From 952bc7a64cd257de733fddaec64e320f973c6350 Mon Sep 17 00:00:00 2001
From: Jonathan Wakely <jwakely@redhat.com>
Date: Wed, 29 Apr 2015 17:07:47 +0100
Subject: [PATCH] re PR libstdc++/65760 (invalid use of incomplete type with
 std::is_convertible<C, C>)

	PR libstdc++/65760
	* include/std/functional (__check_func_return_type): Use is_same to
	avoid using _is_convertible on incomplete types.
	* testsuite/20_util/function/65760.cc: New.

From-SVN: r222581
---
 libstdc++-v3/ChangeLog                        |  5 +++
 libstdc++-v3/include/std/functional           |  2 +-
 .../testsuite/20_util/function/65760.cc       | 38 +++++++++++++++++++
 3 files changed, 44 insertions(+), 1 deletion(-)
 create mode 100644 libstdc++-v3/testsuite/20_util/function/65760.cc

diff --git a/libstdc++-v3/ChangeLog b/libstdc++-v3/ChangeLog
index fde307fb9ed..8f06de185ad 100644
--- a/libstdc++-v3/ChangeLog
+++ b/libstdc++-v3/ChangeLog
@@ -1,5 +1,10 @@
 2015-04-29  Jonathan Wakely  <jwakely@redhat.com>
 
+	PR libstdc++/65760
+	* include/std/functional (__check_func_return_type): Use is_same to
+	avoid using _is_convertible on incomplete types.
+	* testsuite/20_util/function/65760.cc: New.
+
 	PR libstdc++/64657
 	* include/bits/basic_string (basic_string::_S_copy_chars): Cast
 	expression to void.
diff --git a/libstdc++-v3/include/std/functional b/libstdc++-v3/include/std/functional
index e9d48e40877..946cf63ace2 100644
--- a/libstdc++-v3/include/std/functional
+++ b/libstdc++-v3/include/std/functional
@@ -1962,7 +1962,7 @@ _GLIBCXX_MEM_FN_TRAITS(&&, false_type, true_type)
 
   template<typename _From, typename _To>
     using __check_func_return_type
-      = __or_<is_void<_To>, is_convertible<_From, _To>>;
+      = __or_<is_void<_To>, is_same<_From, _To>, is_convertible<_From, _To>>;
 
   /**
    *  @brief Primary class template for std::function.
diff --git a/libstdc++-v3/testsuite/20_util/function/65760.cc b/libstdc++-v3/testsuite/20_util/function/65760.cc
new file mode 100644
index 00000000000..e3858b476f9
--- /dev/null
+++ b/libstdc++-v3/testsuite/20_util/function/65760.cc
@@ -0,0 +1,38 @@
+// Copyright (C) 2015 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++11" }
+// { dg-do compile }
+
+// libstdc++/65760
+// c.f. https://gcc.gnu.org/ml/libstdc++/2015-04/msg00116.html
+
+#include <functional>
+
+struct C {
+    C() = default;
+
+    C(std::function<C(int)>);
+    C(std::function<C(int, int)>);
+    C operator()(int);
+    C operator()(int, int);
+};
+
+int main() {
+    C c = C();
+}
+
-- 
2.30.2