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1 : // Allocators -*- C++ -*-
2 :
3 : // Copyright (C) 2001-2016 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 : /*
26 : * Copyright (c) 1996-1997
27 : * Silicon Graphics Computer Systems, Inc.
28 : *
29 : * Permission to use, copy, modify, distribute and sell this software
30 : * and its documentation for any purpose is hereby granted without fee,
31 : * provided that the above copyright notice appear in all copies and
32 : * that both that copyright notice and this permission notice appear
33 : * in supporting documentation. Silicon Graphics makes no
34 : * representations about the suitability of this software for any
35 : * purpose. It is provided "as is" without express or implied warranty.
36 : */
37 :
38 : /** @file bits/allocator.h
39 : * This is an internal header file, included by other library headers.
40 : * Do not attempt to use it directly. @headername{memory}
41 : */
42 :
43 : #ifndef _ALLOCATOR_H
44 : #define _ALLOCATOR_H 1
45 :
46 : #include <bits/c++allocator.h> // Define the base class to std::allocator.
47 : #include <bits/memoryfwd.h>
48 : #if __cplusplus >= 201103L
49 : #include <type_traits>
50 : #endif
51 :
52 : #define __cpp_lib_incomplete_container_elements 201505
53 : #if __cplusplus >= 201103L
54 : # define __cpp_lib_allocator_is_always_equal 201411
55 : #endif
56 :
57 : namespace std _GLIBCXX_VISIBILITY(default)
58 : {
59 : _GLIBCXX_BEGIN_NAMESPACE_VERSION
60 :
61 : /**
62 : * @addtogroup allocators
63 : * @{
64 : */
65 :
66 : /// allocator<void> specialization.
67 : template<>
68 : class allocator<void>
69 : {
70 : public:
71 : typedef size_t size_type;
72 : typedef ptrdiff_t difference_type;
73 : typedef void* pointer;
74 : typedef const void* const_pointer;
75 : typedef void value_type;
76 :
77 : template<typename _Tp1>
78 : struct rebind
79 : { typedef allocator<_Tp1> other; };
80 :
81 : #if __cplusplus >= 201103L
82 : // _GLIBCXX_RESOLVE_LIB_DEFECTS
83 : // 2103. std::allocator propagate_on_container_move_assignment
84 : typedef true_type propagate_on_container_move_assignment;
85 :
86 : typedef true_type is_always_equal;
87 :
88 : template<typename _Up, typename... _Args>
89 : void
90 : construct(_Up* __p, _Args&&... __args)
91 : { ::new((void *)__p) _Up(std::forward<_Args>(__args)...); }
92 :
93 : template<typename _Up>
94 : void
95 : destroy(_Up* __p) { __p->~_Up(); }
96 : #endif
97 : };
98 :
99 : /**
100 : * @brief The @a standard allocator, as per [20.4].
101 : *
102 : * See https://gcc.gnu.org/onlinedocs/libstdc++/manual/memory.html#std.util.memory.allocator
103 : * for further details.
104 : *
105 : * @tparam _Tp Type of allocated object.
106 : */
107 : template<typename _Tp>
108 : class allocator: public __allocator_base<_Tp>
109 : {
110 : public:
111 : typedef size_t size_type;
112 : typedef ptrdiff_t difference_type;
113 : typedef _Tp* pointer;
114 : typedef const _Tp* const_pointer;
115 : typedef _Tp& reference;
116 : typedef const _Tp& const_reference;
117 : typedef _Tp value_type;
118 :
119 : template<typename _Tp1>
120 : struct rebind
121 : { typedef allocator<_Tp1> other; };
122 :
123 : #if __cplusplus >= 201103L
124 : // _GLIBCXX_RESOLVE_LIB_DEFECTS
125 : // 2103. std::allocator propagate_on_container_move_assignment
126 : typedef true_type propagate_on_container_move_assignment;
127 :
128 : typedef true_type is_always_equal;
129 : #endif
130 :
131 2905 : allocator() throw() { }
132 :
133 453 : allocator(const allocator& __a) throw()
134 453 : : __allocator_base<_Tp>(__a) { }
135 :
136 : template<typename _Tp1>
137 592 : allocator(const allocator<_Tp1>&) throw() { }
138 :
139 3950 : ~allocator() throw() { }
140 :
141 : // Inherit everything else.
142 : };
143 :
144 : template<typename _T1, typename _T2>
145 : inline bool
146 : operator==(const allocator<_T1>&, const allocator<_T2>&)
147 : _GLIBCXX_USE_NOEXCEPT
148 : { return true; }
149 :
150 : template<typename _Tp>
151 : inline bool
152 : operator==(const allocator<_Tp>&, const allocator<_Tp>&)
153 : _GLIBCXX_USE_NOEXCEPT
154 : { return true; }
155 :
156 : template<typename _T1, typename _T2>
157 : inline bool
158 : operator!=(const allocator<_T1>&, const allocator<_T2>&)
159 : _GLIBCXX_USE_NOEXCEPT
160 : { return false; }
161 :
162 : template<typename _Tp>
163 : inline bool
164 0 : operator!=(const allocator<_Tp>&, const allocator<_Tp>&)
165 : _GLIBCXX_USE_NOEXCEPT
166 0 : { return false; }
167 :
168 : /// @} group allocator
169 :
170 : // Inhibit implicit instantiations for required instantiations,
171 : // which are defined via explicit instantiations elsewhere.
172 : #if _GLIBCXX_EXTERN_TEMPLATE
173 : extern template class allocator<char>;
174 : extern template class allocator<wchar_t>;
175 : #endif
176 :
177 : // Undefine.
178 : #undef __allocator_base
179 :
180 : // To implement Option 3 of DR 431.
181 : template<typename _Alloc, bool = __is_empty(_Alloc)>
182 : struct __alloc_swap
183 : { static void _S_do_it(_Alloc&, _Alloc&) _GLIBCXX_NOEXCEPT { } };
184 :
185 : template<typename _Alloc>
186 : struct __alloc_swap<_Alloc, false>
187 : {
188 : static void
189 : _S_do_it(_Alloc& __one, _Alloc& __two) _GLIBCXX_NOEXCEPT
190 : {
191 : // Precondition: swappable allocators.
192 : if (__one != __two)
193 : swap(__one, __two);
194 : }
195 : };
196 :
197 : // Optimize for stateless allocators.
198 : template<typename _Alloc, bool = __is_empty(_Alloc)>
199 : struct __alloc_neq
200 : {
201 : static bool
202 : _S_do_it(const _Alloc&, const _Alloc&)
203 : { return false; }
204 : };
205 :
206 : template<typename _Alloc>
207 : struct __alloc_neq<_Alloc, false>
208 : {
209 : static bool
210 : _S_do_it(const _Alloc& __one, const _Alloc& __two)
211 : { return __one != __two; }
212 : };
213 :
214 : #if __cplusplus >= 201103L
215 : template<typename _Tp, bool
216 : = __or_<is_copy_constructible<typename _Tp::value_type>,
217 : is_nothrow_move_constructible<typename _Tp::value_type>>::value>
218 : struct __shrink_to_fit_aux
219 : { static bool _S_do_it(_Tp&) noexcept { return false; } };
220 :
221 : template<typename _Tp>
222 : struct __shrink_to_fit_aux<_Tp, true>
223 : {
224 : static bool
225 : _S_do_it(_Tp& __c) noexcept
226 : {
227 : #if __cpp_exceptions
228 : try
229 : {
230 : _Tp(__make_move_if_noexcept_iterator(__c.begin()),
231 : __make_move_if_noexcept_iterator(__c.end()),
232 : __c.get_allocator()).swap(__c);
233 : return true;
234 : }
235 : catch(...)
236 : { return false; }
237 : #else
238 : return false;
239 : #endif
240 : }
241 : };
242 : #endif
243 :
244 : _GLIBCXX_END_NAMESPACE_VERSION
245 : } // namespace std
246 :
247 : #endif
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