From: Jonathan Wakely <jwakely@redhat.com>
Date: Wed, 16 Dec 2015 17:09:52 +0000 (+0000)
Subject: Fix cv-qualifiers in std::bind invocation
X-Git-Tag: releases/gcc-4.9.4~444
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=4c5b54fc6dc18294e3597b8e61a92ca78a5d6ea9;p=thirdparty%2Fgcc.git

Fix cv-qualifiers in std::bind invocation

	PR libstdc++/68912
	* include/std/functional (_Bind::operator()): Use lvalue functor to
	deduce return type.
	* testsuite/20_util/bind/68912.cc: New.

From-SVN: r231702
---

diff --git a/libstdc++-v3/ChangeLog b/libstdc++-v3/ChangeLog
index 8a1a86af099e..0116cd62e0db 100644
--- a/libstdc++-v3/ChangeLog
+++ b/libstdc++-v3/ChangeLog
@@ -1,5 +1,10 @@
 2015-12-16  Jonathan Wakely  <jwakely@redhat.com>
 
+	PR libstdc++/68912
+	* include/std/functional (_Bind::operator()): Use lvalue functor to
+	deduce return type.
+	* testsuite/20_util/bind/68912.cc: New.
+
 	Backport from mainline
 	2015-12-02  Jonathan Wakely  <jwakely@redhat.com>
 
diff --git a/libstdc++-v3/include/std/functional b/libstdc++-v3/include/std/functional
index fac1c6708f1c..d84fd264bc29 100644
--- a/libstdc++-v3/include/std/functional
+++ b/libstdc++-v3/include/std/functional
@@ -1312,7 +1312,7 @@ _GLIBCXX_HAS_NESTED_TYPE(result_type)
 
       // Call unqualified
       template<typename... _Args, typename _Result
-	= decltype( std::declval<_Functor>()(
+	= decltype( std::declval<_Functor&>()(
 	      _Mu<_Bound_args>()( std::declval<_Bound_args&>(),
 				  std::declval<tuple<_Args...>&>() )... ) )>
 	_Result
@@ -1326,7 +1326,7 @@ _GLIBCXX_HAS_NESTED_TYPE(result_type)
       // Call as const
       template<typename... _Args, typename _Result
 	= decltype( std::declval<typename enable_if<(sizeof...(_Args) >= 0),
-		       typename add_const<_Functor>::type>::type>()(
+		       typename add_const<_Functor>::type&>::type>()(
 	      _Mu<_Bound_args>()( std::declval<const _Bound_args&>(),
 				  std::declval<tuple<_Args...>&>() )... ) )>
 	_Result
@@ -1340,7 +1340,7 @@ _GLIBCXX_HAS_NESTED_TYPE(result_type)
       // Call as volatile
       template<typename... _Args, typename _Result
 	= decltype( std::declval<typename enable_if<(sizeof...(_Args) >= 0),
-                       typename add_volatile<_Functor>::type>::type>()(
+                       typename add_volatile<_Functor>::type&>::type>()(
 	      _Mu<_Bound_args>()( std::declval<volatile _Bound_args&>(),
 				  std::declval<tuple<_Args...>&>() )... ) )>
 	_Result
@@ -1354,7 +1354,7 @@ _GLIBCXX_HAS_NESTED_TYPE(result_type)
       // Call as const volatile
       template<typename... _Args, typename _Result
 	= decltype( std::declval<typename enable_if<(sizeof...(_Args) >= 0),
-                       typename add_cv<_Functor>::type>::type>()(
+                       typename add_cv<_Functor>::type&>::type>()(
 	      _Mu<_Bound_args>()( std::declval<const volatile _Bound_args&>(),
 				  std::declval<tuple<_Args...>&>() )... ) )>
 	_Result
diff --git a/libstdc++-v3/testsuite/20_util/bind/68912.cc b/libstdc++-v3/testsuite/20_util/bind/68912.cc
new file mode 100644
index 000000000000..7a00b75124a7
--- /dev/null
+++ b/libstdc++-v3/testsuite/20_util/bind/68912.cc
@@ -0,0 +1,53 @@
+// 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 }
+
+#include<functional>
+
+struct Wrong {};
+struct A {};
+struct B {};
+struct C{};
+struct D{};
+
+struct X {
+  A operator()(int, double) & { return {}; }
+  Wrong operator()(int, double) && {return {}; }
+
+  B operator()(int, double) const & { return {}; }
+  Wrong operator()(int, double) const && {return {}; }
+
+  C operator()(int, double) volatile & { return {}; }
+  Wrong operator()(int, double) volatile && {return {}; }
+
+  D operator()(int, double) const volatile & { return {}; }
+  Wrong operator()(int, double) const volatile && {return {}; }
+};
+
+void test01()
+{
+  auto bound = std::bind(X{}, 5, std::placeholders::_1);
+  A res = bound(1.0);
+  const auto bound_c = bound;
+  B res_c = bound_c(1.0);
+  volatile auto bound_v = bound;
+  C res_v = bound_v(1.0);
+  volatile const auto bound_cv = bound;
+  D res_cv = bound_cv(1.0);
+}