ceph/src/boost/boost/compute/algorithm/transform.hpp

   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_ALGORITHM_TRANSFORM_HPP
  12 #define BOOST_COMPUTE_ALGORITHM_TRANSFORM_HPP
  13
  14 #include <boost/static_assert.hpp>
  15
  16 #include <boost/compute/system.hpp>
  17 #include <boost/compute/command_queue.hpp>
  18 #include <boost/compute/algorithm/copy.hpp>
  19 #include <boost/compute/iterator/transform_iterator.hpp>
  20 #include <boost/compute/iterator/zip_iterator.hpp>
  21 #include <boost/compute/functional/detail/unpack.hpp>
  22 #include <boost/compute/type_traits/is_device_iterator.hpp>
  23
  24 namespace boost {
  25 namespace compute {
  26
  27 /// Transforms the elements in the range [\p first, \p last) using
  28 /// operator \p op and stores the results in the range beginning at
  29 /// \p result.
  30 ///
  31 /// For example, to calculate the absolute value for each element in a vector:
  32 ///
  33 /// \snippet test/test_transform.cpp transform_abs
  34 ///
  35 /// Space complexity: \Omega(1)
  36 ///
  37 /// \see copy()
  38 template<class InputIterator, class OutputIterator, class UnaryOperator>
  39 inline OutputIterator transform(InputIterator first,
  40                                 InputIterator last,
  41                                 OutputIterator result,
  42                                 UnaryOperator op,
  43                                 command_queue &queue = system::default_queue())
  44 {
  45     BOOST_STATIC_ASSERT(is_device_iterator<InputIterator>::value);
  46     BOOST_STATIC_ASSERT(is_device_iterator<OutputIterator>::value);
  47     return copy(
  48                ::boost::compute::make_transform_iterator(first, op),
  49                ::boost::compute::make_transform_iterator(last, op),
  50                result,
  51                queue
  52            );
  53 }
  54
  55 /// \overload
  56 template<class InputIterator1,
  57          class InputIterator2,
  58          class OutputIterator,
  59          class BinaryOperator>
  60 inline OutputIterator transform(InputIterator1 first1,
  61                                 InputIterator1 last1,
  62                                 InputIterator2 first2,
  63                                 OutputIterator result,
  64                                 BinaryOperator op,
  65                                 command_queue &queue = system::default_queue())
  66 {
  67     BOOST_STATIC_ASSERT(is_device_iterator<InputIterator1>::value);
  68     BOOST_STATIC_ASSERT(is_device_iterator<InputIterator2>::value);
  69     BOOST_STATIC_ASSERT(is_device_iterator<OutputIterator>::value);
  70
  71     typedef typename std::iterator_traits<InputIterator1>::difference_type difference_type;
  72
  73     difference_type n = std::distance(first1, last1);
  74
  75     return transform(
  76                ::boost::compute::make_zip_iterator(boost::make_tuple(first1, first2)),
  77                ::boost::compute::make_zip_iterator(boost::make_tuple(last1, first2 + n)),
  78                result,
  79                detail::unpack(op),
  80                queue
  81            );
  82 }
  83
  84 } // end compute namespace
  85 } // end boost namespace
  86
  87 #endif // BOOST_COMPUTE_ALGORITHM_TRANSFORM_HPP