[v3] Fix libstdc++/65543

[Paolo Carlini]

Hi,

as I said in the audit trail, this isn't a regression but the fix seems 
safe enough to me even for mainline: it's matter of reverting a dumb, 
supposedly "cosmetic" change of mine dating back to 2009. I mean to 
apply it to 4_9 and 4_8 too. Tested x86_64-linux.

Thanks,
Paolo.

/////////////////
-------------- next part --------------
2015-03-25  Paolo Carlini  <paolo.carlini@oracle.com>

	PR libstdc++/65543
	* include/std/istream (operator>>(basic_istream<>&&, _Tp&): Revert
	thinko in r150387.
	* include/std/ostream (operator<<(basic_ostream<>&&, const _Tp&):
	Likewise.
	* testsuite/27_io/rvalue_streams-2.cc: Likewise.
-------------- next part --------------
Index: include/std/istream
===================================================================
--- include/std/istream	(revision 221642)
+++ include/std/istream	(working copy)
@@ -922,7 +922,10 @@
   template<typename _CharT, typename _Traits, typename _Tp>
     inline basic_istream<_CharT, _Traits>&
     operator>>(basic_istream<_CharT, _Traits>&& __is, _Tp& __x)
-    { return (__is >> __x); }
+    { 
+      __is >> __x;
+      return __is;
+    }
 #endif // C++11
 
 _GLIBCXX_END_NAMESPACE_VERSION
Index: include/std/ostream
===================================================================
--- include/std/ostream	(revision 221642)
+++ include/std/ostream	(working copy)
@@ -626,7 +626,10 @@
   template<typename _CharT, typename _Traits, typename _Tp>
     inline basic_ostream<_CharT, _Traits>&
     operator<<(basic_ostream<_CharT, _Traits>&& __os, const _Tp& __x)
-    { return (__os << __x); }
+    {
+      __os << __x;
+      return __os;
+    }
 #endif // C++11
 
 _GLIBCXX_END_NAMESPACE_VERSION
Index: testsuite/27_io/rvalue_streams-2.cc
===================================================================
--- testsuite/27_io/rvalue_streams-2.cc	(revision 0)
+++ testsuite/27_io/rvalue_streams-2.cc	(working copy)
@@ -0,0 +1,35 @@
+// { dg-options "-std=gnu++11" }
+// { dg-do compile }
+
+// 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/>.
+
+#include <sstream>
+
+struct A {};
+
+void operator<<(std::ostream&, const A&) { }
+void operator>>(std::istream&, A&) { }
+
+// PR libstdc++/65543
+int main()
+{
+  A a;
+
+  std::ostringstream() << a;
+  std::istringstream() >> a;
+}