libstdc++
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00001 // Allocators -*- C++ -*- 00002 00003 // Copyright (C) 2001-2016 Free Software Foundation, Inc. 00004 // 00005 // This file is part of the GNU ISO C++ Library. This library is free 00006 // software; you can redistribute it and/or modify it under the 00007 // terms of the GNU General Public License as published by the 00008 // Free Software Foundation; either version 3, or (at your option) 00009 // any later version. 00010 00011 // This library is distributed in the hope that it will be useful, 00012 // but WITHOUT ANY WARRANTY; without even the implied warranty of 00013 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 00014 // GNU General Public License for more details. 00015 00016 // Under Section 7 of GPL version 3, you are granted additional 00017 // permissions described in the GCC Runtime Library Exception, version 00018 // 3.1, as published by the Free Software Foundation. 00019 00020 // You should have received a copy of the GNU General Public License and 00021 // a copy of the GCC Runtime Library Exception along with this program; 00022 // see the files COPYING3 and COPYING.RUNTIME respectively. If not, see 00023 // <http://www.gnu.org/licenses/>. 00024 00025 /* 00026 * Copyright (c) 1996-1997 00027 * Silicon Graphics Computer Systems, Inc. 00028 * 00029 * Permission to use, copy, modify, distribute and sell this software 00030 * and its documentation for any purpose is hereby granted without fee, 00031 * provided that the above copyright notice appear in all copies and 00032 * that both that copyright notice and this permission notice appear 00033 * in supporting documentation. Silicon Graphics makes no 00034 * representations about the suitability of this software for any 00035 * purpose. It is provided "as is" without express or implied warranty. 00036 */ 00037 00038 /** @file bits/allocator.h 00039 * This is an internal header file, included by other library headers. 00040 * Do not attempt to use it directly. @headername{memory} 00041 */ 00042 00043 #ifndef _ALLOCATOR_H 00044 #define _ALLOCATOR_H 1 00045 00046 #include <bits/c++allocator.h> // Define the base class to std::allocator. 00047 #include <bits/memoryfwd.h> 00048 #if __cplusplus >= 201103L 00049 #include <type_traits> 00050 #endif 00051 00052 #define __cpp_lib_incomplete_container_elements 201505 00053 00054 namespace std _GLIBCXX_VISIBILITY(default) 00055 { 00056 _GLIBCXX_BEGIN_NAMESPACE_VERSION 00057 00058 /** 00059 * @addtogroup allocators 00060 * @{ 00061 */ 00062 00063 /// allocator<void> specialization. 00064 template<> 00065 class allocator<void> 00066 { 00067 public: 00068 typedef size_t size_type; 00069 typedef ptrdiff_t difference_type; 00070 typedef void* pointer; 00071 typedef const void* const_pointer; 00072 typedef void value_type; 00073 00074 template<typename _Tp1> 00075 struct rebind 00076 { typedef allocator<_Tp1> other; }; 00077 00078 #if __cplusplus >= 201103L 00079 // _GLIBCXX_RESOLVE_LIB_DEFECTS 00080 // 2103. std::allocator propagate_on_container_move_assignment 00081 typedef true_type propagate_on_container_move_assignment; 00082 00083 #define __cpp_lib_allocator_is_always_equal 201411 00084 typedef true_type is_always_equal; 00085 #endif 00086 }; 00087 00088 /** 00089 * @brief The @a standard allocator, as per [20.4]. 00090 * 00091 * See https://gcc.gnu.org/onlinedocs/libstdc++/manual/memory.html#std.util.memory.allocator 00092 * for further details. 00093 * 00094 * @tparam _Tp Type of allocated object. 00095 */ 00096 template<typename _Tp> 00097 class allocator: public __allocator_base<_Tp> 00098 { 00099 public: 00100 typedef size_t size_type; 00101 typedef ptrdiff_t difference_type; 00102 typedef _Tp* pointer; 00103 typedef const _Tp* const_pointer; 00104 typedef _Tp& reference; 00105 typedef const _Tp& const_reference; 00106 typedef _Tp value_type; 00107 00108 template<typename _Tp1> 00109 struct rebind 00110 { typedef allocator<_Tp1> other; }; 00111 00112 #if __cplusplus >= 201103L 00113 // _GLIBCXX_RESOLVE_LIB_DEFECTS 00114 // 2103. std::allocator propagate_on_container_move_assignment 00115 typedef true_type propagate_on_container_move_assignment; 00116 #endif 00117 00118 allocator() throw() { } 00119 00120 allocator(const allocator& __a) throw() 00121 : __allocator_base<_Tp>(__a) { } 00122 00123 template<typename _Tp1> 00124 allocator(const allocator<_Tp1>&) throw() { } 00125 00126 ~allocator() throw() { } 00127 00128 // Inherit everything else. 00129 }; 00130 00131 template<typename _T1, typename _T2> 00132 inline bool 00133 operator==(const allocator<_T1>&, const allocator<_T2>&) 00134 _GLIBCXX_USE_NOEXCEPT 00135 { return true; } 00136 00137 template<typename _Tp> 00138 inline bool 00139 operator==(const allocator<_Tp>&, const allocator<_Tp>&) 00140 _GLIBCXX_USE_NOEXCEPT 00141 { return true; } 00142 00143 template<typename _T1, typename _T2> 00144 inline bool 00145 operator!=(const allocator<_T1>&, const allocator<_T2>&) 00146 _GLIBCXX_USE_NOEXCEPT 00147 { return false; } 00148 00149 template<typename _Tp> 00150 inline bool 00151 operator!=(const allocator<_Tp>&, const allocator<_Tp>&) 00152 _GLIBCXX_USE_NOEXCEPT 00153 { return false; } 00154 00155 /// @} group allocator 00156 00157 // Inhibit implicit instantiations for required instantiations, 00158 // which are defined via explicit instantiations elsewhere. 00159 #if _GLIBCXX_EXTERN_TEMPLATE 00160 extern template class allocator<char>; 00161 extern template class allocator<wchar_t>; 00162 #endif 00163 00164 // Undefine. 00165 #undef __allocator_base 00166 00167 // To implement Option 3 of DR 431. 00168 template<typename _Alloc, bool = __is_empty(_Alloc)> 00169 struct __alloc_swap 00170 { static void _S_do_it(_Alloc&, _Alloc&) _GLIBCXX_NOEXCEPT { } }; 00171 00172 template<typename _Alloc> 00173 struct __alloc_swap<_Alloc, false> 00174 { 00175 static void 00176 _S_do_it(_Alloc& __one, _Alloc& __two) _GLIBCXX_NOEXCEPT 00177 { 00178 // Precondition: swappable allocators. 00179 if (__one != __two) 00180 swap(__one, __two); 00181 } 00182 }; 00183 00184 // Optimize for stateless allocators. 00185 template<typename _Alloc, bool = __is_empty(_Alloc)> 00186 struct __alloc_neq 00187 { 00188 static bool 00189 _S_do_it(const _Alloc&, const _Alloc&) 00190 { return false; } 00191 }; 00192 00193 template<typename _Alloc> 00194 struct __alloc_neq<_Alloc, false> 00195 { 00196 static bool 00197 _S_do_it(const _Alloc& __one, const _Alloc& __two) 00198 { return __one != __two; } 00199 }; 00200 00201 #if __cplusplus >= 201103L 00202 template<typename _Tp, bool 00203 = __or_<is_copy_constructible<typename _Tp::value_type>, 00204 is_nothrow_move_constructible<typename _Tp::value_type>>::value> 00205 struct __shrink_to_fit_aux 00206 { static bool _S_do_it(_Tp&) noexcept { return false; } }; 00207 00208 template<typename _Tp> 00209 struct __shrink_to_fit_aux<_Tp, true> 00210 { 00211 static bool 00212 _S_do_it(_Tp& __c) noexcept 00213 { 00214 #if __cpp_exceptions 00215 try 00216 { 00217 _Tp(__make_move_if_noexcept_iterator(__c.begin()), 00218 __make_move_if_noexcept_iterator(__c.end()), 00219 __c.get_allocator()).swap(__c); 00220 return true; 00221 } 00222 catch(...) 00223 { return false; } 00224 #else 00225 return false; 00226 #endif 00227 } 00228 }; 00229 #endif 00230 00231 _GLIBCXX_END_NAMESPACE_VERSION 00232 } // namespace std 00233 00234 #endif