thrust

◆ unique_copy() [4/4]

template<typename InputIterator , typename OutputIterator , typename BinaryPredicate >
OutputIterator thrust::unique_copy ( InputIterator  first,
InputIterator  last,
OutputIterator  result,
BinaryPredicate  binary_pred 
)

unique_copy copies elements from the range [first, last) to a range beginning with result, except that in a consecutive group of duplicate elements only the first one is copied. The return value is the end of the range to which the elements are copied.

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

Parameters
firstThe beginning of the input range.
lastThe end of the input range.
resultThe beginning of the output range.
binary_predThe binary predicate used to determine equality.
Returns
The end of the unique range [result, result_end).
Template Parameters
InputIteratoris a model of Input Iterator, and InputIterator's value_type is a model of Equality Comparable.
OutputIteratoris a model of Output Iterator and and InputIterator's value_type is convertible to OutputIterator's value_type.
BinaryPredicateis a model of Binary Predicate.
Precondition
The range [first,last) and the range [result, result + (last - first)) shall not overlap.

The following code snippet demonstrates how to use unique_copy to compact a sequence of numbers to remove consecutive duplicates.

#include <thrust/unique.h>
...
const int N = 7;
int A[N] = {1, 3, 3, 3, 2, 2, 1};
int B[N];
int *result_end = thrust::unique_copy(A, A + N, B, thrust::equal_to<int>());
// The first four values of B are now {1, 3, 2, 1} and (result_end - B) is 4
// Values beyond result_end are unspecified.
See also
unique
http://www.sgi.com/tech/stl/unique_copy.html