re PR libstdc++/56492 (std::packaged_task requires CopyConstructible stored task)

	PR libstdc++/56492
	* include/std/future (__future_base::_Result): Add result_type
	typedef.
	(__future_base::_S_allocate_result): Overload for std::allocator.
	(__future_base::_Task_setter): Use _Result::result_type instead of
	deducing the type from the task.
	(__future_base::_Task_state): Store allocator to allow shared state
	to be reset.  Replace std::function with member of target object type
	accessed via ...
	(__future_base::_Task_state_base): New abstract base class.
	(__future_base::_Task_state_base::_M_run): New virtual function to
	invoke type-erased target object.
	(__future_base::_Task_state_base::_M_reset): New virtual function to
	create new shared_state using same target object and allocator.
	(__future_base::__create_task_state): Allocate a new _Task_state.
	(packaged_task::packaged_task): Use __create_task_state.
	(packaged_task::reset): Use _Task_state_base::_M_reset.
	* testsuite/30_threads/packaged_task/cons/56492.cc: New.

From-SVN: r196695

libstdc++-v3/ChangeLog

+2013-03-16  Jonathan Wakely  <jwakely.gcc@gmail.com>
+
+	PR libstdc++/56492
+	* include/std/future (__future_base::_Result): Add result_type
+	typedef.
+	(__future_base::_S_allocate_result): Overload for std::allocator.
+	(__future_base::_Task_setter): Use _Result::result_type instead of
+	deducing the type from the task.
+	(__future_base::_Task_state): Store allocator to allow shared state
+	to be reset.  Replace std::function with member of target object type
+	accessed via ...
+	(__future_base::_Task_state_base): New abstract base class.
+	(__future_base::_Task_state_base::_M_run): New virtual function to
+	invoke type-erased target object.
+	(__future_base::_Task_state_base::_M_reset): New virtual function to
+	create new shared_state using same target object and allocator.
+	(__future_base::__create_task_state): Allocate a new _Task_state.
+	(packaged_task::packaged_task): Use __create_task_state.
+	(packaged_task::reset): Use _Task_state_base::_M_reset.
+	* testsuite/30_threads/packaged_task/cons/56492.cc: New.
+
 2013-03-15  Tom Tromey  <tromey@redhat.com>
 
 	* libsupc++/unwind-cxx.h: Include sys/sdt.h if detected.

libstdc++-v3/testsuite/30_threads/packaged_task/cons/56492.cc

+// { dg-do compile { target *-*-freebsd* *-*-netbsd* *-*-linux* *-*-solaris* *-*-cygwin *-*-darwin* powerpc-ibm-aix* } }
+// { dg-options " -std=gnu++11 -pthread" { target *-*-freebsd* *-*-netbsd* *-*-linux* powerpc-ibm-aix* } }
+// { dg-options " -std=gnu++11 -pthreads" { target *-*-solaris* } }
+// { dg-options " -std=gnu++11 " { target *-*-cygwin *-*-darwin* } }
+// { dg-require-cstdint "" }
+// { dg-require-gthreads "" }
+// { dg-require-atomic-builtins "" }
+
+// Copyright (C) 2013 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 <future>
+
+struct S
+{
+  S() = default;
+  S(S&&) = default;
+  void operator()() { }
+};
+
+std::packaged_task<void ()> pt{ S{} };