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			73 lines
		
	
	
		
			2.6 KiB
		
	
	
	
		
			Plaintext
		
	
	
	
	
	
|   | //---------------------------------------------------------------------------// | ||
|  | // Copyright (c) 2014 Roshan <thisisroshansmail@gmail.com> | ||
|  | // | ||
|  | // Distributed under the Boost Software License, Version 1.0 | ||
|  | // See accompanying file LICENSE_1_0.txt or copy at | ||
|  | // http://www.boost.org/LICENSE_1_0.txt | ||
|  | // | ||
|  | // See http://boostorg.github.com/compute for more information. | ||
|  | //---------------------------------------------------------------------------// | ||
|  | 
 | ||
|  | #ifndef BOOST_COMPUTE_ALGORITHM_STABLE_PARTITION_HPP | ||
|  | #define BOOST_COMPUTE_ALGORITHM_STABLE_PARTITION_HPP | ||
|  | 
 | ||
|  | #include <boost/compute/system.hpp> | ||
|  | #include <boost/compute/context.hpp> | ||
|  | #include <boost/compute/functional.hpp> | ||
|  | #include <boost/compute/command_queue.hpp> | ||
|  | #include <boost/compute/algorithm/copy_if.hpp> | ||
|  | #include <boost/compute/container/vector.hpp> | ||
|  | 
 | ||
|  | namespace boost { | ||
|  | namespace compute { | ||
|  | 
 | ||
|  | /// | ||
|  | /// \brief Partitioning algorithm | ||
|  | /// | ||
|  | /// Partitions the elements in the range [\p first, \p last) according to | ||
|  | /// \p predicate. The order of the elements is preserved. | ||
|  | /// \return Iterator pointing to end of true values | ||
|  | /// | ||
|  | /// \param first Iterator pointing to start of range | ||
|  | /// \param last Iterator pointing to end of range | ||
|  | /// \param predicate Unary predicate to be applied on each element | ||
|  | /// \param queue Queue on which to execute | ||
|  | /// | ||
|  | /// \see is_partitioned() and partition() | ||
|  | /// | ||
|  | template<class Iterator, class UnaryPredicate> | ||
|  | inline Iterator stable_partition(Iterator first, | ||
|  |                                  Iterator last, | ||
|  |                                  UnaryPredicate predicate, | ||
|  |                                  command_queue &queue = system::default_queue()) | ||
|  | { | ||
|  |     typedef typename std::iterator_traits<Iterator>::value_type value_type; | ||
|  | 
 | ||
|  |     // make temporary copy of the input | ||
|  |     ::boost::compute::vector<value_type> tmp(first, last, queue); | ||
|  | 
 | ||
|  |     // copy true values | ||
|  |     Iterator last_true = | ||
|  |         ::boost::compute::copy_if(tmp.begin(), | ||
|  |                                   tmp.end(), | ||
|  |                                   first, | ||
|  |                                   predicate, | ||
|  |                                   queue); | ||
|  | 
 | ||
|  |     // copy false values | ||
|  |     Iterator last_false = | ||
|  |         ::boost::compute::copy_if(tmp.begin(), | ||
|  |                                   tmp.end(), | ||
|  |                                   last_true, | ||
|  |                                   not1(predicate), | ||
|  |                                   queue); | ||
|  | 
 | ||
|  |     // return iterator pointing to the last true value | ||
|  |     return last_true; | ||
|  | } | ||
|  | 
 | ||
|  | } // end compute namespace | ||
|  | } // end boost namespace | ||
|  | 
 | ||
|  | #endif // BOOST_COMPUTE_ALGORITHM_STABLE_PARTITION_HPP |