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
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
|
// Boost.TypeErasure library
//
// Copyright 2011 Steven Watanabe
//
// Distributed under the Boost Software License Version 1.0. (See
// accompanying file LICENSE_1_0.txt or copy at
// http://www.boost.org/LICENSE_1_0.txt)
//
// $Id$
#ifndef BOOST_TYPE_ERASURE_ITERATOR_HPP_INCLUDED
#define BOOST_TYPE_ERASURE_ITERATOR_HPP_INCLUDED
#include <iterator>
#include <boost/mpl/vector.hpp>
#include <boost/mpl/if.hpp>
#include <boost/iterator/iterator_adaptor.hpp>
#include <boost/iterator/iterator_categories.hpp>
#include <boost/type_traits/remove_const.hpp>
#include <boost/type_traits/remove_reference.hpp>
#include <boost/type_erasure/operators.hpp>
#include <boost/type_erasure/builtin.hpp>
#include <boost/type_erasure/deduced.hpp>
#include <boost/type_erasure/is_placeholder.hpp>
namespace boost {
namespace type_erasure {
/** INTERNAL ONLY */
template<>
struct is_placeholder< ::boost::use_default> : ::boost::mpl::false_ {};
namespace detail {
template<class T>
struct iterator_value_type_impl
{
typedef typename ::std::iterator_traits<T>::value_type type;
};
}
/** INTERNAL ONLY */
template<class T>
struct iterator_value_type
{
typedef typename ::boost::mpl::eval_if<
::boost::type_erasure::is_placeholder<T>,
::boost::mpl::identity<void>,
::boost::type_erasure::detail::iterator_value_type_impl<T>
>::type type;
};
template<
class Traversal,
class T = _self,
class Reference = ::boost::use_default,
class DifferenceType = ::std::ptrdiff_t,
class ValueType = typename deduced<iterator_value_type<T> >::type
>
struct iterator;
#ifdef BOOST_TYPE_ERASURE_DOXYGEN
/**
* The @ref iterator concept can be used for any iterator category.
*
* \tparam Traversal must be one of @c boost::incrementable_traversal_tag,
* @c boost::single_pass_traversal_tag, @c boost::forward_traversal_tag,
* @c boost::bidirectional_traversal_tag, and @c boost::random_access_traversal_tag.
* \tparam T The placeholder representing the iterator.
* \tparam Reference The reference type. If it is boost::use_default, then
* reference will be value_type&.
* \tparam DifferenceType The iterator's difference type.
*
* The value_type of the iterator is deduced. To force it to be
* a specific type, use the @ref same_type concept.
*
* Example:
*
* \code
* mpl::vector<
* iterator<boost::forward_traversal_tag>,
* same_type<iterator<boost::forward_traversal_tag>::value_type, int> > int_it;
* \endcode
*/
template<
class Traversal,
class T = _self,
class Reference = boost::use_default,
class DifferenceType = std::ptrdiff_t
>
struct iterator
{
typedef detail::unspecified value_type;
typedef Reference reference;
typedef DifferenceType difference_type;
};
template<
class T = _self,
class Reference = boost::use_default,
class DifferenceType = std::ptrdiff_t
>
struct forward_iterator :
iterator<boost::forward_traversal_tag, T, Reference, DifferenceType>
{};
template<
class T = _self,
class Reference = boost::use_default,
class DifferenceType = std::ptrdiff_t
>
struct bidirectional_iterator :
iterator<boost::bidirectional_traversal_tag, T, Reference, DifferenceType>
{};
template<
class T = _self,
class Reference = boost::use_default,
class DifferenceType = std::ptrdiff_t
>
struct random_access_iterator :
iterator<boost::random_access_traversal_tag, T, Reference, DifferenceType>
{
};
#else
/** INTERNAL ONLY */
template<class Reference, class ValueType>
struct iterator_reference
{
typedef Reference type;
};
/** INTERNAL ONLY */
template<class ValueType>
struct iterator_reference< ::boost::use_default, ValueType>
{
typedef ValueType& type;
};
template<class T, class Reference, class DifferenceType, class ValueType>
struct iterator< ::boost::no_traversal_tag, T, Reference, DifferenceType, ValueType> :
boost::mpl::vector<
copy_constructible<T>,
constructible<T()>,
equality_comparable<T>,
dereferenceable<typename iterator_reference<Reference, ValueType>::type, T>,
assignable<T>
>
{
typedef ValueType value_type;
typedef typename iterator_reference<Reference, ValueType>::type reference;
typedef DifferenceType difference_type;
};
template<class T, class Reference, class DifferenceType, class ValueType>
struct iterator< ::boost::incrementable_traversal_tag, T, Reference, DifferenceType, ValueType> :
boost::mpl::vector<
iterator< ::boost::no_traversal_tag, T, Reference, DifferenceType>,
incrementable<T>
>
{
typedef ValueType value_type;
typedef typename iterator_reference<Reference, ValueType>::type reference;
typedef DifferenceType difference_type;
};
template<class T, class Reference, class DifferenceType, class ValueType>
struct iterator< ::boost::single_pass_traversal_tag, T, Reference, DifferenceType, ValueType> :
iterator< ::boost::incrementable_traversal_tag, T, Reference, DifferenceType, ValueType>
{};
template<class T, class Reference, class DifferenceType, class ValueType>
struct iterator< ::boost::forward_traversal_tag, T, Reference, DifferenceType, ValueType> :
iterator< ::boost::incrementable_traversal_tag, T, Reference, DifferenceType, ValueType>
{};
template<class T, class Reference, class DifferenceType, class ValueType>
struct iterator< ::boost::bidirectional_traversal_tag, T, Reference, DifferenceType, ValueType> :
boost::mpl::vector<
iterator< ::boost::incrementable_traversal_tag, T, Reference, DifferenceType, ValueType>,
decrementable<T>
>
{
typedef ValueType value_type;
typedef typename iterator_reference<Reference, ValueType>::type reference;
typedef DifferenceType difference_type;
};
template<class T, class Reference, class DifferenceType, class ValueType>
struct iterator< ::boost::random_access_traversal_tag, T, Reference, DifferenceType, ValueType> :
boost::mpl::vector<
iterator< ::boost::bidirectional_traversal_tag, T, Reference, DifferenceType, ValueType>,
addable<T, DifferenceType, T>,
addable<DifferenceType, T, T>,
subtractable<T, DifferenceType, T>,
subtractable<T, T, DifferenceType>,
subscriptable<typename iterator_reference<Reference, ValueType>::type, T, DifferenceType>
>
{
typedef ValueType value_type;
typedef typename iterator_reference<Reference, ValueType>::type reference;
typedef DifferenceType difference_type;
};
template<
class T = _self,
class Reference = ::boost::use_default,
class DifferenceType = ::std::ptrdiff_t,
class ValueType = typename deduced<iterator_value_type<T> >::type
>
struct forward_iterator :
iterator< ::boost::forward_traversal_tag, T, Reference, DifferenceType, ValueType>
{};
template<
class T = _self,
class Reference = ::boost::use_default,
class DifferenceType = ::std::ptrdiff_t,
class ValueType = typename deduced<iterator_value_type<T> >::type
>
struct bidirectional_iterator :
iterator< ::boost::bidirectional_traversal_tag, T, Reference, DifferenceType, ValueType>
{};
template<
class T = _self,
class Reference = ::boost::use_default,
class DifferenceType = ::std::ptrdiff_t,
class ValueType = typename deduced<iterator_value_type<T> >::type
>
struct random_access_iterator :
iterator< ::boost::random_access_traversal_tag, T, Reference, DifferenceType, ValueType>
{
};
#endif
/// \cond show_operators
template<class T, class Reference, class DifferenceType, class ValueType, class Base>
struct concept_interface<iterator< ::boost::no_traversal_tag, T, Reference, DifferenceType, ValueType>, Base, T>
: Base
{
typedef typename rebind_any<Base, ValueType>::type value_type;
typedef typename rebind_any<
Base,
typename iterator_reference<Reference, ValueType>::type
>::type reference;
typedef DifferenceType difference_type;
typedef typename ::boost::mpl::if_< ::boost::is_reference<reference>,
typename ::boost::remove_reference<reference>::type*,
value_type*
>::type pointer;
};
template<class T, class Reference, class DifferenceType, class ValueType, class Base>
struct concept_interface<iterator< ::boost::forward_traversal_tag, T, Reference, DifferenceType, ValueType>, Base, T>
: Base
{
typedef std::forward_iterator_tag iterator_category;
};
template<class T, class Reference, class DifferenceType, class ValueType, class Base>
struct concept_interface<forward_iterator<T, Reference, DifferenceType, ValueType>, Base, T>
: Base
{
typedef std::forward_iterator_tag iterator_category;
};
template<class T, class Reference, class DifferenceType, class ValueType, class Base>
struct concept_interface<iterator< ::boost::bidirectional_traversal_tag, T, Reference, DifferenceType, ValueType>, Base, T>
: Base
{
typedef std::bidirectional_iterator_tag iterator_category;
};
template<class T, class Reference, class DifferenceType, class ValueType, class Base>
struct concept_interface<bidirectional_iterator<T, Reference, DifferenceType, ValueType>, Base, T>
: Base
{
typedef std::bidirectional_iterator_tag iterator_category;
};
template<class T, class Reference, class DifferenceType, class ValueType, class Base>
struct concept_interface<iterator< ::boost::random_access_traversal_tag, T, Reference, DifferenceType, ValueType>, Base, T>
: Base
{
typedef std::random_access_iterator_tag iterator_category;
};
template<class T, class Reference, class DifferenceType, class ValueType, class Base>
struct concept_interface<random_access_iterator<T, Reference, DifferenceType, ValueType>, Base, T>
: Base
{
typedef std::random_access_iterator_tag iterator_category;
};
/// \endcond
}
}
#endif
|
