| # ============================================================================ |
| # http://www.gnu.org/software/autoconf-archive/ax_cxx_compile_stdcxx_11.html |
| # ============================================================================ |
| # |
| # SYNOPSIS |
| # |
| # AX_CXX_COMPILE_STDCXX_11([ext|noext],[mandatory|optional]) |
| # |
| # DESCRIPTION |
| # |
| # Check for baseline language coverage in the compiler for the C++11 |
| # standard; if necessary, add switches to CXXFLAGS to enable support. |
| # |
| # The first argument, if specified, indicates whether you insist on an |
| # extended mode (e.g. -std=gnu++11) or a strict conformance mode (e.g. |
| # -std=c++11). If neither is specified, you get whatever works, with |
| # preference for an extended mode. |
| # |
| # The second argument, if specified 'mandatory' or if left unspecified, |
| # indicates that baseline C++11 support is required and that the macro |
| # should error out if no mode with that support is found. If specified |
| # 'optional', then configuration proceeds regardless, after defining |
| # HAVE_CXX11 if and only if a supporting mode is found. |
| # |
| # LICENSE |
| # |
| # Copyright (c) 2008 Benjamin Kosnik <bkoz@redhat.com> |
| # Copyright (c) 2012 Zack Weinberg <zackw@panix.com> |
| # Copyright (c) 2013 Roy Stogner <roystgnr@ices.utexas.edu> |
| # |
| # Copying and distribution of this file, with or without modification, are |
| # permitted in any medium without royalty provided the copyright notice |
| # and this notice are preserved. This file is offered as-is, without any |
| # warranty. |
| |
| #serial 3 |
| |
| m4_define([_AX_CXX_COMPILE_STDCXX_11_testbody], [ |
| template <typename T> |
| struct check |
| { |
| static_assert(sizeof(int) <= sizeof(T), "not big enough"); |
| }; |
| |
| typedef check<check<bool>> right_angle_brackets; |
| |
| int a; |
| decltype(a) b; |
| |
| typedef check<int> check_type; |
| check_type c; |
| check_type&& cr = static_cast<check_type&&>(c); |
| |
| auto d = a; |
| ]) |
| |
| AC_DEFUN([AX_CXX_COMPILE_STDCXX_11], [dnl |
| m4_if([$1], [], [], |
| [$1], [ext], [], |
| [$1], [noext], [], |
| [m4_fatal([invalid argument `$1' to AX_CXX_COMPILE_STDCXX_11])])dnl |
| m4_if([$2], [], [ax_cxx_compile_cxx11_required=true], |
| [$2], [mandatory], [ax_cxx_compile_cxx11_required=true], |
| [$2], [optional], [ax_cxx_compile_cxx11_required=false], |
| [m4_fatal([invalid second argument `$2' to AX_CXX_COMPILE_STDCXX_11])])dnl |
| AC_LANG_PUSH([C++])dnl |
| ac_success=no |
| AC_CACHE_CHECK(whether $CXX supports C++11 features by default, |
| ax_cv_cxx_compile_cxx11, |
| [AC_COMPILE_IFELSE([AC_LANG_SOURCE([_AX_CXX_COMPILE_STDCXX_11_testbody])], |
| [ax_cv_cxx_compile_cxx11=yes], |
| [ax_cv_cxx_compile_cxx11=no])]) |
| if test x$ax_cv_cxx_compile_cxx11 = xyes; then |
| ac_success=yes |
| fi |
| |
| m4_if([$1], [noext], [], [dnl |
| if test x$ac_success = xno; then |
| for switch in -std=gnu++11; do |
| cachevar=AS_TR_SH([ax_cv_cxx_compile_cxx11_$switch]) |
| AC_CACHE_CHECK(whether $CXX supports C++11 features with $switch, |
| $cachevar, |
| [ac_save_CXXFLAGS="$CXXFLAGS" |
| CXXFLAGS="$CXXFLAGS $switch" |
| AC_COMPILE_IFELSE([AC_LANG_SOURCE([_AX_CXX_COMPILE_STDCXX_11_testbody])], |
| [eval $cachevar=yes], |
| [eval $cachevar=no]) |
| CXXFLAGS="$ac_save_CXXFLAGS"]) |
| if eval test x\$$cachevar = xyes; then |
| CXXFLAGS="$CXXFLAGS $switch" |
| ac_success=yes |
| break |
| fi |
| done |
| fi]) |
| |
| m4_if([$1], [ext], [], [dnl |
| if test x$ac_success = xno; then |
| for switch in -std=c++11; do |
| cachevar=AS_TR_SH([ax_cv_cxx_compile_cxx11_$switch]) |
| AC_CACHE_CHECK(whether $CXX supports C++11 features with $switch, |
| $cachevar, |
| [ac_save_CXXFLAGS="$CXXFLAGS" |
| CXXFLAGS="$CXXFLAGS $switch" |
| AC_COMPILE_IFELSE([AC_LANG_SOURCE([_AX_CXX_COMPILE_STDCXX_11_testbody])], |
| [eval $cachevar=yes], |
| [eval $cachevar=no]) |
| CXXFLAGS="$ac_save_CXXFLAGS"]) |
| if eval test x\$$cachevar = xyes; then |
| CXXFLAGS="$CXXFLAGS $switch" |
| ac_success=yes |
| break |
| fi |
| done |
| fi]) |
| AC_LANG_POP([C++]) |
| if test x$ax_cxx_compile_cxx11_required = xtrue; then |
| if test x$ac_success = xno; then |
| AC_MSG_ERROR([*** A compiler with support for C++11 language features is required.]) |
| fi |
| else |
| if test x$ac_success = xno; then |
| HAVE_CXX11=0 |
| AC_MSG_NOTICE([No compiler with C++11 support was found]) |
| else |
| HAVE_CXX11=1 |
| AC_DEFINE(HAVE_CXX11,1, |
| [define if the compiler supports basic C++11 syntax]) |
| fi |
| |
| AC_SUBST(HAVE_CXX11) |
| fi |
| ]) |
| |