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1 | // Types used in iterator implementation -*- C++ -*- |
2 | ||
8f94053d | 3 | // Copyright (C) 2001, 2002 Free Software Foundation, Inc. |
42526146 PE |
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 2, 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 | // You should have received a copy of the GNU General Public License along | |
17 | // with this library; see the file COPYING. If not, write to the Free | |
18 | // Software Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307, | |
19 | // USA. | |
20 | ||
21 | // As a special exception, you may use this file as part of a free software | |
22 | // library without restriction. Specifically, if other files instantiate | |
23 | // templates or use macros or inline functions from this file, or you compile | |
24 | // this file and link it with other files to produce an executable, this | |
25 | // file does not by itself cause the resulting executable to be covered by | |
26 | // the GNU General Public License. This exception does not however | |
27 | // invalidate any other reasons why the executable file might be covered by | |
28 | // the GNU General Public License. | |
29 | ||
725dc051 BK |
30 | /* |
31 | * | |
32 | * Copyright (c) 1994 | |
33 | * Hewlett-Packard Company | |
34 | * | |
35 | * Permission to use, copy, modify, distribute and sell this software | |
36 | * and its documentation for any purpose is hereby granted without fee, | |
37 | * provided that the above copyright notice appear in all copies and | |
38 | * that both that copyright notice and this permission notice appear | |
39 | * in supporting documentation. Hewlett-Packard Company makes no | |
40 | * representations about the suitability of this software for any | |
41 | * purpose. It is provided "as is" without express or implied warranty. | |
42 | * | |
43 | * | |
44 | * Copyright (c) 1996-1998 | |
45 | * Silicon Graphics Computer Systems, Inc. | |
46 | * | |
47 | * Permission to use, copy, modify, distribute and sell this software | |
48 | * and its documentation for any purpose is hereby granted without fee, | |
49 | * provided that the above copyright notice appear in all copies and | |
50 | * that both that copyright notice and this permission notice appear | |
51 | * in supporting documentation. Silicon Graphics makes no | |
52 | * representations about the suitability of this software for any | |
53 | * purpose. It is provided "as is" without express or implied warranty. | |
54 | */ | |
55 | ||
729e3d3f PE |
56 | /** @file stl_iterator_base_types.h |
57 | * This is an internal header file, included by other library headers. | |
58 | * You should not attempt to use it directly. | |
82b61df5 PE |
59 | * |
60 | * This file contains all of the general iterator-related utility types, | |
61 | * such as iterator_traits and struct iterator. | |
725dc051 BK |
62 | */ |
63 | ||
3d7c150e BK |
64 | #ifndef _ITERATOR_BASE_TYPES_H |
65 | #define _ITERATOR_BASE_TYPES_H 1 | |
725dc051 | 66 | |
aa53cb52 | 67 | #pragma GCC system_header |
725dc051 | 68 | |
d53d7f6e PE |
69 | namespace std |
70 | { | |
840ceb34 PE |
71 | //@{ |
72 | /** | |
82b61df5 PE |
73 | * @defgroup iterator_tags Iterator Tags |
74 | * These are empty types, used to distinguish different iterators. The | |
75 | * distinction is not made by what they contain, but simply by what they | |
76 | * are. Different underlying algorithms can then be used based on the | |
77 | * different operations supporetd by different iterator types. | |
82b61df5 PE |
78 | */ |
79 | /// Marking input iterators. | |
02d92e3b | 80 | struct input_iterator_tag {}; |
82b61df5 | 81 | /// Marking output iterators. |
02d92e3b | 82 | struct output_iterator_tag {}; |
82b61df5 | 83 | /// Forward iterators support a superset of input iterator operations. |
02d92e3b | 84 | struct forward_iterator_tag : public input_iterator_tag {}; |
82b61df5 | 85 | /// Bidirectional iterators support a superset of forward iterator operations. |
02d92e3b | 86 | struct bidirectional_iterator_tag : public forward_iterator_tag {}; |
82b61df5 | 87 | /// Random-access iterators support a superset of bidirectional iterator operations. |
02d92e3b | 88 | struct random_access_iterator_tag : public bidirectional_iterator_tag {}; |
82b61df5 | 89 | //@} |
02d92e3b | 90 | |
02d92e3b | 91 | |
82b61df5 | 92 | /** |
aa2d5ba2 PE |
93 | * @brief Common %iterator class. |
94 | * | |
8f94053d | 95 | * This class does nothing but define nested typedefs. %Iterator classes |
82b61df5 PE |
96 | * can inherit from this class to save some work. The typedefs are then |
97 | * used in specializations and overloading. | |
8f94053d PE |
98 | * |
99 | * In particular, there are no default implementations of requirements | |
100 | * such as @c operator++ and the like. (How could there be?) | |
82b61df5 | 101 | */ |
02d92e3b | 102 | template<typename _Category, typename _Tp, typename _Distance = ptrdiff_t, |
aa2d5ba2 PE |
103 | typename _Pointer = _Tp*, typename _Reference = _Tp&> |
104 | struct iterator | |
105 | { | |
82b61df5 | 106 | /// One of the @link iterator_tags tag types@endlink. |
02d92e3b | 107 | typedef _Category iterator_category; |
82b61df5 | 108 | /// The type "pointed to" by the iterator. |
02d92e3b | 109 | typedef _Tp value_type; |
82b61df5 | 110 | /// Distance between iterators is represented as this type. |
02d92e3b | 111 | typedef _Distance difference_type; |
82b61df5 | 112 | /// This type represents a pointer-to-value_type. |
02d92e3b | 113 | typedef _Pointer pointer; |
82b61df5 | 114 | /// This type represents a reference-to-value_type. |
02d92e3b SW |
115 | typedef _Reference reference; |
116 | }; | |
117 | ||
82b61df5 PE |
118 | /** |
119 | * This class does nothing but define nested typedefs. The general | |
120 | * version simply "forwards" the nested typedefs from the Iterator | |
121 | * argument. Specialized versions for pointers and pointers-to-const | |
122 | * provide tighter, more correct semantics. | |
123 | */ | |
02d92e3b SW |
124 | template<typename _Iterator> |
125 | struct iterator_traits { | |
126 | typedef typename _Iterator::iterator_category iterator_category; | |
127 | typedef typename _Iterator::value_type value_type; | |
128 | typedef typename _Iterator::difference_type difference_type; | |
129 | typedef typename _Iterator::pointer pointer; | |
130 | typedef typename _Iterator::reference reference; | |
131 | }; | |
132 | ||
133 | template<typename _Tp> | |
134 | struct iterator_traits<_Tp*> { | |
135 | typedef random_access_iterator_tag iterator_category; | |
136 | typedef _Tp value_type; | |
137 | typedef ptrdiff_t difference_type; | |
138 | typedef _Tp* pointer; | |
139 | typedef _Tp& reference; | |
140 | }; | |
141 | ||
142 | template<typename _Tp> | |
143 | struct iterator_traits<const _Tp*> { | |
144 | typedef random_access_iterator_tag iterator_category; | |
145 | typedef _Tp value_type; | |
146 | typedef ptrdiff_t difference_type; | |
147 | typedef const _Tp* pointer; | |
148 | typedef const _Tp& reference; | |
149 | }; | |
150 | ||
82b61df5 | 151 | /** |
04b7c941 | 152 | * @if maint |
82b61df5 PE |
153 | * This function is not a part of the C++ standard but is syntactic |
154 | * sugar for internal library use only. | |
04b7c941 | 155 | * @endif |
82b61df5 | 156 | */ |
02d92e3b SW |
157 | template<typename _Iter> |
158 | inline typename iterator_traits<_Iter>::iterator_category | |
159 | __iterator_category(const _Iter&) | |
160 | { return typename iterator_traits<_Iter>::iterator_category(); } | |
725dc051 | 161 | |
d53d7f6e | 162 | } // namespace std |
725dc051 | 163 | |
3d7c150e | 164 | #endif /* _ITERATOR_BASE_TYPES_H */ |
725dc051 | 165 |