1 // array allocator -*- C++ -*- 2 3 // Copyright (C) 2004, 2005, 2006 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 2, 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 // You should have received a copy of the GNU General Public License along 17 // with this library; see the file COPYING. If not, write to the Free 18 // Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, 19 // USA. 20 21 // As a special exception, you may use this file as part of a free software 22 // library without restriction. Specifically, if other files instantiate 23 // templates or use macros or inline functions from this file, or you compile 24 // this file and link it with other files to produce an executable, this 25 // file does not by itself cause the resulting executable to be covered by 26 // the GNU General Public License. This exception does not however 27 // invalidate any other reasons why the executable file might be covered by 28 // the GNU General Public License. 29 30 /** @file ext/array_allocator.h 31 * This file is a GNU extension to the Standard C++ Library. 32 */ 33 34 #ifndef _ARRAY_ALLOCATOR_H 35 #define _ARRAY_ALLOCATOR_H 1 36 37 #include <cstddef> 38 #include <new> 39 #include <bits/functexcept.h> 40 #include <tr1/array> 41 42 _GLIBCXX_BEGIN_NAMESPACE(__gnu_cxx) 43 44 using std::size_t; 45 using std::ptrdiff_t; 46 47 /// @brief Base class. 48 template<typename _Tp> 49 class array_allocator_base 50 { 51 public: 52 typedef size_t size_type; 53 typedef ptrdiff_t difference_type; 54 typedef _Tp* pointer; 55 typedef const _Tp* const_pointer; 56 typedef _Tp& reference; 57 typedef const _Tp& const_reference; 58 typedef _Tp value_type; 59 60 pointer 61 address(reference __x) const { return &__x; } 62 63 const_pointer 64 address(const_reference __x) const { return &__x; } 65 66 void 67 deallocate(pointer, size_type) 68 { 69 // Does nothing. 70 } 71 72 size_type 73 max_size() const throw() 74 { return size_t(-1) / sizeof(_Tp); } 75 76 // _GLIBCXX_RESOLVE_LIB_DEFECTS 77 // 402. wrong new expression in [some_] allocator::construct 78 void 79 construct(pointer __p, const _Tp& __val) 80 { ::new(__p) value_type(__val); } 81 82 void 83 destroy(pointer __p) { __p->~_Tp(); } 84 }; 85 86 /** 87 * @brief An allocator that uses previously allocated memory. 88 * This memory can be externally, globally, or otherwise allocated. 89 */ 90 template<typename _Tp, typename _Array = std::tr1::array<_Tp, 1> > 91 class array_allocator : public array_allocator_base<_Tp> 92 { 93 public: 94 typedef size_t size_type; 95 typedef ptrdiff_t difference_type; 96 typedef _Tp* pointer; 97 typedef const _Tp* const_pointer; 98 typedef _Tp& reference; 99 typedef const _Tp& const_reference; 100 typedef _Tp value_type; 101 typedef _Array array_type; 102 103 private: 104 array_type* _M_array; 105 size_type _M_used; 106 107 public: 108 template<typename _Tp1, typename _Array1 = _Array> 109 struct rebind 110 { typedef array_allocator<_Tp1, _Array1> other; }; 111 112 array_allocator(array_type* __array = NULL) throw() 113 : _M_array(__array), _M_used(size_type()) { } 114 115 array_allocator(const array_allocator& __o) throw() 116 : _M_array(__o._M_array), _M_used(__o._M_used) { } 117 118 template<typename _Tp1, typename _Array1> 119 array_allocator(const array_allocator<_Tp1, _Array1>&) throw() 120 : _M_array(NULL), _M_used(size_type()) { } 121 122 ~array_allocator() throw() { } 123 124 pointer 125 allocate(size_type __n, const void* = 0) 126 { 127 if (_M_array == 0 || _M_used + __n > _M_array->size()) 128 std::__throw_bad_alloc(); 129 pointer __ret = _M_array->begin() + _M_used; 130 _M_used += __n; 131 return __ret; 132 } 133 }; 134 135 template<typename _Tp, typename _Array> 136 inline bool 137 operator==(const array_allocator<_Tp, _Array>&, 138 const array_allocator<_Tp, _Array>&) 139 { return true; } 140 141 template<typename _Tp, typename _Array> 142 inline bool 143 operator!=(const array_allocator<_Tp, _Array>&, 144 const array_allocator<_Tp, _Array>&) 145 { return false; } 146 147 _GLIBCXX_END_NAMESPACE 148 149 #endif 150