PR libstdc++/80478 make std::mem_fn work with noexcept functions

	PR libstdc++/80478
	* include/std/functional (_Mem_fn_traits_base): Add specializations
	for noexcept member function types.
	* testsuite/20_util/function_objects/mem_fn/80478.cc: New test.

From-SVN: r248245

libstdc++-v3/ChangeLog

 2017-05-18  Jonathan Wakely  <jwakely@redhat.com>
 
+	PR libstdc++/80478
+	* include/std/functional (_Mem_fn_traits_base): Add specializations
+	for noexcept member function types.
+	* testsuite/20_util/function_objects/mem_fn/80478.cc: New test.
+
+2017-05-18  Jonathan Wakely  <jwakely@redhat.com>
+
 	* doc/xml/manual/policy_data_structures.xml: Fix typo.
 	* doc/xml/manual/test_policy_data_structures.xml: Likewise.
 	* doc/html/*: Regenerate.

libstdc++-v3/include/std/functional

@@ -135,6 +135,12 @@ _GLIBCXX_MEM_FN_TRAITS( , true_type, true_type)
 _GLIBCXX_MEM_FN_TRAITS(&, true_type, false_type)
 _GLIBCXX_MEM_FN_TRAITS(&&, false_type, true_type)
 
+#if __cplusplus > 201402L
+_GLIBCXX_MEM_FN_TRAITS(noexcept, true_type, true_type)
+_GLIBCXX_MEM_FN_TRAITS(& noexcept, true_type, false_type)
+_GLIBCXX_MEM_FN_TRAITS(&& noexcept, false_type, true_type)
+#endif
+
 #undef _GLIBCXX_MEM_FN_TRAITS
 #undef _GLIBCXX_MEM_FN_TRAITS2
 

libstdc++-v3/testsuite/20_util/function_objects/mem_fn/80478.cc

+// Copyright (C) 2017 Free Software Foundation, Inc.
+//
+// This file is part of the GNU ISO C++ Library.  This library 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 3, or (at your option)
+// any later version.
+
+// This library is distributed in the hope that it will be useful,
+// but 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.
+
+// You should have received a copy of the GNU General Public License along
+// with this library; see the file COPYING3.  If not see
+// <http://www.gnu.org/licenses/>.
+
+// { dg-options "-std=gnu++17" }
+// { dg-do compile { target c++1z } }
+
+#include <functional>
+
+struct X {
+  void f() noexcept { }
+};
+
+auto f = std::mem_fn(&X::f);