xref: /openbsd-src/gnu/gcc/libstdc++-v3/include/bits/stl_tempbuf.h (revision 404b540a9034ac75a6199ad1a32d1bbc7a0d4210)
1*404b540aSrobert // Temporary buffer implementation -*- C++ -*-
2*404b540aSrobert 
3*404b540aSrobert // Copyright (C) 2001, 2002, 2003, 2004, 2005, 2006
4*404b540aSrobert // Free Software Foundation, Inc.
5*404b540aSrobert //
6*404b540aSrobert // This file is part of the GNU ISO C++ Library.  This library is free
7*404b540aSrobert // software; you can redistribute it and/or modify it under the
8*404b540aSrobert // terms of the GNU General Public License as published by the
9*404b540aSrobert // Free Software Foundation; either version 2, or (at your option)
10*404b540aSrobert // any later version.
11*404b540aSrobert 
12*404b540aSrobert // This library is distributed in the hope that it will be useful,
13*404b540aSrobert // but WITHOUT ANY WARRANTY; without even the implied warranty of
14*404b540aSrobert // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15*404b540aSrobert // GNU General Public License for more details.
16*404b540aSrobert 
17*404b540aSrobert // You should have received a copy of the GNU General Public License along
18*404b540aSrobert // with this library; see the file COPYING.  If not, write to the Free
19*404b540aSrobert // Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
20*404b540aSrobert // USA.
21*404b540aSrobert 
22*404b540aSrobert // As a special exception, you may use this file as part of a free software
23*404b540aSrobert // library without restriction.  Specifically, if other files instantiate
24*404b540aSrobert // templates or use macros or inline functions from this file, or you compile
25*404b540aSrobert // this file and link it with other files to produce an executable, this
26*404b540aSrobert // file does not by itself cause the resulting executable to be covered by
27*404b540aSrobert // the GNU General Public License.  This exception does not however
28*404b540aSrobert // invalidate any other reasons why the executable file might be covered by
29*404b540aSrobert // the GNU General Public License.
30*404b540aSrobert 
31*404b540aSrobert /*
32*404b540aSrobert  *
33*404b540aSrobert  * Copyright (c) 1994
34*404b540aSrobert  * Hewlett-Packard Company
35*404b540aSrobert  *
36*404b540aSrobert  * Permission to use, copy, modify, distribute and sell this software
37*404b540aSrobert  * and its documentation for any purpose is hereby granted without fee,
38*404b540aSrobert  * provided that the above copyright notice appear in all copies and
39*404b540aSrobert  * that both that copyright notice and this permission notice appear
40*404b540aSrobert  * in supporting documentation.  Hewlett-Packard Company makes no
41*404b540aSrobert  * representations about the suitability of this software for any
42*404b540aSrobert  * purpose.  It is provided "as is" without express or implied warranty.
43*404b540aSrobert  *
44*404b540aSrobert  *
45*404b540aSrobert  * Copyright (c) 1996,1997
46*404b540aSrobert  * Silicon Graphics Computer Systems, Inc.
47*404b540aSrobert  *
48*404b540aSrobert  * Permission to use, copy, modify, distribute and sell this software
49*404b540aSrobert  * and its documentation for any purpose is hereby granted without fee,
50*404b540aSrobert  * provided that the above copyright notice appear in all copies and
51*404b540aSrobert  * that both that copyright notice and this permission notice appear
52*404b540aSrobert  * in supporting documentation.  Silicon Graphics makes no
53*404b540aSrobert  * representations about the suitability of this software for any
54*404b540aSrobert  * purpose.  It is provided "as is" without express or implied warranty.
55*404b540aSrobert  */
56*404b540aSrobert 
57*404b540aSrobert /** @file stl_tempbuf.h
58*404b540aSrobert  *  This is an internal header file, included by other library headers.
59*404b540aSrobert  *  You should not attempt to use it directly.
60*404b540aSrobert  */
61*404b540aSrobert 
62*404b540aSrobert #ifndef _TEMPBUF_H
63*404b540aSrobert #define _TEMPBUF_H 1
64*404b540aSrobert 
65*404b540aSrobert #include <memory>
66*404b540aSrobert 
_GLIBCXX_BEGIN_NAMESPACE(std)67*404b540aSrobert _GLIBCXX_BEGIN_NAMESPACE(std)
68*404b540aSrobert 
69*404b540aSrobert   /**
70*404b540aSrobert    *  @if maint
71*404b540aSrobert    *  This class is used in two places: stl_algo.h and ext/memory,
72*404b540aSrobert    *  where it is wrapped as the temporary_buffer class.  See
73*404b540aSrobert    *  temporary_buffer docs for more notes.
74*404b540aSrobert    *  @endif
75*404b540aSrobert    */
76*404b540aSrobert   template<typename _ForwardIterator, typename _Tp>
77*404b540aSrobert     class _Temporary_buffer
78*404b540aSrobert     {
79*404b540aSrobert       // concept requirements
80*404b540aSrobert       __glibcxx_class_requires(_ForwardIterator, _ForwardIteratorConcept)
81*404b540aSrobert 
82*404b540aSrobert     public:
83*404b540aSrobert       typedef _Tp         value_type;
84*404b540aSrobert       typedef value_type* pointer;
85*404b540aSrobert       typedef pointer     iterator;
86*404b540aSrobert       typedef ptrdiff_t   size_type;
87*404b540aSrobert 
88*404b540aSrobert     protected:
89*404b540aSrobert       size_type  _M_original_len;
90*404b540aSrobert       size_type  _M_len;
91*404b540aSrobert       pointer    _M_buffer;
92*404b540aSrobert 
93*404b540aSrobert       void
94*404b540aSrobert       _M_initialize_buffer(const _Tp&, __true_type) { }
95*404b540aSrobert 
96*404b540aSrobert       void
97*404b540aSrobert       _M_initialize_buffer(const _Tp& __val, __false_type)
98*404b540aSrobert       { std::uninitialized_fill_n(_M_buffer, _M_len, __val); }
99*404b540aSrobert 
100*404b540aSrobert     public:
101*404b540aSrobert       /// As per Table mumble.
102*404b540aSrobert       size_type
103*404b540aSrobert       size() const
104*404b540aSrobert       { return _M_len; }
105*404b540aSrobert 
106*404b540aSrobert       /// Returns the size requested by the constructor; may be >size().
107*404b540aSrobert       size_type
108*404b540aSrobert       requested_size() const
109*404b540aSrobert       { return _M_original_len; }
110*404b540aSrobert 
111*404b540aSrobert       /// As per Table mumble.
112*404b540aSrobert       iterator
113*404b540aSrobert       begin()
114*404b540aSrobert       { return _M_buffer; }
115*404b540aSrobert 
116*404b540aSrobert       /// As per Table mumble.
117*404b540aSrobert       iterator
118*404b540aSrobert       end()
119*404b540aSrobert       { return _M_buffer + _M_len; }
120*404b540aSrobert 
121*404b540aSrobert       /**
122*404b540aSrobert        * Constructs a temporary buffer of a size somewhere between
123*404b540aSrobert        * zero and the size of the given range.
124*404b540aSrobert        */
125*404b540aSrobert       _Temporary_buffer(_ForwardIterator __first, _ForwardIterator __last);
126*404b540aSrobert 
127*404b540aSrobert       ~_Temporary_buffer()
128*404b540aSrobert       {
129*404b540aSrobert 	std::_Destroy(_M_buffer, _M_buffer + _M_len);
130*404b540aSrobert 	std::return_temporary_buffer(_M_buffer);
131*404b540aSrobert       }
132*404b540aSrobert 
133*404b540aSrobert     private:
134*404b540aSrobert       // Disable copy constructor and assignment operator.
135*404b540aSrobert       _Temporary_buffer(const _Temporary_buffer&);
136*404b540aSrobert 
137*404b540aSrobert       void
138*404b540aSrobert       operator=(const _Temporary_buffer&);
139*404b540aSrobert     };
140*404b540aSrobert 
141*404b540aSrobert 
142*404b540aSrobert   template<typename _ForwardIterator, typename _Tp>
143*404b540aSrobert     _Temporary_buffer<_ForwardIterator, _Tp>::
_Temporary_buffer(_ForwardIterator __first,_ForwardIterator __last)144*404b540aSrobert     _Temporary_buffer(_ForwardIterator __first, _ForwardIterator __last)
145*404b540aSrobert     : _M_original_len(std::distance(__first, __last)),
146*404b540aSrobert       _M_len(0), _M_buffer(0)
147*404b540aSrobert     {
148*404b540aSrobert       // Workaround for a __type_traits bug in the pre-7.3 compiler.
149*404b540aSrobert       typedef typename std::__is_scalar<_Tp>::__type _Trivial;
150*404b540aSrobert 
151*404b540aSrobert       try
152*404b540aSrobert 	{
153*404b540aSrobert 	  pair<pointer, size_type> __p(get_temporary_buffer<
154*404b540aSrobert 				       value_type>(_M_original_len));
155*404b540aSrobert 	  _M_buffer = __p.first;
156*404b540aSrobert 	  _M_len = __p.second;
157*404b540aSrobert 	  if (_M_len > 0)
158*404b540aSrobert 	    _M_initialize_buffer(*__first, _Trivial());
159*404b540aSrobert 	}
160*404b540aSrobert       catch(...)
161*404b540aSrobert 	{
162*404b540aSrobert 	  std::return_temporary_buffer(_M_buffer);
163*404b540aSrobert 	  _M_buffer = 0;
164*404b540aSrobert 	  _M_len = 0;
165*404b540aSrobert 	  __throw_exception_again;
166*404b540aSrobert 	}
167*404b540aSrobert     }
168*404b540aSrobert 
169*404b540aSrobert _GLIBCXX_END_NAMESPACE
170*404b540aSrobert 
171*404b540aSrobert #endif /* _TEMPBUF_H */
172*404b540aSrobert 
173