freebsd-dev/contrib/libstdc++/include/bits/stl_tempbuf.h
2002-05-28 16:16:03 +00:00

150 lines
4.8 KiB
C++

// Temporary buffer implementation -*- C++ -*-
// Copyright (C) 2001, 2002 Free Software Foundation, Inc.
//
// This file is part of the GNU ISO C++ Library. This library is free
// software; you can redistribute it and/or modify it under the
// terms of the GNU General Public License as published by the
// Free Software Foundation; either version 2, or (at your option)
// any later version.
// This library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
// You should have received a copy of the GNU General Public License along
// with this library; see the file COPYING. If not, write to the Free
// Software Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307,
// USA.
// As a special exception, you may use this file as part of a free software
// library without restriction. Specifically, if other files instantiate
// templates or use macros or inline functions from this file, or you compile
// this file and link it with other files to produce an executable, this
// file does not by itself cause the resulting executable to be covered by
// the GNU General Public License. This exception does not however
// invalidate any other reasons why the executable file might be covered by
// the GNU General Public License.
/*
*
* Copyright (c) 1994
* Hewlett-Packard Company
*
* Permission to use, copy, modify, distribute and sell this software
* and its documentation for any purpose is hereby granted without fee,
* provided that the above copyright notice appear in all copies and
* that both that copyright notice and this permission notice appear
* in supporting documentation. Hewlett-Packard Company makes no
* representations about the suitability of this software for any
* purpose. It is provided "as is" without express or implied warranty.
*
*
* Copyright (c) 1996,1997
* Silicon Graphics Computer Systems, Inc.
*
* Permission to use, copy, modify, distribute and sell this software
* and its documentation for any purpose is hereby granted without fee,
* provided that the above copyright notice appear in all copies and
* that both that copyright notice and this permission notice appear
* in supporting documentation. Silicon Graphics makes no
* representations about the suitability of this software for any
* purpose. It is provided "as is" without express or implied warranty.
*/
/** @file stl_tempbuf.h
* This is an internal header file, included by other library headers.
* You should not attempt to use it directly.
*/
#ifndef __GLIBCPP_INTERNAL_TEMPBUF_H
#define __GLIBCPP_INTERNAL_TEMPBUF_H
namespace std
{
/**
* @if maint
* This class is used in two places: stl_algo.h and ext/memory, where it
* is wrapped as the temporary_buffer class. See temporary_buffer docs for
* more notes.
* @endif
*/
template <class _ForwardIterator, class _Tp>
class _Temporary_buffer
{
// concept requirements
__glibcpp_class_requires(_ForwardIterator, _ForwardIteratorConcept)
ptrdiff_t _M_original_len;
ptrdiff_t _M_len;
_Tp* _M_buffer;
// this is basically get_temporary_buffer() all over again
void _M_allocate_buffer() {
_M_original_len = _M_len;
_M_buffer = 0;
if (_M_len > (ptrdiff_t)(INT_MAX / sizeof(_Tp)))
_M_len = INT_MAX / sizeof(_Tp);
while (_M_len > 0) {
_M_buffer = (_Tp*) malloc(_M_len * sizeof(_Tp));
if (_M_buffer)
break;
_M_len /= 2;
}
}
void _M_initialize_buffer(const _Tp&, __true_type) {}
void _M_initialize_buffer(const _Tp& val, __false_type) {
uninitialized_fill_n(_M_buffer, _M_len, val);
}
public:
/// As per Table mumble.
ptrdiff_t size() const { return _M_len; }
/// Returns the size requested by the constructor; may be >size().
ptrdiff_t requested_size() const { return _M_original_len; }
/// As per Table mumble.
_Tp* begin() { return _M_buffer; }
/// As per Table mumble.
_Tp* end() { return _M_buffer + _M_len; }
_Temporary_buffer(_ForwardIterator __first, _ForwardIterator __last) {
// Workaround for a __type_traits bug in the pre-7.3 compiler.
typedef typename __type_traits<_Tp>::has_trivial_default_constructor
_Trivial;
try {
_M_len = distance(__first, __last);
_M_allocate_buffer();
if (_M_len > 0)
_M_initialize_buffer(*__first, _Trivial());
}
catch(...)
{
free(_M_buffer);
_M_buffer = 0;
_M_len = 0;
__throw_exception_again;
}
}
~_Temporary_buffer() {
_Destroy(_M_buffer, _M_buffer + _M_len);
free(_M_buffer);
}
private:
// Disable copy constructor and assignment operator.
_Temporary_buffer(const _Temporary_buffer&) {}
void operator=(const _Temporary_buffer&) {}
};
} // namespace std
#endif /* __GLIBCPP_INTERNAL_TEMPBUF_H */