1 // Copyright Neil Groves 2009. Use, modification and
2 // distribution is subject to the Boost Software License, Version
3 // 1.0. (See accompanying file LICENSE_1_0.txt or copy at
4 // http://www.boost.org/LICENSE_1_0.txt)
5 //
6 //
7 // For more information, see http://www.boost.org/libs/range/
8 //
9 #ifndef BOOST_RANGE_ALGORITHM_NTH_ELEMENT_HPP_INCLUDED
10 #define BOOST_RANGE_ALGORITHM_NTH_ELEMENT_HPP_INCLUDED
11
12 #include <boost/concept_check.hpp>
13 #include <boost/range/begin.hpp>
14 #include <boost/range/end.hpp>
15 #include <boost/range/concepts.hpp>
16 #include <algorithm>
17
18 namespace boost
19 {
20 namespace range
21 {
22
23 /// \brief template function nth_element
24 ///
25 /// range-based version of the nth_element std algorithm
26 ///
27 /// \pre RandomAccessRange is a model of the RandomAccessRangeConcept
28 /// \pre BinaryPredicate is a model of the BinaryPredicateConcept
29 template<class RandomAccessRange>
nth_element(RandomAccessRange & rng,BOOST_DEDUCED_TYPENAME range_iterator<RandomAccessRange>::type nth)30 inline RandomAccessRange& nth_element(RandomAccessRange& rng,
31 BOOST_DEDUCED_TYPENAME range_iterator<RandomAccessRange>::type nth)
32 {
33 BOOST_RANGE_CONCEPT_ASSERT(( RandomAccessRangeConcept<RandomAccessRange> ));
34 std::nth_element(boost::begin(rng), nth, boost::end(rng));
35 return rng;
36 }
37
38 /// \overload
39 template<class RandomAccessRange>
nth_element(const RandomAccessRange & rng,BOOST_DEDUCED_TYPENAME range_iterator<const RandomAccessRange>::type nth)40 inline const RandomAccessRange& nth_element(const RandomAccessRange& rng,
41 BOOST_DEDUCED_TYPENAME range_iterator<const RandomAccessRange>::type nth)
42 {
43 BOOST_RANGE_CONCEPT_ASSERT(( RandomAccessRangeConcept<const RandomAccessRange> ));
44 std::nth_element(boost::begin(rng), nth, boost::end(rng));
45 return rng;
46 }
47
48 /// \overload
49 template<class RandomAccessRange, class BinaryPredicate>
nth_element(RandomAccessRange & rng,BOOST_DEDUCED_TYPENAME range_iterator<RandomAccessRange>::type nth,BinaryPredicate sort_pred)50 inline RandomAccessRange& nth_element(RandomAccessRange& rng,
51 BOOST_DEDUCED_TYPENAME range_iterator<RandomAccessRange>::type nth,
52 BinaryPredicate sort_pred)
53 {
54 BOOST_RANGE_CONCEPT_ASSERT(( RandomAccessRangeConcept<RandomAccessRange> ));
55 std::nth_element(boost::begin(rng), nth, boost::end(rng), sort_pred);
56 return rng;
57 }
58
59 /// \overload
60 template<class RandomAccessRange, class BinaryPredicate>
nth_element(const RandomAccessRange & rng,BOOST_DEDUCED_TYPENAME range_iterator<const RandomAccessRange>::type nth,BinaryPredicate sort_pred)61 inline const RandomAccessRange& nth_element(const RandomAccessRange& rng,
62 BOOST_DEDUCED_TYPENAME range_iterator<const RandomAccessRange>::type nth,
63 BinaryPredicate sort_pred)
64 {
65 BOOST_RANGE_CONCEPT_ASSERT(( RandomAccessRangeConcept<const RandomAccessRange> ));
66 std::nth_element(boost::begin(rng), nth, boost::end(rng), sort_pred);
67 return rng;
68 }
69
70 } // namespace range
71 using range::nth_element;
72 } // namespace boost
73
74 #endif // include guard
75