# AC_COMPILE_STDCXX_11
AC_DEFUN([AC_COMPILE_STDCXX_11], [

  AC_CACHE_CHECK(if g++ supports C++11 features with -std=c++0x,
  ac_cv_cxx_compile_cxx11_cxx,
  [AC_LANG_SAVE
  AC_LANG_CPLUSPLUS
  ac_save_CXXFLAGS="$CXXFLAGS"
  CXXFLAGS="$CXXFLAGS -std=gnu++0x"
  AC_TRY_COMPILE([
    #include <functional>
    std::function<int (int, int)> func;
  ],,
  ac_cv_cxx_compile_cxx11_cxx=yes, ac_cv_cxx_compile_cxx11_cxx=no)
  CXXFLAGS="$ac_save_CXXFLAGS"
  AC_LANG_RESTORE
  ])

  if test "$ac_cv_cxx_compile_cxx11_cxx" = yes; then
    AC_DEFINE(HAVE_STDCXX_11,,[Define if g++ supports C++11 features. ])
  fi
])