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

154 lines
4.7 KiB
C++

// Allocators -*- C++ -*-
// Copyright (C) 2001, 2002, 2003, 2004, 2005, 2006
// 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) 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
// Define the base class to std::allocator.
#include <bits/c++allocator.h>
#include <bits/cpp_type_traits.h> // for __is_empty
_GLIBCXX_BEGIN_NAMESPACE(std)
template<typename _Tp>
class allocator;
/// allocator<void> specialization.
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].
*
* Further details:
* http://gcc.gnu.org/onlinedocs/libstdc++/20_util/allocator.html
*/
template<typename _Tp>
class allocator: public __glibcxx_base_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_base_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_base_allocator
// To implement Option 3 of DR 431.
template<typename _Alloc, bool = std::__is_empty<_Alloc>::__value>
struct __alloc_swap
{ static void _S_do_it(_Alloc&, _Alloc&) { } };
template<typename _Alloc>
struct __alloc_swap<_Alloc, false>
{
static void
_S_do_it(_Alloc& __one, _Alloc& __two)
{
// Precondition: swappable allocators.
if (__one != __two)
swap(__one, __two);
}
};
_GLIBCXX_END_NAMESPACE
#endif