00001 // Temporary buffer implementation -*- C++ -*- 00002 00003 // Copyright (C) 2001, 2002, 2003, 2004, 2005, 2006 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 2, 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 // You should have received a copy of the GNU General Public License along 00018 // with this library; see the file COPYING. If not, write to the Free 00019 // Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, 00020 // USA. 00021 00022 // As a special exception, you may use this file as part of a free software 00023 // library without restriction. Specifically, if other files instantiate 00024 // templates or use macros or inline functions from this file, or you compile 00025 // this file and link it with other files to produce an executable, this 00026 // file does not by itself cause the resulting executable to be covered by 00027 // the GNU General Public License. This exception does not however 00028 // invalidate any other reasons why the executable file might be covered by 00029 // the GNU General Public License. 00030 00031 /* 00032 * 00033 * Copyright (c) 1994 00034 * Hewlett-Packard Company 00035 * 00036 * Permission to use, copy, modify, distribute and sell this software 00037 * and its documentation for any purpose is hereby granted without fee, 00038 * provided that the above copyright notice appear in all copies and 00039 * that both that copyright notice and this permission notice appear 00040 * in supporting documentation. Hewlett-Packard Company makes no 00041 * representations about the suitability of this software for any 00042 * purpose. It is provided "as is" without express or implied warranty. 00043 * 00044 * 00045 * Copyright (c) 1996,1997 00046 * Silicon Graphics Computer Systems, Inc. 00047 * 00048 * Permission to use, copy, modify, distribute and sell this software 00049 * and its documentation for any purpose is hereby granted without fee, 00050 * provided that the above copyright notice appear in all copies and 00051 * that both that copyright notice and this permission notice appear 00052 * in supporting documentation. Silicon Graphics makes no 00053 * representations about the suitability of this software for any 00054 * purpose. It is provided "as is" without express or implied warranty. 00055 */ 00056 00057 /** @file stl_tempbuf.h 00058 * This is an internal header file, included by other library headers. 00059 * You should not attempt to use it directly. 00060 */ 00061 00062 #ifndef _TEMPBUF_H 00063 #define _TEMPBUF_H 1 00064 00065 #include <memory> 00066 00067 _GLIBCXX_BEGIN_NAMESPACE(std) 00068 00069 /** 00070 * @if maint 00071 * This class is used in two places: stl_algo.h and ext/memory, 00072 * where it is wrapped as the temporary_buffer class. See 00073 * temporary_buffer docs for more notes. 00074 * @endif 00075 */ 00076 template<typename _ForwardIterator, typename _Tp> 00077 class _Temporary_buffer 00078 { 00079 // concept requirements 00080 __glibcxx_class_requires(_ForwardIterator, _ForwardIteratorConcept) 00081 00082 public: 00083 typedef _Tp value_type; 00084 typedef value_type* pointer; 00085 typedef pointer iterator; 00086 typedef ptrdiff_t size_type; 00087 00088 protected: 00089 size_type _M_original_len; 00090 size_type _M_len; 00091 pointer _M_buffer; 00092 00093 void 00094 _M_initialize_buffer(const _Tp&, __true_type) { } 00095 00096 void 00097 _M_initialize_buffer(const _Tp& __val, __false_type) 00098 { std::uninitialized_fill_n(_M_buffer, _M_len, __val); } 00099 00100 public: 00101 /// As per Table mumble. 00102 size_type 00103 size() const 00104 { return _M_len; } 00105 00106 /// Returns the size requested by the constructor; may be >size(). 00107 size_type 00108 requested_size() const 00109 { return _M_original_len; } 00110 00111 /// As per Table mumble. 00112 iterator 00113 begin() 00114 { return _M_buffer; } 00115 00116 /// As per Table mumble. 00117 iterator 00118 end() 00119 { return _M_buffer + _M_len; } 00120 00121 /** 00122 * Constructs a temporary buffer of a size somewhere between 00123 * zero and the size of the given range. 00124 */ 00125 _Temporary_buffer(_ForwardIterator __first, _ForwardIterator __last); 00126 00127 ~_Temporary_buffer() 00128 { 00129 std::_Destroy(_M_buffer, _M_buffer + _M_len); 00130 std::return_temporary_buffer(_M_buffer); 00131 } 00132 00133 private: 00134 // Disable copy constructor and assignment operator. 00135 _Temporary_buffer(const _Temporary_buffer&); 00136 00137 void 00138 operator=(const _Temporary_buffer&); 00139 }; 00140 00141 00142 template<typename _ForwardIterator, typename _Tp> 00143 _Temporary_buffer<_ForwardIterator, _Tp>:: 00144 _Temporary_buffer(_ForwardIterator __first, _ForwardIterator __last) 00145 : _M_original_len(std::distance(__first, __last)), 00146 _M_len(0), _M_buffer(0) 00147 { 00148 // Workaround for a __type_traits bug in the pre-7.3 compiler. 00149 typedef typename std::__is_scalar<_Tp>::__type _Trivial; 00150 00151 try 00152 { 00153 pair<pointer, size_type> __p(get_temporary_buffer< 00154 value_type>(_M_original_len)); 00155 _M_buffer = __p.first; 00156 _M_len = __p.second; 00157 if (_M_len > 0) 00158 _M_initialize_buffer(*__first, _Trivial()); 00159 } 00160 catch(...) 00161 { 00162 std::return_temporary_buffer(_M_buffer); 00163 _M_buffer = 0; 00164 _M_len = 0; 00165 __throw_exception_again; 00166 } 00167 } 00168 00169 _GLIBCXX_END_NAMESPACE 00170 00171 #endif /* _TEMPBUF_H */ 00172