cmake HAS_CXX14_FLAG examples

patrikhuber/4dface CMakeLists.txt :29 

check_cxx_compiler_flag(-std=c++14 HAS_CXX14_FLAG)

VowpalWabbit/vowpal_wabbit cmake/DetectCXXStandard.cmake :27 

check_cxx_compiler_flag(${CXX_STANDARD14_FLAG} HAS_CXX14_FLAG)