ceph/src/boost/boost/compute/algorithm/replace_copy.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_REPLACE_COPY_HPP
  12 #define BOOST_COMPUTE_ALGORITHM_REPLACE_COPY_HPP
  13
  14 #include <iterator>
  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/algorithm/replace.hpp>
  20
  21 namespace boost {
  22 namespace compute {
  23
  24 /// Copies the value in the range [\p first, \p last) to the range
  25 /// beginning at \p result while replacing each instance of \p old_value
  26 /// with \p new_value.
  27 ///
  28 /// Space complexity: \Omega(1)
  29 ///
  30 /// \see replace()
  31 template<class InputIterator, class OutputIterator, class T>
  32 inline OutputIterator
  33 replace_copy(InputIterator first,
  34              InputIterator last,
  35              OutputIterator result,
  36              const T &old_value,
  37              const T &new_value,
  38              command_queue &queue = system::default_queue())
  39 {
  40     typedef typename std::iterator_traits<OutputIterator>::difference_type difference_type;
  41
  42     difference_type count = std::distance(first, last);
  43     if(count == 0){
  44         return result;
  45     }
  46
  47     // copy data to result
  48     ::boost::compute::copy(first, last, result, queue);
  49
  50     // replace in result
  51     ::boost::compute::replace(result,
  52                               result + count,
  53                               old_value,
  54                               new_value,
  55                               queue);
  56
  57     // return iterator to the end of result
  58     return result + count;
  59 }
  60
  61 } // end compute namespace
  62 } // end boost namespace
  63
  64 #endif // BOOST_COMPUTE_ALGORITHM_REPLACE_COPY_HPP