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