libstdc++
ext/alloc_traits.h
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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>
46 #if __cplusplus >= 201103L
48 #endif
49  {
50  typedef _Alloc allocator_type;
51 #if __cplusplus >= 201103L
53  typedef typename _Base_type::value_type value_type;
54  typedef typename _Base_type::pointer pointer;
56  typedef typename _Base_type::size_type size_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
std::allocator_traits::pointer
__detected_or_t< value_type *, __pointer, _Alloc > pointer
The allocator's pointer type.
Definition: bits/alloc_traits.h:117
std::allocator_traits::difference_type
typename _Diff< _Alloc, pointer >::type difference_type
The allocator's difference type.
Definition: bits/alloc_traits.h:181
alloc_traits.h
std::allocator_traits::const_pointer
typename _Ptr< __c_pointer, const value_type >::type const_pointer
The allocator's const pointer type.
Definition: bits/alloc_traits.h:157
std::allocator_traits::allocator_type
_Alloc allocator_type
The allocator type.
Definition: bits/alloc_traits.h:108
std::allocator_traits::value_type
_Alloc::value_type value_type
The allocated type.
Definition: bits/alloc_traits.h:110
__gnu_cxx
GNU extensions for public use.
std::allocator_traits
Uniform interface to all allocator types.
Definition: bits/alloc_traits.h:105
__gnu_cxx::__alloc_traits
Uniform interface to C++98 and C++11 allocators.
Definition: ext/alloc_traits.h:45
std::allocator_traits::size_type
typename _Size< _Alloc, difference_type >::type size_type
The allocator's size type.
Definition: bits/alloc_traits.h:189