libstdc++
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00001 // array allocator -*- C++ -*- 00002 00003 // Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009 00004 // Free Software Foundation, Inc. 00005 // 00006 // This file is part of the GNU ISO C++ Library. This library is free 00007 // software; you can redistribute it and/or modify it under the 00008 // terms of the GNU General Public License as published by the 00009 // Free Software Foundation; either version 3, or (at your option) 00010 // any later version. 00011 00012 // This library is distributed in the hope that it will be useful, 00013 // but WITHOUT ANY WARRANTY; without even the implied warranty of 00014 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 00015 // GNU General Public License for more details. 00016 00017 // Under Section 7 of GPL version 3, you are granted additional 00018 // permissions described in the GCC Runtime Library Exception, version 00019 // 3.1, as published by the Free Software Foundation. 00020 00021 // You should have received a copy of the GNU General Public License and 00022 // a copy of the GCC Runtime Library Exception along with this program; 00023 // see the files COPYING3 and COPYING.RUNTIME respectively. If not, see 00024 // <http://www.gnu.org/licenses/>. 00025 00026 /** @file ext/array_allocator.h 00027 * This file is a GNU extension to the Standard C++ Library. 00028 */ 00029 00030 #ifndef _ARRAY_ALLOCATOR_H 00031 #define _ARRAY_ALLOCATOR_H 1 00032 00033 #include <cstddef> 00034 #include <new> 00035 #include <bits/functexcept.h> 00036 #include <tr1/array> 00037 #include <bits/move.h> 00038 00039 _GLIBCXX_BEGIN_NAMESPACE(__gnu_cxx) 00040 00041 using std::size_t; 00042 using std::ptrdiff_t; 00043 00044 /// Base class. 00045 template<typename _Tp> 00046 class array_allocator_base 00047 { 00048 public: 00049 typedef size_t size_type; 00050 typedef ptrdiff_t difference_type; 00051 typedef _Tp* pointer; 00052 typedef const _Tp* const_pointer; 00053 typedef _Tp& reference; 00054 typedef const _Tp& const_reference; 00055 typedef _Tp value_type; 00056 00057 pointer 00058 address(reference __x) const { return &__x; } 00059 00060 const_pointer 00061 address(const_reference __x) const { return &__x; } 00062 00063 void 00064 deallocate(pointer, size_type) 00065 { 00066 // Does nothing. 00067 } 00068 00069 size_type 00070 max_size() const throw() 00071 { return size_t(-1) / sizeof(_Tp); } 00072 00073 // _GLIBCXX_RESOLVE_LIB_DEFECTS 00074 // 402. wrong new expression in [some_] allocator::construct 00075 void 00076 construct(pointer __p, const _Tp& __val) 00077 { ::new((void *)__p) value_type(__val); } 00078 00079 #ifdef __GXX_EXPERIMENTAL_CXX0X__ 00080 template<typename... _Args> 00081 void 00082 construct(pointer __p, _Args&&... __args) 00083 { ::new((void *)__p) _Tp(std::forward<_Args>(__args)...); } 00084 #endif 00085 00086 void 00087 destroy(pointer __p) { __p->~_Tp(); } 00088 }; 00089 00090 /** 00091 * @brief An allocator that uses previously allocated memory. 00092 * This memory can be externally, globally, or otherwise allocated. 00093 * @ingroup allocators 00094 */ 00095 template<typename _Tp, typename _Array = std::tr1::array<_Tp, 1> > 00096 class array_allocator : public array_allocator_base<_Tp> 00097 { 00098 public: 00099 typedef size_t size_type; 00100 typedef ptrdiff_t difference_type; 00101 typedef _Tp* pointer; 00102 typedef const _Tp* const_pointer; 00103 typedef _Tp& reference; 00104 typedef const _Tp& const_reference; 00105 typedef _Tp value_type; 00106 typedef _Array array_type; 00107 00108 private: 00109 array_type* _M_array; 00110 size_type _M_used; 00111 00112 public: 00113 template<typename _Tp1, typename _Array1 = _Array> 00114 struct rebind 00115 { typedef array_allocator<_Tp1, _Array1> other; }; 00116 00117 array_allocator(array_type* __array = NULL) throw() 00118 : _M_array(__array), _M_used(size_type()) { } 00119 00120 array_allocator(const array_allocator& __o) throw() 00121 : _M_array(__o._M_array), _M_used(__o._M_used) { } 00122 00123 template<typename _Tp1, typename _Array1> 00124 array_allocator(const array_allocator<_Tp1, _Array1>&) throw() 00125 : _M_array(NULL), _M_used(size_type()) { } 00126 00127 ~array_allocator() throw() { } 00128 00129 pointer 00130 allocate(size_type __n, const void* = 0) 00131 { 00132 if (_M_array == 0 || _M_used + __n > _M_array->size()) 00133 std::__throw_bad_alloc(); 00134 pointer __ret = _M_array->begin() + _M_used; 00135 _M_used += __n; 00136 return __ret; 00137 } 00138 }; 00139 00140 template<typename _Tp, typename _Array> 00141 inline bool 00142 operator==(const array_allocator<_Tp, _Array>&, 00143 const array_allocator<_Tp, _Array>&) 00144 { return true; } 00145 00146 template<typename _Tp, typename _Array> 00147 inline bool 00148 operator!=(const array_allocator<_Tp, _Array>&, 00149 const array_allocator<_Tp, _Array>&) 00150 { return false; } 00151 00152 _GLIBCXX_END_NAMESPACE 00153 00154 #endif