new_allocator.h revision 169691
1// Allocator that wraps operator new -*- C++ -*- 2 3// Copyright (C) 2001, 2002, 2003, 2004, 2005 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/new_allocator.h 31 * This file is a GNU extension to the Standard C++ Library. 32 */ 33 34#ifndef _NEW_ALLOCATOR_H 35#define _NEW_ALLOCATOR_H 1 36 37#include <new> 38#include <bits/functexcept.h> 39 40_GLIBCXX_BEGIN_NAMESPACE(__gnu_cxx) 41 42 using std::size_t; 43 using std::ptrdiff_t; 44 45 /** 46 * @brief An allocator that uses global new, as per [20.4]. 47 * 48 * This is precisely the allocator defined in the C++ Standard. 49 * - all allocation calls operator new 50 * - all deallocation calls operator delete 51 */ 52 template<typename _Tp> 53 class new_allocator 54 { 55 public: 56 typedef size_t size_type; 57 typedef ptrdiff_t difference_type; 58 typedef _Tp* pointer; 59 typedef const _Tp* const_pointer; 60 typedef _Tp& reference; 61 typedef const _Tp& const_reference; 62 typedef _Tp value_type; 63 64 template<typename _Tp1> 65 struct rebind 66 { typedef new_allocator<_Tp1> other; }; 67 68 new_allocator() throw() { } 69 70 new_allocator(const new_allocator&) throw() { } 71 72 template<typename _Tp1> 73 new_allocator(const new_allocator<_Tp1>&) throw() { } 74 75 ~new_allocator() throw() { } 76 77 pointer 78 address(reference __x) const { return &__x; } 79 80 const_pointer 81 address(const_reference __x) const { return &__x; } 82 83 // NB: __n is permitted to be 0. The C++ standard says nothing 84 // about what the return value is when __n == 0. 85 pointer 86 allocate(size_type __n, const void* = 0) 87 { 88 if (__builtin_expect(__n > this->max_size(), false)) 89 std::__throw_bad_alloc(); 90 91 return static_cast<_Tp*>(::operator new(__n * sizeof(_Tp))); 92 } 93 94 // __p is not permitted to be a null pointer. 95 void 96 deallocate(pointer __p, size_type) 97 { ::operator delete(__p); } 98 99 size_type 100 max_size() const throw() 101 { return size_t(-1) / sizeof(_Tp); } 102 103 // _GLIBCXX_RESOLVE_LIB_DEFECTS 104 // 402. wrong new expression in [some_] allocator::construct 105 void 106 construct(pointer __p, const _Tp& __val) 107 { ::new(__p) _Tp(__val); } 108 109 void 110 destroy(pointer __p) { __p->~_Tp(); } 111 }; 112 113 template<typename _Tp> 114 inline bool 115 operator==(const new_allocator<_Tp>&, const new_allocator<_Tp>&) 116 { return true; } 117 118 template<typename _Tp> 119 inline bool 120 operator!=(const new_allocator<_Tp>&, const new_allocator<_Tp>&) 121 { return false; } 122 123_GLIBCXX_END_NAMESPACE 124 125#endif 126