Re: [c++0x] _Tuple_impl and typename reference_wrapper<T>::type&&

[Pedro LamarÃo <pedro dot lamarao at mndfck dot org>]

Paolo Carlini escreveu:
> ... by the way, returning to tuple in the c++0x framework after some
> time, I see that indeed quite a bit of work is needed in order to
> decently implement the current specifications... I'm working on that, as
> I said, but if you have something ready, don't be afraid to propose it
> for review: in this specific area of experimental C++0x features we  are
> allowed some extra time for gcc4.3.

I'll take a shot at this.
I think I can fix my own use case.

Attached is a test case I put in 20_util/tuple/ .


--
 P.

// { dg-options "-std=gnu++0x" }

// Copyright (C) 2007 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, 59 Temple Place - Suite 330, Boston, MA 02111-1307,
// USA.

// As a special exception, you may use this file as part of a free software
// library without restriction.  Specifically, if other files instantiate
// templates or use macros or inline functions from this file, or you compile
// this file and link it with other files to produce an executable, this
// file does not by itself cause the resulting executable to be covered by
// the GNU General Public License.  This exception does not however
// invalidate any other reasons why the executable file might be covered by
// the GNU General Public License.

#include <tuple>
#include <utility>
#include <testsuite_hooks.h>

class MoveOnly {
public:
  
  MoveOnly () { }
  
  MoveOnly (MoveOnly&&) { }
  
  MoveOnly& operator= (MoveOnly&&) { return *this; }
  
private:
  MoveOnly (MoveOnly const&); // = delete
  MoveOnly& operator= (MoveOnly const&); // = delete
};

MoveOnly
make_move_only () { return MoveOnly(); }

int main()
{
  bool test __attribute__((unused)) = true;

  std::tuple<MoveOnly> t1(make_move_only());
  std::tuple<MoveOnly> t2(std::move(t1));
  std::tuple<MoveOnly> t3 = std::move(t2);
  t1 = std::move(t3);
  
  return 0;
}