forked from KolibriOS/kolibrios
350 lines
10 KiB
C
350 lines
10 KiB
C
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// -*- C++ -*-
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// Copyright (C) 2007-2013 Free Software Foundation, Inc.
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//
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// This file is part of the GNU ISO C++ Library. This library is free
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// software; you can redistribute it and/or modify it under the terms
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// of the GNU General Public License as published by the Free Software
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// Foundation; either version 3, or (at your option) any later
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// version.
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// This library is distributed in the hope that it will be useful, but
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// WITHOUT ANY WARRANTY; without even the implied warranty of
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// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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// General Public License for more details.
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// Under Section 7 of GPL version 3, you are granted additional
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// permissions described in the GCC Runtime Library Exception, version
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// 3.1, as published by the Free Software Foundation.
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// You should have received a copy of the GNU General Public License and
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// a copy of the GCC Runtime Library Exception along with this program;
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// see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
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// <http://www.gnu.org/licenses/>.
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/** @file parallel/for_each_selectors.h
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* @brief Functors representing different tasks to be plugged into the
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* generic parallelization methods for embarrassingly parallel functions.
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* This file is a GNU parallel extension to the Standard C++ Library.
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*/
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// Written by Felix Putze.
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#ifndef _GLIBCXX_PARALLEL_FOR_EACH_SELECTORS_H
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#define _GLIBCXX_PARALLEL_FOR_EACH_SELECTORS_H 1
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#include <parallel/basic_iterator.h>
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namespace __gnu_parallel
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{
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/** @brief Generic __selector for embarrassingly parallel functions. */
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template<typename _It>
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struct __generic_for_each_selector
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{
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/** @brief _Iterator on last element processed; needed for some
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* algorithms (e. g. std::transform()).
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*/
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_It _M_finish_iterator;
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};
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/** @brief std::for_each() selector. */
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template<typename _It>
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struct __for_each_selector : public __generic_for_each_selector<_It>
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{
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/** @brief Functor execution.
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* @param __o Operator.
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* @param __i iterator referencing object. */
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template<typename _Op>
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bool
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operator()(_Op& __o, _It __i)
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{
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__o(*__i);
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return true;
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}
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};
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/** @brief std::generate() selector. */
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template<typename _It>
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struct __generate_selector : public __generic_for_each_selector<_It>
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{
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/** @brief Functor execution.
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* @param __o Operator.
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* @param __i iterator referencing object. */
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template<typename _Op>
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bool
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operator()(_Op& __o, _It __i)
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{
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*__i = __o();
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return true;
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}
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};
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/** @brief std::fill() selector. */
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template<typename _It>
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struct __fill_selector : public __generic_for_each_selector<_It>
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{
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/** @brief Functor execution.
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* @param __v Current value.
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* @param __i iterator referencing object. */
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template<typename _ValueType>
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bool
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operator()(_ValueType& __v, _It __i)
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{
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*__i = __v;
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return true;
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}
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};
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/** @brief std::transform() __selector, one input sequence variant. */
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template<typename _It>
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struct __transform1_selector : public __generic_for_each_selector<_It>
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{
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/** @brief Functor execution.
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* @param __o Operator.
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* @param __i iterator referencing object. */
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template<typename _Op>
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bool
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operator()(_Op& __o, _It __i)
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{
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*__i.second = __o(*__i.first);
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return true;
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}
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};
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/** @brief std::transform() __selector, two input sequences variant. */
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template<typename _It>
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struct __transform2_selector : public __generic_for_each_selector<_It>
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{
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/** @brief Functor execution.
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* @param __o Operator.
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* @param __i iterator referencing object. */
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template<typename _Op>
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bool
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operator()(_Op& __o, _It __i)
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{
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*__i._M_third = __o(*__i._M_first, *__i._M_second);
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return true;
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}
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};
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/** @brief std::replace() selector. */
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template<typename _It, typename _Tp>
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struct __replace_selector : public __generic_for_each_selector<_It>
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{
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/** @brief Value to replace with. */
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const _Tp& __new_val;
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/** @brief Constructor
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* @param __new_val Value to replace with. */
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explicit
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__replace_selector(const _Tp &__new_val) : __new_val(__new_val) {}
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/** @brief Functor execution.
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* @param __v Current value.
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* @param __i iterator referencing object. */
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bool
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operator()(_Tp& __v, _It __i)
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{
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if (*__i == __v)
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*__i = __new_val;
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return true;
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}
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};
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/** @brief std::replace() selector. */
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template<typename _It, typename _Op, typename _Tp>
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struct __replace_if_selector : public __generic_for_each_selector<_It>
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{
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/** @brief Value to replace with. */
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const _Tp& __new_val;
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/** @brief Constructor.
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* @param __new_val Value to replace with. */
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explicit
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__replace_if_selector(const _Tp &__new_val) : __new_val(__new_val) { }
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/** @brief Functor execution.
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* @param __o Operator.
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* @param __i iterator referencing object. */
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bool
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operator()(_Op& __o, _It __i)
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{
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if (__o(*__i))
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*__i = __new_val;
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return true;
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}
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};
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/** @brief std::count() selector. */
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template<typename _It, typename _Diff>
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struct __count_selector : public __generic_for_each_selector<_It>
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{
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/** @brief Functor execution.
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* @param __v Current value.
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* @param __i iterator referencing object.
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* @return 1 if count, 0 if does not count. */
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template<typename _ValueType>
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_Diff
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operator()(_ValueType& __v, _It __i)
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{ return (__v == *__i) ? 1 : 0; }
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};
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/** @brief std::count_if () selector. */
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template<typename _It, typename _Diff>
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struct __count_if_selector : public __generic_for_each_selector<_It>
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{
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/** @brief Functor execution.
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* @param __o Operator.
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* @param __i iterator referencing object.
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* @return 1 if count, 0 if does not count. */
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template<typename _Op>
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_Diff
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operator()(_Op& __o, _It __i)
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{ return (__o(*__i)) ? 1 : 0; }
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};
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/** @brief std::accumulate() selector. */
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template<typename _It>
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struct __accumulate_selector : public __generic_for_each_selector<_It>
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{
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/** @brief Functor execution.
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* @param __o Operator (unused).
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* @param __i iterator referencing object.
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* @return The current value. */
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template<typename _Op>
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typename std::iterator_traits<_It>::value_type
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operator()(_Op __o, _It __i)
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{ return *__i; }
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};
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/** @brief std::inner_product() selector. */
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template<typename _It, typename _It2, typename _Tp>
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struct __inner_product_selector : public __generic_for_each_selector<_It>
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{
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/** @brief Begin iterator of first sequence. */
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_It __begin1_iterator;
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/** @brief Begin iterator of second sequence. */
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_It2 __begin2_iterator;
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/** @brief Constructor.
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* @param __b1 Begin iterator of first sequence.
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* @param __b2 Begin iterator of second sequence. */
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explicit
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__inner_product_selector(_It __b1, _It2 __b2)
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: __begin1_iterator(__b1), __begin2_iterator(__b2) { }
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/** @brief Functor execution.
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* @param __mult Multiplication functor.
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* @param __current iterator referencing object.
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* @return Inner product elemental __result. */
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template<typename _Op>
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_Tp
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operator()(_Op __mult, _It __current)
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{
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typename std::iterator_traits<_It>::difference_type __position
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= __current - __begin1_iterator;
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return __mult(*__current, *(__begin2_iterator + __position));
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}
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};
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/** @brief Selector that just returns the passed iterator. */
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template<typename _It>
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struct __identity_selector : public __generic_for_each_selector<_It>
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{
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/** @brief Functor execution.
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* @param __o Operator (unused).
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* @param __i iterator referencing object.
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* @return Passed iterator. */
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template<typename _Op>
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_It
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operator()(_Op __o, _It __i)
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{ return __i; }
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};
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/** @brief Selector that returns the difference between two adjacent
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* __elements.
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*/
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template<typename _It>
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struct __adjacent_difference_selector
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: public __generic_for_each_selector<_It>
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{
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template<typename _Op>
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bool
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operator()(_Op& __o, _It __i)
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{
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typename _It::first_type __go_back_one = __i.first;
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--__go_back_one;
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*__i.second = __o(*__i.first, *__go_back_one);
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return true;
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}
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};
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/** @brief Functor doing nothing
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*
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* For some __reduction tasks (this is not a function object, but is
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* passed as __selector __dummy parameter.
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*/
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struct _Nothing
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{
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/** @brief Functor execution.
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* @param __i iterator referencing object. */
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template<typename _It>
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void
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operator()(_It __i) { }
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};
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/** @brief Reduction function doing nothing. */
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struct _DummyReduct
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{
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bool
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operator()(bool, bool) const
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{ return true; }
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};
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/** @brief Reduction for finding the maximum element, using a comparator. */
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template<typename _Compare, typename _It>
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struct __min_element_reduct
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{
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_Compare& __comp;
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explicit
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__min_element_reduct(_Compare &__c) : __comp(__c) { }
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_It
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operator()(_It __x, _It __y)
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{ return (__comp(*__x, *__y)) ? __x : __y; }
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};
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/** @brief Reduction for finding the maximum element, using a comparator. */
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template<typename _Compare, typename _It>
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struct __max_element_reduct
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{
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_Compare& __comp;
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explicit
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__max_element_reduct(_Compare& __c) : __comp(__c) { }
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_It
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operator()(_It __x, _It __y)
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{ return (__comp(*__x, *__y)) ? __y : __x; }
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};
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/** @brief General reduction, using a binary operator. */
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template<typename _BinOp>
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struct __accumulate_binop_reduct
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{
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_BinOp& __binop;
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explicit
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__accumulate_binop_reduct(_BinOp& __b) : __binop(__b) { }
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template<typename _Result, typename _Addend>
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_Result
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operator()(const _Result& __x, const _Addend& __y)
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{ return __binop(__x, __y); }
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};
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}
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#endif /* _GLIBCXX_PARALLEL_FOR_EACH_SELECTORS_H */
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