Backport libstdc++/60594 fix from mainline.

	PR libstdc++/60594
	* include/std/functional (function::_Callable): Exclude own type
	from the callable checks.
	* testsuite/20_util/function/60594.cc: New.

git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/branches/gcc-4_9-branch@210103 138bc75d-0d04-0410-961f-82ee72b054a4

3 files changed, 55 insertions, 2 deletions

diff --git a/libstdc++-v3/ChangeLog b/libstdc++-v3/ChangeLog
index 12e6b5c56ff..58771cb934e 100644
--- a/libstdc++-v3/ChangeLog
+++ b/libstdc++-v3/ChangeLog
@@ -1,3 +1,13 @@
+2014-05-06  Jonathan Wakely  <jwakely@redhat.com>
+
+	Backport from mainline
+	2014-04-15  Jonathan Wakely  <jwakely@redhat.com>
+
+	PR libstdc++/60594
+	* include/std/functional (function::_Callable): Exclude own type
+	from the callable checks.
+	* testsuite/20_util/function/60594.cc: New.
+
 2014-05-02  Jonathan Wakely  <jwakely@redhat.com>
 
 	PR libstdc++/59476
diff --git a/libstdc++-v3/include/std/functional b/libstdc++-v3/include/std/functional
index 5a987d914b1..0e80fa37cf4 100644
--- a/libstdc++-v3/include/std/functional
+++ b/libstdc++-v3/include/std/functional
@@ -2149,8 +2149,15 @@ _GLIBCXX_HAS_NESTED_TYPE(result_type)
 	using _Invoke = decltype(__callable_functor(std::declval<_Functor&>())
 				 (std::declval<_ArgTypes>()...) );
 
+      // Used so the return type convertibility checks aren't done when
+      // performing overload resolution for copy construction/assignment.
+      template<typename _Tp>
+	using _NotSelf = __not_<is_same<_Tp, function>>;
+
       template<typename _Functor>
-	using _Callable = __check_func_return_type<_Invoke<_Functor>, _Res>;
+	using _Callable
+	  = __and_<_NotSelf<_Functor>,
+		   __check_func_return_type<_Invoke<_Functor>, _Res>>;
 
       template<typename _Cond, typename _Tp>
 	using _Requires = typename enable_if<_Cond::value, _Tp>::type;
@@ -2291,7 +2298,7 @@ _GLIBCXX_HAS_NESTED_TYPE(result_type)
        *  reference_wrapper<F>, this function will not throw.
        */
       template<typename _Functor>
-	_Requires<_Callable<_Functor>, function&>
+	_Requires<_Callable<typename decay<_Functor>::type>, function&>
 	operator=(_Functor&& __f)
 	{
 	  function(std::forward<_Functor>(__f)).swap(*this);
diff --git a/libstdc++-v3/testsuite/20_util/function/60594.cc b/libstdc++-v3/testsuite/20_util/function/60594.cc
new file mode 100644
index 00000000000..be80b3f44d0
--- /dev/null
+++ b/libstdc++-v3/testsuite/20_util/function/60594.cc
@@ -0,0 +1,36 @@
+// { dg-options "-std=gnu++11" }
+// { dg-do compile }
+
+// Copyright (C) 2011-2014 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/>.
+
+// libstdc++/60594
+
+#include <functional>
+#include <type_traits>
+struct bar;
+using F = std::function<bar()>;
+// check for copy constructible and assignable while 'bar' is incomplete
+constexpr int c = std::is_copy_constructible<F>::value;
+constexpr int a = std::is_copy_assignable<F>::value;
+struct bar { };
+bar func();
+void test()
+{
+  F g{ &func };
+  g = func;
+}