Boost
C++ Libraries
...one of the most highly
regarded and expertly designed C++ library projects in the
world.
— Herb Sutter and Andrei
Alexandrescu, C++
Coding Standards
template<class RandomAccessRange> RandomAccessRange& nth_element( RandomAccessRange& rng, typename range_iterator<RandomAccessRange>::type nth); template<class RandomAccessRange> const RandomAccessRange& nth_element( const RandomAccessRange& rng, typename range_iterator<const RandomAccessRange>::type nth); template<class RandomAccessRange> RandomAccessRange& nth_element( RandomAccessRange& rng, typename range_iterator<RandomAccessRange>::type nth, BinaryPredicate sort_pred); template<class RandomAccessRange> const RandomAccessRange& nth_element( const RandomAccessRange& rng, typename range_iterator<const RandomAccessRange>::type nth, BinaryPredicate sort_pred);
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.
Defined in the header file boost/range/algorithm/nth_element.hpp
For the non-predicate version:
RandomAccessRange
is a model of the Random
Access Range Concept.
RandomAccessRange
is mutable.
RandomAccessRange's
value type is a model of the LessThanComparableConcept.
RandomAccessRange's
value type is a strict weak ordering,
as defined in the LessThanComparableConcept
requirements.
For the predicate version:
RandomAccessRange
is a model of the Random
Access Range Concept.
RandomAccessRange
is mutable.
BinaryPredicate is
a model of the StrictWeakOrderingConcept.
RandomAccessRange's
value type is convertible to both of BinaryPredicate's
argument types.
On average, linear in distance(rng).