1 // Allocator traits -*- C++ -*-
2
3 // Copyright (C) 2011-2023 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/alloc_traits.h
26 * This file is a GNU extension to the Standard C++ Library.
27 */
28
29 #ifndef _EXT_ALLOC_TRAITS_H
30 #define _EXT_ALLOC_TRAITS_H 1
31
32 #pragma GCC system_header
33
34 # include <bits/alloc_traits.h>
35
36 namespace __gnu_cxx _GLIBCXX_VISIBILITY(default)
37 {
38 _GLIBCXX_BEGIN_NAMESPACE_VERSION
39
40 /**
41 * @brief Uniform interface to C++98 and C++11 allocators.
42 * @ingroup allocators
43 */
44 template<typename _Alloc, typename = typename _Alloc::value_type>
45 struct __alloc_traits
46 #if __cplusplus >= 201103L
47 : std::allocator_traits<_Alloc>
48 #endif
49 {
50 typedef _Alloc allocator_type;
51 #if __cplusplus >= 201103L
52 typedef std::allocator_traits<_Alloc> _Base_type;
53 typedef typename _Base_type::value_type value_type;
54 typedef typename _Base_type::pointer pointer;
55 typedef typename _Base_type::const_pointer const_pointer;
56 typedef typename _Base_type::size_type size_type;
57 typedef typename _Base_type::difference_type difference_type;
58 // C++11 allocators do not define reference or const_reference
59 typedef value_type& reference;
60 typedef const value_type& const_reference;
61 using _Base_type::allocate;
62 using _Base_type::deallocate;
63 using _Base_type::construct;
64 using _Base_type::destroy;
65 using _Base_type::max_size;
66
67 private:
68 template<typename _Ptr>
69 using __is_custom_pointer
70 = std::__and_<std::is_same<pointer, _Ptr>,
71 std::__not_<std::is_pointer<_Ptr>>>;
72
73 public:
74 // overload construct for non-standard pointer types
75 template<typename _Ptr, typename... _Args>
76 [[__gnu__::__always_inline__]]
77 static _GLIBCXX14_CONSTEXPR
78 std::__enable_if_t<__is_custom_pointer<_Ptr>::value>
79 construct(_Alloc& __a, _Ptr __p, _Args&&... __args)
80 noexcept(noexcept(_Base_type::construct(__a, std::__to_address(__p),
81 std::forward<_Args>(__args)...)))
82 {
83 _Base_type::construct(__a, std::__to_address(__p),
84 std::forward<_Args>(__args)...);
85 }
86
87 // overload destroy for non-standard pointer types
88 template<typename _Ptr>
89 [[__gnu__::__always_inline__]]
90 static _GLIBCXX14_CONSTEXPR
91 std::__enable_if_t<__is_custom_pointer<_Ptr>::value>
92 destroy(_Alloc& __a, _Ptr __p)
93 noexcept(noexcept(_Base_type::destroy(__a, std::__to_address(__p))))
94 { _Base_type::destroy(__a, std::__to_address(__p)); }
95
96 [[__gnu__::__always_inline__]]
97 static constexpr _Alloc _S_select_on_copy(const _Alloc& __a)
98 { return _Base_type::select_on_container_copy_construction(__a); }
99
100 [[__gnu__::__always_inline__]]
101 static _GLIBCXX14_CONSTEXPR void _S_on_swap(_Alloc& __a, _Alloc& __b)
102 { std::__alloc_on_swap(__a, __b); }
103
104 [[__gnu__::__always_inline__]]
105 static constexpr bool _S_propagate_on_copy_assign()
106 { return _Base_type::propagate_on_container_copy_assignment::value; }
107
108 [[__gnu__::__always_inline__]]
109 static constexpr bool _S_propagate_on_move_assign()
110 { return _Base_type::propagate_on_container_move_assignment::value; }
111
112 [[__gnu__::__always_inline__]]
113 static constexpr bool _S_propagate_on_swap()
114 { return _Base_type::propagate_on_container_swap::value; }
115
116 [[__gnu__::__always_inline__]]
117 static constexpr bool _S_always_equal()
118 { return _Base_type::is_always_equal::value; }
119
120 __attribute__((__always_inline__))
121 static constexpr bool _S_nothrow_move()
122 { return _S_propagate_on_move_assign() || _S_always_equal(); }
123
124 template<typename _Tp>
125 struct rebind
126 { typedef typename _Base_type::template rebind_alloc<_Tp> other; };
127 #else // ! C++11
128
129 typedef typename _Alloc::pointer pointer;
130 typedef typename _Alloc::const_pointer const_pointer;
131 typedef typename _Alloc::value_type value_type;
132 typedef typename _Alloc::reference reference;
133 typedef typename _Alloc::const_reference const_reference;
134 typedef typename _Alloc::size_type size_type;
135 typedef typename _Alloc::difference_type difference_type;
136
137 __attribute__((__always_inline__)) _GLIBCXX_NODISCARD
138 static pointer
139 allocate(_Alloc& __a, size_type __n)
140 { return __a.allocate(__n); }
141
142 template<typename _Hint>
143 __attribute__((__always_inline__)) _GLIBCXX_NODISCARD
144 static pointer
145 allocate(_Alloc& __a, size_type __n, _Hint __hint)
146 { return __a.allocate(__n, __hint); }
147
148 __attribute__((__always_inline__))
149 static void deallocate(_Alloc& __a, pointer __p, size_type __n)
150 { __a.deallocate(__p, __n); }
151
152 template<typename _Tp>
153 __attribute__((__always_inline__))
154 static void construct(_Alloc& __a, pointer __p, const _Tp& __arg)
155 { __a.construct(__p, __arg); }
156
157 __attribute__((__always_inline__))
158 static void destroy(_Alloc& __a, pointer __p)
159 { __a.destroy(__p); }
160
161 __attribute__((__always_inline__))
162 static size_type max_size(const _Alloc& __a)
163 { return __a.max_size(); }
164
165 __attribute__((__always_inline__))
166 static const _Alloc& _S_select_on_copy(const _Alloc& __a) { return __a; }
167
168 __attribute__((__always_inline__))
169 static void _S_on_swap(_Alloc& __a, _Alloc& __b)
170 {
171 // _GLIBCXX_RESOLVE_LIB_DEFECTS
172 // 431. Swapping containers with unequal allocators.
173 std::__alloc_swap<_Alloc>::_S_do_it(__a, __b);
174 }
175
176 template<typename _Tp>
177 struct rebind
178 { typedef typename _Alloc::template rebind<_Tp>::other other; };
179 #endif // C++11
180 };
181
182 _GLIBCXX_END_NAMESPACE_VERSION
183 } // namespace __gnu_cxx
184
185 #endif