Merge pull request #4261 from assimp/kimkulling-enable_language_support_issue4257-2

Enable C++11 and C99

CMakeLists.txt

@@ -183,7 +183,9 @@ SET (ASSIMP_SOVERSION 5)
 SET( ASSIMP_PACKAGE_VERSION "0" CACHE STRING "the package-specific version used for uploading the sources" )
 if(NOT ASSIMP_HUNTER_ENABLED)
   # Enable C++11 support globally
-  set_property( GLOBAL PROPERTY CXX_STANDARD 11 )
+  set(CMAKE_CXX_STANDARD 11)
+  set(CMAKE_CXX_STANDARD_REQUIRED ON)
+  set(CMAKE_C_STANDARD 99)
 endif()
 
 IF(NOT ASSIMP_IGNORE_GIT_HASH)