1 // -*- C++ -*-
2 
3 // Copyright (C) 2007-2017 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
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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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22 // see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
23 // <http://www.gnu.org/licenses/>.
24 
25 /** @file parallel/find_selectors.h
26  *  @brief _Function objects representing different tasks to be plugged
27  *  into the parallel find algorithm.
28  *  This file is a GNU parallel extension to the Standard C++ Library.
29  */
30 
31 // Written by Felix Putze.
32 
33 #ifndef _GLIBCXX_PARALLEL_FIND_SELECTORS_H
34 #define _GLIBCXX_PARALLEL_FIND_SELECTORS_H 1
35 
36 #include <parallel/tags.h>
37 #include <parallel/basic_iterator.h>
38 #include <bits/stl_pair.h>
39 
40 namespace __gnu_parallel
41 {
42   /** @brief Base class of all __gnu_parallel::__find_template selectors. */
43   struct __generic_find_selector
44   { };
45 
46   /**
47    *  @brief Test predicate on a single element, used for std::find()
48    *  and std::find_if ().
49    */
50   struct __find_if_selector : public __generic_find_selector
51   {
52     /** @brief Test on one position.
53      * @param __i1 _Iterator on first sequence.
54      * @param __i2 _Iterator on second sequence (unused).
55      * @param __pred Find predicate.
56      */
57     template<typename _RAIter1, typename _RAIter2,
58              typename _Pred>
59       bool
operator__find_if_selector60       operator()(_RAIter1 __i1, _RAIter2 __i2, _Pred __pred)
61       { return __pred(*__i1); }
62 
63     /** @brief Corresponding sequential algorithm on a sequence.
64      *  @param __begin1 Begin iterator of first sequence.
65      *  @param __end1 End iterator of first sequence.
66      *  @param __begin2 Begin iterator of second sequence.
67      *  @param __pred Find predicate.
68      */
69     template<typename _RAIter1, typename _RAIter2,
70              typename _Pred>
71       std::pair<_RAIter1, _RAIter2>
_M_sequential_algorithm__find_if_selector72       _M_sequential_algorithm(_RAIter1 __begin1,
73                            _RAIter1 __end1,
74                            _RAIter2 __begin2, _Pred __pred)
75       { return std::make_pair(find_if(__begin1, __end1, __pred,
76                                       sequential_tag()), __begin2); }
77   };
78 
79   /** @brief Test predicate on two adjacent elements. */
80   struct __adjacent_find_selector : public __generic_find_selector
81   {
82     /** @brief Test on one position.
83      *  @param __i1 _Iterator on first sequence.
84      *  @param __i2 _Iterator on second sequence (unused).
85      *  @param __pred Find predicate.
86      */
87     template<typename _RAIter1, typename _RAIter2,
88              typename _Pred>
89       bool
operator__adjacent_find_selector90       operator()(_RAIter1 __i1, _RAIter2 __i2, _Pred __pred)
91       {
92         // Passed end iterator is one short.
93         return __pred(*__i1, *(__i1 + 1));
94       }
95 
96     /** @brief Corresponding sequential algorithm on a sequence.
97      *  @param __begin1 Begin iterator of first sequence.
98      *  @param __end1 End iterator of first sequence.
99      *  @param __begin2 Begin iterator of second sequence.
100      *  @param __pred Find predicate.
101      */
102     template<typename _RAIter1, typename _RAIter2,
103              typename _Pred>
104       std::pair<_RAIter1, _RAIter2>
_M_sequential_algorithm__adjacent_find_selector105       _M_sequential_algorithm(_RAIter1 __begin1,
106 			      _RAIter1 __end1,
107 			      _RAIter2 __begin2, _Pred __pred)
108       {
109         // Passed end iterator is one short.
110         _RAIter1 __spot = adjacent_find(__begin1, __end1 + 1,
111 					__pred, sequential_tag());
112         if (__spot == (__end1 + 1))
113           __spot = __end1;
114         return std::make_pair(__spot, __begin2);
115       }
116   };
117 
118   /** @brief Test inverted predicate on a single element. */
119   struct __mismatch_selector : public __generic_find_selector
120   {
121     /**
122      *  @brief Test on one position.
123      *  @param __i1 _Iterator on first sequence.
124      *  @param __i2 _Iterator on second sequence (unused).
125      *  @param __pred Find predicate.
126      */
127     template<typename _RAIter1, typename _RAIter2,
128              typename _Pred>
129       bool
operator__mismatch_selector130       operator()(_RAIter1 __i1, _RAIter2 __i2, _Pred __pred)
131       { return !__pred(*__i1, *__i2); }
132 
133     /**
134      *  @brief Corresponding sequential algorithm on a sequence.
135      *  @param __begin1 Begin iterator of first sequence.
136      *  @param __end1 End iterator of first sequence.
137      *  @param __begin2 Begin iterator of second sequence.
138      *  @param __pred Find predicate.
139      */
140     template<typename _RAIter1, typename _RAIter2,
141              typename _Pred>
142       std::pair<_RAIter1, _RAIter2>
_M_sequential_algorithm__mismatch_selector143       _M_sequential_algorithm(_RAIter1 __begin1,
144 			      _RAIter1 __end1,
145 			      _RAIter2 __begin2, _Pred __pred)
146       { return mismatch(__begin1, __end1, __begin2,
147 			__pred, sequential_tag()); }
148   };
149 
150 
151   /** @brief Test predicate on several elements. */
152   template<typename _FIterator>
153     struct __find_first_of_selector : public __generic_find_selector
154     {
155       _FIterator _M_begin;
156       _FIterator _M_end;
157 
__find_first_of_selector__find_first_of_selector158       explicit __find_first_of_selector(_FIterator __begin,
159 					_FIterator __end)
160       : _M_begin(__begin), _M_end(__end) { }
161 
162       /** @brief Test on one position.
163        *  @param __i1 _Iterator on first sequence.
164        *  @param __i2 _Iterator on second sequence (unused).
165        *  @param __pred Find predicate. */
166       template<typename _RAIter1, typename _RAIter2,
167 	       typename _Pred>
168         bool
operator__find_first_of_selector169         operator()(_RAIter1 __i1, _RAIter2 __i2, _Pred __pred)
170         {
171 	  for (_FIterator __pos_in_candidates = _M_begin;
172 	       __pos_in_candidates != _M_end; ++__pos_in_candidates)
173 	    if (__pred(*__i1, *__pos_in_candidates))
174 	      return true;
175 	  return false;
176 	}
177 
178       /** @brief Corresponding sequential algorithm on a sequence.
179        *  @param __begin1 Begin iterator of first sequence.
180        *  @param __end1 End iterator of first sequence.
181        *  @param __begin2 Begin iterator of second sequence.
182        *  @param __pred Find predicate. */
183       template<typename _RAIter1, typename _RAIter2,
184 	       typename _Pred>
185         std::pair<_RAIter1, _RAIter2>
_M_sequential_algorithm__find_first_of_selector186         _M_sequential_algorithm(_RAIter1 __begin1,
187 				_RAIter1 __end1,
188 				_RAIter2 __begin2, _Pred __pred)
189         {
190 	  return std::make_pair(find_first_of(__begin1, __end1,
191 					      _M_begin, _M_end, __pred,
192 					      sequential_tag()), __begin2);
193 	}
194      };
195 }
196 
197 #endif /* _GLIBCXX_PARALLEL_FIND_SELECTORS_H */
198