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
lower_bound(InputIterator first,InputIterator last,const T & value,command_queue & queue=system::default_queue ())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
51