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// Temporary buffer implementation -*- C++ -*-

// Copyright (C) 2001, 2002, 2004, 2005 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.

// 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.

/*

 *

 * Copyright (c) 1994

 * Hewlett-Packard Company

 *

 * Permission to use, copy, modify, distribute and sell this software

 * and its documentation for any purpose is hereby granted without fee,

 * provided that the above copyright notice appear in all copies and

 * that both that copyright notice and this permission notice appear

 * in supporting documentation.  Hewlett-Packard Company makes no

 * representations about the suitability of this software for any

 * purpose.  It is provided "as is" without express or implied warranty.

 *

 *

 * Copyright (c) 1996,1997

 * Silicon Graphics Computer Systems, Inc.

 *

 * Permission to use, copy, modify, distribute and sell this software

 * and its documentation for any purpose is hereby granted without fee,

 * provided that the above copyright notice appear in all copies and

 * that both that copyright notice and this permission notice appear

 * in supporting documentation.  Silicon Graphics makes no

 * representations about the suitability of this software for any

 * purpose.  It is provided "as is" without express or implied warranty.

 */

/** @file stl_tempbuf.h

 *  This is an internal header file, included by other library headers.

 *  You should not attempt to use it directly.

 */

#ifndef _TEMPBUF_H

#define _TEMPBUF_H 1

#include <memory>

namespace std

{

  /**

   *  @if maint

   *  This class is used in two places: stl_algo.h and ext/memory,

   *  where it is wrapped as the temporary_buffer class.  See

   *  temporary_buffer docs for more notes.

   *  @endif

   */

  template<typename _ForwardIterator, typename _Tp>

    class _Temporary_buffer

    {

      // concept requirements

      __glibcxx_class_requires(_ForwardIterator, _ForwardIteratorConcept)

        public:

      typedef _Tp         value_type;

      typedef value_type* pointer;

      typedef pointer     iterator;

      typedef ptrdiff_t   size_type;

    protected:

      size_type  _M_original_len;

      size_type  _M_len;

      pointer    _M_buffer;

      void

      _M_initialize_buffer(const _Tp&, __true_type) { }

      void

      _M_initialize_buffer(const _Tp& val, __false_type)

      { std::uninitialized_fill_n(_M_buffer, _M_len, val); }

    public:

      /// As per Table mumble.

      size_type

      size() const

      { return _M_len; }

      /// Returns the size requested by the constructor; may be >size().

      size_type

      requested_size() const

      { return _M_original_len; }

      /// As per Table mumble.

      iterator

      begin()

      { return _M_buffer; }

      /// As per Table mumble.

      iterator

      end()

      { return _M_buffer + _M_len; }

      /**

       * Constructs a temporary buffer of a size somewhere between

       * zero and the size of the given range.

       */

      _Temporary_buffer(_ForwardIterator __first, _ForwardIterator __last);

      ~_Temporary_buffer()

      {

        std::_Destroy(_M_buffer, _M_buffer + _M_len);

        std::return_temporary_buffer(_M_buffer);

      }

    private:

      // Disable copy constructor and assignment operator.

      _Temporary_buffer(const _Temporary_buffer&);

      void

      operator=(const _Temporary_buffer&);

    };

  template<typename _ForwardIterator, typename _Tp>

    _Temporary_buffer<_ForwardIterator, _Tp>::

    _Temporary_buffer(_ForwardIterator __first, _ForwardIterator __last)

    : _M_original_len(std::distance(__first, __last)),

      _M_len(0), _M_buffer(0)

    {

      // Workaround for a __type_traits bug in the pre-7.3 compiler.

      typedef typename std::__is_scalar<_Tp>::__type _Trivial;

      try

        {

          pair<pointer, size_type> __p(get_temporary_buffer<

                                       value_type>(_M_original_len));

          _M_buffer = __p.first;

          _M_len = __p.second;

          if (_M_len > 0)

            _M_initialize_buffer(*__first, _Trivial());

        }

      catch(...)

        {

          std::return_temporary_buffer(_M_buffer);

          _M_buffer = 0;

          _M_len = 0;

          __throw_exception_again;

        }

    }

} // namespace std

#endif /* _TEMPBUF_H */