1 // Temporary buffer implementation -*- C++ -*-
3 // Copyright (C) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010
4 // Free Software Foundation, Inc.
6 // This file is part of the GNU ISO C++ Library. This library is free
7 // software; you can redistribute it and/or modify it under the
8 // terms of the GNU General Public License as published by the
9 // Free Software Foundation; either version 3, or (at your option)
12 // This library is distributed in the hope that it will be useful,
13 // but WITHOUT ANY WARRANTY; without even the implied warranty of
14 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 // GNU General Public License for more details.
17 // Under Section 7 of GPL version 3, you are granted additional
18 // permissions described in the GCC Runtime Library Exception, version
19 // 3.1, as published by the Free Software Foundation.
21 // You should have received a copy of the GNU General Public License and
22 // a copy of the GCC Runtime Library Exception along with this program;
23 // see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
24 // <http://www.gnu.org/licenses/>.
29 * Hewlett-Packard Company
31 * Permission to use, copy, modify, distribute and sell this software
32 * and its documentation for any purpose is hereby granted without fee,
33 * provided that the above copyright notice appear in all copies and
34 * that both that copyright notice and this permission notice appear
35 * in supporting documentation. Hewlett-Packard Company makes no
36 * representations about the suitability of this software for any
37 * purpose. It is provided "as is" without express or implied warranty.
40 * Copyright (c) 1996,1997
41 * Silicon Graphics Computer Systems, Inc.
43 * Permission to use, copy, modify, distribute and sell this software
44 * and its documentation for any purpose is hereby granted without fee,
45 * provided that the above copyright notice appear in all copies and
46 * that both that copyright notice and this permission notice appear
47 * in supporting documentation. Silicon Graphics makes no
48 * representations about the suitability of this software for any
49 * purpose. It is provided "as is" without express or implied warranty.
52 /** @file stl_tempbuf.h
53 * This is an internal header file, included by other library headers.
54 * You should not attempt to use it directly.
57 #ifndef _STL_TEMPBUF_H
58 #define _STL_TEMPBUF_H 1
60 #include <bits/stl_algobase.h>
61 #include <bits/stl_construct.h>
62 #include <bits/stl_uninitialized.h>
64 _GLIBCXX_BEGIN_NAMESPACE(std
)
67 * @brief Allocates a temporary buffer.
68 * @param len The number of objects of type Tp.
69 * @return See full description.
71 * Reinventing the wheel, but this time with prettier spokes!
73 * This function tries to obtain storage for @c len adjacent Tp
74 * objects. The objects themselves are not constructed, of course.
75 * A pair<> is returned containing <em>the buffer s address and
76 * capacity (in the units of sizeof(Tp)), or a pair of 0 values if
77 * no storage can be obtained.</em> Note that the capacity obtained
78 * may be less than that requested if the memory is unavailable;
79 * you should compare len with the .second return value.
81 * Provides the nothrow exception guarantee.
83 template<typename _Tp
>
85 get_temporary_buffer(ptrdiff_t __len
)
87 const ptrdiff_t __max
=
88 __gnu_cxx::__numeric_traits
<ptrdiff_t>::__max
/ sizeof(_Tp
);
94 _Tp
* __tmp
= static_cast<_Tp
*>(::operator new(__len
* sizeof(_Tp
),
97 return std::pair
<_Tp
*, ptrdiff_t>(__tmp
, __len
);
100 return std::pair
<_Tp
*, ptrdiff_t>(static_cast<_Tp
*>(0), 0);
104 * @brief The companion to get_temporary_buffer().
105 * @param p A buffer previously allocated by get_temporary_buffer.
108 * Frees the memory pointed to by p.
110 template<typename _Tp
>
112 return_temporary_buffer(_Tp
* __p
)
113 { ::operator delete(__p
, std::nothrow
); }
117 * This class is used in two places: stl_algo.h and ext/memory,
118 * where it is wrapped as the temporary_buffer class. See
119 * temporary_buffer docs for more notes.
121 template<typename _ForwardIterator
, typename _Tp
>
122 class _Temporary_buffer
124 // concept requirements
125 __glibcxx_class_requires(_ForwardIterator
, _ForwardIteratorConcept
)
128 typedef _Tp value_type
;
129 typedef value_type
* pointer
;
130 typedef pointer iterator
;
131 typedef ptrdiff_t size_type
;
134 size_type _M_original_len
;
139 /// As per Table mumble.
144 /// Returns the size requested by the constructor; may be >size().
146 requested_size() const
147 { return _M_original_len
; }
149 /// As per Table mumble.
152 { return _M_buffer
; }
154 /// As per Table mumble.
157 { return _M_buffer
+ _M_len
; }
160 * Constructs a temporary buffer of a size somewhere between
161 * zero and the size of the given range.
163 _Temporary_buffer(_ForwardIterator __first
, _ForwardIterator __last
);
167 std::_Destroy(_M_buffer
, _M_buffer
+ _M_len
);
168 std::return_temporary_buffer(_M_buffer
);
172 // Disable copy constructor and assignment operator.
173 _Temporary_buffer(const _Temporary_buffer
&);
176 operator=(const _Temporary_buffer
&);
179 template<typename _ForwardIterator
, typename _Tp
>
180 _Temporary_buffer
<_ForwardIterator
, _Tp
>::
181 _Temporary_buffer(_ForwardIterator __first
, _ForwardIterator __last
)
182 : _M_original_len(std::distance(__first
, __last
)),
183 _M_len(0), _M_buffer(0)
187 std::pair
<pointer
, size_type
> __p(std::get_temporary_buffer
<
188 value_type
>(_M_original_len
));
189 _M_buffer
= __p
.first
;
192 std::__uninitialized_construct_range(_M_buffer
, _M_buffer
+ _M_len
,
197 std::return_temporary_buffer(_M_buffer
);
200 __throw_exception_again
;
204 _GLIBCXX_END_NAMESPACE
206 #endif /* _STL_TEMPBUF_H */