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/static_assert.hpp>
  15
  16 #include <boost/compute/algorithm/transform_if.hpp>
  17 #include <boost/compute/functional/identity.hpp>
  18 #include <boost/compute/type_traits/is_device_iterator.hpp>
  19
  20 namespace boost {
  21 namespace compute {
  22 namespace detail {
  23
  24 // like the copy_if() algorithm but writes the indices of the values for which
  25 // predicate returns true.
  26 template<class InputIterator, class OutputIterator, class Predicate>
  27 inline OutputIterator copy_index_if(InputIterator first,
  28                                     InputIterator last,
  29                                     OutputIterator result,
  30                                     Predicate predicate,
  31                                     command_queue &queue = system::default_queue())
  32 {
  33     BOOST_STATIC_ASSERT(is_device_iterator<InputIterator>::value);
  34     BOOST_STATIC_ASSERT(is_device_iterator<OutputIterator>::value);
  35     typedef typename std::iterator_traits<InputIterator>::value_type T;
  36
  37     return detail::transform_if_impl(
  38         first, last, result, identity<T>(), predicate, true, queue
  39     );
  40 }
  41
  42 } // end detail namespace
  43
  44 /// Copies each element in the range [\p first, \p last) for which
  45 /// \p predicate returns \c true to the range beginning at \p result.
  46 ///
  47 /// Space complexity: \Omega(2n)
  48 template<class InputIterator, class OutputIterator, class Predicate>
  49 inline OutputIterator copy_if(InputIterator first,
  50                               InputIterator last,
  51                               OutputIterator result,
  52                               Predicate predicate,
  53                               command_queue &queue = system::default_queue())
  54 {
  55     BOOST_STATIC_ASSERT(is_device_iterator<InputIterator>::value);
  56     BOOST_STATIC_ASSERT(is_device_iterator<OutputIterator>::value);
  57     typedef typename std::iterator_traits<InputIterator>::value_type T;
  58
  59     return ::boost::compute::transform_if(
  60         first, last, result, identity<T>(), predicate, queue
  61     );
  62 }
  63
  64 } // end compute namespace
  65 } // end boost namespace
  66
  67 #endif // BOOST_COMPUTE_ALGORITHM_COPY_IF_HPP