mingw/lib/gcc/mingw32/4.3.3/include/c++/parallel/find_selectors.h

   1 // -*- C++ -*-
   2
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  14 // General Public License for more details.
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  30
  31 /** @file parallel/find_selectors.h
  32  *  @brief Function objects representing different tasks to be plugged
  33  *  into the parallel find algorithm.
  34  *  This file is a GNU parallel extension to the Standard C++ Library.
  35  */
  36
  37 // Written by Felix Putze.
  38
  39 #ifndef _GLIBCXX_PARALLEL_FIND_FUNCTIONS_H
  40 #define _GLIBCXX_PARALLEL_FIND_FUNCTIONS_H 1
  41
  42 #include <parallel/tags.h>
  43 #include <parallel/basic_iterator.h>
  44 #include <bits/stl_pair.h>
  45
  46 namespace __gnu_parallel
  47 {
  48   /** @brief Base class of all __gnu_parallel::find_template selectors. */
  49   struct generic_find_selector
  50   { };
  51
  52   /**
  53    *  @brief Test predicate on a single element, used for std::find()
  54    *  and std::find_if ().
  55    */
  56   struct find_if_selector : public generic_find_selector
  57   {
  58     /** @brief Test on one position.
  59      * @param i1 Iterator on first sequence.
  60      * @param i2 Iterator on second sequence (unused).
  61      * @param pred Find predicate.
  62      */
  63     template<typename RandomAccessIterator1, typename RandomAccessIterator2,
  64              typename Pred>
  65       bool
  66       operator()(RandomAccessIterator1 i1, RandomAccessIterator2 i2, Pred pred)
  67       { return pred(*i1); }
  68
  69     /** @brief Corresponding sequential algorithm on a sequence.
  70      *  @param begin1 Begin iterator of first sequence.
  71      *  @param end1 End iterator of first sequence.
  72      *  @param begin2 Begin iterator of second sequence.
  73      *  @param pred Find predicate.
  74      */
  75     template<typename RandomAccessIterator1, typename RandomAccessIterator2,
  76              typename Pred>
  77       std::pair<RandomAccessIterator1, RandomAccessIterator2>
  78       sequential_algorithm(RandomAccessIterator1 begin1,
  79                            RandomAccessIterator1 end1,
  80                            RandomAccessIterator2 begin2, Pred pred)
  81       { return std::make_pair(find_if(begin1, end1, pred,
  82                                       sequential_tag()), begin2); }
  83   };
  84
  85   /** @brief Test predicate on two adjacent elements. */
  86   struct adjacent_find_selector : public generic_find_selector
  87   {
  88     /** @brief Test on one position.
  89      *  @param i1 Iterator on first sequence.
  90      *  @param i2 Iterator on second sequence (unused).
  91      *  @param pred Find predicate.
  92      */
  93     template<typename RandomAccessIterator1, typename RandomAccessIterator2,
  94              typename Pred>
  95       bool
  96       operator()(RandomAccessIterator1 i1, RandomAccessIterator2 i2, Pred pred)
  97       {
  98         // Passed end iterator is one short.
  99         return pred(*i1, *(i1 + 1));
 100       }
 101
 102     /** @brief Corresponding sequential algorithm on a sequence.
 103      *  @param begin1 Begin iterator of first sequence.
 104      *  @param end1 End iterator of first sequence.
 105      *  @param begin2 Begin iterator of second sequence.
 106      *  @param pred Find predicate.
 107      */
 108     template<typename RandomAccessIterator1, typename RandomAccessIterator2,
 109              typename Pred>
 110       std::pair<RandomAccessIterator1, RandomAccessIterator2>
 111       sequential_algorithm(RandomAccessIterator1 begin1,
 112                            RandomAccessIterator1 end1,
 113                            RandomAccessIterator2 begin2, Pred pred)
 114       {
 115         // Passed end iterator is one short.
 116         RandomAccessIterator1 spot = adjacent_find(begin1, end1 + 1,
 117                                                    pred, sequential_tag());
 118         if (spot == (end1 + 1))
 119           spot = end1;
 120         return std::make_pair(spot, begin2);
 121       }
 122   };
 123
 124   /** @brief Test inverted predicate on a single element. */
 125   struct mismatch_selector : public generic_find_selector
 126   {
 127     /**
 128      *  @brief Test on one position.
 129      *  @param i1 Iterator on first sequence.
 130      *  @param i2 Iterator on second sequence (unused).
 131      *  @param pred Find predicate.
 132      */
 133     template<typename RandomAccessIterator1, typename RandomAccessIterator2,
 134              typename Pred>
 135       bool
 136       operator()(RandomAccessIterator1 i1, RandomAccessIterator2 i2, Pred pred)
 137       { return !pred(*i1, *i2); }
 138
 139     /**
 140      *  @brief Corresponding sequential algorithm on a sequence.
 141      *  @param begin1 Begin iterator of first sequence.
 142      *  @param end1 End iterator of first sequence.
 143      *  @param begin2 Begin iterator of second sequence.
 144      *  @param pred Find predicate.
 145      */
 146     template<typename RandomAccessIterator1, typename RandomAccessIterator2,
 147              typename Pred>
 148       std::pair<RandomAccessIterator1, RandomAccessIterator2>
 149       sequential_algorithm(RandomAccessIterator1 begin1,
 150                            RandomAccessIterator1 end1,
 151                            RandomAccessIterator2 begin2, Pred pred)
 152       { return mismatch(begin1, end1, begin2, pred, sequential_tag()); }
 153   };
 154
 155
 156   /** @brief Test predicate on several elements. */
 157   template<typename ForwardIterator>
 158   struct find_first_of_selector : public generic_find_selector
 159   {
 160     ForwardIterator begin;
 161     ForwardIterator end;
 162
 163     explicit find_first_of_selector(ForwardIterator begin, ForwardIterator end)
 164     : begin(begin), end(end) { }
 165
 166     /** @brief Test on one position.
 167      *  @param i1 Iterator on first sequence.
 168      *  @param i2 Iterator on second sequence (unused).
 169      *  @param pred Find predicate. */
 170     template<typename RandomAccessIterator1, typename RandomAccessIterator2,
 171              typename Pred>
 172       bool
 173       operator()(RandomAccessIterator1 i1, RandomAccessIterator2 i2, Pred pred)
 174       {
 175         for (ForwardIterator pos_in_candidates = begin;
 176              pos_in_candidates != end; ++pos_in_candidates)
 177           if (pred(*i1, *pos_in_candidates))
 178             return true;
 179         return false;
 180       }
 181
 182     /** @brief Corresponding sequential algorithm on a sequence.
 183      *  @param begin1 Begin iterator of first sequence.
 184      *  @param end1 End iterator of first sequence.
 185      *  @param begin2 Begin iterator of second sequence.
 186      *  @param pred Find predicate. */
 187     template<typename RandomAccessIterator1, typename RandomAccessIterator2,
 188              typename Pred>
 189       std::pair<RandomAccessIterator1, RandomAccessIterator2>
 190       sequential_algorithm(RandomAccessIterator1 begin1,
 191                            RandomAccessIterator1 end1,
 192                            RandomAccessIterator2 begin2, Pred pred)
 193       { return std::make_pair(find_first_of(begin1, end1, begin, end, pred,
 194                                             sequential_tag()), begin2); }
 195   };
 196 }
 197
 198 #endif