1 // array allocator -*- C++ -*-
2
3 // Copyright (C) 2004-2017 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
_GLIBCXX_VISIBILITY(default)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>
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 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