ceph/src/boost/boost/compute/algorithm/copy_if.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_COPY_IF_HPP
  12 #define BOOST_COMPUTE_ALGORITHM_COPY_IF_HPP
  13
  14 #include <boost/compute/algorithm/transform_if.hpp>
  15 #include <boost/compute/functional/identity.hpp>
  16
  17 namespace boost {
  18 namespace compute {
  19 namespace detail {
  20
  21 // like the copy_if() algorithm but writes the indices of the values for which
  22 // predicate returns true.
  23 template<class InputIterator, class OutputIterator, class Predicate>
  24 inline OutputIterator copy_index_if(InputIterator first,
  25                                     InputIterator last,
  26                                     OutputIterator result,
  27                                     Predicate predicate,
  28                                     command_queue &queue = system::default_queue())
  29 {
  30     typedef typename std::iterator_traits<InputIterator>::value_type T;
  31
  32     return detail::transform_if_impl(
  33         first, last, result, identity<T>(), predicate, true, queue
  34     );
  35 }
  36
  37 } // end detail namespace
  38
  39 /// Copies each element in the range [\p first, \p last) for which
  40 /// \p predicate returns \c true to the range beginning at \p result.
  41 ///
  42 /// Space complexity: \Omega(2n)
  43 template<class InputIterator, class OutputIterator, class Predicate>
  44 inline OutputIterator copy_if(InputIterator first,
  45                               InputIterator last,
  46                               OutputIterator result,
  47                               Predicate predicate,
  48                               command_queue &queue = system::default_queue())
  49 {
  50     typedef typename std::iterator_traits<InputIterator>::value_type T;
  51
  52     return ::boost::compute::transform_if(
  53         first, last, result, identity<T>(), predicate, queue
  54     );
  55 }
  56
  57 } // end compute namespace
  58 } // end boost namespace
  59
  60 #endif // BOOST_COMPUTE_ALGORITHM_COPY_IF_HPP