1// array allocator -*- C++ -*-
2
3// Copyright (C) 2004-2019 Free Software Foundation, Inc.
4//
5// This file is part of the GNU ISO C++ Library.  This library is free
6// software; you can redistribute it and/or modify it under the
7// terms of the GNU General Public License as published by the
8// Free Software Foundation; either version 3, or (at your option)
9// any later version.
10
11// This library is distributed in the hope that it will be useful,
12// but WITHOUT ANY WARRANTY; without even the implied warranty of
13// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14// GNU General Public License for more details.
15
16// Under Section 7 of GPL version 3, you are granted additional
17// permissions described in the GCC Runtime Library Exception, version
18// 3.1, as published by the Free Software Foundation.
19
20// You should have received a copy of the GNU General Public License and
21// a copy of the GCC Runtime Library Exception along with this program;
22// see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
23// <http://www.gnu.org/licenses/>.
24
25/** @file ext/array_allocator.h
26 *  This file is a GNU extension to the Standard C++ Library.
27 */
28
29#ifndef _ARRAY_ALLOCATOR_H
30#define _ARRAY_ALLOCATOR_H 1
31
32#include <bits/c++config.h>
33#include <new>
34#include <bits/functexcept.h>
35#include <tr1/array>
36#include <bits/move.h>
37#if __cplusplus >= 201103L
38#include <type_traits>
39#endif
40
41// Suppress deprecated warning for this file.
42#pragma GCC diagnostic push
43#pragma GCC diagnostic ignored "-Wdeprecated-declarations"
44
45namespace __gnu_cxx _GLIBCXX_VISIBILITY(default)
46{
47_GLIBCXX_BEGIN_NAMESPACE_VERSION
48
49 using std::size_t;
50 using std::ptrdiff_t;
51
52  /// Base class.
53 template<typename _Tp>
54    class array_allocator_base
55    {
56    public:
57      typedef size_t     	size_type;
58      typedef ptrdiff_t  	difference_type;
59      typedef _Tp*       	pointer;
60      typedef const _Tp* 	const_pointer;
61      typedef _Tp&       	reference;
62      typedef const _Tp&	const_reference;
63      typedef _Tp        	value_type;
64
65      pointer
66      address(reference __x) const _GLIBCXX_NOEXCEPT
67      { return std::__addressof(__x); }
68
69      const_pointer
70      address(const_reference __x) const _GLIBCXX_NOEXCEPT
71      { return std::__addressof(__x); }
72
73      void
74      deallocate(pointer, size_type)
75      {
76	// Does nothing.
77      }
78
79      size_type
80      max_size() const _GLIBCXX_USE_NOEXCEPT
81      { return size_t(-1) / sizeof(_Tp); }
82
83#if __cplusplus >= 201103L
84      template<typename _Up, typename... _Args>
85        void
86        construct(_Up* __p, _Args&&... __args)
87	{ ::new((void *)__p) _Up(std::forward<_Args>(__args)...); }
88
89      template<typename _Up>
90        void
91        destroy(_Up* __p) { __p->~_Up(); }
92#else
93      // _GLIBCXX_RESOLVE_LIB_DEFECTS
94      // 402. wrong new expression in [some_] allocator::construct
95      void
96      construct(pointer __p, const _Tp& __val)
97      { ::new((void *)__p) value_type(__val); }
98
99      void
100      destroy(pointer __p) { __p->~_Tp(); }
101#endif
102    } _GLIBCXX_DEPRECATED;
103
104  /**
105   *  @brief  An allocator that uses previously allocated memory.
106   *  This memory can be externally, globally, or otherwise allocated.
107   *  @ingroup allocators
108   */
109  template<typename _Tp, typename _Array = std::tr1::array<_Tp, 1> >
110    class array_allocator : public array_allocator_base<_Tp>
111    {
112    public:
113      typedef size_t     	size_type;
114      typedef ptrdiff_t  	difference_type;
115      typedef _Tp*       	pointer;
116      typedef const _Tp* 	const_pointer;
117      typedef _Tp&       	reference;
118      typedef const _Tp& 	const_reference;
119      typedef _Tp        	value_type;
120      typedef _Array		array_type;
121
122#if __cplusplus >= 201103L
123      // _GLIBCXX_RESOLVE_LIB_DEFECTS
124      // 2103. std::allocator propagate_on_container_move_assignment
125      typedef std::true_type propagate_on_container_move_assignment;
126
127      typedef std::true_type is_always_equal;
128#endif
129
130    private:
131      array_type* 	_M_array;
132      size_type 	_M_used;
133
134    public:
135     template<typename _Tp1, typename _Array1 = _Array>
136        struct rebind
137        {
138	  typedef array_allocator<_Tp1, _Array1> other _GLIBCXX_DEPRECATED;
139	} _GLIBCXX_DEPRECATED;
140
141      array_allocator(array_type* __array = 0) _GLIBCXX_USE_NOEXCEPT
142      : _M_array(__array), _M_used(size_type()) { }
143
144      array_allocator(const array_allocator& __o) _GLIBCXX_USE_NOEXCEPT
145      : _M_array(__o._M_array), _M_used(__o._M_used) { }
146
147      template<typename _Tp1, typename _Array1>
148        array_allocator(const array_allocator<_Tp1, _Array1>&)
149	_GLIBCXX_USE_NOEXCEPT
150	: _M_array(0), _M_used(size_type()) { }
151
152      ~array_allocator() _GLIBCXX_USE_NOEXCEPT { }
153
154      _GLIBCXX_NODISCARD pointer
155      allocate(size_type __n, const void* = 0)
156      {
157	if (_M_array == 0 || _M_used + __n > _M_array->size())
158	  std::__throw_bad_alloc();
159	pointer __ret = _M_array->begin() + _M_used;
160	_M_used += __n;
161	return __ret;
162      }
163    } _GLIBCXX_DEPRECATED;
164
165  template<typename _Tp, typename _Array>
166    inline bool
167    operator==(const array_allocator<_Tp, _Array>&,
168	       const array_allocator<_Tp, _Array>&)
169    { return true; }
170
171  template<typename _Tp, typename _Array>
172    inline bool
173    operator!=(const array_allocator<_Tp, _Array>&,
174	       const array_allocator<_Tp, _Array>&)
175    { return false; }
176
177_GLIBCXX_END_NAMESPACE_VERSION
178} // namespace
179
180#pragma GCC diagnostic pop
181
182#endif
183