1 // array allocator -*- C++ -*- 2 3 // Copyright (C) 2004-2013 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/array_allocator.h 26 * This file is a GNU extension to the Standard C++ Library. 27 */ 28 29 #ifndef _ARRAY_ALLOCATOR_H 30 #define _ARRAY_ALLOCATOR_H 1 31 32 #include <bits/c++config.h> 33 #include <new> 34 #include <bits/functexcept.h> 35 #include <tr1/array> 36 #include <bits/move.h> 37 #if __cplusplus >= 201103L 38 #include <type_traits> 39 #endif 40 41 namespace __gnu_cxx _GLIBCXX_VISIBILITY(default) 42 { 43 _GLIBCXX_BEGIN_NAMESPACE_VERSION 44 45 using std::size_t; 46 using std::ptrdiff_t; 47 48 /// Base class. 49 template<typename _Tp> 50 class array_allocator_base 51 { 52 public: 53 typedef size_t size_type; 54 typedef ptrdiff_t difference_type; 55 typedef _Tp* pointer; 56 typedef const _Tp* const_pointer; 57 typedef _Tp& reference; 58 typedef const _Tp& const_reference; 59 typedef _Tp value_type; 60 61 pointer 62 address(reference __x) const _GLIBCXX_NOEXCEPT 63 { return std::__addressof(__x); } 64 65 const_pointer 66 address(const_reference __x) const _GLIBCXX_NOEXCEPT 67 { return std::__addressof(__x); } 68 69 void 70 deallocate(pointer, size_type) 71 { 72 // Does nothing. 73 } 74 75 size_type 76 max_size() const _GLIBCXX_USE_NOEXCEPT 77 { return size_t(-1) / sizeof(_Tp); } 78 79 #if __cplusplus >= 201103L 80 template<typename _Up, typename... _Args> 81 void 82 construct(_Up* __p, _Args&&... __args) 83 { ::new((void *)__p) _Up(std::forward<_Args>(__args)...); } 84 85 template<typename _Up> 86 void 87 destroy(_Up* __p) { __p->~_Up(); } 88 #else 89 // _GLIBCXX_RESOLVE_LIB_DEFECTS 90 // 402. wrong new expression in [some_] allocator::construct 91 void 92 construct(pointer __p, const _Tp& __val) 93 { ::new((void *)__p) value_type(__val); } 94 95 void 96 destroy(pointer __p) { __p->~_Tp(); } 97 #endif 98 }; 99 100 /** 101 * @brief An allocator that uses previously allocated memory. 102 * This memory can be externally, globally, or otherwise allocated. 103 * @ingroup allocators 104 */ 105 template<typename _Tp, typename _Array = std::tr1::array<_Tp, 1> > 106 class array_allocator : public array_allocator_base<_Tp> 107 { 108 public: 109 typedef size_t size_type; 110 typedef ptrdiff_t difference_type; 111 typedef _Tp* pointer; 112 typedef const _Tp* const_pointer; 113 typedef _Tp& reference; 114 typedef const _Tp& const_reference; 115 typedef _Tp value_type; 116 typedef _Array array_type; 117 118 #if __cplusplus >= 201103L 119 // _GLIBCXX_RESOLVE_LIB_DEFECTS 120 // 2103. std::allocator propagate_on_container_move_assignment 121 typedef std::true_type propagate_on_container_move_assignment; 122 #endif 123 124 private: 125 array_type* _M_array; 126 size_type _M_used; 127 128 public: 129 template<typename _Tp1, typename _Array1 = _Array> 130 struct rebind 131 { typedef array_allocator<_Tp1, _Array1> other; }; 132 133 array_allocator(array_type* __array = 0) _GLIBCXX_USE_NOEXCEPT 134 : _M_array(__array), _M_used(size_type()) { } 135 136 array_allocator(const array_allocator& __o) _GLIBCXX_USE_NOEXCEPT 137 : _M_array(__o._M_array), _M_used(__o._M_used) { } 138 139 template<typename _Tp1, typename _Array1> 140 array_allocator(const array_allocator<_Tp1, _Array1>&) 141 _GLIBCXX_USE_NOEXCEPT 142 : _M_array(0), _M_used(size_type()) { } 143 144 ~array_allocator() _GLIBCXX_USE_NOEXCEPT { } 145 146 pointer 147 allocate(size_type __n, const void* = 0) 148 { 149 if (_M_array == 0 || _M_used + __n > _M_array->size()) 150 std::__throw_bad_alloc(); 151 pointer __ret = _M_array->begin() + _M_used; 152 _M_used += __n; 153 return __ret; 154 } 155 }; 156 157 template<typename _Tp, typename _Array> 158 inline bool 159 operator==(const array_allocator<_Tp, _Array>&, 160 const array_allocator<_Tp, _Array>&) 161 { return true; } 162 163 template<typename _Tp, typename _Array> 164 inline bool 165 operator!=(const array_allocator<_Tp, _Array>&, 166 const array_allocator<_Tp, _Array>&) 167 { return false; } 168 169 _GLIBCXX_END_NAMESPACE_VERSION 170 } // namespace 171 172 #endif 173
