1 // array allocator -*- C++ -*- 2 3 // Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009 4 // Free Software Foundation, Inc. 5 // 6 // This file is part of the GNU ISO C++ Library. This library is free 7 // software; you can redistribute it and/or modify it under the 8 // terms of the GNU General Public License as published by the 9 // Free Software Foundation; either version 3, or (at your option) 10 // any later version. 11 12 // This library is distributed in the hope that it will be useful, 13 // but WITHOUT ANY WARRANTY; without even the implied warranty of 14 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 15 // GNU General Public License for more details. 16 17 // Under Section 7 of GPL version 3, you are granted additional 18 // permissions described in the GCC Runtime Library Exception, version 19 // 3.1, as published by the Free Software Foundation. 20 21 // You should have received a copy of the GNU General Public License and 22 // a copy of the GCC Runtime Library Exception along with this program; 23 // see the files COPYING3 and COPYING.RUNTIME respectively. If not, see 24 // <http://www.gnu.org/licenses/>. 25 26 /** @file ext/array_allocator.h 27 * This file is a GNU extension to the Standard C++ Library. 28 */ 29 30 #ifndef _ARRAY_ALLOCATOR_H 31 #define _ARRAY_ALLOCATOR_H 1 32 33 #include <cstddef> 34 #include <new> 35 #include <bits/functexcept.h> 36 #include <tr1/array> 37 #include <bits/move.h> 38 39 _GLIBCXX_BEGIN_NAMESPACE(__gnu_cxx) 40 41 using std::size_t; 42 using std::ptrdiff_t; 43 44 /// Base class. 45 template<typename _Tp> 46 class array_allocator_base 47 { 48 public: 49 typedef size_t size_type; 50 typedef ptrdiff_t difference_type; 51 typedef _Tp* pointer; 52 typedef const _Tp* const_pointer; 53 typedef _Tp& reference; 54 typedef const _Tp& const_reference; 55 typedef _Tp value_type; 56 57 pointer 58 address(reference __x) const { return &__x; } 59 60 const_pointer 61 address(const_reference __x) const { return &__x; } 62 63 void 64 deallocate(pointer, size_type) 65 { 66 // Does nothing. 67 } 68 69 size_type 70 max_size() const throw() 71 { return size_t(-1) / sizeof(_Tp); } 72 73 // _GLIBCXX_RESOLVE_LIB_DEFECTS 74 // 402. wrong new expression in [some_] allocator::construct 75 void 76 construct(pointer __p, const _Tp& __val) 77 { ::new((void *)__p) value_type(__val); } 78 79 #ifdef __GXX_EXPERIMENTAL_CXX0X__ 80 template<typename... _Args> 81 void 82 construct(pointer __p, _Args&&... __args) 83 { ::new((void *)__p) _Tp(std::forward<_Args>(__args)...); } 84 #endif 85 86 void 87 destroy(pointer __p) { __p->~_Tp(); } 88 }; 89 90 /** 91 * @brief An allocator that uses previously allocated memory. 92 * This memory can be externally, globally, or otherwise allocated. 93 * @ingroup allocators 94 */ 95 template<typename _Tp, typename _Array = std::tr1::array<_Tp, 1> > 96 class array_allocator : public array_allocator_base<_Tp> 97 { 98 public: 99 typedef size_t size_type; 100 typedef ptrdiff_t difference_type; 101 typedef _Tp* pointer; 102 typedef const _Tp* const_pointer; 103 typedef _Tp& reference; 104 typedef const _Tp& const_reference; 105 typedef _Tp value_type; 106 typedef _Array array_type; 107 108 private: 109 array_type* _M_array; 110 size_type _M_used; 111 112 public: 113 template<typename _Tp1, typename _Array1 = _Array> 114 struct rebind 115 { typedef array_allocator<_Tp1, _Array1> other; }; 116 117 array_allocator(array_type* __array = NULL) throw() 118 : _M_array(__array), _M_used(size_type()) { } 119 120 array_allocator(const array_allocator& __o) throw() 121 : _M_array(__o._M_array), _M_used(__o._M_used) { } 122 123 template<typename _Tp1, typename _Array1> 124 array_allocator(const array_allocator<_Tp1, _Array1>&) throw() 125 : _M_array(NULL), _M_used(size_type()) { } 126 127 ~array_allocator() throw() { } 128 129 pointer 130 allocate(size_type __n, const void* = 0) 131 { 132 if (_M_array == 0 || _M_used + __n > _M_array->size()) 133 std::__throw_bad_alloc(); 134 pointer __ret = _M_array->begin() + _M_used; 135 _M_used += __n; 136 return __ret; 137 } 138 }; 139 140 template<typename _Tp, typename _Array> 141 inline bool 142 operator==(const array_allocator<_Tp, _Array>&, 143 const array_allocator<_Tp, _Array>&) 144 { return true; } 145 146 template<typename _Tp, typename _Array> 147 inline bool 148 operator!=(const array_allocator<_Tp, _Array>&, 149 const array_allocator<_Tp, _Array>&) 150 { return false; } 151 152 _GLIBCXX_END_NAMESPACE 153 154 #endif 155
