//this file checks in order to ensure that right version of std::filesystem is returned for the version of c++ // We haven't checked which filesystem to include yet #ifndef INCLUDE_STD_FILESYSTEM_EXPERIMENTAL // Check for feature test macro for <filesystem> # if defined(__cpp_lib_filesystem) # define INCLUDE_STD_FILESYSTEM_EXPERIMENTAL 0 // Check for feature test macro for <experimental/filesystem> # elif defined(__cpp_lib_experimental_filesystem) # define INCLUDE_STD_FILESYSTEM_EXPERIMENTAL 1 // We can't check if headers exist... // Let's assume experimental to be safe # elif !defined(__has_include) # define INCLUDE_STD_FILESYSTEM_EXPERIMENTAL 1 // Check if the header "<filesystem>" exists # elif __has_include(<filesystem>) // If we're compiling on Visual Studio and are not compiling with C++17, we need to use experimental # ifdef _MSC_VER // Check and include header that defines "_HAS_CXX17" # if __has_include(<yvals_core.h>) # include <yvals_core.h> // Check for enabled C++17 support # if defined(_HAS_CXX17) && _HAS_CXX17 // We're using C++17, so let's use the normal version # define INCLUDE_STD_FILESYSTEM_EXPERIMENTAL 0 # endif # endif // If the marco isn't defined yet, that means any of the other VS specific checks failed, so we need to use experimental # ifndef INCLUDE_STD_FILESYSTEM_EXPERIMENTAL # define INCLUDE_STD_FILESYSTEM_EXPERIMENTAL 1 # endif // Not on Visual Studio. Let's use the normal version # else // #ifdef _MSC_VER # define INCLUDE_STD_FILESYSTEM_EXPERIMENTAL 0 # endif // Check if the header "<filesystem>" exists # elif __has_include(<experimental/filesystem>) # define INCLUDE_STD_FILESYSTEM_EXPERIMENTAL 1 // Fail if neither header is available with a nice error message # else # error Could not find system header "<filesystem>" or "<experimental/filesystem>" # endif // We priously determined that we need the exprimental version # if INCLUDE_STD_FILESYSTEM_EXPERIMENTAL // Include it # include <experimental/filesystem> // We need the alias from std::experimental::filesystem to std::filesystem namespace std { namespace filesystem = experimental::filesystem; } # else // We have a decent compiler and can use the normal version # include <filesystem>// Include it # endif #endif // #ifndef INCLUDE_STD_FILESYSTEM_EXPERIMENTAL