gcc/libstdc++-v3/include/bits/allocator.h

// Allocators -*- C++ -*-

// Copyright (C) 2001, 2002, 2003, 2004 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.

/*
 * 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 allocator.h
 *  This is an internal header file, included by other library headers.
 *  You should not attempt to use it directly.
 */

#ifndef _ALLOCATOR_H
#define _ALLOCATOR_H 1

#if 1
# include <ext/mt_allocator.h>
# define __glibcxx_default_allocator  __gnu_cxx::__mt_alloc
#endif

#if 0
# include <ext/pool_allocator.h>
# define __glibcxx_default_allocator  __gnu_cxx::__pool_alloc
#endif

namespace std
{
  template<typename _Tp>
    class allocator;

  template<>
    class allocator<void>
    {
    public:
      typedef size_t      size_type;
      typedef ptrdiff_t   difference_type;
      typedef void*       pointer;
      typedef const void* const_pointer;
      typedef void        value_type;

      template<typename _Tp1>
        struct rebind
        { typedef allocator<_Tp1> other; };
    };

  /**
   *  @brief  The "standard" allocator, as per [20.4].
   *
   *  (See @link Allocators allocators info @endlink for more.)
   */
  template<typename _Tp>
    class allocator: public __glibcxx_default_allocator<_Tp>  
    {
   public:
      typedef size_t     size_type;
      typedef ptrdiff_t  difference_type;
      typedef _Tp*       pointer;
      typedef const _Tp* const_pointer;
      typedef _Tp&       reference;
      typedef const _Tp& const_reference;
      typedef _Tp        value_type;

      template<typename _Tp1>
        struct rebind
        { typedef allocator<_Tp1> other; };

      allocator() throw() { }

      allocator(const allocator& a) throw() 
      : __glibcxx_default_allocator<_Tp>(a) { }

      template<typename _Tp1>
        allocator(const allocator<_Tp1>&) throw() { }

      ~allocator() throw() { }

      // Inherit everything else.
    };

  template<typename _T1, typename _T2>
    inline bool
    operator==(const allocator<_T1>&, const allocator<_T2>&)
    { return true; }

  template<typename _T1, typename _T2>
    inline bool
    operator!=(const allocator<_T1>&, const allocator<_T2>&)
    { return false; }

  // Inhibit implicit instantiations for required instantiations,
  // which are defined via explicit instantiations elsewhere.
  // NB: This syntax is a GNU extension.
#if _GLIBCXX_EXTERN_TEMPLATE
  extern template class allocator<char>;
  extern template class allocator<wchar_t>;
#endif

  // Undefine.
#undef __glibcxx_default_allocator
} // namespace std

#endif