if(CMAKE_CXX_STANDARD AND NOT DEFINED CMake_HAVE_CXX11_UNORDERED_MAP) message(STATUS "Checking if compiler supports C++11 unordered_map") try_compile(CMake_HAVE_CXX11_UNORDERED_MAP ${CMAKE_CURRENT_BINARY_DIR} ${CMAKE_CURRENT_LIST_DIR}/cm_cxx11_unordered_map.cpp CMAKE_FLAGS -DCMAKE_CXX_STANDARD=${CMAKE_CXX_STANDARD} OUTPUT_VARIABLE OUTPUT ) if(CMake_HAVE_CXX11_UNORDERED_MAP) message(STATUS "Checking if compiler supports C++11 unordered_map - yes") file(APPEND ${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/CMakeOutput.log "Determining if compiler supports C++11 unordered_map passed with the following output:\n" "${OUTPUT}\n" "\n" ) else() message(STATUS "Checking if compiler supports C++11 unordered_map - no") file(APPEND ${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/CMakeError.log "Determining if compiler supports C++11 unordered_map failed with the following output:\n" "${OUTPUT}\n" "\n" ) endif() endif()