62
64
m4_if([$2], [], [ax_cxx_compile_cxx11_required=true],
63
65
[$2], [mandatory], [ax_cxx_compile_cxx11_required=true],
64
66
[$2], [optional], [ax_cxx_compile_cxx11_required=false],
68
70
AC_CACHE_CHECK(whether $CXX supports C++11 features by default,