##### http://autoconf-archive.cryp.to/ac_cxx_have_freeze_sstream.html
#
# SYNOPSIS
#
#   AC_CXX_HAVE_FREEZE_SSTREAM
#
# DESCRIPTION
#
#   Check if the compiler has (need) freeze method call in
#   stringstream/ strstream. Seems that Win32 and STLPort have it,
#   libstdc++ not ...
#
#   Eg:
#
#     #include <sstream>
#     #ifdef HAVE_NAMESPACES
#     using namespace std;
#     #endif
#     #ifdef HAVE_SSTREAM
#     stringstream message;
#     #else
#     strstream message;
#     #endif
#     message << "Hello";
#     #ifdef HAVE_FREEZE_SSTREAM
#     message.freeze(0);
#     #endif
#
# LAST MODIFICATION
#
#   2002-09-04
#
# COPYLEFT
#
#   Copyright (c) 2002 Alain BARBET <alian@cpan.org>
#
#   This program is free software; you can redistribute it and/or
#   modify it under the terms of the GNU General Public License as
#   published by the Free Software Foundation; either version 2 of the
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#
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#   WITHOUT ANY WARRANTY; without even the implied warranty of
#   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
#   General Public License for more details.
#
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AC_DEFUN([AC_CXX_HAVE_FREEZE_SSTREAM],
[AC_CACHE_CHECK(whether the compiler has freeze in stringstream,
ac_cv_cxx_have_freeze_sstream,
[AC_REQUIRE([AC_CXX_NAMESPACES])
  AC_REQUIRE([AC_CXX_HAVE_SSTREAM])
  AC_LANG_SAVE
  AC_LANG_CPLUSPLUS
  AC_TRY_COMPILE([#include <sstream>
#ifdef HAVE_NAMESPACES
using namespace std;
#endif],
[#ifdef HAVE_SSTREAM
stringstream message;
#else
strstream message;
#endif
message << "Hello"; message.freeze(0); return 0;],
  ac_cv_cxx_have_freeze_sstream=yes, ac_cv_cxx_have_freeze_sstream=no)
  AC_LANG_RESTORE
])
if test "$ac_cv_cxx_have_freeze_sstream" = yes; then
   AC_DEFINE(HAVE_FREEZE_SSTREAM,,[define if the compiler has freeze in
stringstream])
fi
])