libstdc++
ext/memory
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1 // Memory extensions -*- C++ -*-
2 
3 // Copyright (C) 2002-2023 Free Software Foundation, Inc.
4 //
5 // This file is part of the GNU ISO C++ Library. This library is free
6 // software; you can redistribute it and/or modify it under the
7 // terms of the GNU General Public License as published by the
8 // Free Software Foundation; either version 3, or (at your option)
9 // any later version.
10 
11 // This library is distributed in the hope that it will be useful,
12 // but WITHOUT ANY WARRANTY; without even the implied warranty of
13 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 // GNU General Public License for more details.
15 
16 // Under Section 7 of GPL version 3, you are granted additional
17 // permissions described in the GCC Runtime Library Exception, version
18 // 3.1, as published by the Free Software Foundation.
19 
20 // You should have received a copy of the GNU General Public License and
21 // a copy of the GCC Runtime Library Exception along with this program;
22 // see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
23 // <http://www.gnu.org/licenses/>.
24 
25 /*
26  *
27  * Copyright (c) 1994
28  * Hewlett-Packard Company
29  *
30  * Permission to use, copy, modify, distribute and sell this software
31  * and its documentation for any purpose is hereby granted without fee,
32  * provided that the above copyright notice appear in all copies and
33  * that both that copyright notice and this permission notice appear
34  * in supporting documentation. Hewlett-Packard Company makes no
35  * representations about the suitability of this software for any
36  * purpose. It is provided "as is" without express or implied warranty.
37  *
38  *
39  * Copyright (c) 1996
40  * Silicon Graphics Computer Systems, Inc.
41  *
42  * Permission to use, copy, modify, distribute and sell this software
43  * and its documentation for any purpose is hereby granted without fee,
44  * provided that the above copyright notice appear in all copies and
45  * that both that copyright notice and this permission notice appear
46  * in supporting documentation. Silicon Graphics makes no
47  * representations about the suitability of this software for any
48  * purpose. It is provided "as is" without express or implied warranty.
49  */
50 
51 /** @file ext/memory
52  * This file is a GNU extension to the Standard C++ Library (possibly
53  * containing extensions from the HP/SGI STL subset).
54  */
55 
56 #ifndef _EXT_MEMORY
57 #define _EXT_MEMORY 1
58 
59 #pragma GCC system_header
60 
61 #include <bits/requires_hosted.h> // GNU extensions are currently omitted
62 
63 #include <memory>
64 #include <bits/stl_tempbuf.h>
65 
66 namespace __gnu_cxx _GLIBCXX_VISIBILITY(default)
67 {
68 _GLIBCXX_BEGIN_NAMESPACE_VERSION
69 
70  using std::_Temporary_buffer;
71 
72  template<typename _InputIter, typename _Size, typename _ForwardIter>
73  std::pair<_InputIter, _ForwardIter>
74  __uninitialized_copy_n(_InputIter __first, _Size __count,
75  _ForwardIter __result, std::input_iterator_tag)
76  {
77  _ForwardIter __cur = __result;
78  __try
79  {
80  for (; __count > 0 ; --__count, ++__first, ++__cur)
81  std::_Construct(&*__cur, *__first);
82  return std::pair<_InputIter, _ForwardIter>(__first, __cur);
83  }
84  __catch(...)
85  {
86  std::_Destroy(__result, __cur);
87  __throw_exception_again;
88  }
89  }
90 
91  template<typename _RandomAccessIter, typename _Size, typename _ForwardIter>
92  inline std::pair<_RandomAccessIter, _ForwardIter>
93  __uninitialized_copy_n(_RandomAccessIter __first, _Size __count,
94  _ForwardIter __result,
95  std::random_access_iterator_tag)
96  {
97  _RandomAccessIter __last = __first + __count;
98  return (std::pair<_RandomAccessIter, _ForwardIter>
99  (__last, std::uninitialized_copy(__first, __last, __result)));
100  }
101 
102  template<typename _InputIter, typename _Size, typename _ForwardIter>
103  inline std::pair<_InputIter, _ForwardIter>
104  __uninitialized_copy_n(_InputIter __first, _Size __count,
105  _ForwardIter __result)
106  {
107  return __gnu_cxx::__uninitialized_copy_n(__first, __count, __result,
108  std::__iterator_category(__first));
109  }
110 
111  /**
112  * @brief Copies the range [first,last) into result.
113  * @param __first An input iterator.
114  * @param __count Length
115  * @param __result An output iterator.
116  * @return __result + (__first + __count)
117  * @ingroup SGIextensions
118  *
119  * Like copy(), but does not require an initialized output range.
120  */
121  template<typename _InputIter, typename _Size, typename _ForwardIter>
122  inline std::pair<_InputIter, _ForwardIter>
123  uninitialized_copy_n(_InputIter __first, _Size __count,
124  _ForwardIter __result)
125  {
126  return __gnu_cxx::__uninitialized_copy_n(__first, __count, __result,
127  std::__iterator_category(__first));
128  }
129 
130 
131  // An alternative version of uninitialized_copy_n that constructs
132  // and destroys objects with a user-provided allocator.
133  template<typename _InputIter, typename _Size, typename _ForwardIter,
134  typename _Allocator>
135  std::pair<_InputIter, _ForwardIter>
136  __uninitialized_copy_n_a(_InputIter __first, _Size __count,
137  _ForwardIter __result,
138  _Allocator __alloc)
139  {
140  _ForwardIter __cur = __result;
141  __try
142  {
143  for (; __count > 0 ; --__count, ++__first, ++__cur)
144  __alloc.construct(&*__cur, *__first);
145  return std::pair<_InputIter, _ForwardIter>(__first, __cur);
146  }
147  __catch(...)
148  {
149  std::_Destroy(__result, __cur, __alloc);
150  __throw_exception_again;
151  }
152  }
153 
154  template<typename _InputIter, typename _Size, typename _ForwardIter,
155  typename _Tp>
156  inline std::pair<_InputIter, _ForwardIter>
157  __uninitialized_copy_n_a(_InputIter __first, _Size __count,
158  _ForwardIter __result,
159  std::allocator<_Tp>)
160  {
161  return __gnu_cxx::uninitialized_copy_n(__first, __count, __result);
162  }
163 
164  /**
165  * This class provides similar behavior and semantics of the standard
166  * functions get_temporary_buffer() and return_temporary_buffer(), but
167  * encapsulated in a type vaguely resembling a standard container.
168  *
169  * By default, a temporary_buffer<Iter> stores space for objects of
170  * whatever type the Iter iterator points to. It is constructed from a
171  * typical [first,last) range, and provides the begin(), end(), size()
172  * functions, as well as requested_size(). For non-trivial types, copies
173  * of *first will be used to initialize the storage.
174  *
175  * @c malloc is used to obtain underlying storage.
176  *
177  * Like get_temporary_buffer(), not all the requested memory may be
178  * available. Ideally, the created buffer will be large enough to hold a
179  * copy of [first,last), but if size() is less than requested_size(),
180  * then this didn't happen.
181  *
182  * @ingroup SGIextensions
183  */
184  template <class _ForwardIterator, class _Tp
185  = typename std::iterator_traits<_ForwardIterator>::value_type >
186  struct temporary_buffer : public _Temporary_buffer<_ForwardIterator, _Tp>
187  {
188  /// Requests storage large enough to hold a copy of [first,last).
189  temporary_buffer(_ForwardIterator __first, _ForwardIterator __last)
190  : _Temporary_buffer<_ForwardIterator, _Tp>(__first,
191  std::distance(__first, __last))
192  { }
193 
194  /// Destroys objects and frees storage.
195  ~temporary_buffer() { }
196  };
197 
198 _GLIBCXX_END_NAMESPACE_VERSION
199 } // namespace
200 
201 #endif
202