libstdc++: iterator Source File

libstdc++

ext/iterator
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1// HP/SGI iterator extensions -*- C++ -*-
2
3// Copyright (C) 2001-2026 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) 1996-1998
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#ifdef _GLIBCXX_SYSHDR
60#pragma GCC system_header
61#endif
62
63#include <bits/concept_check.h>
64#include <iterator>
65
66namespace __gnu_cxx _GLIBCXX_VISIBILITY(default)
67{
68_GLIBCXX_BEGIN_NAMESPACE_VERSION
69
70 // There are two signatures for distance. In addition to the one
71 // taking two iterators and returning a result, there is another
72 // taking two iterators and a reference-to-result variable, and
73 // returning nothing. The latter seems to be an SGI extension.
74 // -- pedwards
75 template<typename _InputIterator, typename _Distance>
76 inline void
77 __distance(_InputIterator __first, _InputIterator __last,
78 _Distance& __n, std::input_iterator_tag)
79 {
80 // concept requirements
81 __glibcxx_function_requires(_InputIteratorConcept<_InputIterator>)
82 while (__first != __last)
83 {
84 ++__first;
85 ++__n;
86 }
87 }
88
89 template<typename _RandomAccessIterator, typename _Distance>
90 inline void
91 __distance(_RandomAccessIterator __first, _RandomAccessIterator __last,
92 _Distance& __n, std::random_access_iterator_tag)
93 {
94 // concept requirements
95 __glibcxx_function_requires(_RandomAccessIteratorConcept<
96 _RandomAccessIterator>)
97 __n += __last - __first;
98 }
99
100 /**
101 * This is an SGI extension.
102 * @ingroup SGIextensions
103 * @doctodo
104 */
105 template<typename _InputIterator, typename _Distance>
106 inline void
107 distance(_InputIterator __first, _InputIterator __last,
108 _Distance& __n)
109 {
110 // concept requirements -- taken care of in __distance
111 __distance(__first, __last, __n, std::__iterator_category(__first));
112 }
113
114_GLIBCXX_END_NAMESPACE_VERSION
115} // namespace
116
117#endif
118
concept_check.h
__gnu_cxx::distance
void distance(_InputIterator __first, _InputIterator __last, _Distance &__n)
Definition ext/iterator:107
__gnu_cxx
GNU extensions for public use.
iterator