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1 : : // Types used in iterator implementation -*- C++ -*-
2 : :
3 : : // Copyright (C) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010
4 : : // Free Software Foundation, Inc.
5 : : //
6 : : // This file is part of the GNU ISO C++ Library. This library is free
7 : : // software; you can redistribute it and/or modify it under the
8 : : // terms of the GNU General Public License as published by the
9 : : // Free Software Foundation; either version 3, or (at your option)
10 : : // any later version.
11 : :
12 : : // This library is distributed in the hope that it will be useful,
13 : : // but WITHOUT ANY WARRANTY; without even the implied warranty of
14 : : // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 : : // GNU General Public License for more details.
16 : :
17 : : // Under Section 7 of GPL version 3, you are granted additional
18 : : // permissions described in the GCC Runtime Library Exception, version
19 : : // 3.1, as published by the Free Software Foundation.
20 : :
21 : : // You should have received a copy of the GNU General Public License and
22 : : // a copy of the GCC Runtime Library Exception along with this program;
23 : : // see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
24 : : // <http://www.gnu.org/licenses/>.
25 : :
26 : : /*
27 : : *
28 : : * Copyright (c) 1994
29 : : * Hewlett-Packard Company
30 : : *
31 : : * Permission to use, copy, modify, distribute and sell this software
32 : : * and its documentation for any purpose is hereby granted without fee,
33 : : * provided that the above copyright notice appear in all copies and
34 : : * that both that copyright notice and this permission notice appear
35 : : * in supporting documentation. Hewlett-Packard Company makes no
36 : : * representations about the suitability of this software for any
37 : : * purpose. It is provided "as is" without express or implied warranty.
38 : : *
39 : : *
40 : : * Copyright (c) 1996-1998
41 : : * Silicon Graphics Computer Systems, Inc.
42 : : *
43 : : * Permission to use, copy, modify, distribute and sell this software
44 : : * and its documentation for any purpose is hereby granted without fee,
45 : : * provided that the above copyright notice appear in all copies and
46 : : * that both that copyright notice and this permission notice appear
47 : : * in supporting documentation. Silicon Graphics makes no
48 : : * representations about the suitability of this software for any
49 : : * purpose. It is provided "as is" without express or implied warranty.
50 : : */
51 : :
52 : : /** @file bits/stl_iterator_base_types.h
53 : : * This is an internal header file, included by other library headers.
54 : : * Do not attempt to use it directly. @headername{iterator}
55 : : *
56 : : * This file contains all of the general iterator-related utility types,
57 : : * such as iterator_traits and struct iterator.
58 : : */
59 : :
60 : : #ifndef _STL_ITERATOR_BASE_TYPES_H
61 : : #define _STL_ITERATOR_BASE_TYPES_H 1
62 : :
63 : : #pragma GCC system_header
64 : :
65 : : #include <bits/c++config.h>
66 : :
67 : : #ifdef __GXX_EXPERIMENTAL_CXX0X__
68 : : # include <type_traits> // For _GLIBCXX_HAS_NESTED_TYPE
69 : : #endif
70 : :
71 : : namespace std _GLIBCXX_VISIBILITY(default)
72 : : {
73 : : _GLIBCXX_BEGIN_NAMESPACE_VERSION
74 : :
75 : : /**
76 : : * @defgroup iterators Iterators
77 : : * Abstractions for uniform iterating through various underlying types.
78 : : */
79 : : //@{
80 : :
81 : : /**
82 : : * @defgroup iterator_tags Iterator Tags
83 : : * These are empty types, used to distinguish different iterators. The
84 : : * distinction is not made by what they contain, but simply by what they
85 : : * are. Different underlying algorithms can then be used based on the
86 : : * different operations supported by different iterator types.
87 : : */
88 : : //@{
89 : : /// Marking input iterators.
90 : : struct input_iterator_tag { };
91 : :
92 : : /// Marking output iterators.
93 : : struct output_iterator_tag { };
94 : :
95 : : /// Forward iterators support a superset of input iterator operations.
96 : : struct forward_iterator_tag : public input_iterator_tag { };
97 : :
98 : : /// Bidirectional iterators support a superset of forward iterator
99 : : /// operations.
100 : : struct bidirectional_iterator_tag : public forward_iterator_tag { };
101 : :
102 : : /// Random-access iterators support a superset of bidirectional
103 : : /// iterator operations.
104 : : struct random_access_iterator_tag : public bidirectional_iterator_tag { };
105 : : //@}
106 : :
107 : : /**
108 : : * @brief Common %iterator class.
109 : : *
110 : : * This class does nothing but define nested typedefs. %Iterator classes
111 : : * can inherit from this class to save some work. The typedefs are then
112 : : * used in specializations and overloading.
113 : : *
114 : : * In particular, there are no default implementations of requirements
115 : : * such as @c operator++ and the like. (How could there be?)
116 : : */
117 : : template<typename _Category, typename _Tp, typename _Distance = ptrdiff_t,
118 : : typename _Pointer = _Tp*, typename _Reference = _Tp&>
119 : 1551009 : struct iterator
120 : : {
121 : : /// One of the @link iterator_tags tag types@endlink.
122 : : typedef _Category iterator_category;
123 : : /// The type "pointed to" by the iterator.
124 : : typedef _Tp value_type;
125 : : /// Distance between iterators is represented as this type.
126 : : typedef _Distance difference_type;
127 : : /// This type represents a pointer-to-value_type.
128 : : typedef _Pointer pointer;
129 : : /// This type represents a reference-to-value_type.
130 : : typedef _Reference reference;
131 : : };
132 : :
133 : : /**
134 : : * @brief Traits class for iterators.
135 : : *
136 : : * This class does nothing but define nested typedefs. The general
137 : : * version simply @a forwards the nested typedefs from the Iterator
138 : : * argument. Specialized versions for pointers and pointers-to-const
139 : : * provide tighter, more correct semantics.
140 : : */
141 : : #ifdef __GXX_EXPERIMENTAL_CXX0X__
142 : :
143 : : _GLIBCXX_HAS_NESTED_TYPE(iterator_category)
144 : :
145 : : template<typename _Iterator,
146 : : bool = __has_iterator_category<_Iterator>::value>
147 : : struct __iterator_traits { };
148 : :
149 : : template<typename _Iterator>
150 : : struct __iterator_traits<_Iterator, true>
151 : : {
152 : : typedef typename _Iterator::iterator_category iterator_category;
153 : : typedef typename _Iterator::value_type value_type;
154 : : typedef typename _Iterator::difference_type difference_type;
155 : : typedef typename _Iterator::pointer pointer;
156 : : typedef typename _Iterator::reference reference;
157 : : };
158 : :
159 : : template<typename _Iterator>
160 : : struct iterator_traits
161 : : : public __iterator_traits<_Iterator> { };
162 : : #else
163 : : template<typename _Iterator>
164 : : struct iterator_traits
165 : : {
166 : : typedef typename _Iterator::iterator_category iterator_category;
167 : : typedef typename _Iterator::value_type value_type;
168 : : typedef typename _Iterator::difference_type difference_type;
169 : : typedef typename _Iterator::pointer pointer;
170 : : typedef typename _Iterator::reference reference;
171 : : };
172 : : #endif
173 : :
174 : : /// Partial specialization for pointer types.
175 : : template<typename _Tp>
176 : : struct iterator_traits<_Tp*>
177 : : {
178 : : typedef random_access_iterator_tag iterator_category;
179 : : typedef _Tp value_type;
180 : : typedef ptrdiff_t difference_type;
181 : : typedef _Tp* pointer;
182 : : typedef _Tp& reference;
183 : : };
184 : :
185 : : /// Partial specialization for const pointer types.
186 : : template<typename _Tp>
187 : : struct iterator_traits<const _Tp*>
188 : : {
189 : : typedef random_access_iterator_tag iterator_category;
190 : : typedef _Tp value_type;
191 : : typedef ptrdiff_t difference_type;
192 : : typedef const _Tp* pointer;
193 : : typedef const _Tp& reference;
194 : : };
195 : :
196 : : /**
197 : : * This function is not a part of the C++ standard but is syntactic
198 : : * sugar for internal library use only.
199 : : */
200 : : template<typename _Iter>
201 : : inline typename iterator_traits<_Iter>::iterator_category
202 : 16626068 : __iterator_category(const _Iter&)
203 : 16626068 : { return typename iterator_traits<_Iter>::iterator_category(); }
204 : :
205 : : //@}
206 : :
207 : : // If _Iterator has a base returns it otherwise _Iterator is returned
208 : : // untouched
209 : : template<typename _Iterator, bool _HasBase>
210 : : struct _Iter_base
211 : : {
212 : : typedef _Iterator iterator_type;
213 : 1542091098 : static iterator_type _S_base(_Iterator __it)
214 : 1542091098 : { return __it; }
215 : : };
216 : :
217 : : template<typename _Iterator>
218 : : struct _Iter_base<_Iterator, true>
219 : : {
220 : : typedef typename _Iterator::iterator_type iterator_type;
221 : 24337050 : static iterator_type _S_base(_Iterator __it)
222 : 24337050 : { return __it.base(); }
223 : : };
224 : :
225 : : _GLIBCXX_END_NAMESPACE_VERSION
226 : : } // namespace
227 : :
228 : : #endif /* _STL_ITERATOR_BASE_TYPES_H */
229 : :
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