Template Function thrust::unique(ForwardIterator, ForwardIterator, BinaryPredicate)¶

Function Documentation¶

template<typename ForwardIterator, typename BinaryPredicate> ForwardIterator thrust::unique(ForwardIterator first, ForwardIterator last, BinaryPredicate binary_pred)

For each group of consecutive elements in the range [first, last) with the same value, unique removes all but the first element of the group. The return value is an iterator new_last such that no two consecutive elements in the range [first, new_last) are equal. The iterators in the range [new_last, last) are all still dereferenceable, but the elements that they point to are unspecified. unique is stable, meaning that the relative order of elements that are not removed is unchanged.

This version of unique uses the function object binary_pred to test for equality.

The following code snippet demonstrates how to use

unique to compact a sequence of numbers to remove consecutive duplicates.

Return

The end of the unique range [first, new_last)

Parameters

first: The beginning of the input range.
last: The end of the input range.
binary_pred: The binary predicate used to determine equality.

Template Parameters

ForwardIterator: is a model of Forward Iterator, and ForwardIterator is mutable, and ForwardIterator's value_type is convertible to BinaryPredicate's first_argument_type and to BinaryPredicate's second_argument_type.
BinaryPredicate: is a model of Binary Predicate.

#include <thrust/unique.h>
...
const int N = 7;
int A[N] = {1, 3, 3, 3, 2, 2, 1};
int *new_end = thrust::unique(A, A + N, thrust::equal_to<int>());
// The first four values of A are now {1, 3, 2, 1}
// Values beyond new_end are unspecified.

See: http://www.sgi.com/tech/stl/unique.html
See: unique_copy