ceph/src/boost/boost/compute/algorithm/lower_bound.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_LOWER_BOUND_HPP
  12 #define BOOST_COMPUTE_ALGORITHM_LOWER_BOUND_HPP
  13
  14 #include <boost/static_assert.hpp>
  15
  16 #include <boost/compute/lambda.hpp>
  17 #include <boost/compute/system.hpp>
  18 #include <boost/compute/command_queue.hpp>
  19 #include <boost/compute/algorithm/detail/binary_find.hpp>
  20 #include <boost/compute/type_traits/is_device_iterator.hpp>
  21
  22 namespace boost {
  23 namespace compute {
  24
  25 /// Returns an iterator pointing to the first element in the sorted
  26 /// range [\p first, \p last) that is not less than \p value.
  27 ///
  28 /// Space complexity: \Omega(1)
  29 ///
  30 /// \see upper_bound()
  31 template<class InputIterator, class T>
  32 inline InputIterator
  33 lower_bound(InputIterator first,
  34             InputIterator last,
  35             const T &value,
  36             command_queue &queue = system::default_queue())
  37 {
  38     BOOST_STATIC_ASSERT(is_device_iterator<InputIterator>::value);
  39     using ::boost::compute::_1;
  40
  41     InputIterator position =
  42         detail::binary_find(first, last, _1 >= value, queue);
  43
  44     return position;
  45 }
  46
  47 } // end compute namespace
  48 } // end boost namespace
  49
  50 #endif // BOOST_COMPUTE_ALGORITHM_LOWER_BOUND_HPP