1 // Allocator traits -*- C++ -*- 2 3 // Copyright (C) 2011-2018 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 #if __cplusplus >= 201103L 35 # include <bits/move.h> 36 # include <bits/alloc_traits.h> 37 #else 38 # include <bits/allocator.h> // for __alloc_swap 39 #endif 40 41 namespace __gnu_cxx _GLIBCXX_VISIBILITY(default) 42 { 43 _GLIBCXX_BEGIN_NAMESPACE_VERSION 44 45 /** 46 * @brief Uniform interface to C++98 and C++11 allocators. 47 * @ingroup allocators 48 */ 49 template<typename _Alloc, typename = typename _Alloc::value_type> 50 struct __alloc_traits 51 #if __cplusplus >= 201103L 52 : std::allocator_traits<_Alloc> 53 #endif 54 { 55 typedef _Alloc allocator_type; 56 #if __cplusplus >= 201103L 57 typedef std::allocator_traits<_Alloc> _Base_type; 58 typedef typename _Base_type::value_type value_type; 59 typedef typename _Base_type::pointer pointer; 60 typedef typename _Base_type::const_pointer const_pointer; 61 typedef typename _Base_type::size_type size_type; 62 typedef typename _Base_type::difference_type difference_type; 63 // C++11 allocators do not define reference or const_reference 64 typedef value_type& reference; 65 typedef const value_type& const_reference; 66 using _Base_type::allocate; 67 using _Base_type::deallocate; 68 using _Base_type::construct; 69 using _Base_type::destroy; 70 using _Base_type::max_size; 71 72 private: 73 template<typename _Ptr> 74 using __is_custom_pointer 75 = std::__and_<std::is_same<pointer, _Ptr>, 76 std::__not_<std::is_pointer<_Ptr>>>; 77 78 public: 79 // overload construct for non-standard pointer types 80 template<typename _Ptr, typename... _Args> 81 static typename std::enable_if<__is_custom_pointer<_Ptr>::value>::type 82 construct(_Alloc& __a, _Ptr __p, _Args&&... __args) 83 { 84 _Base_type::construct(__a, std::__to_address(__p), 85 std::forward<_Args>(__args)...); 86 } 87 88 // overload destroy for non-standard pointer types 89 template<typename _Ptr> 90 static typename std::enable_if<__is_custom_pointer<_Ptr>::value>::type 91 destroy(_Alloc& __a, _Ptr __p) 92 { _Base_type::destroy(__a, std::__to_address(__p)); } 93 94 static _Alloc _S_select_on_copy(const _Alloc& __a) 95 { return _Base_type::select_on_container_copy_construction(__a); } 96 97 static void _S_on_swap(_Alloc& __a, _Alloc& __b) 98 { std::__alloc_on_swap(__a, __b); } 99 100 static constexpr bool _S_propagate_on_copy_assign() 101 { return _Base_type::propagate_on_container_copy_assignment::value; } 102 103 static constexpr bool _S_propagate_on_move_assign() 104 { return _Base_type::propagate_on_container_move_assignment::value; } 105 106 static constexpr bool _S_propagate_on_swap() 107 { return _Base_type::propagate_on_container_swap::value; } 108 109 static constexpr bool _S_always_equal() 110 { return _Base_type::is_always_equal::value; } 111 112 static constexpr bool _S_nothrow_move() 113 { return _S_propagate_on_move_assign() || _S_always_equal(); } 114 115 template<typename _Tp> 116 struct rebind 117 { typedef typename _Base_type::template rebind_alloc<_Tp> other; }; 118 #else 119 120 typedef typename _Alloc::pointer pointer; 121 typedef typename _Alloc::const_pointer const_pointer; 122 typedef typename _Alloc::value_type value_type; 123 typedef typename _Alloc::reference reference; 124 typedef typename _Alloc::const_reference const_reference; 125 typedef typename _Alloc::size_type size_type; 126 typedef typename _Alloc::difference_type difference_type; 127 128 static pointer 129 allocate(_Alloc& __a, size_type __n) 130 { return __a.allocate(__n); } 131 132 static void deallocate(_Alloc& __a, pointer __p, size_type __n) 133 { __a.deallocate(__p, __n); } 134 135 template<typename _Tp> 136 static void construct(_Alloc& __a, pointer __p, const _Tp& __arg) 137 { __a.construct(__p, __arg); } 138 139 static void destroy(_Alloc& __a, pointer __p) 140 { __a.destroy(__p); } 141 142 static size_type max_size(const _Alloc& __a) 143 { return __a.max_size(); } 144 145 static const _Alloc& _S_select_on_copy(const _Alloc& __a) { return __a; } 146 147 static void _S_on_swap(_Alloc& __a, _Alloc& __b) 148 { 149 // _GLIBCXX_RESOLVE_LIB_DEFECTS 150 // 431. Swapping containers with unequal allocators. 151 std::__alloc_swap<_Alloc>::_S_do_it(__a, __b); 152 } 153 154 template<typename _Tp> 155 struct rebind 156 { typedef typename _Alloc::template rebind<_Tp>::other other; }; 157 #endif 158 }; 159 160 _GLIBCXX_END_NAMESPACE_VERSION 161 } // namespace __gnu_cxx 162 163 #endif 164