+function(check_flag FLAG DEFAULT)
+ unset(FLAG_CONSTANT)
+ string(MAKE_C_IDENTIFIER CXX${FLAG} FLAG_CONSTANT)
+ check_cxx_compiler_flag(${FLAG} ${FLAG_CONSTANT})
+ if(${FLAG_CONSTANT})
+ add_compile_options(${FLAG})
+ elseif(DEFAULT)
+ add_compile_options(${DEFAULT})
+ endif()
+endfunction()
+