# and this notice are preserved. This file is offered as-is, without any
# warranty.
-#serial 15
+#serial 18
dnl This macro is based on the code from the AX_CXX_COMPILE_STDCXX_11 macro
dnl (serial version number 13).
dnl HP's aCC needs +std=c++11 according to:
dnl http://h21007.www2.hp.com/portal/download/files/unprot/aCxx/PDF_Release_Notes/769149-001.pdf
dnl Cray's crayCC needs "-h std=c++11"
+ dnl MSVC needs -std:c++NN for C++17 and later (default is C++14)
for alternative in ${ax_cxx_compile_alternatives}; do
- for switch in -std=c++${alternative} +std=c++${alternative} "-h std=c++${alternative}"; do
- cachevar=AS_TR_SH([ax_cv_cxx_compile_cxx$1_$switch])
+ for switch in -std=c++${alternative} +std=c++${alternative} "-h std=c++${alternative}" MSVC; do
+ if test x"$switch" = xMSVC; then
+ dnl AS_TR_SH maps both `:` and `=` to `_` so -std:c++17 would collide
+ dnl with -std=c++17. We suffix the cache variable name with _MSVC to
+ dnl avoid this.
+ switch=-std:c++${alternative}
+ cachevar=AS_TR_SH([ax_cv_cxx_compile_cxx$1_${switch}_MSVC])
+ else
+ cachevar=AS_TR_SH([ax_cv_cxx_compile_cxx$1_$switch])
+ fi
AC_CACHE_CHECK(whether $CXX supports C++$1 features with $switch,
$cachevar,
[ac_save_CXX="$CXX"