libstdc++
|
00001 // Allocator that wraps operator new -*- C++ -*- 00002 00003 // Copyright (C) 2001, 2002, 2003, 2004, 2005, 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/new_allocator.h 00027 * This file is a GNU extension to the Standard C++ Library. 00028 */ 00029 00030 #ifndef _NEW_ALLOCATOR_H 00031 #define _NEW_ALLOCATOR_H 1 00032 00033 #include <new> 00034 #include <bits/functexcept.h> 00035 #include <bits/move.h> 00036 00037 _GLIBCXX_BEGIN_NAMESPACE(__gnu_cxx) 00038 00039 using std::size_t; 00040 using std::ptrdiff_t; 00041 00042 /** 00043 * @brief An allocator that uses global new, as per [20.4]. 00044 * @ingroup allocators 00045 * 00046 * This is precisely the allocator defined in the C++ Standard. 00047 * - all allocation calls operator new 00048 * - all deallocation calls operator delete 00049 */ 00050 template<typename _Tp> 00051 class new_allocator 00052 { 00053 public: 00054 typedef size_t size_type; 00055 typedef ptrdiff_t difference_type; 00056 typedef _Tp* pointer; 00057 typedef const _Tp* const_pointer; 00058 typedef _Tp& reference; 00059 typedef const _Tp& const_reference; 00060 typedef _Tp value_type; 00061 00062 template<typename _Tp1> 00063 struct rebind 00064 { typedef new_allocator<_Tp1> other; }; 00065 00066 new_allocator() throw() { } 00067 00068 new_allocator(const new_allocator&) throw() { } 00069 00070 template<typename _Tp1> 00071 new_allocator(const new_allocator<_Tp1>&) throw() { } 00072 00073 ~new_allocator() throw() { } 00074 00075 pointer 00076 address(reference __x) const { return &__x; } 00077 00078 const_pointer 00079 address(const_reference __x) const { return &__x; } 00080 00081 // NB: __n is permitted to be 0. The C++ standard says nothing 00082 // about what the return value is when __n == 0. 00083 pointer 00084 allocate(size_type __n, const void* = 0) 00085 { 00086 if (__builtin_expect(__n > this->max_size(), false)) 00087 std::__throw_bad_alloc(); 00088 00089 return static_cast<_Tp*>(::operator new(__n * sizeof(_Tp))); 00090 } 00091 00092 // __p is not permitted to be a null pointer. 00093 void 00094 deallocate(pointer __p, size_type) 00095 { ::operator delete(__p); } 00096 00097 size_type 00098 max_size() const throw() 00099 { return size_t(-1) / sizeof(_Tp); } 00100 00101 // _GLIBCXX_RESOLVE_LIB_DEFECTS 00102 // 402. wrong new expression in [some_] allocator::construct 00103 void 00104 construct(pointer __p, const _Tp& __val) 00105 { ::new((void *)__p) _Tp(__val); } 00106 00107 #ifdef __GXX_EXPERIMENTAL_CXX0X__ 00108 template<typename... _Args> 00109 void 00110 construct(pointer __p, _Args&&... __args) 00111 { ::new((void *)__p) _Tp(std::forward<_Args>(__args)...); } 00112 #endif 00113 00114 void 00115 destroy(pointer __p) { __p->~_Tp(); } 00116 }; 00117 00118 template<typename _Tp> 00119 inline bool 00120 operator==(const new_allocator<_Tp>&, const new_allocator<_Tp>&) 00121 { return true; } 00122 00123 template<typename _Tp> 00124 inline bool 00125 operator!=(const new_allocator<_Tp>&, const new_allocator<_Tp>&) 00126 { return false; } 00127 00128 _GLIBCXX_END_NAMESPACE 00129 00130 #endif