libstdc++
iterator.h
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1 // -*- C++ -*-
2 
3 // Copyright (C) 2007, 2008, 2009 Free Software Foundation, Inc.
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 terms
7 // of the GNU General Public License as published by the Free Software
8 // Foundation; either version 3, or (at your option) any later
9 // version.
10 
11 // This library is distributed in the hope that it will be useful, but
12 // WITHOUT ANY WARRANTY; without even the implied warranty of
13 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 // General Public License for more details.
15 
16 // Under Section 7 of GPL version 3, you are granted additional
17 // permissions described in the GCC Runtime Library Exception, version
18 // 3.1, as published by the Free Software Foundation.
19 
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24 
25 /** @file parallel/iterator.h
26  * @brief Helper iterator classes for the std::transform() functions.
27  * This file is a GNU parallel extension to the Standard C++ Library.
28  */
29 
30 // Written by Johannes Singler.
31 
32 #ifndef _GLIBCXX_PARALLEL_ITERATOR_H
33 #define _GLIBCXX_PARALLEL_ITERATOR_H 1
34 
36 #include <bits/stl_pair.h>
37 
38 namespace __gnu_parallel
39 {
40  /** @brief A pair of iterators. The usual iterator operations are
41  * applied to both child iterators.
42  */
43  template<typename Iterator1, typename Iterator2, typename IteratorCategory>
44  class iterator_pair : public std::pair<Iterator1, Iterator2>
45  {
46  private:
49 
50  public:
51  typedef IteratorCategory iterator_category;
52  typedef void value_type;
53 
55  typedef typename traits_type::difference_type difference_type;
56  typedef type* pointer;
57  typedef type& reference;
58 
59  iterator_pair() { }
60 
61  iterator_pair(const Iterator1& first, const Iterator2& second)
62  : base_type(first, second) { }
63 
64  // Pre-increment operator.
65  type&
66  operator++()
67  {
70  return *this;
71  }
72 
73  // Post-increment operator.
74  const type
75  operator++(int)
76  { return type(base_type::first++, base_type::second++); }
77 
78  // Pre-decrement operator.
79  type&
80  operator--()
81  {
84  return *this;
85  }
86 
87  // Post-decrement operator.
88  const type
89  operator--(int)
90  { return type(base_type::first--, base_type::second--); }
91 
92  // Type conversion.
93  operator Iterator2() const
94  { return base_type::second; }
95 
96  type&
97  operator=(const type& other)
98  {
99  base_type::first = other.first;
100  base_type::second = other.second;
101  return *this;
102  }
103 
104  type
105  operator+(difference_type delta) const
106  { return type(base_type::first + delta, base_type::second + delta); }
107 
108  difference_type
109  operator-(const type& other) const
110  { return base_type::first - other.first; }
111  };
112 
113 
114  /** @brief A triple of iterators. The usual iterator operations are
115  applied to all three child iterators.
116  */
117  template<typename Iterator1, typename Iterator2, typename Iterator3,
118  typename IteratorCategory>
120  {
121  private:
122  typedef iterator_triple<Iterator1, Iterator2, Iterator3,
123  IteratorCategory> type;
124 
125  public:
126  typedef IteratorCategory iterator_category;
127  typedef void value_type;
128  typedef typename std::iterator_traits<Iterator1>::difference_type
129  difference_type;
130  typedef type* pointer;
131  typedef type& reference;
132 
133  Iterator1 first;
134  Iterator2 second;
135  Iterator3 third;
136 
137  iterator_triple() { }
138 
139  iterator_triple(const Iterator1& _first, const Iterator2& _second,
140  const Iterator3& _third)
141  {
142  first = _first;
143  second = _second;
144  third = _third;
145  }
146 
147  // Pre-increment operator.
148  type&
149  operator++()
150  {
151  ++first;
152  ++second;
153  ++third;
154  return *this;
155  }
156 
157  // Post-increment operator.
158  const type
159  operator++(int)
160  { return type(first++, second++, third++); }
161 
162  // Pre-decrement operator.
163  type&
164  operator--()
165  {
166  --first;
167  --second;
168  --third;
169  return *this;
170  }
171 
172  // Post-decrement operator.
173  const type
174  operator--(int)
175  { return type(first--, second--, third--); }
176 
177  // Type conversion.
178  operator Iterator3() const
179  { return third; }
180 
181  type&
182  operator=(const type& other)
183  {
184  first = other.first;
185  second = other.second;
186  third = other.third;
187  return *this;
188  }
189 
190  type
191  operator+(difference_type delta) const
192  { return type(first + delta, second + delta, third + delta); }
193 
194  difference_type
195  operator-(const type& other) const
196  { return first - other.first; }
197  };
198 }
199 
200 #endif /* _GLIBCXX_PARALLEL_ITERATOR_H */