re PR libstdc++/44487 ([C++0x] pair of references doesn't work)

2010-06-10  Paolo Carlini  <paolo.carlini@oracle.com>

	PR libstdc++/44487
	* include/bits/stl_pair.h (pair(pair&&)): Remove.
	(pair(pair<_U1, _U2>&&): Use forward, consistently with Bullet 5
	of LWG 1326.
	* include/std/tuple (tuple(pair<_U1, _U2>&&)): Likewise.
	* testsuite/20_util/pair/44487.cc: Add.
	* testsuite/20_util/tuple/cons/44487.cc: Likewise.
	* testsuite/20_util/weak_ptr/comparison/cmp_neg.cc: Adjust dg-warning
	line numbers.

From-SVN: r160528

libstdc++-v3/ChangeLog

+2010-06-10  Paolo Carlini  <paolo.carlini@oracle.com>
+
+	PR libstdc++/44487
+	* include/bits/stl_pair.h (pair(pair&&)): Remove.
+	(pair(pair<_U1, _U2>&&): Use forward, consistently with Bullet 5
+	of LWG 1326.
+	* include/std/tuple (tuple(pair<_U1, _U2>&&)): Likewise.
+	* testsuite/20_util/pair/44487.cc: Add.
+	* testsuite/20_util/tuple/cons/44487.cc: Likewise.
+	* testsuite/20_util/weak_ptr/comparison/cmp_neg.cc: Adjust dg-warning
+	line numbers.
+
 2010-06-09  Paolo Carlini  <paolo.carlini@oracle.com>
 
 	* include/std/type_traits (is_nothrow_constructible): Add.

libstdc++-v3/include/bits/stl_pair.h

@@ -120,10 +120,6 @@ _GLIBCXX_BEGIN_NAMESPACE(std)
 	: first(std::forward<_U1>(__x)),
 	  second(std::forward<_U2>(__y)) { }
 
-      pair(pair&& __p)
-      : first(std::move(__p.first)),
-	second(std::move(__p.second)) { }
-
       template<class... _Args1, class... _Args2>
         pair(piecewise_construct_t,
 	     tuple<_Args1...> __first_args,
@@ -141,8 +137,8 @@ _GLIBCXX_BEGIN_NAMESPACE(std)
 #ifdef __GXX_EXPERIMENTAL_CXX0X__
       template<class _U1, class _U2>
         pair(pair<_U1, _U2>&& __p)
-	: first(std::move(__p.first)),
-	  second(std::move(__p.second)) { }
+	: first(std::forward<_U1>(__p.first)),
+	  second(std::forward<_U2>(__p.second)) { }
 
       pair&
       operator=(pair&& __p)

libstdc++-v3/include/std/tuple

@@ -341,7 +341,8 @@ namespace std
 
       template<typename _U1, typename _U2>
         tuple(pair<_U1, _U2>&& __in)
-	: _Inherited(std::move(__in.first), std::move(__in.second)) { }
+	: _Inherited(std::forward<_U1>(__in.first),
+		     std::forward<_U2>(__in.second)) { }
 
       tuple&
       operator=(const tuple& __in)

libstdc++-v3/testsuite/20_util/pair/44487.cc

+// { dg-options "-std=gnu++0x" }
+// { dg-do compile }
+
+// Copyright (C) 2010 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 <utility>
+
+int x, y;
+
+std::pair<int&, int&>
+foo1()
+{
+  std::pair<int&, int&> blah(x, y);
+  return blah;
+}
+
+std::pair<int&, int&>
+foo2()
+{
+  const std::pair<int&, int&> blah(x, y);
+  return blah;
+}
+
+std::pair<int&, int&>
+foo3()
+{
+  std::pair<int&, int&> blah(x, y);
+  return std::pair<int&, int&>(std::move(blah));
+}
+
+std::pair<int&, int&>
+foo4()
+{
+  const std::pair<int&, int&> blah(x, y);
+  return std::pair<int&, int&>(std::move(blah));
+}

libstdc++-v3/testsuite/20_util/tuple/cons/44487.cc

+// { dg-options "-std=gnu++0x" }
+// { dg-do compile }
+
+// Copyright (C) 2010 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 <tuple>
+
+int x, y;
+
+std::tuple<int&, int&>
+foo1()
+{
+  std::pair<int&, int&> blah(x, y);
+  return blah;
+}
+
+std::tuple<int&, int&>
+foo2()
+{
+  const std::pair<int&, int&> blah(x, y);
+  return blah;
+}
+
+std::tuple<int&, int&>
+foo3()
+{
+  std::pair<int&, int&> blah(x, y);
+  return std::tuple<int&, int&>(std::move(blah));
+}
+
+std::tuple<int&, int&>
+foo4()
+{
+  const std::pair<int&, int&> blah(x, y);
+  return std::tuple<int&, int&>(std::move(blah));
+}

libstdc++-v3/testsuite/20_util/weak_ptr/comparison/cmp_neg.cc

@@ -44,8 +44,8 @@ main()
 // { dg-warning "note" "" { target *-*-* } 324 }
 // { dg-warning "note" "" { target *-*-* } 423 }
 // { dg-warning "note" "" { target *-*-* } 862 }
-// { dg-warning "note" "" { target *-*-* } 511 }
+// { dg-warning "note" "" { target *-*-* } 512 }
 // { dg-warning "note" "" { target *-*-* } 1005 }
 // { dg-warning "note" "" { target *-*-* } 340 }
 // { dg-warning "note" "" { target *-*-* } 290 }
-// { dg-warning "note" "" { target *-*-* } 201 }
+// { dg-warning "note" "" { target *-*-* } 197 }