1 // -*- C++ -*-
2 
3 // Copyright (C) 2007-2019 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 
20 // You should have received a copy of the GNU General Public License and
21 // a copy of the GCC Runtime Library Exception along with this program;
22 // see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
23 // <http://www.gnu.org/licenses/>.
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 
35 #include <parallel/basic_iterator.h>
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,
44            typename _IteratorCategory>
45     class _IteratorPair : public std::pair<_Iterator1, _Iterator2>
46     {
47     private:
48       typedef std::pair<_Iterator1, _Iterator2> _Base;
49 
50     public:
51       typedef _IteratorCategory iterator_category;
52       typedef void value_type;
53 
54       typedef std::iterator_traits<_Iterator1> _TraitsType;
55       typedef typename _TraitsType::difference_type difference_type;
56       typedef _IteratorPair* pointer;
57       typedef _IteratorPair& reference;
58 
_IteratorPair()59       _IteratorPair() { }
60 
_IteratorPair(const _Iterator1 & __first,const _Iterator2 & __second)61       _IteratorPair(const _Iterator1& __first, const _Iterator2& __second)
62       : _Base(__first, __second) { }
63 
64       // Pre-increment operator.
65       _IteratorPair&
66       operator++()
67       {
68         ++_Base::first;
69         ++_Base::second;
70         return *this;
71       }
72 
73       // Post-increment operator.
74       const _IteratorPair
75       operator++(int)
76       { return _IteratorPair(_Base::first++, _Base::second++); }
77 
78       // Pre-decrement operator.
79       _IteratorPair&
80       operator--()
81       {
82         --_Base::first;
83         --_Base::second;
84         return *this;
85       }
86 
87       // Post-decrement operator.
88       const _IteratorPair
89       operator--(int)
90       { return _IteratorPair(_Base::first--, _Base::second--); }
91 
92       // Type conversion.
_Iterator2()93       operator _Iterator2() const
94       { return _Base::second; }
95 
96       _IteratorPair&
97       operator=(const _IteratorPair& __other)
98       {
99         _Base::first = __other.first;
100         _Base::second = __other.second;
101         return *this;
102       }
103 
104       _IteratorPair
105       operator+(difference_type __delta) const
106       { return _IteratorPair(_Base::first + __delta, _Base::second + __delta);
107         }
108 
109       difference_type
110       operator-(const _IteratorPair& __other) const
111       { return _Base::first - __other.first; }
112   };
113 
114 
115   /** @brief A triple of iterators. The usual iterator operations are
116       applied to all three child iterators.
117    */
118   template<typename _Iterator1, typename _Iterator2, typename _Iterator3,
119            typename _IteratorCategory>
120     class _IteratorTriple
121     {
122     public:
123       typedef _IteratorCategory iterator_category;
124       typedef void value_type;
125       typedef typename std::iterator_traits<_Iterator1>::difference_type
126                                                             difference_type;
127       typedef _IteratorTriple* pointer;
128       typedef _IteratorTriple& reference;
129 
130       _Iterator1 _M_first;
131       _Iterator2 _M_second;
132       _Iterator3 _M_third;
133 
_IteratorTriple()134       _IteratorTriple() { }
135 
_IteratorTriple(const _Iterator1 & __first,const _Iterator2 & __second,const _Iterator3 & __third)136       _IteratorTriple(const _Iterator1& __first, const _Iterator2& __second,
137                       const _Iterator3& __third)
138       {
139         _M_first = __first;
140         _M_second = __second;
141         _M_third = __third;
142       }
143 
144       // Pre-increment operator.
145       _IteratorTriple&
146       operator++()
147       {
148         ++_M_first;
149         ++_M_second;
150         ++_M_third;
151         return *this;
152       }
153 
154       // Post-increment operator.
155       const _IteratorTriple
156       operator++(int)
157       { return _IteratorTriple(_M_first++, _M_second++, _M_third++); }
158 
159       // Pre-decrement operator.
160       _IteratorTriple&
161       operator--()
162       {
163         --_M_first;
164         --_M_second;
165         --_M_third;
166         return *this;
167       }
168 
169       // Post-decrement operator.
170       const _IteratorTriple
171       operator--(int)
172       { return _IteratorTriple(_M_first--, _M_second--, _M_third--); }
173 
174       // Type conversion.
_Iterator3()175       operator _Iterator3() const
176       { return _M_third; }
177 
178       _IteratorTriple&
179       operator=(const _IteratorTriple& __other)
180       {
181         _M_first = __other._M_first;
182         _M_second = __other._M_second;
183         _M_third = __other._M_third;
184         return *this;
185       }
186 
187       _IteratorTriple
188       operator+(difference_type __delta) const
189       { return _IteratorTriple(_M_first + __delta, _M_second + __delta,
190                                _M_third + __delta); }
191 
192       difference_type
193       operator-(const _IteratorTriple& __other) const
194       { return _M_first - __other._M_first; }
195   };
196 }
197 
198 #endif /* _GLIBCXX_PARALLEL_ITERATOR_H */
199