is_partitioned#

Overloads#

is_partitioned(exec, first, last, pred)#

template<typename DerivedPolicy, typename InputIterator, typename Predicate>
bool thrust::is_partitioned(
const thrust::detail::execution_policy_base<DerivedPolicy> &exec,
InputIterator first,
InputIterator last,
Predicate pred,
)#

is_partitioned returns true if the given range is partitioned with respect to a predicate, and false otherwise.

Specifically, is_partitioned returns true if [first, last) is empty of if [first, last) is partitioned by pred, i.e. if all elements that satisfy pred appear before those that do not.

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

#include <thrust/partition.h>
#include <thrust/execution_policy.h>

struct is_even
{
  __host__ __device__
  bool operator()(const int &x)
  {
    return (x % 2) == 0;
  }
};

...

int A[] = {2, 4, 6, 8, 10, 1, 3, 5, 7, 9};
int B[] = {1, 2, 3, 4, 5, 6, 7, 8, 9, 10};

thrust::is_partitioned(thrust::host, A, A + 10, is_even()); // returns true
thrust::is_partitioned(thrust::host, B, B + 10, is_even()); // returns false

See also

partition

Parameters:

  • exec – The execution policy to use for parallelization.

  • first – The beginning of the range to consider.

  • last – The end of the range to consider.

  • pred – A function object which decides to which partition each element of the range [first, last) belongs.

Template Parameters:

  • DerivedPolicy – The name of the derived execution policy.

  • InputIterator – is a model of Input Iterator, and InputIterator's value_type is convertible to Predicate's argument type.

  • Predicate – is a model of Predicate.

Returns:

true if the range [first, last) is partitioned with respect to pred, or if [first, last) is empty. false, otherwise.

is_partitioned(first, last, pred)#

template<typename InputIterator, typename Predicate>
bool thrust::is_partitioned(
InputIterator first,
InputIterator last,
Predicate pred,
)#

is_partitioned returns true if the given range is partitioned with respect to a predicate, and false otherwise.

Specifically, is_partitioned returns true if [first, last) is empty of if [first, last) is partitioned by pred, i.e. if all elements that satisfy pred appear before those that do not.

#include <thrust/partition.h>

struct is_even
{
  __host__ __device__
  bool operator()(const int &x)
  {
    return (x % 2) == 0;
  }
};

...

int A[] = {2, 4, 6, 8, 10, 1, 3, 5, 7, 9};
int B[] = {1, 2, 3, 4, 5, 6, 7, 8, 9, 10};

thrust::is_partitioned(A, A + 10, is_even()); // returns true
thrust::is_partitioned(B, B + 10, is_even()); // returns false

See also

partition

Parameters:

  • first – The beginning of the range to consider.

  • last – The end of the range to consider.

  • pred – A function object which decides to which partition each element of the range [first, last) belongs.

Template Parameters:

  • InputIterator – is a model of Input Iterator, and InputIterator's value_type is convertible to Predicate's argument type.

  • Predicate – is a model of Predicate.

Returns:

true if the range [first, last) is partitioned with respect to pred, or if [first, last) is empty. false, otherwise.