summaryrefslogtreecommitdiff
path: root/libcult/cult/containers/iterator.hxx
blob: 132043b00b1919917fbb34da154d7606f1f93f2e (plain)
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
// file      : cult/containers/iterator.hxx
// author    : Boris Kolpackov <boris@kolpackov.net>
// copyright : Copyright (c) 2005-2010 Boris Kolpackov
// license   : GNU GPL v2 + exceptions; see accompanying LICENSE file

#ifndef CULT_CONTAINERS_ITERATOR_HXX
#define CULT_CONTAINERS_ITERATOR_HXX

#include <cult/types.hxx>

#include <iterator>

namespace Cult
{
  namespace Containers
  {
    template <typename I>
    class IteratorAdapter
    {
    public:
      typedef typename std::iterator_traits<I>::value_type Value;
      typedef typename std::iterator_traits<I>::difference_type Difference;
      typedef typename std::iterator_traits<I>::pointer Pointer;
      typedef typename std::iterator_traits<I>::reference Reference;
      typedef typename std::iterator_traits<I>::iterator_category Category;

      // For compatibility with std::iterator_traits
      //
    public:
      typedef Value value_type;
      typedef Reference reference;
      typedef Pointer pointer;
      typedef Category iterator_category;
      typedef Difference difference_type;

    public:
      IteratorAdapter ()
          : i_ () // i_ can be of a pointer type.
      {
      }

      explicit
      IteratorAdapter (I const& i)
          : i_ (i)
      {
      }

      template <typename J>
      IteratorAdapter (IteratorAdapter<J> const& j)
          : i_ (j.i_)
      {
      }
    public:
      // Forward iterator requirements.
      //
      Reference
      operator* () const
      {
        return *i_;
      }

      Pointer
      operator-> () const
      {
        return &(*i_);
      }

      IteratorAdapter&
      operator++ ()
      {
        ++i_;
        return *this;
      }

      IteratorAdapter
      operator++ (Int)
      {
        return IteratorAdapter (i_++);
      }

    public:
      // Bidirectional iterator requirements.
      //
      IteratorAdapter&
      operator-- ()
      {
        --i_;
        return *this;
      }

      IteratorAdapter
      operator-- (Int)
      {
        return IteratorAdapter (i_--);
      }

    public:
      // Random access iterator requirements.
      //
      Reference
      operator[] (Difference n) const
      {
        return i_[n];
      }

      IteratorAdapter
      operator+ (Difference n) const
      {
        return IteratorAdapter (i_ + n);
      }

      IteratorAdapter&
      operator+= (Difference n)
      {
        i_ += n;
        return *this;
      }

      IteratorAdapter
      operator- (Difference n) const
      {
        return IteratorAdapter (i_ - n);
      }

      IteratorAdapter&
      operator-= (Difference n)
      {
        i_ += n;
        return *this;
      }

    public:
      I const&
      base () const
      {
        return i_;
      }

      // @@ This is needed so that call to functions such as erase()
      // be possible without writing a wrapper. This should be a temporary
      // measure.

      operator I& ()
      {
        return i_;
      }

      operator I const& () const
      {
        return i_;
      }

    private:
      template<typename>
      friend class IteratorAdapter;

      I i_;
    };

    // Note: We use different types for left- and right-hand-side
    // arguments to allow comparison between iterator and const_iterator.
    //

    // Forward iterator requirements.
    //
    template <typename I, typename J>
    inline Boolean
    operator== (IteratorAdapter<I> const& i, IteratorAdapter<J> const& j)
    {
      return i.base () == j.base ();
    }

    template <typename I, typename J>
    inline Boolean
    operator!= (IteratorAdapter<I> const& i, IteratorAdapter<J> const& j)
    {
      return i.base () != j.base ();
    }

    // Random access iterator requirements
    //
    template <typename I, typename J>
    inline Boolean
    operator< (IteratorAdapter<I> const& i, IteratorAdapter<J> const& j)
    {
      return i.base() < j.base();
    }

    template <typename I, typename J>
    inline Boolean
    operator> (IteratorAdapter<I> const& i, IteratorAdapter<J> const& j)
    {
      return i.base() > j.base();
    }

    template <typename I, typename J>
    inline Boolean
    operator<= (IteratorAdapter<I> const& i, IteratorAdapter<J> const& j)
    {
      return i.base() <= j.base();
    }

    template <typename I, typename J>
    inline Boolean
    operator>= (IteratorAdapter<I> const& i, IteratorAdapter<J> const& j)
    {
      return i.base() >= j.base();
    }

    template <typename I, typename J>
    inline typename IteratorAdapter<I>::Difference
    operator- (IteratorAdapter<I> const& i, IteratorAdapter<J> const& j)
    {
      return i.base () - j.base ();
    }

    template <typename I>
    IteratorAdapter<I>
    operator+ (typename IteratorAdapter<I>::Difference n,
               IteratorAdapter<I> const& x)
    {
      return x + n;
    }
  }
}

#endif  // CULT_CONTAINERS_ITERATOR_HXX