1 // Allocators -*- C++ -*-
3 // Copyright (C) 2001-2018 Free Software Foundation, Inc.
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)
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.
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.
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/>.
26 * Copyright (c) 1996-1997
27 * Silicon Graphics Computer Systems, Inc.
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
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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}
44 #define _ALLOCATOR_H 1
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>
52 #define __cpp_lib_incomplete_container_elements 201505
53 #if __cplusplus >= 201103L
54 # define __cpp_lib_allocator_is_always_equal 201411
57 namespace std
_GLIBCXX_VISIBILITY(default)
59 _GLIBCXX_BEGIN_NAMESPACE_VERSION
62 * @addtogroup allocators
66 /// allocator<void> specialization.
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
;
77 template<typename _Tp1
>
79 { typedef allocator
<_Tp1
> other
; };
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
;
86 typedef true_type is_always_equal
;
88 template<typename _Up
, typename
... _Args
>
90 construct(_Up
* __p
, _Args
&&... __args
)
91 { ::new((void *)__p
) _Up(std::forward
<_Args
>(__args
)...); }
93 template<typename _Up
>
95 destroy(_Up
* __p
) { __p
->~_Up(); }
100 * @brief The @a standard allocator, as per [20.4].
102 * See https://gcc.gnu.org/onlinedocs/libstdc++/manual/memory.html#std.util.memory.allocator
103 * for further details.
105 * @tparam _Tp Type of allocated object.
107 template<typename _Tp
>
108 class allocator
: public __allocator_base
<_Tp
>
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
;
119 template<typename _Tp1
>
121 { typedef allocator
<_Tp1
> other
; };
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
;
128 typedef true_type is_always_equal
;
131 // _GLIBCXX_RESOLVE_LIB_DEFECTS
132 // 3035. std::allocator's constructors should be constexpr
134 allocator() _GLIBCXX_NOTHROW
{ }
137 allocator(const allocator
& __a
) _GLIBCXX_NOTHROW
138 : __allocator_base
<_Tp
>(__a
) { }
140 #if __cplusplus >= 201103L
141 // Avoid implicit deprecation.
142 allocator
& operator=(const allocator
&) = default;
145 template<typename _Tp1
>
147 allocator(const allocator
<_Tp1
>&) _GLIBCXX_NOTHROW
{ }
149 ~allocator() _GLIBCXX_NOTHROW
{ }
151 // Inherit everything else.
154 template<typename _T1
, typename _T2
>
156 operator==(const allocator
<_T1
>&, const allocator
<_T2
>&)
160 template<typename _Tp
>
162 operator==(const allocator
<_Tp
>&, const allocator
<_Tp
>&)
166 template<typename _T1
, typename _T2
>
168 operator!=(const allocator
<_T1
>&, const allocator
<_T2
>&)
172 template<typename _Tp
>
174 operator!=(const allocator
<_Tp
>&, const allocator
<_Tp
>&)
178 // Invalid allocator<cv T> partial specializations.
179 // allocator_traits::rebind_alloc can be used to form a valid allocator type.
180 template<typename _Tp
>
181 class allocator
<const _Tp
>
184 typedef _Tp value_type
;
185 template<typename _Up
> allocator(const allocator
<_Up
>&) { }
188 template<typename _Tp
>
189 class allocator
<volatile _Tp
>
192 typedef _Tp value_type
;
193 template<typename _Up
> allocator(const allocator
<_Up
>&) { }
196 template<typename _Tp
>
197 class allocator
<const volatile _Tp
>
200 typedef _Tp value_type
;
201 template<typename _Up
> allocator(const allocator
<_Up
>&) { }
204 /// @} group allocator
206 // Inhibit implicit instantiations for required instantiations,
207 // which are defined via explicit instantiations elsewhere.
208 #if _GLIBCXX_EXTERN_TEMPLATE
209 extern template class allocator
<char>;
210 extern template class allocator
<wchar_t>;
214 #undef __allocator_base
216 // To implement Option 3 of DR 431.
217 template<typename _Alloc
, bool = __is_empty(_Alloc
)>
219 { static void _S_do_it(_Alloc
&, _Alloc
&) _GLIBCXX_NOEXCEPT
{ } };
221 template<typename _Alloc
>
222 struct __alloc_swap
<_Alloc
, false>
225 _S_do_it(_Alloc
& __one
, _Alloc
& __two
) _GLIBCXX_NOEXCEPT
227 // Precondition: swappable allocators.
233 // Optimize for stateless allocators.
234 template<typename _Alloc
, bool = __is_empty(_Alloc
)>
238 _S_do_it(const _Alloc
&, const _Alloc
&)
242 template<typename _Alloc
>
243 struct __alloc_neq
<_Alloc
, false>
246 _S_do_it(const _Alloc
& __one
, const _Alloc
& __two
)
247 { return __one
!= __two
; }
250 #if __cplusplus >= 201103L
251 template<typename _Tp
, bool
252 = __or_
<is_copy_constructible
<typename
_Tp::value_type
>,
253 is_nothrow_move_constructible
<typename
_Tp::value_type
>>::value
>
254 struct __shrink_to_fit_aux
255 { static bool _S_do_it(_Tp
&) noexcept
{ return false; } };
257 template<typename _Tp
>
258 struct __shrink_to_fit_aux
<_Tp
, true>
261 _S_do_it(_Tp
& __c
) noexcept
266 _Tp(__make_move_if_noexcept_iterator(__c
.begin()),
267 __make_move_if_noexcept_iterator(__c
.end()),
268 __c
.get_allocator()).swap(__c
);
280 _GLIBCXX_END_NAMESPACE_VERSION