cmake HAVE_FILESYSTEM_IN_STD examples

PacktPublishing/The-Modern-Vulkan-Cookbook source/chapter8/app/src/main/cpp/thirdparty/OpenXR-SDK/src/cmake/StdFilesystemFlags.cmake :113 

check_cxx_source_compiles("${_stdfs_source}" HAVE_FILESYSTEM_IN_STD)

rbfx/rbfx Source/ThirdParty/OpenXRSDK/src/cmake/StdFilesystemFlags.cmake :113 

check_cxx_source_compiles("${_stdfs_source}" HAVE_FILESYSTEM_IN_STD)

RavEngine/RavEngine deps/OpenXR-SDK/src/cmake/StdFilesystemFlags.cmake :113 

check_cxx_source_compiles("${_stdfs_source}" HAVE_FILESYSTEM_IN_STD)