libstdc++
ext/iterator
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1 // HP/SGI iterator extensions -*- C++ -*-
2 
3 // Copyright (C) 2001-2017 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 
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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) 1996-1998
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/iterator
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_ITERATOR
57 #define _EXT_ITERATOR 1
58 
59 #pragma GCC system_header
60 
61 #include <bits/concept_check.h>
62 #include <iterator>
63 
64 namespace __gnu_cxx _GLIBCXX_VISIBILITY(default)
65 {
66 _GLIBCXX_BEGIN_NAMESPACE_VERSION
67 
68  // There are two signatures for distance. In addition to the one
69  // taking two iterators and returning a result, there is another
70  // taking two iterators and a reference-to-result variable, and
71  // returning nothing. The latter seems to be an SGI extension.
72  // -- pedwards
73  template<typename _InputIterator, typename _Distance>
74  inline void
75  __distance(_InputIterator __first, _InputIterator __last,
76  _Distance& __n, std::input_iterator_tag)
77  {
78  // concept requirements
79  __glibcxx_function_requires(_InputIteratorConcept<_InputIterator>)
80  while (__first != __last)
81  {
82  ++__first;
83  ++__n;
84  }
85  }
86 
87  template<typename _RandomAccessIterator, typename _Distance>
88  inline void
89  __distance(_RandomAccessIterator __first, _RandomAccessIterator __last,
90  _Distance& __n, std::random_access_iterator_tag)
91  {
92  // concept requirements
93  __glibcxx_function_requires(_RandomAccessIteratorConcept<
94  _RandomAccessIterator>)
95  __n += __last - __first;
96  }
97 
98  /**
99  * This is an SGI extension.
100  * @ingroup SGIextensions
101  * @doctodo
102  */
103  template<typename _InputIterator, typename _Distance>
104  inline void
105  distance(_InputIterator __first, _InputIterator __last,
106  _Distance& __n)
107  {
108  // concept requirements -- taken care of in __distance
109  __distance(__first, __last, __n, std::__iterator_category(__first));
110  }
111 
112 _GLIBCXX_END_NAMESPACE_VERSION
113 } // namespace
114 
115 #endif
116 
void distance(_InputIterator __first, _InputIterator __last, _Distance &__n)
Definition: ext/iterator:105
constexpr iterator_traits< _Iter >::iterator_category __iterator_category(const _Iter &)
GNU extensions for public use.
Marking input iterators.
Random-access iterators support a superset of bidirectional iterator operations.