# stl_tempbuf.h

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    00001 // Temporary buffer implementation -*- C++ -*-
    00002
    00003 // Copyright (C) 2001, 2002 Free Software Foundation, Inc.
    00004 //
    00005 // This file is part of the GNU ISO C++ Library.  This library is free
    00006 // software; you can redistribute it and/or modify it under the
    00007 // terms of the GNU General Public License as published by the
    00008 // Free Software Foundation; either version 2, or (at your option)
    00009 // any later version.
    00010
    00011 // This library is distributed in the hope that it will be useful,
    00012 // but WITHOUT ANY WARRANTY; without even the implied warranty of
    00013 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    00014 // GNU General Public License for more details.
    00015
    00016 // You should have received a copy of the GNU General Public License along
    00017 // with this library; see the file COPYING.  If not, write to the Free
    00018 // Software Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307,
    00019 // USA.
    00020
    00021 // As a special exception, you may use this file as part of a free software
    00022 // library without restriction.  Specifically, if other files instantiate
    00023 // templates or use macros or inline functions from this file, or you compile
    00024 // this file and link it with other files to produce an executable, this
    00025 // file does not by itself cause the resulting executable to be covered by
    00026 // the GNU General Public License.  This exception does not however
    00027 // invalidate any other reasons why the executable file might be covered by
    00028 // the GNU General Public License.
    00029
    00030 /*
    00031  *
    00032  * Copyright (c) 1994
    00033  * Hewlett-Packard Company
    00034  *
    00035  * Permission to use, copy, modify, distribute and sell this software
    00036  * and its documentation for any purpose is hereby granted without fee,
    00037  * provided that the above copyright notice appear in all copies and
    00038  * that both that copyright notice and this permission notice appear
    00039  * in supporting documentation.  Hewlett-Packard Company makes no
    00040  * representations about the suitability of this software for any
    00041  * purpose.  It is provided "as is" without express or implied warranty.
    00042  *
    00043  *
    00044  * Copyright (c) 1996,1997
    00045  * Silicon Graphics Computer Systems, Inc.
    00046  *
    00047  * Permission to use, copy, modify, distribute and sell this software
    00048  * and its documentation for any purpose is hereby granted without fee,
    00049  * provided that the above copyright notice appear in all copies and
    00050  * that both that copyright notice and this permission notice appear
    00051  * in supporting documentation.  Silicon Graphics makes no
    00052  * representations about the suitability of this software for any
    00053  * purpose.  It is provided "as is" without express or implied warranty.
    00054  */
    00055
    00061 #ifndef __GLIBCPP_INTERNAL_TEMPBUF_H
    00062 #define __GLIBCPP_INTERNAL_TEMPBUF_H
    00063
    00064 namespace std
    00065 {
    00066
    00074 template <class _ForwardIterator, class _Tp>
    00075   class _Temporary_buffer
    00076 {
    00077   // concept requirements
    00078   __glibcpp_class_requires(_ForwardIterator, _ForwardIteratorConcept)
    00079
    00080   ptrdiff_t  _M_original_len;
    00081   ptrdiff_t  _M_len;
    00082   _Tp*       _M_buffer;
    00083
    00084   // this is basically get_temporary_buffer() all over again
    00085   void _M_allocate_buffer() {
    00086     _M_original_len = _M_len;
    00087     _M_buffer = 0;
    00088
    00089     if (_M_len > (ptrdiff_t)(INT_MAX / sizeof(_Tp)))
    00090       _M_len = INT_MAX / sizeof(_Tp);
    00091
    00092     while (_M_len > 0) {
    00093       _M_buffer = (_Tp*) malloc(_M_len * sizeof(_Tp));
    00094       if (_M_buffer)
    00095         break;
    00096       _M_len /= 2;
    00097     }
    00098   }
    00099
    00100   void _M_initialize_buffer(const _Tp&, __true_type) {}
    00101   void _M_initialize_buffer(const _Tp& val, __false_type) {
    00102     uninitialized_fill_n(_M_buffer, _M_len, val);
    00103   }
    00104
    00105 public:
    00107   ptrdiff_t size() const { return _M_len; }
    00109   ptrdiff_t requested_size() const { return _M_original_len; }
    00111   _Tp* begin() { return _M_buffer; }
    00113   _Tp* end() { return _M_buffer + _M_len; }
    00114
    00115   _Temporary_buffer(_ForwardIterator __first, _ForwardIterator __last) {
    00116     // Workaround for a __type_traits bug in the pre-7.3 compiler.
    00117     typedef typename __type_traits<_Tp>::has_trivial_default_constructor
    00118             _Trivial;
    00119
    00120     try {
    00121       _M_len = distance(__first, __last);
    00122       _M_allocate_buffer();
    00123       if (_M_len > 0)
    00124         _M_initialize_buffer(*__first, _Trivial());
    00125     }
    00126     catch(...)
    00127       {
    00128     free(_M_buffer);
    00129     _M_buffer = 0;
    00130     _M_len = 0;
    00131     __throw_exception_again;
    00132       }
    00133   }
    00134
    00135   ~_Temporary_buffer() {
    00136     _Destroy(_M_buffer, _M_buffer + _M_len);
    00137     free(_M_buffer);
    00138   }
    00139
    00140 private:
    00141   // Disable copy constructor and assignment operator.
    00142   _Temporary_buffer(const _Temporary_buffer&) {}
    00143   void operator=(const _Temporary_buffer&) {}
    00144 };
    00145
    00146 } // namespace std
    00147
    00148 #endif /* __GLIBCPP_INTERNAL_TEMPBUF_H */
    00149