1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
|
// Functions used by iterators -*- C++ -*-
// Copyright (C) 2001-2015 Free Software Foundation, Inc.
//
// This file is part of the GNU ISO C++ Library. This library is free
// software; you can redistribute it and/or modify it under the
// terms of the GNU General Public License as published by the
// Free Software Foundation; either version 3, or (at your option)
// any later version.
// This library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
// Under Section 7 of GPL version 3, you are granted additional
// permissions described in the GCC Runtime Library Exception, version
// 3.1, as published by the Free Software Foundation.
// You should have received a copy of the GNU General Public License and
// a copy of the GCC Runtime Library Exception along with this program;
// see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
// <http://www.gnu.org/licenses/>.
/*
*
* Copyright (c) 1994
* Hewlett-Packard Company
*
* Permission to use, copy, modify, distribute and sell this software
* and its documentation for any purpose is hereby granted without fee,
* provided that the above copyright notice appear in all copies and
* that both that copyright notice and this permission notice appear
* in supporting documentation. Hewlett-Packard Company makes no
* representations about the suitability of this software for any
* purpose. It is provided "as is" without express or implied warranty.
*
*
* Copyright (c) 1996-1998
* Silicon Graphics Computer Systems, Inc.
*
* Permission to use, copy, modify, distribute and sell this software
* and its documentation for any purpose is hereby granted without fee,
* provided that the above copyright notice appear in all copies and
* that both that copyright notice and this permission notice appear
* in supporting documentation. Silicon Graphics makes no
* representations about the suitability of this software for any
* purpose. It is provided "as is" without express or implied warranty.
*/
/** @file bits/stl_iterator_base_funcs.h
* This is an internal header file, included by other library headers.
* Do not attempt to use it directly. @headername{iterator}
*
* This file contains all of the general iterator-related utility
* functions, such as distance() and advance().
*/
#ifndef _STL_ITERATOR_BASE_FUNCS_H
#define _STL_ITERATOR_BASE_FUNCS_H 1
#pragma GCC system_header
#include <bits/concept_check.h>
#include <debug/debug.h>
namespace std _GLIBCXX_VISIBILITY(default)
{
_GLIBCXX_BEGIN_NAMESPACE_VERSION
template<typename _InputIterator>
inline typename iterator_traits<_InputIterator>::difference_type
__distance(_InputIterator __first, _InputIterator __last,
input_iterator_tag)
{
// concept requirements
__glibcxx_function_requires(_InputIteratorConcept<_InputIterator>)
typename iterator_traits<_InputIterator>::difference_type __n = 0;
while (__first != __last)
{
++__first;
++__n;
}
return __n;
}
template<typename _RandomAccessIterator>
inline typename iterator_traits<_RandomAccessIterator>::difference_type
__distance(_RandomAccessIterator __first, _RandomAccessIterator __last,
random_access_iterator_tag)
{
// concept requirements
__glibcxx_function_requires(_RandomAccessIteratorConcept<
_RandomAccessIterator>)
return __last - __first;
}
/**
* @brief A generalization of pointer arithmetic.
* @param __first An input iterator.
* @param __last An input iterator.
* @return The distance between them.
*
* Returns @c n such that __first + n == __last. This requires
* that @p __last must be reachable from @p __first. Note that @c
* n may be negative.
*
* For random access iterators, this uses their @c + and @c - operations
* and are constant time. For other %iterator classes they are linear time.
*/
template<typename _InputIterator>
inline typename iterator_traits<_InputIterator>::difference_type
distance(_InputIterator __first, _InputIterator __last)
{
// concept requirements -- taken care of in __distance
return std::__distance(__first, __last,
std::__iterator_category(__first));
}
template<typename _InputIterator, typename _Distance>
inline void
__advance(_InputIterator& __i, _Distance __n, input_iterator_tag)
{
// concept requirements
__glibcxx_function_requires(_InputIteratorConcept<_InputIterator>)
_GLIBCXX_DEBUG_ASSERT(__n >= 0);
while (__n--)
++__i;
}
template<typename _BidirectionalIterator, typename _Distance>
inline void
__advance(_BidirectionalIterator& __i, _Distance __n,
bidirectional_iterator_tag)
{
// concept requirements
__glibcxx_function_requires(_BidirectionalIteratorConcept<
_BidirectionalIterator>)
if (__n > 0)
while (__n--)
++__i;
else
while (__n++)
--__i;
}
template<typename _RandomAccessIterator, typename _Distance>
inline void
__advance(_RandomAccessIterator& __i, _Distance __n,
random_access_iterator_tag)
{
// concept requirements
__glibcxx_function_requires(_RandomAccessIteratorConcept<
_RandomAccessIterator>)
__i += __n;
}
/**
* @brief A generalization of pointer arithmetic.
* @param __i An input iterator.
* @param __n The @a delta by which to change @p __i.
* @return Nothing.
*
* This increments @p i by @p n. For bidirectional and random access
* iterators, @p __n may be negative, in which case @p __i is decremented.
*
* For random access iterators, this uses their @c + and @c - operations
* and are constant time. For other %iterator classes they are linear time.
*/
template<typename _InputIterator, typename _Distance>
inline void
advance(_InputIterator& __i, _Distance __n)
{
// concept requirements -- taken care of in __advance
typename iterator_traits<_InputIterator>::difference_type __d = __n;
std::__advance(__i, __d, std::__iterator_category(__i));
}
#if __cplusplus >= 201103L
template<typename _ForwardIterator>
inline _ForwardIterator
next(_ForwardIterator __x, typename
iterator_traits<_ForwardIterator>::difference_type __n = 1)
{
std::advance(__x, __n);
return __x;
}
template<typename _BidirectionalIterator>
inline _BidirectionalIterator
prev(_BidirectionalIterator __x, typename
iterator_traits<_BidirectionalIterator>::difference_type __n = 1)
{
std::advance(__x, -__n);
return __x;
}
#endif // C++11
_GLIBCXX_END_NAMESPACE_VERSION
} // namespace
#endif /* _STL_ITERATOR_BASE_FUNCS_H */
|
