ceph/src/boost/boost/compute/algorithm/is_sorted.hpp

   1 //---------------------------------------------------------------------------//
   2 // Copyright (c) 2013-2014 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_IS_SORTED_HPP
  12 #define BOOST_COMPUTE_ALGORITHM_IS_SORTED_HPP
  13
  14 #include <boost/static_assert.hpp>
  15
  16 #include <boost/compute/command_queue.hpp>
  17 #include <boost/compute/system.hpp>
  18 #include <boost/compute/functional/bind.hpp>
  19 #include <boost/compute/functional/operator.hpp>
  20 #include <boost/compute/algorithm/adjacent_find.hpp>
  21 #include <boost/compute/type_traits/is_device_iterator.hpp>
  22
  23 namespace boost {
  24 namespace compute {
  25
  26 /// Returns \c true if the values in the range [\p first, \p last)
  27 /// are in sorted order.
  28 ///
  29 /// \param first first element in the range to check
  30 /// \param last last element in the range to check
  31 /// \param compare comparison function (by default \c less)
  32 /// \param queue command queue to perform the operation
  33 ///
  34 /// \return \c true if the range [\p first, \p last) is sorted
  35 ///
  36 /// Space complexity: \Omega(1)
  37 ///
  38 /// \see sort()
  39 template<class InputIterator, class Compare>
  40 inline bool is_sorted(InputIterator first,
  41                       InputIterator last,
  42                       Compare compare,
  43                       command_queue &queue = system::default_queue())
  44 {
  45     BOOST_STATIC_ASSERT(is_device_iterator<InputIterator>::value);
  46     using ::boost::compute::placeholders::_1;
  47     using ::boost::compute::placeholders::_2;
  48
  49     return ::boost::compute::adjacent_find(
  50         first, last, ::boost::compute::bind(compare, _2, _1), queue
  51     ) == last;
  52 }
  53
  54 /// \overload
  55 template<class InputIterator>
  56 inline bool is_sorted(InputIterator first,
  57                       InputIterator last,
  58                       command_queue &queue = system::default_queue())
  59 {
  60     BOOST_STATIC_ASSERT(is_device_iterator<InputIterator>::value);
  61     typedef typename std::iterator_traits<InputIterator>::value_type value_type;
  62
  63     return ::boost::compute::is_sorted(
  64         first, last, ::boost::compute::less<value_type>(), queue
  65     );
  66 }
  67
  68 } // end compute namespace
  69 } // end boost namespace
  70
  71 #endif // BOOST_COMPUTE_ALGORITHM_IS_SORTED_HPP