1 //---------------------------------------------------------------------------// 2 // Copyright (c) 2013 Kyle Lutz <kyle.r.lutz@gmail.com> 3 // 4 // Distributed under the Boost Software License, Version 1.0 5 // See accompanying file LICENSE_1_0.txt or copy at 6 // http://www.boost.org/LICENSE_1_0.txt 7 // 8 // See http://boostorg.github.com/compute for more information. 9 //---------------------------------------------------------------------------// 10 11 #ifndef BOOST_COMPUTE_EXPERIMENTAL_SORT_BY_TRANSFORM_HPP 12 #define BOOST_COMPUTE_EXPERIMENTAL_SORT_BY_TRANSFORM_HPP 13 14 #include <iterator> 15 16 #include <boost/compute/algorithm/sort_by_key.hpp> 17 #include <boost/compute/algorithm/transform.hpp> 18 #include <boost/compute/container/vector.hpp> 19 #include <boost/compute/detail/iterator_range_size.hpp> 20 #include <boost/compute/type_traits/result_of.hpp> 21 22 namespace boost { 23 namespace compute { 24 namespace experimental { 25 26 template<class Iterator, class Transform, class Compare> 27 inline void sort_by_transform(Iterator first, malloc(std::size_t size,const context & context=system::default_context ())28 Iterator last, 29 Transform transform, 30 Compare compare, 31 command_queue &queue = system::default_queue()) 32 { 33 typedef typename std::iterator_traits<Iterator>::value_type value_type; 34 typedef typename boost::compute::result_of<Transform(value_type)>::type key_type; 35 36 size_t n = detail::iterator_range_size(first, last); 37 if(n < 2){ 38 return; 39 } 40 41 const context &context = queue.get_context(); 42 43 ::boost::compute::vector<key_type> keys(n, context); 44 45 ::boost::compute::transform( 46 first, 47 last, 48 keys.begin(), 49 transform, 50 queue 51 ); 52 53 ::boost::compute::sort_by_key( 54 keys.begin(), 55 keys.end(), 56 first, 57 compare, 58 queue 59 ); 60 } 61 62 } // end experimental namespace 63 } // end compute namespace 64 } // end boost namespace 65 66 #endif // BOOST_COMPUTE_EXPERIMENTAL_SORT_BY_TRANSFORM_HPP 67