freebsd-dev/contrib/libstdc++/include/ext/array_allocator.h

150 lines
4.5 KiB
C++

// array allocator -*- C++ -*-
// Copyright (C) 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.
/** @file ext/array_allocator.h
* This file is a GNU extension to the Standard C++ Library.
*/
#ifndef _ARRAY_ALLOCATOR_H
#define _ARRAY_ALLOCATOR_H 1
#include <cstddef>
#include <new>
#include <bits/functexcept.h>
#include <tr1/array>
_GLIBCXX_BEGIN_NAMESPACE(__gnu_cxx)
using std::size_t;
using std::ptrdiff_t;
/// @brief Base class.
template<typename _Tp>
class array_allocator_base
{
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;
pointer
address(reference __x) const { return &__x; }
const_pointer
address(const_reference __x) const { return &__x; }
void
deallocate(pointer, size_type)
{
// Does nothing.
}
size_type
max_size() const throw()
{ return size_t(-1) / sizeof(_Tp); }
// _GLIBCXX_RESOLVE_LIB_DEFECTS
// 402. wrong new expression in [some_] allocator::construct
void
construct(pointer __p, const _Tp& __val)
{ ::new(__p) value_type(__val); }
void
destroy(pointer __p) { __p->~_Tp(); }
};
/**
* @brief An allocator that uses previously allocated memory.
* This memory can be externally, globally, or otherwise allocated.
*/
template<typename _Tp, typename _Array = std::tr1::array<_Tp, 1> >
class array_allocator : public array_allocator_base<_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;
typedef _Array array_type;
private:
array_type* _M_array;
size_type _M_used;
public:
template<typename _Tp1, typename _Array1 = _Array>
struct rebind
{ typedef array_allocator<_Tp1, _Array1> other; };
array_allocator(array_type* __array = NULL) throw()
: _M_array(__array), _M_used(size_type()) { }
array_allocator(const array_allocator& __o) throw()
: _M_array(__o._M_array), _M_used(__o._M_used) { }
template<typename _Tp1, typename _Array1>
array_allocator(const array_allocator<_Tp1, _Array1>&) throw()
: _M_array(NULL), _M_used(size_type()) { }
~array_allocator() throw() { }
pointer
allocate(size_type __n, const void* = 0)
{
if (_M_array == 0 || _M_used + __n > _M_array->size())
std::__throw_bad_alloc();
pointer __ret = _M_array->begin() + _M_used;
_M_used += __n;
return __ret;
}
};
template<typename _Tp, typename _Array>
inline bool
operator==(const array_allocator<_Tp, _Array>&,
const array_allocator<_Tp, _Array>&)
{ return true; }
template<typename _Tp, typename _Array>
inline bool
operator!=(const array_allocator<_Tp, _Array>&,
const array_allocator<_Tp, _Array>&)
{ return false; }
_GLIBCXX_END_NAMESPACE
#endif