1 // Allocator that wraps "C" malloc -*- C++ -*- 2 3 // Copyright (C) 2001-2014 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/malloc_allocator.h 26 * This file is a GNU extension to the Standard C++ Library. 27 */ 28 29 #ifndef _MALLOC_ALLOCATOR_H 30 #define _MALLOC_ALLOCATOR_H 1 31 32 #include <cstdlib> 33 #include <new> 34 #include <bits/functexcept.h> 35 #include <bits/move.h> 36 #if __cplusplus >= 201103L 37 #include <type_traits> 38 #endif 39 40 namespace __gnu_cxx _GLIBCXX_VISIBILITY(default) 41 { 42 _GLIBCXX_BEGIN_NAMESPACE_VERSION 43 44 using std::size_t; 45 using std::ptrdiff_t; 46 47 /** 48 * @brief An allocator that uses malloc. 49 * @ingroup allocators 50 * 51 * This is precisely the allocator defined in the C++ Standard. 52 * - all allocation calls malloc 53 * - all deallocation calls free 54 */ 55 template<typename _Tp> 56 class malloc_allocator 57 { 58 public: 59 typedef size_t size_type; 60 typedef ptrdiff_t difference_type; 61 typedef _Tp* pointer; 62 typedef const _Tp* const_pointer; 63 typedef _Tp& reference; 64 typedef const _Tp& const_reference; 65 typedef _Tp value_type; 66 67 template<typename _Tp1> 68 struct rebind 69 { typedef malloc_allocator<_Tp1> other; }; 70 71 #if __cplusplus >= 201103L 72 // _GLIBCXX_RESOLVE_LIB_DEFECTS 73 // 2103. propagate_on_container_move_assignment 74 typedef std::true_type propagate_on_container_move_assignment; 75 #endif 76 77 malloc_allocator() _GLIBCXX_USE_NOEXCEPT { } 78 79 malloc_allocator(const malloc_allocator&) _GLIBCXX_USE_NOEXCEPT { } 80 81 template<typename _Tp1> 82 malloc_allocator(const malloc_allocator<_Tp1>&) 83 _GLIBCXX_USE_NOEXCEPT { } 84 85 ~malloc_allocator() _GLIBCXX_USE_NOEXCEPT { } 86 87 pointer 88 address(reference __x) const _GLIBCXX_NOEXCEPT 89 { return std::__addressof(__x); } 90 91 const_pointer 92 address(const_reference __x) const _GLIBCXX_NOEXCEPT 93 { return std::__addressof(__x); } 94 95 // NB: __n is permitted to be 0. The C++ standard says nothing 96 // about what the return value is when __n == 0. 97 pointer 98 allocate(size_type __n, const void* = 0) 99 { 100 if (__n > this->max_size()) 101 std::__throw_bad_alloc(); 102 103 pointer __ret = static_cast<_Tp*>(std::malloc(__n * sizeof(_Tp))); 104 if (!__ret) 105 std::__throw_bad_alloc(); 106 return __ret; 107 } 108 109 // __p is not permitted to be a null pointer. 110 void 111 deallocate(pointer __p, size_type) 112 { std::free(static_cast<void*>(__p)); } 113 114 size_type 115 max_size() const _GLIBCXX_USE_NOEXCEPT 116 { return size_t(-1) / sizeof(_Tp); } 117 118 #if __cplusplus >= 201103L 119 template<typename _Up, typename... _Args> 120 void 121 construct(_Up* __p, _Args&&... __args) 122 { ::new((void *)__p) _Up(std::forward<_Args>(__args)...); } 123 124 template<typename _Up> 125 void 126 destroy(_Up* __p) { __p->~_Up(); } 127 #else 128 // _GLIBCXX_RESOLVE_LIB_DEFECTS 129 // 402. wrong new expression in [some_] allocator::construct 130 void 131 construct(pointer __p, const _Tp& __val) 132 { ::new((void *)__p) value_type(__val); } 133 134 void 135 destroy(pointer __p) { __p->~_Tp(); } 136 #endif 137 }; 138 139 template<typename _Tp> 140 inline bool 141 operator==(const malloc_allocator<_Tp>&, const malloc_allocator<_Tp>&) 142 { return true; } 143 144 template<typename _Tp> 145 inline bool 146 operator!=(const malloc_allocator<_Tp>&, const malloc_allocator<_Tp>&) 147 { return false; } 148 149 _GLIBCXX_END_NAMESPACE_VERSION 150 } // namespace 151 152 #endif 153
