libstdc++
array_allocator.h
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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 
45 namespace __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>
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> >
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
126 
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>
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>&,
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
integral_constant
Definition: type_traits:57
An allocator that uses previously allocated memory. This memory can be externally, globally, or otherwise allocated.
constexpr _Tp * __addressof(_Tp &__r) noexcept
Same as C++11 std::addressof.
Definition: move.h:47
GNU extensions for public use.