libstdc++
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00001 // Allocators -*- C++ -*- 00002 00003 // Copyright (C) 2001-2015 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 namespace std _GLIBCXX_VISIBILITY(default) 00053 { 00054 _GLIBCXX_BEGIN_NAMESPACE_VERSION 00055 00056 /** 00057 * @addtogroup allocators 00058 * @{ 00059 */ 00060 00061 /// allocator<void> specialization. 00062 template<> 00063 class allocator<void> 00064 { 00065 public: 00066 typedef size_t size_type; 00067 typedef ptrdiff_t difference_type; 00068 typedef void* pointer; 00069 typedef const void* const_pointer; 00070 typedef void value_type; 00071 00072 template<typename _Tp1> 00073 struct rebind 00074 { typedef allocator<_Tp1> other; }; 00075 00076 #if __cplusplus >= 201103L 00077 // _GLIBCXX_RESOLVE_LIB_DEFECTS 00078 // 2103. std::allocator propagate_on_container_move_assignment 00079 typedef true_type propagate_on_container_move_assignment; 00080 #endif 00081 }; 00082 00083 /** 00084 * @brief The @a standard allocator, as per [20.4]. 00085 * 00086 * See https://gcc.gnu.org/onlinedocs/libstdc++/manual/memory.html#std.util.memory.allocator 00087 * for further details. 00088 * 00089 * @tparam _Tp Type of allocated object. 00090 */ 00091 template<typename _Tp> 00092 class allocator: public __allocator_base<_Tp> 00093 { 00094 public: 00095 typedef size_t size_type; 00096 typedef ptrdiff_t difference_type; 00097 typedef _Tp* pointer; 00098 typedef const _Tp* const_pointer; 00099 typedef _Tp& reference; 00100 typedef const _Tp& const_reference; 00101 typedef _Tp value_type; 00102 00103 template<typename _Tp1> 00104 struct rebind 00105 { typedef allocator<_Tp1> other; }; 00106 00107 #if __cplusplus >= 201103L 00108 // _GLIBCXX_RESOLVE_LIB_DEFECTS 00109 // 2103. std::allocator propagate_on_container_move_assignment 00110 typedef true_type propagate_on_container_move_assignment; 00111 #endif 00112 00113 allocator() throw() { } 00114 00115 allocator(const allocator& __a) throw() 00116 : __allocator_base<_Tp>(__a) { } 00117 00118 template<typename _Tp1> 00119 allocator(const allocator<_Tp1>&) throw() { } 00120 00121 ~allocator() throw() { } 00122 00123 // Inherit everything else. 00124 }; 00125 00126 template<typename _T1, typename _T2> 00127 inline bool 00128 operator==(const allocator<_T1>&, const allocator<_T2>&) 00129 _GLIBCXX_USE_NOEXCEPT 00130 { return true; } 00131 00132 template<typename _Tp> 00133 inline bool 00134 operator==(const allocator<_Tp>&, const allocator<_Tp>&) 00135 _GLIBCXX_USE_NOEXCEPT 00136 { return true; } 00137 00138 template<typename _T1, typename _T2> 00139 inline bool 00140 operator!=(const allocator<_T1>&, const allocator<_T2>&) 00141 _GLIBCXX_USE_NOEXCEPT 00142 { return false; } 00143 00144 template<typename _Tp> 00145 inline bool 00146 operator!=(const allocator<_Tp>&, const allocator<_Tp>&) 00147 _GLIBCXX_USE_NOEXCEPT 00148 { return false; } 00149 00150 /// @} group allocator 00151 00152 // Inhibit implicit instantiations for required instantiations, 00153 // which are defined via explicit instantiations elsewhere. 00154 #if _GLIBCXX_EXTERN_TEMPLATE 00155 extern template class allocator<char>; 00156 extern template class allocator<wchar_t>; 00157 #endif 00158 00159 // Undefine. 00160 #undef __allocator_base 00161 00162 // To implement Option 3 of DR 431. 00163 template<typename _Alloc, bool = __is_empty(_Alloc)> 00164 struct __alloc_swap 00165 { static void _S_do_it(_Alloc&, _Alloc&) _GLIBCXX_NOEXCEPT { } }; 00166 00167 template<typename _Alloc> 00168 struct __alloc_swap<_Alloc, false> 00169 { 00170 static void 00171 _S_do_it(_Alloc& __one, _Alloc& __two) _GLIBCXX_NOEXCEPT 00172 { 00173 // Precondition: swappable allocators. 00174 if (__one != __two) 00175 swap(__one, __two); 00176 } 00177 }; 00178 00179 // Optimize for stateless allocators. 00180 template<typename _Alloc, bool = __is_empty(_Alloc)> 00181 struct __alloc_neq 00182 { 00183 static bool 00184 _S_do_it(const _Alloc&, const _Alloc&) 00185 { return false; } 00186 }; 00187 00188 template<typename _Alloc> 00189 struct __alloc_neq<_Alloc, false> 00190 { 00191 static bool 00192 _S_do_it(const _Alloc& __one, const _Alloc& __two) 00193 { return __one != __two; } 00194 }; 00195 00196 #if __cplusplus >= 201103L 00197 template<typename _Tp, bool 00198 = __or_<is_copy_constructible<typename _Tp::value_type>, 00199 is_nothrow_move_constructible<typename _Tp::value_type>>::value> 00200 struct __shrink_to_fit_aux 00201 { static bool _S_do_it(_Tp&) noexcept { return false; } }; 00202 00203 template<typename _Tp> 00204 struct __shrink_to_fit_aux<_Tp, true> 00205 { 00206 static bool 00207 _S_do_it(_Tp& __c) noexcept 00208 { 00209 #if __cpp_exceptions 00210 try 00211 { 00212 _Tp(__make_move_if_noexcept_iterator(__c.begin()), 00213 __make_move_if_noexcept_iterator(__c.end()), 00214 __c.get_allocator()).swap(__c); 00215 return true; 00216 } 00217 catch(...) 00218 { return false; } 00219 #else 00220 return false; 00221 #endif 00222 } 00223 }; 00224 #endif 00225 00226 _GLIBCXX_END_NAMESPACE_VERSION 00227 } // namespace std 00228 00229 #endif