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@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
25AU_ALIAS([AC_CXX_NAMESPACE_STD], [AX_CXX_NAMESPACE_STD])
26AC_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