1// Allocator traits -*- C++ -*- 
2 
3// Copyright (C) 2011-2021 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#if __cplusplus < 201103L 
36# include <bits/allocator.h> // for __alloc_swap 
37#endif 
38 
39namespace __gnu_cxx _GLIBCXX_VISIBILITY(default) 
40{ 
41_GLIBCXX_BEGIN_NAMESPACE_VERSION 
42 
43/** 
44 * @brief Uniform interface to C++98 and C++11 allocators. 
45 * @ingroup allocators 
46*/ 
47template<typename _Alloc, typename = typename _Alloc::value_type> 
48 struct __alloc_traits 
49#if __cplusplus >= 201103L 
50 : std::allocator_traits<_Alloc> 
51#endif 
52 { 
53 typedef _Alloc allocator_type; 
54#if __cplusplus >= 201103L 
55 typedef std::allocator_traits<_Alloc> _Base_type; 
56 typedef typename _Base_type::value_type value_type; 
57 typedef typename _Base_type::pointer pointer; 
58 typedef typename _Base_type::const_pointer const_pointer; 
59 typedef typename _Base_type::size_type size_type; 
60 typedef typename _Base_type::difference_type difference_type; 
61 // C++11 allocators do not define reference or const_reference 
62 typedef value_type& reference; 
63 typedef const value_type& const_reference; 
64 using _Base_type::allocate; 
65 using _Base_type::deallocate; 
66 using _Base_type::construct; 
67 using _Base_type::destroy; 
68 using _Base_type::max_size; 
69 
70 private: 
71 template<typename _Ptr> 
72 using __is_custom_pointer 
73 = std::__and_<std::is_same<pointer, _Ptr>, 
74 std::__not_<std::is_pointer<_Ptr>>>; 
75 
76 public: 
77 // overload construct for non-standard pointer types 
78 template<typename _Ptr, typename... _Args> 
79 static _GLIBCXX14_CONSTEXPR 
80 std::__enable_if_t<__is_custom_pointer<_Ptr>::value> 
81 construct(_Alloc& __a, _Ptr __p, _Args&&... __args) 
82 noexcept(noexcept(_Base_type::construct(__a, std::__to_address(__p), 
83 std::forward<_Args>(__args)...))) 
84 { 
85 _Base_type::construct(__a, std::__to_address(__p), 
86 std::forward<_Args>(__args)...); 
87 } 
88 
89 // overload destroy for non-standard pointer types 
90 template<typename _Ptr> 
91 static _GLIBCXX14_CONSTEXPR 
92 std::__enable_if_t<__is_custom_pointer<_Ptr>::value> 
93 destroy(_Alloc& __a, _Ptr __p) 
94 noexcept(noexcept(_Base_type::destroy(__a, std::__to_address(__p)))) 
95 { _Base_type::destroy(__a, std::__to_address(__p)); } 
96 
97 static constexpr _Alloc _S_select_on_copy(const _Alloc& __a) 
98 { return _Base_type::select_on_container_copy_construction(__a); } 
99 
100 static _GLIBCXX14_CONSTEXPR void _S_on_swap(_Alloc& __a, _Alloc& __b) 
101 { std::__alloc_on_swap(__a, __b); } 
102 
103 static constexpr bool _S_propagate_on_copy_assign() 
104 { return _Base_type::propagate_on_container_copy_assignment::value; } 
105 
106 static constexpr bool _S_propagate_on_move_assign() 
107 { return _Base_type::propagate_on_container_move_assignment::value; } 
108 
109 static constexpr bool _S_propagate_on_swap() 
110 { return _Base_type::propagate_on_container_swap::value; } 
111 
112 static constexpr bool _S_always_equal() 
113 { return _Base_type::is_always_equal::value; } 
114 
115 static constexpr bool _S_nothrow_move() 
116 { return _S_propagate_on_move_assign() || _S_always_equal(); } 
117 
118 template<typename _Tp> 
119 struct rebind 
120 { typedef typename _Base_type::template rebind_alloc<_Tp> other; }; 
121#else // ! C++11 
122 
123 typedef typename _Alloc::pointer pointer; 
124 typedef typename _Alloc::const_pointer const_pointer; 
125 typedef typename _Alloc::value_type value_type; 
126 typedef typename _Alloc::reference reference; 
127 typedef typename _Alloc::const_reference const_reference; 
128 typedef typename _Alloc::size_type size_type; 
129 typedef typename _Alloc::difference_type difference_type; 
130 
131 _GLIBCXX_NODISCARD static pointer 
132 allocate(_Alloc& __a, size_type __n) 
133 { return __a.allocate(__n); } 
134 
135 template<typename _Hint> 
136 _GLIBCXX_NODISCARD static pointer 
137 allocate(_Alloc& __a, size_type __n, _Hint __hint) 
138 { return __a.allocate(__n, __hint); } 
139 
140 static void deallocate(_Alloc& __a, pointer __p, size_type __n) 
141 { __a.deallocate(__p, __n); } 
142 
143 template<typename _Tp> 
144 static void construct(_Alloc& __a, pointer __p, const _Tp& __arg) 
145 { __a.construct(__p, __arg); } 
146 
147 static void destroy(_Alloc& __a, pointer __p) 
148 { __a.destroy(__p); } 
149 
150 static size_type max_size(const _Alloc& __a) 
151 { return __a.max_size(); } 
152 
153 static const _Alloc& _S_select_on_copy(const _Alloc& __a) { return __a; } 
154 
155 static void _S_on_swap(_Alloc& __a, _Alloc& __b) 
156 { 
157 // _GLIBCXX_RESOLVE_LIB_DEFECTS 
158 // 431. Swapping containers with unequal allocators. 
159 std::__alloc_swap<_Alloc>::_S_do_it(__a, __b); 
160 } 
161 
162 template<typename _Tp> 
163 struct rebind 
164 { typedef typename _Alloc::template rebind<_Tp>::other other; }; 
165#endif // C++11 
166 }; 
167 
168_GLIBCXX_END_NAMESPACE_VERSION 
169} // namespace __gnu_cxx 
170 
171#endif 
172