1 # =========================================================================== 2 # https://www.gnu.org/software/autoconf-archive/ax_cxx_namespace_std.html 3 # =========================================================================== 4 # 5 # SYNOPSIS 6 # 7 # AX_CXX_NAMESPACE_STD 8 # 9 # DESCRIPTION 10 # 11 # If the compiler supports namespace std, define HAVE_NAMESPACE_STD. 12 # 13 # LICENSE 14 # 15 # Copyright (c) 2009 Todd Veldhuizen 16 # Copyright (c) 2009 Luc Maisonobe <luc (a] spaceroots.org> 17 # 18 # Copying and distribution of this file, with or without modification, are 19 # permitted in any medium without royalty provided the copyright notice 20 # and this notice are preserved. This file is offered as-is, without any 21 # warranty. 22 23 #serial 8 24 25 AU_ALIAS([AC_CXX_NAMESPACE_STD], [AX_CXX_NAMESPACE_STD]) 26 AC_DEFUN([AX_CXX_NAMESPACE_STD], [ 27 AC_CACHE_CHECK(if g++ supports namespace std, 28 ax_cv_cxx_have_std_namespace, 29 [AC_LANG_PUSH([C++]) 30 AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[#include <iostream> 31 std::istream& is = std::cin;]], [])], 32 [ax_cv_cxx_have_std_namespace=yes], [ax_cv_cxx_have_std_namespace=no]) 33 AC_LANG_POP([C++]) 34 ]) 35 if test "$ax_cv_cxx_have_std_namespace" = yes; then 36 AC_DEFINE(HAVE_NAMESPACE_STD,,[Define if g++ supports namespace std. ]) 37 fi 38 ]) 39
