call.c (convert_class_to_reference): Binding an lvalue to an rvalue reference is bad.

	* call.c (convert_class_to_reference): Binding an lvalue to an
	rvalue reference is bad.  If the user-defined conversion is bad,
	set bad_p before merging conversions.
	(maybe_handle_ref_bind): Don't push down bad_p.
	(reference_binding): Binding an lvalue to an rvalue reference is bad.
	(convert_like_real): Give a helpful error about binding lvalue
	to rvalue reference.
	(reference_related_p): No longer static.
	* typeck.c (build_typed_address): New.
	(build_static_cast_1): Add static_cast from lvalue to &&.
	* cp-tree.h: Adjust.

	* include/bits/move.h (forward): Implement as in N2835.
	(move): Implement as in N2831.
	* include/std/istream (rvalue stream operator>>): New.
	* include/std/ostream (rvalue stream operator<<): New.

Co-Authored-By: Douglas Gregor <doug.gregor@gmail.com>

From-SVN: r150327

1 files changed, 43 insertions, 0 deletions

diff --git a/libstdc++-v3/testsuite/27_io/rvalue_streams.cc b/libstdc++-v3/testsuite/27_io/rvalue_streams.cc
new file mode 100644
index 00000000000..b3cc630edc0
--- /dev/null
+++ b/libstdc++-v3/testsuite/27_io/rvalue_streams.cc
@@ -0,0 +1,43 @@
+// Copyright (C) 2008 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 2, 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 COPYING.  If not, write to the Free
+// Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
+// USA.
+
+// { dg-do run }
+
+#include <sstream>
+#include <string>
+#include <testsuite_hooks.h>
+
+void
+test01()
+{
+  int i = 1742;
+  // This usage isn't supported by the current draft.
+  // std::string result = (std::ostringstream() << i).str();
+  std::ostringstream() << i;
+  std::string result ("1742");
+  int i2;
+  std::istringstream(result) >> i2;
+  VERIFY (i == i2);
+}
+
+int
+main()
+{
+  test01();
+  return 0;
+}