Add webthing-cpp v1.1.0 (#6453)

* add webthing-cpp v1.1.0

* Make it headeronly, limit to linux&macosx

* fixup ontest("linux", "macosx", ->on_install("linux", "macosx",

packages/w/webthing-cpp/xmake.lua

@@ -0,0 +1,39 @@
+package("webthing-cpp")
+    set_kind("library", {headeronly = true})
+    set_homepage("https://github.com/bw-hro/webthing-cpp")
+    set_description("Webthing-CPP is a modern CPP/C++17 implementation of the WebThings API.")
+    set_license("MIT")
+
+    add_urls("https://github.com/bw-hro/webthing-cpp/archive/refs/tags/$(version).tar.gz",
+             "https://github.com/bw-hro/webthing-cpp.git")
+
+    add_versions("v1.1.0", "7f32651813168b7a51f95005be626cfaf30868db134a5bf9ca491a9d07949f5a")
+
+    add_configs("ssl", {description = "Build with SSL", default = true, type = "boolean"})
+
+    add_deps("cmake", "mdns", "libuv", "zlib", "json-schema-validator", "uwebsockets")
+    add_deps("usockets", {configs = {ssl = "openssl3"}})
+    add_deps("nlohmann_json", {configs = {cmake = true}})
+
+    on_load(function (package)
+        if package:config("ssl") then
+            package:add("deps", "openssl3")
+        end
+    end)
+
+    on_install("linux", "macosx", function (package)
+        local configs = {"-DWT_BUILD_EXAMPLES=OFF", "-DWT_BUILD_TESTS=OFF"}
+        table.insert(configs, "-DWT_WITH_SSL=" .. (package:config("ssl") and "ON" or "OFF"))
+        table.insert(configs, "-DCMAKE_BUILD_TYPE=" .. (package:is_debug() and "Debug" or "Release"))
+        table.insert(configs, "-DBUILD_SHARED_LIBS=" .. (package:config("shared") and "ON" or "OFF"))
+        import("package.tools.cmake").install(package, configs)
+    end)
+
+    on_test(function (package)
+        assert(package:check_cxxsnippets({test = [[
+            using namespace bw::webthing;
+            void test() {
+                auto thing = make_thing("urn:gui-thing-123", "The WebThing Slot Machine", "SLOT_MACHINE_THING", "A slot machine thing with GUI");
+            }
+        ]]}, {configs = {languages = "c++17"}, includes = "bw/webthing/webthing.hpp"}))
+    end)