ceph/src/boost/boost/compute/algorithm/partition_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_PARTITION_COPY_HPP
  12 #define BOOST_COMPUTE_ALGORITHM_PARTITION_COPY_HPP
  13
  14 #include <boost/static_assert.hpp>
  15
  16 #include <boost/compute/system.hpp>
  17 #include <boost/compute/functional.hpp>
  18 #include <boost/compute/command_queue.hpp>
  19 #include <boost/compute/algorithm/copy_if.hpp>
  20 #include <boost/compute/type_traits/is_device_iterator.hpp>
  21
  22 namespace boost {
  23 namespace compute {
  24
  25 /// Copies all of the elements in the range [\p first, \p last) for which
  26 /// \p predicate returns \c true to the range beginning at \p first_true
  27 /// and all of the elements for which \p predicate returns \c false to
  28 /// the range beginning at \p first_false.
  29 ///
  30 /// Space complexity: \Omega(2n)
  31 ///
  32 /// \see partition()
  33 template<class InputIterator,
  34          class OutputIterator1,
  35          class OutputIterator2,
  36          class UnaryPredicate>
  37 inline std::pair<OutputIterator1, OutputIterator2>
  38 partition_copy(InputIterator first,
  39                InputIterator last,
  40                OutputIterator1 first_true,
  41                OutputIterator2 first_false,
  42                UnaryPredicate predicate,
  43                command_queue &queue = system::default_queue())
  44 {
  45     BOOST_STATIC_ASSERT(is_device_iterator<InputIterator>::value);
  46     BOOST_STATIC_ASSERT(is_device_iterator<OutputIterator1>::value);
  47     BOOST_STATIC_ASSERT(is_device_iterator<OutputIterator2>::value);
  48
  49     // copy true values
  50     OutputIterator1 last_true =
  51         ::boost::compute::copy_if(first,
  52                                   last,
  53                                   first_true,
  54                                   predicate,
  55                                   queue);
  56
  57     // copy false values
  58     OutputIterator2 last_false =
  59         ::boost::compute::copy_if(first,
  60                                   last,
  61                                   first_false,
  62                                   not1(predicate),
  63                                   queue);
  64
  65     // return iterators to the end of the true and the false ranges
  66     return std::make_pair(last_true, last_false);
  67 }
  68
  69 } // end compute namespace
  70 } // end boost namespace
  71
  72 #endif // BOOST_COMPUTE_ALGORITHM_PARTITION_COPY_HPP