unique

Prototype

template<class ForwardRange>
typename range_return<ForwardRange, return_begin_found>::type
unique(ForwardRange& rng);

template<class ForwardRange>
typename range_return<const ForwardRange, return_begin_found>::type
unique(const ForwardRange& rng);

template<class ForwardRange, class BinaryPredicate>
typename range_return<ForwardRange, return_begin_found>::type
unique(ForwardRange& rng, BinaryPredicate pred);

template<class ForwardRange, class BinaryPredicate>
typename range_return<const ForwardRange, return_begin_found>::type
unique(const ForwardRange& rng, BinaryPredicate pred);

template<range_return_value re, class ForwardRange>
typename range_return<ForwardRange, re>::type
unique(ForwardRange& rng);

template<range_return_value re, class ForwardRange>
typename range_return<const ForwardRange, re>::type
unique(const ForwardRange& rng);

template<range_return_value re, class ForwardRange, class BinaryPredicate>
typename range_return<ForwardRange, re>::type
unique(ForwardRange& rng, BinaryPredicate pred);

template<range_return_value re, class ForwardRange, class BinaryPredicate>
typename range_return<const ForwardRange, re>::type
unique(const ForwardRange& rng, BinaryPredicate pred);

Description

unique removes all but the first element of each sequence of duplicate encountered in rng.

Elements in the range [new_last, end(rng)) are dereferenceable but undefined.

Equality is determined by the predicate if one is supplied, or by operator==() for ForwardRange's value type.

Definition

Defined in the header file boost/range/algorithm/unique.hpp

Requirements

For the non-predicate versions of unique:

ForwardRange is a model of the Forward Range Concept.
ForwardRange is mutable.
ForwardRange's value type is a model of the EqualityComparableConcept.

For the predicate versions of unique:

ForwardRange is a model of the Forward Range Concept.
ForwardRange is mutable.
BinaryPredicate is a model of the BinaryPredicateConcept.
ForwardRange's value type is convertible to BinaryPredicate's first argument type and to BinaryPredicate's second argument type.

Complexity

Linear. O(N) where N is distance(rng). Exactly distance(rng) comparisons are performed.