libstdc++-v3/include/parallel/for_each_selectors.h - gcc - Git at Google

 // -*- C++ -*-

 // Copyright (C) 2007-2020 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/for_each_selectors.h
  *  @brief Functors representing different tasks to be plugged into the
  *  generic parallelization methods for embarrassingly parallel functions.
  *  This file is a GNU parallel extension to the Standard C++ Library.
  */

 // Written by Felix Putze.

 #ifndef _GLIBCXX_PARALLEL_FOR_EACH_SELECTORS_H
 #define _GLIBCXX_PARALLEL_FOR_EACH_SELECTORS_H 1

 #include <parallel/basic_iterator.h>

 namespace __gnu_parallel
 {
   /** @brief Generic __selector for embarrassingly parallel functions. */
   template<typename _It>
     struct __generic_for_each_selector
     {
       /** @brief _Iterator on last element processed; needed for some
        *  algorithms (e. g. std::transform()).
        */
       _It _M_finish_iterator;
     };

   /** @brief std::for_each() selector. */
   template<typename _It>
     struct __for_each_selector : public __generic_for_each_selector<_It>
     {
       /** @brief Functor execution.
        *  @param __o Operator.
        *  @param __i iterator referencing object. */
       template<typename _Op>
         bool
         operator()(_Op& __o, _It __i)
         {
           __o(*__i);
           return true;
         }
     };

   /** @brief std::generate() selector. */
   template<typename _It>
     struct __generate_selector : public __generic_for_each_selector<_It>
     {
       /** @brief Functor execution.
        *  @param __o Operator.
        *  @param __i iterator referencing object. */
       template<typename _Op>
         bool
         operator()(_Op& __o, _It __i)
         {
           *__i = __o();
           return true;
         }
     };

   /** @brief std::fill() selector. */
   template<typename _It>
     struct __fill_selector : public __generic_for_each_selector<_It>
     {
       /** @brief Functor execution.
        *  @param __v Current value.
        *  @param __i iterator referencing object. */
       template<typename _ValueType>
         bool
         operator()(_ValueType& __v, _It __i)
         {
           *__i = __v;
           return true;
         }
     };

   /** @brief std::transform() __selector, one input sequence variant. */
   template<typename _It>
     struct __transform1_selector : public __generic_for_each_selector<_It>
     {
       /** @brief Functor execution.
        *  @param __o Operator.
        *  @param __i iterator referencing object. */
       template<typename _Op>
         bool
         operator()(_Op& __o, _It __i)
         {
           *__i.second = __o(*__i.first);
           return true;
         }
     };

   /** @brief std::transform() __selector, two input sequences variant. */
   template<typename _It>
     struct __transform2_selector : public __generic_for_each_selector<_It>
     {
       /** @brief Functor execution.
        *  @param __o Operator.
        *  @param __i iterator referencing object. */
       template<typename _Op>
         bool
         operator()(_Op& __o, _It __i)
         {
           *__i._M_third = __o(*__i._M_first, *__i._M_second);
           return true;
         }
     };

   /** @brief std::replace() selector. */
   template<typename _It, typename _Tp>
     struct __replace_selector : public __generic_for_each_selector<_It>
     {
       /** @brief Value to replace with. */
       const _Tp& __new_val;

       /** @brief Constructor
        *  @param __new_val Value to replace with. */
       explicit
       __replace_selector(const _Tp &__new_val) : __new_val(__new_val) {}

       /** @brief Functor execution.
        *  @param __v Current value.
        *  @param __i iterator referencing object. */
       bool
       operator()(_Tp& __v, _It __i)
       {
         if (*__i == __v)
           *__i = __new_val;
         return true;
       }
     };

   /** @brief std::replace() selector. */
   template<typename _It, typename _Op, typename _Tp>
     struct __replace_if_selector : public __generic_for_each_selector<_It>
     {
       /** @brief Value to replace with. */
       const _Tp& __new_val;

       /** @brief Constructor.
        *  @param __new_val Value to replace with. */
       explicit
       __replace_if_selector(const _Tp &__new_val) : __new_val(__new_val) { }

       /** @brief Functor execution.
        *  @param __o Operator.
        *  @param __i iterator referencing object. */
       bool
       operator()(_Op& __o, _It __i)
       {
         if (__o(*__i))
           *__i = __new_val;
         return true;
       }
     };

   /** @brief std::count() selector. */
   template<typename _It, typename _Diff>
     struct __count_selector : public __generic_for_each_selector<_It>
     {
       /** @brief Functor execution.
        *  @param __v Current value.
        *  @param __i iterator referencing object.
        *  @return 1 if count, 0 if does not count. */
       template<typename _ValueType>
         _Diff
         operator()(_ValueType& __v, _It __i)
         { return (__v == *__i) ? 1 : 0; }
     };

   /** @brief std::count_if () selector. */
   template<typename _It, typename _Diff>
     struct __count_if_selector : public __generic_for_each_selector<_It>
     {
       /** @brief Functor execution.
        *  @param __o Operator.
        *  @param __i iterator referencing object.
        *  @return 1 if count, 0 if does not count. */
       template<typename _Op>
         _Diff
         operator()(_Op& __o, _It __i)
         { return (__o(*__i)) ? 1 : 0; }
     };

   /** @brief std::accumulate() selector. */
   template<typename _It>
     struct __accumulate_selector : public __generic_for_each_selector<_It>
     {
       /** @brief Functor execution.
        *  @param __o Operator (unused).
        *  @param __i iterator referencing object.
        *  @return The current value. */
       template<typename _Op>
         typename std::iterator_traits<_It>::value_type
         operator()(_Op __o, _It __i)
         { return *__i; }
     };

   /** @brief std::inner_product() selector. */
   template<typename _It, typename _It2, typename _Tp>
     struct __inner_product_selector : public __generic_for_each_selector<_It>
     {
       /** @brief Begin iterator of first sequence. */
       _It  __begin1_iterator;

       /** @brief Begin iterator of second sequence. */
       _It2 __begin2_iterator;

       /** @brief Constructor.
        *  @param __b1 Begin iterator of first sequence.
        *  @param __b2 Begin iterator of second sequence. */
       explicit
       __inner_product_selector(_It __b1, _It2 __b2)
       : __begin1_iterator(__b1), __begin2_iterator(__b2) { }

       /** @brief Functor execution.
        *  @param __mult Multiplication functor.
        *  @param __current iterator referencing object.
        *  @return Inner product elemental __result. */
       template<typename _Op>
         _Tp
         operator()(_Op __mult, _It __current)
         {
           typename std::iterator_traits<_It>::difference_type __position
             = __current - __begin1_iterator;
           return __mult(*__current, *(__begin2_iterator + __position));
         }
     };

   /** @brief Selector that just returns the passed iterator. */
   template<typename _It>
     struct __identity_selector : public __generic_for_each_selector<_It>
     {
       /** @brief Functor execution.
        *  @param __o Operator (unused).
        *  @param __i iterator referencing object.
        *  @return Passed iterator. */
       template<typename _Op>
         _It
         operator()(_Op __o, _It __i)
         { return __i; }
     };

   /** @brief Selector that returns the difference between two adjacent
    *  __elements.
    */
   template<typename _It>
     struct __adjacent_difference_selector
     : public __generic_for_each_selector<_It>
     {
       template<typename _Op>
         bool
         operator()(_Op& __o, _It __i)
         {
           typename _It::first_type __go_back_one = __i.first;
           --__go_back_one;
           *__i.second = __o(*__i.first, *__go_back_one);
           return true;
         }
     };

   /** @brief Functor doing nothing
    *
    *  For some __reduction tasks (this is not a function object, but is
    *  passed as __selector __dummy parameter.
    */
   struct _Nothing
   {
     /** @brief Functor execution.
      *  @param __i iterator referencing object. */
     template<typename _It>
       void
       operator()(_It __i) { }
   };

   /** @brief Reduction function doing nothing. */
   struct _DummyReduct
   {
     bool
     operator()(bool, bool) const
     { return true; }
   };

   /** @brief Reduction for finding the maximum element, using a comparator. */
   template<typename _Compare, typename _It>
     struct __min_element_reduct
     {
       _Compare& __comp;

       explicit
       __min_element_reduct(_Compare &__c) : __comp(__c) { }

       _It
       operator()(_It __x, _It __y)
       { return (__comp(*__x, *__y)) ? __x : __y; }
     };

   /** @brief Reduction for finding the maximum element, using a comparator. */
   template<typename _Compare, typename _It>
     struct __max_element_reduct
     {
       _Compare& __comp;

       explicit
       __max_element_reduct(_Compare& __c) : __comp(__c) { }

       _It
       operator()(_It __x, _It __y)
       { return (__comp(*__x, *__y)) ? __y : __x; }
     };

   /** @brief General reduction, using a binary operator. */
   template<typename _BinOp>
     struct __accumulate_binop_reduct
     {
       _BinOp& __binop;

       explicit
       __accumulate_binop_reduct(_BinOp& __b) : __binop(__b) { }

       template<typename _Result, typename _Addend>
         _Result
         operator()(const _Result& __x, const _Addend& __y)
         { return __binop(__x, __y); }
     };
 }

 #endif /* _GLIBCXX_PARALLEL_FOR_EACH_SELECTORS_H */
	// -- C++ --

	// Copyright (C) 2007-2020 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/for_each_selectors.h
	* @brief Functors representing different tasks to be plugged into the
	* generic parallelization methods for embarrassingly parallel functions.
	* This file is a GNU parallel extension to the Standard C++ Library.
	*/

	// Written by Felix Putze.

	#ifndef _GLIBCXX_PARALLEL_FOR_EACH_SELECTORS_H
	#define _GLIBCXX_PARALLEL_FOR_EACH_SELECTORS_H 1

	#include <parallel/basic_iterator.h>

	namespace __gnu_parallel
	{
	/** @brief Generic __selector for embarrassingly parallel functions. */
	template<typename _It>
	struct __generic_for_each_selector
	{
	/** @brief _Iterator on last element processed; needed for some
	* algorithms (e. g. std::transform()).
	*/
	_It _M_finish_iterator;
	};

	/** @brief std::for_each() selector. */
	template<typename _It>
	struct __for_each_selector : public __generic_for_each_selector<_It>
	{
	/** @brief Functor execution.
	* @param __o Operator.
	* @param __i iterator referencing object. */
	template<typename _Op>
	bool
	operator()(_Op& __o, _It __i)
	{
	__o(*__i);
	return true;
	}
	};

	/** @brief std::generate() selector. */
	template<typename _It>
	struct __generate_selector : public __generic_for_each_selector<_It>
	{
	/** @brief Functor execution.
	* @param __o Operator.
	* @param __i iterator referencing object. */
	template<typename _Op>
	bool
	operator()(_Op& __o, _It __i)
	{
	*__i = __o();
	return true;
	}
	};

	/** @brief std::fill() selector. */
	template<typename _It>
	struct __fill_selector : public __generic_for_each_selector<_It>
	{
	/** @brief Functor execution.
	* @param __v Current value.
	* @param __i iterator referencing object. */
	template<typename _ValueType>
	bool
	operator()(_ValueType& __v, _It __i)
	{
	*__i = __v;
	return true;
	}
	};

	/** @brief std::transform() __selector, one input sequence variant. */
	template<typename _It>
	struct __transform1_selector : public __generic_for_each_selector<_It>
	{
	/** @brief Functor execution.
	* @param __o Operator.
	* @param __i iterator referencing object. */
	template<typename _Op>
	bool
	operator()(_Op& __o, _It __i)
	{
	__i.second = __o(__i.first);
	return true;
	}
	};

	/** @brief std::transform() __selector, two input sequences variant. */
	template<typename _It>
	struct __transform2_selector : public __generic_for_each_selector<_It>
	{
	/** @brief Functor execution.
	* @param __o Operator.
	* @param __i iterator referencing object. */
	template<typename _Op>
	bool
	operator()(_Op& __o, _It __i)
	{
	__i._M_third = __o(__i._M_first, *__i._M_second);
	return true;
	}
	};

	/** @brief std::replace() selector. */
	template<typename _It, typename _Tp>
	struct __replace_selector : public __generic_for_each_selector<_It>
	{
	/** @brief Value to replace with. */
	const _Tp& __new_val;

	/** @brief Constructor
	* @param __new_val Value to replace with. */
	explicit
	__replace_selector(const _Tp &__new_val) : __new_val(__new_val) {}

	/** @brief Functor execution.
	* @param __v Current value.
	* @param __i iterator referencing object. */
	bool
	operator()(_Tp& __v, _It __i)
	{
	if (*__i == __v)
	*__i = __new_val;
	return true;
	}
	};

	/** @brief std::replace() selector. */
	template<typename _It, typename _Op, typename _Tp>
	struct __replace_if_selector : public __generic_for_each_selector<_It>
	{
	/** @brief Value to replace with. */
	const _Tp& __new_val;

	/** @brief Constructor.
	* @param __new_val Value to replace with. */
	explicit
	__replace_if_selector(const _Tp &__new_val) : __new_val(__new_val) { }

	/** @brief Functor execution.
	* @param __o Operator.
	* @param __i iterator referencing object. */
	bool
	operator()(_Op& __o, _It __i)
	{
	if (__o(*__i))
	*__i = __new_val;
	return true;
	}
	};

	/** @brief std::count() selector. */
	template<typename _It, typename _Diff>
	struct __count_selector : public __generic_for_each_selector<_It>
	{
	/** @brief Functor execution.
	* @param __v Current value.
	* @param __i iterator referencing object.
	* @return 1 if count, 0 if does not count. */
	template<typename _ValueType>
	_Diff
	operator()(_ValueType& __v, _It __i)
	{ return (__v == *__i) ? 1 : 0; }
	};

	/** @brief std::count_if () selector. */
	template<typename _It, typename _Diff>
	struct __count_if_selector : public __generic_for_each_selector<_It>
	{
	/** @brief Functor execution.
	* @param __o Operator.
	* @param __i iterator referencing object.
	* @return 1 if count, 0 if does not count. */
	template<typename _Op>
	_Diff
	operator()(_Op& __o, _It __i)
	{ return (__o(*__i)) ? 1 : 0; }
	};

	/** @brief std::accumulate() selector. */
	template<typename _It>
	struct __accumulate_selector : public __generic_for_each_selector<_It>
	{
	/** @brief Functor execution.
	* @param __o Operator (unused).
	* @param __i iterator referencing object.
	* @return The current value. */
	template<typename _Op>
	typename std::iterator_traits<_It>::value_type
	operator()(_Op __o, _It __i)
	{ return *__i; }
	};

	/** @brief std::inner_product() selector. */
	template<typename _It, typename _It2, typename _Tp>
	struct __inner_product_selector : public __generic_for_each_selector<_It>
	{
	/** @brief Begin iterator of first sequence. */
	_It __begin1_iterator;

	/** @brief Begin iterator of second sequence. */
	_It2 __begin2_iterator;

	/** @brief Constructor.
	* @param __b1 Begin iterator of first sequence.
	* @param __b2 Begin iterator of second sequence. */
	explicit
	__inner_product_selector(_It __b1, _It2 __b2)
	: __begin1_iterator(__b1), __begin2_iterator(__b2) { }

	/** @brief Functor execution.
	* @param __mult Multiplication functor.
	* @param __current iterator referencing object.
	* @return Inner product elemental __result. */
	template<typename _Op>
	_Tp
	operator()(_Op __mult, _It __current)
	{
	typename std::iterator_traits<_It>::difference_type __position
	= __current - __begin1_iterator;
	return __mult(__current, (__begin2_iterator + __position));
	}
	};

	/** @brief Selector that just returns the passed iterator. */
	template<typename _It>
	struct __identity_selector : public __generic_for_each_selector<_It>
	{
	/** @brief Functor execution.
	* @param __o Operator (unused).
	* @param __i iterator referencing object.
	* @return Passed iterator. */
	template<typename _Op>
	_It
	operator()(_Op __o, _It __i)
	{ return __i; }
	};

	/** @brief Selector that returns the difference between two adjacent
	* __elements.
	*/
	template<typename _It>
	struct __adjacent_difference_selector
	: public __generic_for_each_selector<_It>
	{
	template<typename _Op>
	bool
	operator()(_Op& __o, _It __i)
	{
	typename _It::first_type __go_back_one = __i.first;
	--__go_back_one;
	__i.second = __o(__i.first, *__go_back_one);
	return true;
	}
	};

	/** @brief Functor doing nothing
	*
	* For some __reduction tasks (this is not a function object, but is
	* passed as __selector __dummy parameter.
	*/
	struct _Nothing
	{
	/** @brief Functor execution.
	* @param __i iterator referencing object. */
	template<typename _It>
	void
	operator()(_It __i) { }
	};

	/** @brief Reduction function doing nothing. */
	struct _DummyReduct
	{
	bool
	operator()(bool, bool) const
	{ return true; }
	};

	/** @brief Reduction for finding the maximum element, using a comparator. */
	template<typename _Compare, typename _It>
	struct __min_element_reduct
	{
	_Compare& __comp;

	explicit
	__min_element_reduct(_Compare &__c) : __comp(__c) { }

	_It
	operator()(_It __x, _It __y)
	{ return (__comp(__x, __y)) ? __x : __y; }
	};

	/** @brief Reduction for finding the maximum element, using a comparator. */
	template<typename _Compare, typename _It>
	struct __max_element_reduct
	{
	_Compare& __comp;

	explicit
	__max_element_reduct(_Compare& __c) : __comp(__c) { }

	_It
	operator()(_It __x, _It __y)
	{ return (__comp(__x, __y)) ? __y : __x; }
	};

	/** @brief General reduction, using a binary operator. */
	template<typename _BinOp>
	struct __accumulate_binop_reduct
	{
	_BinOp& __binop;

	explicit
	__accumulate_binop_reduct(_BinOp& __b) : __binop(__b) { }

	template<typename _Result, typename _Addend>
	_Result
	operator()(const _Result& __x, const _Addend& __y)
	{ return __binop(__x, __y); }
	};
	}

	#endif /* _GLIBCXX_PARALLEL_FOR_EACH_SELECTORS_H */