--- /dev/null
+// -*- 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/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 */
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