enable_cxx11_support.cmake

#######################################################################################################################
# enable_cxx11_support.cmake
#
# NOTE: Do not use this routine! Use enable_latest_css_support.cmake instead, even if you only need C++11, as the
#       compiler always uses the strictest ("oldest") specified standard if mulitple flags are given. This will create
#       problems when combining multiple projects (libraries...) requiring different C++ standards.
#
# Enable C++-11 support by selecting the appropriate compiler flag. The flag will be appended to all of the following
# cmake variables:
# - CMAKE_CXX_FLAGS
# - ${PROJECT_NAME}_CXX_FLAGS
# - ${PROJECT_NAME}_CMAKE_CXX_FLAGS
#
#######################################################################################################################

#######################################################################################################################
#
# IMPORTANT NOTE:
#
# DO NOT MODIFY THIS FILE inside a project. Instead update the project-template repository and pull the change from
# there. Make sure to keep the file generic, since it will be used by other projects, too.
#
# If you have modified this file inside a project despite this warning, make sure to cherry-pick all your changes
# into the project-template repository immediately.
#
#######################################################################################################################

include(CheckCXXCompilerFlag)
CHECK_CXX_COMPILER_FLAG("-std=c++11" COMPILER_SUPPORTS_CXX11)
CHECK_CXX_COMPILER_FLAG("-std=c++0x" COMPILER_SUPPORTS_CXX0X)
if(COMPILER_SUPPORTS_CXX11)
    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -std=c++11")
    set(${PROJECT_NAME}_CXX_FLAGS "${${PROJECT_NAME}_CXX_FLAGS} -std=c++11")
    set(${PROJECT_NAME}_CMAKE_CXX_FLAGS "${${PROJECT_NAME}_CMAKE_CXX_FLAGS} -std=c++11")
elseif(COMPILER_SUPPORTS_CXX0X)
    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -std=c++0x")
    set(${PROJECT_NAME}_CXX_FLAGS "${${PROJECT_NAME}_CXX_FLAGS} -std=c++0x")
    set(${PROJECT_NAME}_CMAKE_CXX_FLAGS "${${PROJECT_NAME}_CMAKE_CXX_FLAGS} -std=c++0x")
else()
    message(STATUS "The compiler ${CMAKE_CXX_COMPILER} has no C++11 support. Please use a different C++ compiler.")
endif()