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// -*- C++ -*-
// Copyright (C) 2007, 2008, 2009 Free Software Foundation, Inc.
//
// This file is part of the GNU ISO C++ Library. This library is free
// software; you can redistribute it and/or modify it under the terms
// of the GNU General Public License as published by the Free Software
// Foundation; either version 3, or (at your option) any later
// version.
// This library is distributed in the hope that it will be useful, but
// WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
// General Public License for more details.
// Under Section 7 of GPL version 3, you are granted additional
// permissions described in the GCC Runtime Library Exception, version
// 3.1, as published by the Free Software Foundation.
// You should have received a copy of the GNU General Public License and
// a copy of the GCC Runtime Library Exception along with this program;
// see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
// <http://www.gnu.org/licenses/>.
/** @file parallel/find_selectors.h
* @brief Function objects representing different tasks to be plugged
* into the parallel find algorithm.
* This file is a GNU parallel extension to the Standard C++ Library.
*/
// Written by Felix Putze.
#ifndef _GLIBCXX_PARALLEL_FIND_SELECTORS_H
#define _GLIBCXX_PARALLEL_FIND_SELECTORS_H 1
#include <parallel/tags.h>
#include <parallel/basic_iterator.h>
#include <bits/stl_pair.h>
namespace __gnu_parallel
{
/** @brief Base class of all __gnu_parallel::find_template selectors. */
struct generic_find_selector
{ };
/**
* @brief Test predicate on a single element, used for std::find()
* and std::find_if ().
*/
struct find_if_selector : public generic_find_selector
{
/** @brief Test on one position.
* @param i1 Iterator on first sequence.
* @param i2 Iterator on second sequence (unused).
* @param pred Find predicate.
*/
template<typename RandomAccessIterator1, typename RandomAccessIterator2,
typename Pred>
bool
operator()(RandomAccessIterator1 i1, RandomAccessIterator2 i2, Pred pred)
{ return pred(*i1); }
/** @brief Corresponding sequential algorithm on a sequence.
* @param begin1 Begin iterator of first sequence.
* @param end1 End iterator of first sequence.
* @param begin2 Begin iterator of second sequence.
* @param pred Find predicate.
*/
template<typename RandomAccessIterator1, typename RandomAccessIterator2,
typename Pred>
std::pair<RandomAccessIterator1, RandomAccessIterator2>
sequential_algorithm(RandomAccessIterator1 begin1,
RandomAccessIterator1 end1,
RandomAccessIterator2 begin2, Pred pred)
{ return std::make_pair(find_if(begin1, end1, pred,
sequential_tag()), begin2); }
};
/** @brief Test predicate on two adjacent elements. */
struct adjacent_find_selector : public generic_find_selector
{
/** @brief Test on one position.
* @param i1 Iterator on first sequence.
* @param i2 Iterator on second sequence (unused).
* @param pred Find predicate.
*/
template<typename RandomAccessIterator1, typename RandomAccessIterator2,
typename Pred>
bool
operator()(RandomAccessIterator1 i1, RandomAccessIterator2 i2, Pred pred)
{
// Passed end iterator is one short.
return pred(*i1, *(i1 + 1));
}
/** @brief Corresponding sequential algorithm on a sequence.
* @param begin1 Begin iterator of first sequence.
* @param end1 End iterator of first sequence.
* @param begin2 Begin iterator of second sequence.
* @param pred Find predicate.
*/
template<typename RandomAccessIterator1, typename RandomAccessIterator2,
typename Pred>
std::pair<RandomAccessIterator1, RandomAccessIterator2>
sequential_algorithm(RandomAccessIterator1 begin1,
RandomAccessIterator1 end1,
RandomAccessIterator2 begin2, Pred pred)
{
// Passed end iterator is one short.
RandomAccessIterator1 spot = adjacent_find(begin1, end1 + 1,
pred, sequential_tag());
if (spot == (end1 + 1))
spot = end1;
return std::make_pair(spot, begin2);
}
};
/** @brief Test inverted predicate on a single element. */
struct mismatch_selector : public generic_find_selector
{
/**
* @brief Test on one position.
* @param i1 Iterator on first sequence.
* @param i2 Iterator on second sequence (unused).
* @param pred Find predicate.
*/
template<typename RandomAccessIterator1, typename RandomAccessIterator2,
typename Pred>
bool
operator()(RandomAccessIterator1 i1, RandomAccessIterator2 i2, Pred pred)
{ return !pred(*i1, *i2); }
/**
* @brief Corresponding sequential algorithm on a sequence.
* @param begin1 Begin iterator of first sequence.
* @param end1 End iterator of first sequence.
* @param begin2 Begin iterator of second sequence.
* @param pred Find predicate.
*/
template<typename RandomAccessIterator1, typename RandomAccessIterator2,
typename Pred>
std::pair<RandomAccessIterator1, RandomAccessIterator2>
sequential_algorithm(RandomAccessIterator1 begin1,
RandomAccessIterator1 end1,
RandomAccessIterator2 begin2, Pred pred)
{ return mismatch(begin1, end1, begin2, pred, sequential_tag()); }
};
/** @brief Test predicate on several elements. */
template<typename ForwardIterator>
struct find_first_of_selector : public generic_find_selector
{
ForwardIterator begin;
ForwardIterator end;
explicit find_first_of_selector(ForwardIterator begin, ForwardIterator end)
: begin(begin), end(end) { }
/** @brief Test on one position.
* @param i1 Iterator on first sequence.
* @param i2 Iterator on second sequence (unused).
* @param pred Find predicate. */
template<typename RandomAccessIterator1, typename RandomAccessIterator2,
typename Pred>
bool
operator()(RandomAccessIterator1 i1, RandomAccessIterator2 i2, Pred pred)
{
for (ForwardIterator pos_in_candidates = begin;
pos_in_candidates != end; ++pos_in_candidates)
if (pred(*i1, *pos_in_candidates))
return true;
return false;
}
/** @brief Corresponding sequential algorithm on a sequence.
* @param begin1 Begin iterator of first sequence.
* @param end1 End iterator of first sequence.
* @param begin2 Begin iterator of second sequence.
* @param pred Find predicate. */
template<typename RandomAccessIterator1, typename RandomAccessIterator2,
typename Pred>
std::pair<RandomAccessIterator1, RandomAccessIterator2>
sequential_algorithm(RandomAccessIterator1 begin1,
RandomAccessIterator1 end1,
RandomAccessIterator2 begin2, Pred pred)
{ return std::make_pair(find_first_of(begin1, end1, begin, end, pred,
sequential_tag()), begin2); }
};
}
#endif /* _GLIBCXX_PARALLEL_FIND_SELECTORS_H */
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