+         Expected: to be called once
+           Actual: never called - unsatisfied and active
+
+[  FAILED  ] GMockOutputTest.MismatchArguments
+[ RUN      ] GMockOutputTest.MismatchWith
+unknown file: Failure
+
+Unexpected mock function call - returning default value.
+    Function call: Bar2(2, 3)
+          Returns: false
+Google Mock tried the following 1 expectation, but it didn't match:
+
+FILE:#: EXPECT_CALL(foo_, Bar2(Ge(2), Ge(1)))...
+    Expected args: are a pair where the first >= the second
+           Actual: don't match
+         Expected: to be called once
+           Actual: never called - unsatisfied and active
+
+[  FAILED  ] GMockOutputTest.MismatchWith
+[ RUN      ] GMockOutputTest.MismatchArgumentsAndWith
+unknown file: Failure
+
+Unexpected mock function call - returning default value.
+    Function call: Bar2(1, 3)
+          Returns: false
+Google Mock tried the following 1 expectation, but it didn't match:
+
+FILE:#: EXPECT_CALL(foo_, Bar2(Ge(2), Ge(1)))...
+  Expected arg #0: is >= 2
+           Actual: 1
+    Expected args: are a pair where the first >= the second
+           Actual: don't match
+         Expected: to be called once
+           Actual: never called - unsatisfied and active
+
+[  FAILED  ] GMockOutputTest.MismatchArgumentsAndWith
+[ RUN      ] GMockOutputTest.UnexpectedCallWithDefaultAction
+unknown file: Failure
+
+Unexpected mock function call - taking default action specified at:
+FILE:#:
+    Function call: Bar2(1, 0)
+          Returns: false
+Google Mock tried the following 1 expectation, but it didn't match:
+
+FILE:#: EXPECT_CALL(foo_, Bar2(2, 2))...
+  Expected arg #0: is equal to 2
+           Actual: 1
+  Expected arg #1: is equal to 2
+           Actual: 0
+         Expected: to be called once
+           Actual: never called - unsatisfied and active
+
+unknown file: Failure
+
+Unexpected mock function call - taking default action specified at:
+FILE:#:
+    Function call: Bar2(0, 0)
+          Returns: true
+Google Mock tried the following 1 expectation, but it didn't match:
+
+FILE:#: EXPECT_CALL(foo_, Bar2(2, 2))...
+  Expected arg #0: is equal to 2
+           Actual: 0
+  Expected arg #1: is equal to 2
+           Actual: 0
+         Expected: to be called once
+           Actual: never called - unsatisfied and active
+
+[  FAILED  ] GMockOutputTest.UnexpectedCallWithDefaultAction
+[ RUN      ] GMockOutputTest.ExcessiveCallWithDefaultAction
+FILE:#: Failure
+Mock function called more times than expected - taking default action specified at:
+FILE:#:
+    Function call: Bar2(2, 2)
+          Returns: true
+         Expected: to be called once
+           Actual: called twice - over-saturated and active
+
+FILE:#: Failure
+Mock function called more times than expected - taking default action specified at:
+FILE:#:
+    Function call: Bar2(1, 1)
+          Returns: false
+         Expected: to be called once
+           Actual: called twice - over-saturated and active
+
+[  FAILED  ] GMockOutputTest.ExcessiveCallWithDefaultAction
+[ RUN      ] GMockOutputTest.UninterestingCallWithDefaultAction
+
+GMOCK WARNING:
+Uninteresting mock function call - taking default action specified at:
+FILE:#:
+    Function call: Bar2(2, 2)
+          Returns: true
+NOTE: You can safely ignore the above warning unless this call should not happen.  Do not suppress it by blindly adding an EXPECT_CALL() if you don't mean to enforce the call.  See https://github.com/google/googletest/blob/main/docs/gmock_cook_book.md#knowing-when-to-expect-useoncall for details.
+
+GMOCK WARNING:
+Uninteresting mock function call - taking default action specified at:
+FILE:#:
+    Function call: Bar2(1, 1)
+          Returns: false
+NOTE: You can safely ignore the above warning unless this call should not happen.  Do not suppress it by blindly adding an EXPECT_CALL() if you don't mean to enforce the call.  See https://github.com/google/googletest/blob/main/docs/gmock_cook_book.md#knowing-when-to-expect-useoncall for details.
+[       OK ] GMockOutputTest.UninterestingCallWithDefaultAction
+[ RUN      ] GMockOutputTest.ExplicitActionsRunOutWithDefaultAction
+
+GMOCK WARNING:
+FILE:#: Too few actions specified in EXPECT_CALL(foo_, Bar2(_, _))...
+Expected to be called twice, but has only 1 WillOnce().
+GMOCK WARNING:
+FILE:#: Actions ran out in EXPECT_CALL(foo_, Bar2(_, _))...
+Called 2 times, but only 1 WillOnce() is specified - taking default action specified at:
+FILE:#:
+Stack trace:
+[       OK ] GMockOutputTest.ExplicitActionsRunOutWithDefaultAction
+[ RUN      ] GMockOutputTest.CatchesLeakedMocks
+[       OK ] GMockOutputTest.CatchesLeakedMocks
+[ RUN      ] GMockOutputTest.PrintsMatcher
+FILE:#: Failure
+Value of: (std::pair<int, bool>(42, true))
+Expected: is pair (first: is >= 48, second: true)
+  Actual: (42, true) (of type std::pair<int,bool>)
+
+[  FAILED  ] GMockOutputTest.PrintsMatcher
+[  FAILED  ] GMockOutputTest.UnexpectedCall
+[  FAILED  ] GMockOutputTest.UnexpectedCallToVoidFunction
+[  FAILED  ] GMockOutputTest.ExcessiveCall
+[  FAILED  ] GMockOutputTest.ExcessiveCallToVoidFunction
+[  FAILED  ] GMockOutputTest.RetiredExpectation
+[  FAILED  ] GMockOutputTest.UnsatisfiedPrerequisite
+[  FAILED  ] GMockOutputTest.UnsatisfiedPrerequisites
+[  FAILED  ] GMockOutputTest.UnsatisfiedWith
+[  FAILED  ] GMockOutputTest.UnsatisfiedExpectation
+[  FAILED  ] GMockOutputTest.MismatchArguments
+[  FAILED  ] GMockOutputTest.MismatchWith
+[  FAILED  ] GMockOutputTest.MismatchArgumentsAndWith
+[  FAILED  ] GMockOutputTest.UnexpectedCallWithDefaultAction
+[  FAILED  ] GMockOutputTest.ExcessiveCallWithDefaultAction
+[  FAILED  ] GMockOutputTest.PrintsMatcher
+
+
+FILE:#: ERROR: this mock object should be deleted but never is. Its address is @0x#.
+FILE:#: ERROR: this mock object should be deleted but never is. Its address is @0x#.
+FILE:#: ERROR: this mock object should be deleted but never is. Its address is @0x#.
+ERROR: 3 leaked mock objects found at program exit. Expectations on a mock object are verified when the object is destructed. Leaking a mock means that its expectations aren't verified, which is usually a test bug. If you really intend to leak a mock, you can suppress this error using testing::Mock::AllowLeak(mock_object), or you may use a fake or stub instead of a mock.

contrib/googletest/googlemock/test/gmock_stress_test.cc

@@ -0,0 +1,227 @@
+// Copyright 2007, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+// Tests that Google Mock constructs can be used in a large number of
+// threads concurrently.
+
+#include "gmock/gmock.h"
+#include "gtest/gtest.h"
+
+namespace testing {
+namespace {
+
+// From gtest-port.h.
+using ::testing::internal::ThreadWithParam;
+
+// The maximum number of test threads (not including helper threads)
+// to create.
+const int kMaxTestThreads = 50;
+
+// How many times to repeat a task in a test thread.
+const int kRepeat = 50;
+
+class MockFoo {
+ public:
+  MOCK_METHOD1(Bar, int(int n));                                   // NOLINT
+  MOCK_METHOD2(Baz, char(const char* s1, const std::string& s2));  // NOLINT
+};
+
+// Helper for waiting for the given thread to finish and then deleting it.
+template <typename T>
+void JoinAndDelete(ThreadWithParam<T>* t) {
+  t->Join();
+  delete t;
+}
+
+struct Dummy {};
+
+// Tests that different mock objects can be used in their respective
+// threads.  This should generate no Google Test failure.
+void TestConcurrentMockObjects(Dummy /* dummy */) {
+  // Creates a mock and does some typical operations on it.
+  MockFoo foo;
+  ON_CALL(foo, Bar(_)).WillByDefault(Return(1));
+  ON_CALL(foo, Baz(_, _)).WillByDefault(Return('b'));
+  ON_CALL(foo, Baz(_, "you")).WillByDefault(Return('a'));
+
+  EXPECT_CALL(foo, Bar(0)).Times(AtMost(3));
+  EXPECT_CALL(foo, Baz(_, _));
+  EXPECT_CALL(foo, Baz("hi", "you"))
+      .WillOnce(Return('z'))
+      .WillRepeatedly(DoDefault());
+
+  EXPECT_EQ(1, foo.Bar(0));
+  EXPECT_EQ(1, foo.Bar(0));
+  EXPECT_EQ('z', foo.Baz("hi", "you"));
+  EXPECT_EQ('a', foo.Baz("hi", "you"));
+  EXPECT_EQ('b', foo.Baz("hi", "me"));
+}
+
+// Tests invoking methods of the same mock object in multiple threads.
+
+struct Helper1Param {
+  MockFoo* mock_foo;
+  int* count;
+};
+
+void Helper1(Helper1Param param) {
+  for (int i = 0; i < kRepeat; i++) {
+    const char ch = param.mock_foo->Baz("a", "b");
+    if (ch == 'a') {
+      // It was an expected call.
+      (*param.count)++;
+    } else {
+      // It was an excessive call.
+      EXPECT_EQ('\0', ch);
+    }
+
+    // An unexpected call.
+    EXPECT_EQ('\0', param.mock_foo->Baz("x", "y")) << "Expected failure.";
+
+    // An uninteresting call.
+    EXPECT_EQ(1, param.mock_foo->Bar(5));
+  }
+}
+
+// This should generate 3*kRepeat + 1 failures in total.
+void TestConcurrentCallsOnSameObject(Dummy /* dummy */) {
+  MockFoo foo;
+
+  ON_CALL(foo, Bar(_)).WillByDefault(Return(1));
+  EXPECT_CALL(foo, Baz(_, "b")).Times(kRepeat).WillRepeatedly(Return('a'));
+  EXPECT_CALL(foo, Baz(_, "c"));  // Expected to be unsatisfied.
+
+  // This chunk of code should generate kRepeat failures about
+  // excessive calls, and 2*kRepeat failures about unexpected calls.
+  int count1 = 0;
+  const Helper1Param param = {&foo, &count1};
+  ThreadWithParam<Helper1Param>* const t =
+      new ThreadWithParam<Helper1Param>(Helper1, param, nullptr);
+
+  int count2 = 0;
+  const Helper1Param param2 = {&foo, &count2};
+  Helper1(param2);
+  JoinAndDelete(t);
+
+  EXPECT_EQ(kRepeat, count1 + count2);
+
+  // foo's destructor should generate one failure about unsatisfied
+  // expectation.
+}
+
+// Tests using the same mock object in multiple threads when the
+// expectations are partially ordered.
+
+void Helper2(MockFoo* foo) {
+  for (int i = 0; i < kRepeat; i++) {
+    foo->Bar(2);
+    foo->Bar(3);
+  }
+}
+
+// This should generate no Google Test failures.
+void TestPartiallyOrderedExpectationsWithThreads(Dummy /* dummy */) {
+  MockFoo foo;
+  Sequence s1, s2;
+
+  {
+    InSequence dummy;
+    EXPECT_CALL(foo, Bar(0));
+    EXPECT_CALL(foo, Bar(1)).InSequence(s1, s2);
+  }
+
+  EXPECT_CALL(foo, Bar(2))
+      .Times(2 * kRepeat)
+      .InSequence(s1)
+      .RetiresOnSaturation();
+  EXPECT_CALL(foo, Bar(3)).Times(2 * kRepeat).InSequence(s2);
+
+  {
+    InSequence dummy;
+    EXPECT_CALL(foo, Bar(2)).InSequence(s1, s2);
+    EXPECT_CALL(foo, Bar(4));
+  }
+
+  foo.Bar(0);
+  foo.Bar(1);
+
+  ThreadWithParam<MockFoo*>* const t =
+      new ThreadWithParam<MockFoo*>(Helper2, &foo, nullptr);
+  Helper2(&foo);
+  JoinAndDelete(t);
+
+  foo.Bar(2);
+  foo.Bar(4);
+}
+
+// Tests using Google Mock constructs in many threads concurrently.
+TEST(StressTest, CanUseGMockWithThreads) {
+  void (*test_routines[])(Dummy dummy) = {
+      &TestConcurrentMockObjects,
+      &TestConcurrentCallsOnSameObject,
+      &TestPartiallyOrderedExpectationsWithThreads,
+  };
+
+  const int kRoutines = sizeof(test_routines) / sizeof(test_routines[0]);
+  const int kCopiesOfEachRoutine = kMaxTestThreads / kRoutines;
+  const int kTestThreads = kCopiesOfEachRoutine * kRoutines;
+  ThreadWithParam<Dummy>* threads[kTestThreads] = {};
+  for (int i = 0; i < kTestThreads; i++) {
+    // Creates a thread to run the test function.
+    threads[i] = new ThreadWithParam<Dummy>(test_routines[i % kRoutines],
+                                            Dummy(), nullptr);
+    GTEST_LOG_(INFO) << "Thread #" << i << " running . . .";
+  }
+
+  // At this point, we have many threads running.
+  for (int i = 0; i < kTestThreads; i++) {
+    JoinAndDelete(threads[i]);
+  }
+
+  // Ensures that the correct number of failures have been reported.
+  const TestInfo* const info = UnitTest::GetInstance()->current_test_info();
+  const TestResult& result = *info->result();
+  const int kExpectedFailures = (3 * kRepeat + 1) * kCopiesOfEachRoutine;
+  GTEST_CHECK_(kExpectedFailures == result.total_part_count())
+      << "Expected " << kExpectedFailures << " failures, but got "
+      << result.total_part_count();
+}
+
+}  // namespace
+}  // namespace testing
+
+int main(int argc, char** argv) {
+  testing::InitGoogleMock(&argc, argv);
+
+  const int exit_code = RUN_ALL_TESTS();  // Expected to fail.
+  GTEST_CHECK_(exit_code != 0) << "RUN_ALL_TESTS() did not fail as expected";
+
+  printf("\nPASS\n");
+  return 0;
+}

contrib/googletest/googlemock/test/gmock_test.cc

@@ -0,0 +1,179 @@
+// Copyright 2008, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+// Google Mock - a framework for writing C++ mock classes.
+//
+// This file tests code in gmock.cc.
+
+#include "gmock/gmock.h"
+
+#include <string>
+
+#include "gtest/gtest.h"
+#include "gtest/internal/custom/gtest.h"
+
+#if !defined(GTEST_CUSTOM_INIT_GOOGLE_TEST_FUNCTION_)
+
+using testing::InitGoogleMock;
+
+// Verifies that calling InitGoogleMock() on argv results in new_argv,
+// and the gmock_verbose flag's value is set to expected_gmock_verbose.
+template <typename Char, int M, int N>
+void TestInitGoogleMock(const Char* (&argv)[M], const Char* (&new_argv)[N],
+                        const ::std::string& expected_gmock_verbose) {
+  const ::std::string old_verbose = GMOCK_FLAG_GET(verbose);
+
+  int argc = M - 1;
+  InitGoogleMock(&argc, const_cast<Char**>(argv));
+  ASSERT_EQ(N - 1, argc) << "The new argv has wrong number of elements.";
+
+  for (int i = 0; i < N; i++) {
+    EXPECT_STREQ(new_argv[i], argv[i]);
+  }
+
+  EXPECT_EQ(expected_gmock_verbose, GMOCK_FLAG_GET(verbose));
+  GMOCK_FLAG_SET(verbose, old_verbose);  // Restores the gmock_verbose flag.
+}
+
+TEST(InitGoogleMockTest, ParsesInvalidCommandLine) {
+  const char* argv[] = {nullptr};
+
+  const char* new_argv[] = {nullptr};
+
+  TestInitGoogleMock(argv, new_argv, GMOCK_FLAG_GET(verbose));
+}
+
+TEST(InitGoogleMockTest, ParsesEmptyCommandLine) {
+  const char* argv[] = {"foo.exe", nullptr};
+
+  const char* new_argv[] = {"foo.exe", nullptr};
+
+  TestInitGoogleMock(argv, new_argv, GMOCK_FLAG_GET(verbose));
+}
+
+TEST(InitGoogleMockTest, ParsesSingleFlag) {
+  const char* argv[] = {"foo.exe", "--gmock_verbose=info", nullptr};
+
+  const char* new_argv[] = {"foo.exe", nullptr};
+
+  TestInitGoogleMock(argv, new_argv, "info");
+}
+
+TEST(InitGoogleMockTest, ParsesMultipleFlags) {
+  int old_default_behavior = GMOCK_FLAG_GET(default_mock_behavior);
+  const wchar_t* argv[] = {L"foo.exe", L"--gmock_verbose=info",
+                           L"--gmock_default_mock_behavior=2", nullptr};
+
+  const wchar_t* new_argv[] = {L"foo.exe", nullptr};
+
+  TestInitGoogleMock(argv, new_argv, "info");
+  EXPECT_EQ(2, GMOCK_FLAG_GET(default_mock_behavior));
+  EXPECT_NE(2, old_default_behavior);
+  GMOCK_FLAG_SET(default_mock_behavior, old_default_behavior);
+}
+
+TEST(InitGoogleMockTest, ParsesUnrecognizedFlag) {
+  const char* argv[] = {"foo.exe", "--non_gmock_flag=blah", nullptr};
+
+  const char* new_argv[] = {"foo.exe", "--non_gmock_flag=blah", nullptr};
+
+  TestInitGoogleMock(argv, new_argv, GMOCK_FLAG_GET(verbose));
+}
+
+TEST(InitGoogleMockTest, ParsesGoogleMockFlagAndUnrecognizedFlag) {
+  const char* argv[] = {"foo.exe", "--non_gmock_flag=blah",
+                        "--gmock_verbose=error", nullptr};
+
+  const char* new_argv[] = {"foo.exe", "--non_gmock_flag=blah", nullptr};
+
+  TestInitGoogleMock(argv, new_argv, "error");
+}
+
+TEST(WideInitGoogleMockTest, ParsesInvalidCommandLine) {
+  const wchar_t* argv[] = {nullptr};
+
+  const wchar_t* new_argv[] = {nullptr};
+
+  TestInitGoogleMock(argv, new_argv, GMOCK_FLAG_GET(verbose));
+}
+
+TEST(WideInitGoogleMockTest, ParsesEmptyCommandLine) {
+  const wchar_t* argv[] = {L"foo.exe", nullptr};
+
+  const wchar_t* new_argv[] = {L"foo.exe", nullptr};
+
+  TestInitGoogleMock(argv, new_argv, GMOCK_FLAG_GET(verbose));
+}
+
+TEST(WideInitGoogleMockTest, ParsesSingleFlag) {
+  const wchar_t* argv[] = {L"foo.exe", L"--gmock_verbose=info", nullptr};
+
+  const wchar_t* new_argv[] = {L"foo.exe", nullptr};
+
+  TestInitGoogleMock(argv, new_argv, "info");
+}
+
+TEST(WideInitGoogleMockTest, ParsesMultipleFlags) {
+  int old_default_behavior = GMOCK_FLAG_GET(default_mock_behavior);
+  const wchar_t* argv[] = {L"foo.exe", L"--gmock_verbose=info",
+                           L"--gmock_default_mock_behavior=2", nullptr};
+
+  const wchar_t* new_argv[] = {L"foo.exe", nullptr};
+
+  TestInitGoogleMock(argv, new_argv, "info");
+  EXPECT_EQ(2, GMOCK_FLAG_GET(default_mock_behavior));
+  EXPECT_NE(2, old_default_behavior);
+  GMOCK_FLAG_SET(default_mock_behavior, old_default_behavior);
+}
+
+TEST(WideInitGoogleMockTest, ParsesUnrecognizedFlag) {
+  const wchar_t* argv[] = {L"foo.exe", L"--non_gmock_flag=blah", nullptr};
+
+  const wchar_t* new_argv[] = {L"foo.exe", L"--non_gmock_flag=blah", nullptr};
+
+  TestInitGoogleMock(argv, new_argv, GMOCK_FLAG_GET(verbose));
+}
+
+TEST(WideInitGoogleMockTest, ParsesGoogleMockFlagAndUnrecognizedFlag) {
+  const wchar_t* argv[] = {L"foo.exe", L"--non_gmock_flag=blah",
+                           L"--gmock_verbose=error", nullptr};
+
+  const wchar_t* new_argv[] = {L"foo.exe", L"--non_gmock_flag=blah", nullptr};
+
+  TestInitGoogleMock(argv, new_argv, "error");
+}
+
+#endif  // !defined(GTEST_CUSTOM_INIT_GOOGLE_TEST_FUNCTION_)
+
+// Makes sure Google Mock flags can be accessed in code.
+TEST(FlagTest, IsAccessibleInCode) {
+  bool dummy =
+      GMOCK_FLAG_GET(catch_leaked_mocks) && GMOCK_FLAG_GET(verbose).empty();
+  (void)dummy;  // Avoids the "unused local variable" warning.
+}

contrib/googletest/googlemock/test/gmock_test_utils.py

@@ -0,0 +1,91 @@
+# Copyright 2006, Google Inc.
+# All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are
+# met:
+#
+#     * Redistributions of source code must retain the above copyright
+# notice, this list of conditions and the following disclaimer.
+#     * Redistributions in binary form must reproduce the above
+# copyright notice, this list of conditions and the following disclaimer
+# in the documentation and/or other materials provided with the
+# distribution.
+#     * Neither the name of Google Inc. nor the names of its
+# contributors may be used to endorse or promote products derived from
+# this software without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+"""Unit test utilities for Google C++ Mocking Framework."""
+
+import os
+
+# pylint: disable=C6204
+from googletest.test import gtest_test_utils
+
+
+def GetSourceDir():
+  """Returns the absolute path of the directory where the .py files are."""
+
+  return gtest_test_utils.GetSourceDir()
+
+
+def GetTestExecutablePath(executable_name):
+  """Returns the absolute path of the test binary given its name.
+
+  The function will print a message and abort the program if the resulting file
+  doesn't exist.
+
+  Args:
+    executable_name: name of the test binary that the test script runs.
+
+  Returns:
+    The absolute path of the test binary.
+  """
+
+  return gtest_test_utils.GetTestExecutablePath(executable_name)
+
+
+def GetExitStatus(exit_code):
+  """Returns the argument to exit(), or -1 if exit() wasn't called.
+
+  Args:
+    exit_code: the result value of os.system(command).
+  """
+
+  if os.name == 'nt':
+    # On Windows, os.WEXITSTATUS() doesn't work and os.system() returns
+    # the argument to exit() directly.
+    return exit_code
+  else:
+    # On Unix, os.WEXITSTATUS() must be used to extract the exit status
+    # from the result of os.system().
+    if os.WIFEXITED(exit_code):
+      return os.WEXITSTATUS(exit_code)
+    else:
+      return -1
+
+
+# Exposes utilities from gtest_test_utils.
+Subprocess = gtest_test_utils.Subprocess
+TestCase = gtest_test_utils.TestCase
+environ = gtest_test_utils.environ
+SetEnvVar = gtest_test_utils.SetEnvVar
+PREMATURE_EXIT_FILE_ENV_VAR = gtest_test_utils.PREMATURE_EXIT_FILE_ENV_VAR
+
+
+def Main():
+  """Runs the unit test."""
+
+  gtest_test_utils.Main()

contrib/gtest/CMakeLists.txt → contrib/googletest/googletest/CMakeLists.txt

@@ -46,14 +46,9 @@ endif()
 
 # Project version:
 
-cmake_minimum_required(VERSION 3.5)
-cmake_policy(SET CMP0048 NEW)
+cmake_minimum_required(VERSION 3.13)
 project(gtest VERSION ${GOOGLETEST_VERSION} LANGUAGES CXX C)
 
-if (POLICY CMP0063) # Visibility
-  cmake_policy(SET CMP0063 NEW)
-endif (POLICY CMP0063)
-
 if (COMMAND set_up_hermetic_build)
   set_up_hermetic_build()
 endif()
@@ -100,12 +95,14 @@ if (INSTALL_GTEST)
   set(version_file "${generated_dir}/${cmake_package_name}ConfigVersion.cmake")
   write_basic_package_version_file(${version_file} VERSION ${GOOGLETEST_VERSION} COMPATIBILITY AnyNewerVersion)
   install(EXPORT ${targets_export_name}
+    COMPONENT "${PROJECT_NAME}"
     NAMESPACE ${cmake_package_name}::
     DESTINATION ${cmake_files_install_dir})
   set(config_file "${generated_dir}/${cmake_package_name}Config.cmake")
   configure_package_config_file("${gtest_SOURCE_DIR}/cmake/Config.cmake.in"
     "${config_file}" INSTALL_DESTINATION ${cmake_files_install_dir})
   install(FILES ${version_file} ${config_file}
+    COMPONENT "${PROJECT_NAME}"
     DESTINATION ${cmake_files_install_dir})
 endif()
 
@@ -125,20 +122,31 @@ include_directories(${gtest_build_include_dirs})
 # aggressive about warnings.
 cxx_library(gtest "${cxx_strict}" src/gtest-all.cc)
 set_target_properties(gtest PROPERTIES VERSION ${GOOGLETEST_VERSION})
+if(GTEST_HAS_ABSL)
+  target_compile_definitions(gtest PUBLIC GTEST_HAS_ABSL=1)
+  target_link_libraries(gtest PUBLIC
+    absl::failure_signal_handler
+    absl::stacktrace
+    absl::symbolize
+    absl::flags_parse
+    absl::flags_reflection
+    absl::flags_usage
+    absl::strings
+    absl::any
+    absl::optional
+    absl::variant
+    re2::re2
+  )
+endif()
 cxx_library(gtest_main "${cxx_strict}" src/gtest_main.cc)
 set_target_properties(gtest_main PROPERTIES VERSION ${GOOGLETEST_VERSION})
-# If the CMake version supports it, attach header directory information
-# to the targets for when we are part of a parent build (ie being pulled
-# in via add_subdirectory() rather than being a standalone build).
-if (DEFINED CMAKE_VERSION AND NOT "${CMAKE_VERSION}" VERSION_LESS "2.8.11")
-  string(REPLACE ";" "$<SEMICOLON>" dirs "${gtest_build_include_dirs}")
-  target_include_directories(gtest SYSTEM INTERFACE
-    "$<BUILD_INTERFACE:${dirs}>"
-    "$<INSTALL_INTERFACE:$<INSTALL_PREFIX>/${CMAKE_INSTALL_INCLUDEDIR}>")
-  target_include_directories(gtest_main SYSTEM INTERFACE
-    "$<BUILD_INTERFACE:${dirs}>"
-    "$<INSTALL_INTERFACE:$<INSTALL_PREFIX>/${CMAKE_INSTALL_INCLUDEDIR}>")
-endif()
+string(REPLACE ";" "$<SEMICOLON>" dirs "${gtest_build_include_dirs}")
+target_include_directories(gtest SYSTEM INTERFACE
+  "$<BUILD_INTERFACE:${dirs}>"
+  "$<INSTALL_INTERFACE:$<INSTALL_PREFIX>/${CMAKE_INSTALL_INCLUDEDIR}>")
+target_include_directories(gtest_main SYSTEM INTERFACE
+  "$<BUILD_INTERFACE:${dirs}>"
+  "$<INSTALL_INTERFACE:$<INSTALL_PREFIX>/${CMAKE_INSTALL_INCLUDEDIR}>")
 if(CMAKE_SYSTEM_NAME MATCHES "QNX")
   target_link_libraries(gtest PUBLIC regex)
 endif()

contrib/gtest/README.md → contrib/googletest/googletest/README.md

@@ -9,7 +9,7 @@ depends on which build system you use, and is usually straightforward.
 ### Build with CMake
 
 GoogleTest comes with a CMake build script
-([CMakeLists.txt](https://github.com/google/googletest/blob/master/CMakeLists.txt))
+([CMakeLists.txt](https://github.com/google/googletest/blob/main/CMakeLists.txt))
 that can be used on a wide range of platforms ("C" stands for cross-platform.).
 If you don't have CMake installed already, you can download it for free from
 <http://www.cmake.org/>.
@@ -25,7 +25,7 @@ When building GoogleTest as a standalone project, the typical workflow starts
 with
 
 ```
-git clone https://github.com/google/googletest.git -b release-1.11.0
+git clone https://github.com/google/googletest.git -b v1.13.0
 cd googletest        # Main directory of the cloned repository.
 mkdir build          # Create a directory to hold the build output.
 cd build
@@ -94,7 +94,7 @@ include(FetchContent)
 FetchContent_Declare(
   googletest
   # Specify the commit you depend on and update it regularly.
-  URL https://github.com/google/googletest/archive/e2239ee6043f73722e7aa812a459f54a28552929.zip
+  URL https://github.com/google/googletest/archive/5376968f6948923e2411081fd9372e71a59d8e77.zip
 )
 # For Windows: Prevent overriding the parent project's compiler/linker settings
 set(gtest_force_shared_crt ON CACHE BOOL "" FORCE)
@@ -124,12 +124,12 @@ match the project in which it is included.
 
 #### C++ Standard Version
 
-An environment that supports C++11 is required in order to successfully build
+An environment that supports C++14 is required in order to successfully build
 GoogleTest. One way to ensure this is to specify the standard in the top-level
-project, for example by using the `set(CMAKE_CXX_STANDARD 11)` command. If this
-is not feasible, for example in a C project using GoogleTest for validation,
-then it can be specified by adding it to the options for cmake via the
-`DCMAKE_CXX_FLAGS` option.
+project, for example by using the `set(CMAKE_CXX_STANDARD 14)` command along
+with `set(CMAKE_CXX_STANDARD_REQUIRED ON)`. If this is not feasible, for example
+in a C project using GoogleTest for validation, then it can be specified by
+adding it to the options for cmake via the`-DCMAKE_CXX_FLAGS` option.
 
 ### Tweaking GoogleTest
 
@@ -140,23 +140,27 @@ command line. Generally, these macros are named like `GTEST_XYZ` and you define
 them to either 1 or 0 to enable or disable a certain feature.
 
 We list the most frequently used macros below. For a complete list, see file
-[include/gtest/internal/gtest-port.h](https://github.com/google/googletest/blob/master/googletest/include/gtest/internal/gtest-port.h).
+[include/gtest/internal/gtest-port.h](https://github.com/google/googletest/blob/main/googletest/include/gtest/internal/gtest-port.h).
 
 ### Multi-threaded Tests
 
 GoogleTest is thread-safe where the pthread library is available. After
-`#include "gtest/gtest.h"`, you can check the
+`#include <gtest/gtest.h>`, you can check the
 `GTEST_IS_THREADSAFE` macro to see whether this is the case (yes if the macro is
 `#defined` to 1, no if it's undefined.).
 
 If GoogleTest doesn't correctly detect whether pthread is available in your
 environment, you can force it with
 
-    -DGTEST_HAS_PTHREAD=1
+```
+-DGTEST_HAS_PTHREAD=1
+```
 
 or
 
-    -DGTEST_HAS_PTHREAD=0
+```
+-DGTEST_HAS_PTHREAD=0
+```
 
 When GoogleTest uses pthread, you may need to add flags to your compiler and/or
 linker to select the pthread library, or you'll get link errors. If you use the
@@ -172,23 +176,27 @@ as a DLL on Windows) if you prefer.
 
 To compile *gtest* as a shared library, add
 
-    -DGTEST_CREATE_SHARED_LIBRARY=1
+```
+-DGTEST_CREATE_SHARED_LIBRARY=1
+```
 
 to the compiler flags. You'll also need to tell the linker to produce a shared
 library instead - consult your linker's manual for how to do it.
 
 To compile your *tests* that use the gtest shared library, add
 
-    -DGTEST_LINKED_AS_SHARED_LIBRARY=1
+```
+-DGTEST_LINKED_AS_SHARED_LIBRARY=1
+```
 
 to the compiler flags.
 
 Note: while the above steps aren't technically necessary today when using some
 compilers (e.g. GCC), they may become necessary in the future, if we decide to
 improve the speed of loading the library (see
-<http://gcc.gnu.org/wiki/Visibility> for details). Therefore you are recommended
-to always add the above flags when using GoogleTest as a shared library.
-Otherwise a future release of GoogleTest may break your build script.
+<https://gcc.gnu.org/wiki/Visibility> for details). Therefore you are
+recommended to always add the above flags when using GoogleTest as a shared
+library. Otherwise a future release of GoogleTest may break your build script.
 
 ### Avoiding Macro Name Clashes
 
@@ -200,7 +208,9 @@ rename its macro to avoid the conflict.
 Specifically, if both GoogleTest and some other code define macro FOO, you can
 add
 
-    -DGTEST_DONT_DEFINE_FOO=1
+```
+-DGTEST_DONT_DEFINE_FOO=1
+```
 
 to the compiler flags to tell GoogleTest to change the macro's name from `FOO`
 to `GTEST_FOO`. Currently `FOO` can be `ASSERT_EQ`, `ASSERT_FALSE`, `ASSERT_GE`,
@@ -208,10 +218,14 @@ to `GTEST_FOO`. Currently `FOO` can be `ASSERT_EQ`, `ASSERT_FALSE`, `ASSERT_GE`,
 `EXPECT_FALSE`, `EXPECT_TRUE`, `FAIL`, `SUCCEED`, `TEST`, or `TEST_F`. For
 example, with `-DGTEST_DONT_DEFINE_TEST=1`, you'll need to write
 
-    GTEST_TEST(SomeTest, DoesThis) { ... }
+```
+GTEST_TEST(SomeTest, DoesThis) { ... }
+```
 
 instead of
 
-    TEST(SomeTest, DoesThis) { ... }
+```
+TEST(SomeTest, DoesThis) { ... }
+```
 
 in order to define a test.