unique_copy#

Overloads#

unique_copy(exec, first, last, result)#

template<typename DerivedPolicy, typename InputIterator, typename OutputIterator>
OutputIterator thrust::unique_copy(
const thrust::detail::execution_policy_base<DerivedPolicy> &exec,
InputIterator first,
InputIterator last,
OutputIterator result,
)#

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.

The reason there are two different versions of unique_copy is that there are two different definitions of what it means for a consecutive group of elements to be duplicates. In the first version, the test is simple equality: the elements in a range [f, l) are duplicates if, for every iterator i in the range, either i == f or else *i == *(i-1). In the second, the test is an arbitrary BinaryPredicate binary_pred: the elements in [f, l) are duplicates if, for every iterator i in the range, either i == f or else binary_pred(*i, *(i-1)) is true.

This version of unique_copy uses operator== to test for equality.

The algorithm’s execution is parallelized as determined by exec.

The following code snippet demonstrates how to use unique_copy to compact a sequence of numbers to remove consecutive duplicates using the thrust::host execution policy for parallelization:

#include <thrust/unique.h>
#include <thrust/execution_policy.h>
...
const int N = 7;
int A[N] = {1, 3, 3, 3, 2, 2, 1};
int B[N];
int *result_end = thrust::unique_copy(thrust::host, A, A + N, B);
// 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

See also

https://en.cppreference.com/w/cpp/algorithm/unique_copy

Parameters:

  • exec – The execution policy to use for parallelization.

  • first – The beginning of the input range.

  • last – The end of the input range.

  • result – The beginning of the output range.

Template Parameters:

  • DerivedPolicy – The name of the derived execution policy.

  • InputIterator – is a model of Input Iterator, and InputIterator's value_type is a model of Equality Comparable.

  • OutputIterator – is a model of Output Iterator and and InputIterator's value_type is convertible to OutputIterator's value_type.

Returns:

The end of the unique range [result, result_end).

Pre:

The range [first,last) and the range [result, result + (last - first)) shall not overlap.

unique_copy(first, last, result)#

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

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.

The reason there are two different versions of unique_copy is that there are two different definitions of what it means for a consecutive group of elements to be duplicates. In the first version, the test is simple equality: the elements in a range [f, l) are duplicates if, for every iterator i in the range, either i == f or else *i == *(i-1). In the second, the test is an arbitrary BinaryPredicate binary_pred: the elements in [f, l) are duplicates if, for every iterator i in the range, either i == f or else binary_pred(*i, *(i-1)) is true.

This version of unique_copy uses operator== to test for equality.

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);
// 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

See also

https://en.cppreference.com/w/cpp/algorithm/unique_copy

Parameters:

  • first – The beginning of the input range.

  • last – The end of the input range.

  • result – The beginning of the output range.

Template Parameters:

  • InputIterator – is a model of Input Iterator, and InputIterator's value_type is a model of Equality Comparable.

  • OutputIterator – is a model of Output Iterator and and InputIterator's value_type is convertible to OutputIterator's value_type.

Returns:

The end of the unique range [result, result_end).

Pre:

The range [first,last) and the range [result, result + (last - first)) shall not overlap.

unique_copy(exec, first, last, result, binary_pred)#

template<typename DerivedPolicy, typename InputIterator, typename OutputIterator, typename BinaryPredicate>
OutputIterator thrust::unique_copy(
const thrust::detail::execution_policy_base<DerivedPolicy> &exec,
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.

The algorithm’s execution is parallelized as determined by exec.

The following code snippet demonstrates how to use unique_copy to compact a sequence of numbers to remove consecutive duplicates using the thrust::host execution policy for parallelization:

#include <thrust/unique.h>
#include <thrust/execution_policy.h>
...
const int N = 7;
int A[N] = {1, 3, 3, 3, 2, 2, 1};
int B[N];
int *result_end = thrust::unique_copy(thrust::host, A, A + N, B, ::cuda::std::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

See also

https://en.cppreference.com/w/cpp/algorithm/unique_copy

Parameters:

  • exec – The execution policy to use for parallelization.

  • first – The beginning of the input range.

  • last – The end of the input range.

  • result – The beginning of the output range.

  • binary_pred – The binary predicate used to determine equality.

Template Parameters:

  • DerivedPolicy – The name of the derived execution policy.

  • InputIterator – is a model of Input Iterator, and InputIterator's value_type is a model of Equality Comparable.

  • OutputIterator – is a model of Output Iterator and and InputIterator's value_type is convertible to OutputIterator's value_type.

  • BinaryPredicate – is a model of Binary Predicate.

Returns:

The end of the unique range [result, result_end).

Pre:

The range [first,last) and the range [result, result + (last - first)) shall not overlap.

unique_copy(first, last, result, binary_pred)#

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.

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, ::cuda::std::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

See also

https://en.cppreference.com/w/cpp/algorithm/unique_copy

Parameters:

  • first – The beginning of the input range.

  • last – The end of the input range.

  • result – The beginning of the output range.

  • binary_pred – The binary predicate used to determine equality.

Template Parameters:
Returns:

The end of the unique range [result, result_end).

Pre:

The range [first,last) and the range [result, result + (last - first)) shall not overlap.