message(STATUS "Using GCC version ${GCC_VERSION}")
if(GCC_VERSION VERSION_LESS 4.9)
# <regex> in gcc is unusable in versions less than 4.9.0
message(STATUS "Using GCC version ${GCC_VERSION}")
if(GCC_VERSION VERSION_LESS 4.9)
# <regex> in gcc is unusable in versions less than 4.9.0