1// Allocators -*- C++ -*- 2 3// Copyright (C) 2001-2015 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/* 26 * Copyright (c) 1996-1997 27 * Silicon Graphics Computer Systems, Inc. 28 * 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 32 * that both that copyright notice and this permission notice appear 33 * in supporting documentation. Silicon Graphics makes no 34 * representations about the suitability of this software for any 35 * purpose. It is provided "as is" without express or implied warranty. 36 */ 37 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} 41 */ 42 43#ifndef _ALLOCATOR_H 44#define _ALLOCATOR_H 1 45 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> 50#endif 51 52namespace std _GLIBCXX_VISIBILITY(default) 53{ 54_GLIBCXX_BEGIN_NAMESPACE_VERSION 55 56 /** 57 * @addtogroup allocators 58 * @{ 59 */ 60 61 /// allocator<void> specialization. 62 template<> 63 class allocator<void> 64 { 65 public: 66 typedef size_t size_type; 67 typedef ptrdiff_t difference_type; 68 typedef void* pointer; 69 typedef const void* const_pointer; 70 typedef void value_type; 71 72 template<typename _Tp1> 73 struct rebind 74 { typedef allocator<_Tp1> other; }; 75 76#if __cplusplus >= 201103L 77 // _GLIBCXX_RESOLVE_LIB_DEFECTS 78 // 2103. std::allocator propagate_on_container_move_assignment 79 typedef true_type propagate_on_container_move_assignment; 80#endif 81 }; 82 83 /** 84 * @brief The @a standard allocator, as per [20.4]. 85 * 86 * See https://gcc.gnu.org/onlinedocs/libstdc++/manual/memory.html#std.util.memory.allocator 87 * for further details. 88 * 89 * @tparam _Tp Type of allocated object. 90 */ 91 template<typename _Tp> 92 class allocator: public __allocator_base<_Tp> 93 { 94 public: 95 typedef size_t size_type; 96 typedef ptrdiff_t difference_type; 97 typedef _Tp* pointer; 98 typedef const _Tp* const_pointer; 99 typedef _Tp& reference; 100 typedef const _Tp& const_reference; 101 typedef _Tp value_type; 102 103 template<typename _Tp1> 104 struct rebind 105 { typedef allocator<_Tp1> other; }; 106 107#if __cplusplus >= 201103L 108 // _GLIBCXX_RESOLVE_LIB_DEFECTS 109 // 2103. std::allocator propagate_on_container_move_assignment 110 typedef true_type propagate_on_container_move_assignment; 111#endif 112 113 allocator() throw() { } 114 115 allocator(const allocator& __a) throw() 116 : __allocator_base<_Tp>(__a) { } 117 118 template<typename _Tp1> 119 allocator(const allocator<_Tp1>&) throw() { } 120 121 ~allocator() throw() { } 122 123 // Inherit everything else. 124 }; 125 126 template<typename _T1, typename _T2> 127 inline bool 128 operator==(const allocator<_T1>&, const allocator<_T2>&) 129 _GLIBCXX_USE_NOEXCEPT 130 { return true; } 131 132 template<typename _Tp> 133 inline bool 134 operator==(const allocator<_Tp>&, const allocator<_Tp>&) 135 _GLIBCXX_USE_NOEXCEPT 136 { return true; } 137 138 template<typename _T1, typename _T2> 139 inline bool 140 operator!=(const allocator<_T1>&, const allocator<_T2>&) 141 _GLIBCXX_USE_NOEXCEPT 142 { return false; } 143 144 template<typename _Tp> 145 inline bool 146 operator!=(const allocator<_Tp>&, const allocator<_Tp>&) 147 _GLIBCXX_USE_NOEXCEPT 148 { return false; } 149 150 /// @} group allocator 151 152 // Inhibit implicit instantiations for required instantiations, 153 // which are defined via explicit instantiations elsewhere. 154#if _GLIBCXX_EXTERN_TEMPLATE 155 extern template class allocator<char>; 156 extern template class allocator<wchar_t>; 157#endif 158 159 // Undefine. 160#undef __allocator_base 161 162 // To implement Option 3 of DR 431. 163 template<typename _Alloc, bool = __is_empty(_Alloc)> 164 struct __alloc_swap 165 { static void _S_do_it(_Alloc&, _Alloc&) _GLIBCXX_NOEXCEPT { } }; 166 167 template<typename _Alloc> 168 struct __alloc_swap<_Alloc, false> 169 { 170 static void 171 _S_do_it(_Alloc& __one, _Alloc& __two) _GLIBCXX_NOEXCEPT 172 { 173 // Precondition: swappable allocators. 174 if (__one != __two) 175 swap(__one, __two); 176 } 177 }; 178 179 // Optimize for stateless allocators. 180 template<typename _Alloc, bool = __is_empty(_Alloc)> 181 struct __alloc_neq 182 { 183 static bool 184 _S_do_it(const _Alloc&, const _Alloc&) 185 { return false; } 186 }; 187 188 template<typename _Alloc> 189 struct __alloc_neq<_Alloc, false> 190 { 191 static bool 192 _S_do_it(const _Alloc& __one, const _Alloc& __two) 193 { return __one != __two; } 194 }; 195 196#if __cplusplus >= 201103L 197 template<typename _Tp, bool 198 = __or_<is_copy_constructible<typename _Tp::value_type>, 199 is_nothrow_move_constructible<typename _Tp::value_type>>::value> 200 struct __shrink_to_fit_aux 201 { static bool _S_do_it(_Tp&) noexcept { return false; } }; 202 203 template<typename _Tp> 204 struct __shrink_to_fit_aux<_Tp, true> 205 { 206 static bool 207 _S_do_it(_Tp& __c) noexcept 208 { 209#if __cpp_exceptions 210 try 211 { 212 _Tp(__make_move_if_noexcept_iterator(__c.begin()), 213 __make_move_if_noexcept_iterator(__c.end()), 214 __c.get_allocator()).swap(__c); 215 return true; 216 } 217 catch(...) 218 { return false; } 219#else 220 return false; 221#endif 222 } 223 }; 224#endif 225 226_GLIBCXX_END_NAMESPACE_VERSION 227} // namespace std 228 229#endif 230