| Brian Silverman | 598d029 | 2018-08-04 23:56:47 -0700 | [diff] [blame^] | 1 | [/ |
| 2 | Copyright 2010 Neil Groves |
| 3 | Distributed under the Boost Software License, Version 1.0. |
| 4 | (See accompanying file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt) |
| 5 | /] |
| 6 | [section:nth_element nth_element] |
| 7 | |
| 8 | [heading Prototype] |
| 9 | |
| 10 | `` |
| 11 | template<class RandomAccessRange> |
| 12 | RandomAccessRange& nth_element( |
| 13 | RandomAccessRange& rng, |
| 14 | typename range_iterator<RandomAccessRange>::type nth); |
| 15 | |
| 16 | template<class RandomAccessRange> |
| 17 | const RandomAccessRange& nth_element( |
| 18 | const RandomAccessRange& rng, |
| 19 | typename range_iterator<const RandomAccessRange>::type nth); |
| 20 | |
| 21 | template<class RandomAccessRange> |
| 22 | RandomAccessRange& nth_element( |
| 23 | RandomAccessRange& rng, |
| 24 | typename range_iterator<RandomAccessRange>::type nth, |
| 25 | BinaryPredicate sort_pred); |
| 26 | |
| 27 | template<class RandomAccessRange> |
| 28 | const RandomAccessRange& nth_element( |
| 29 | const RandomAccessRange& rng, |
| 30 | typename range_iterator<const RandomAccessRange>::type nth, |
| 31 | BinaryPredicate sort_pred); |
| 32 | `` |
| 33 | |
| 34 | [heading Description] |
| 35 | |
| 36 | `nth_element` partially orders a range of elements. `nth_element` arranges the range `rng` such that the element corresponding with the iterator `nth` is the same as the element that would be in that position if `rng` has been sorted. |
| 37 | |
| 38 | |
| 39 | [heading Definition] |
| 40 | |
| 41 | Defined in the header file `boost/range/algorithm/nth_element.hpp` |
| 42 | |
| 43 | [heading Requirements] |
| 44 | |
| 45 | [*For the non-predicate version:] |
| 46 | |
| 47 | * `RandomAccessRange` is a model of the __random_access_range__ Concept. |
| 48 | * `RandomAccessRange` is mutable. |
| 49 | * `RandomAccessRange`'s value type is a model of the `LessThanComparableConcept`. |
| 50 | * The ordering relation on `RandomAccessRange`'s value type is a [*/strict weak ordering/], as defined in the `LessThanComparableConcept` requirements. |
| 51 | |
| 52 | |
| 53 | [*For the predicate version:] |
| 54 | |
| 55 | * `RandomAccessRange` is a model of the __random_access_range__ Concept. |
| 56 | * `RandomAccessRange` is mutable. |
| 57 | * `BinaryPredicate` is a model of the `StrictWeakOrderingConcept`. |
| 58 | * `RandomAccessRange`'s value type is convertible to both of `BinaryPredicate`'s argument types. |
| 59 | |
| 60 | |
| 61 | [heading Complexity] |
| 62 | |
| 63 | On average, linear in `distance(rng)`. |
| 64 | |
| 65 | [endsect] |
| 66 | |
| 67 | |