thrust::partition_copy#

Overloads#

partition_copy(exec, first, last, out_true, out_false, pred)#

template<typename DerivedPolicy, typename InputIterator, typename OutputIterator1, typename OutputIterator2, typename Predicate>
::cuda::std::pair<OutputIterator1, OutputIterator2> thrust::partition_copy(
const thrust::detail::execution_policy_base<DerivedPolicy> &exec,
InputIterator first,
InputIterator last,
OutputIterator1 out_true,
OutputIterator2 out_false,
Predicate pred
)#

partition_copy differs from partition only in that the reordered sequence is written to different output sequences, rather than in place.

partition_copy copies the elements [first, last) based on the function object pred. All of the elements that satisfy pred are copied to the range beginning at out_true and all the elements that fail to satisfy it are copied to the range beginning at out_false.

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

The following code snippet demonstrates how to use partition_copy to separate a sequence into two output sequences of even and odd numbers using the thrust::host execution policy for parallelization:

#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[] = {1, 2, 3, 4, 5, 6, 7, 8, 9, 10};
int result[10];
const int N = sizeof(A)/sizeof(int);
int *evens = result;
int *odds  = result + 5;
thrust::partition_copy(thrust::host, A, A + N, evens, odds, is_even());
// A remains {1, 2, 3, 4, 5, 6, 7, 8, 9, 10}
// result is now {2, 4, 6, 8, 10, 1, 3, 5, 7, 9}
// evens points to {2, 4, 6, 8, 10}
// odds points to {1, 3, 5, 7, 9}

Added in version 2.2.0.

See also

http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2008/n2569.pdf

See also

stable_partition_copy

See also

partition

Note

The relative order of elements in the two reordered sequences is not necessarily the same as it was in the original sequence. A different algorithm, stable_partition_copy, does guarantee to preserve the relative order.

Parameters:

  • exec – The execution policy to use for parallelization.

  • first – The beginning of the sequence to reorder.

  • last – The end of the sequence to reorder.

  • out_true – The destination of the resulting sequence of elements which satisfy pred.

  • out_false – The destination of the resulting sequence of elements which fail to satisfy pred.

  • pred – A function object which decides to which partition each element of the sequence [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 and InputIterator's value_type is convertible to OutputIterator1 and OutputIterator2's value_types.

  • OutputIterator1 – is a model of Output Iterator.

  • OutputIterator2 – is a model of Output Iterator.

  • Predicate – is a model of Predicate.

Returns:

A pair p such that p.first is the end of the output range beginning at out_true and p.second is the end of the output range beginning at out_false.

Pre:

The input range shall not overlap with either output range.

partition_copy(first, last, out_true, out_false, pred)#

template<typename InputIterator, typename OutputIterator1, typename OutputIterator2, typename Predicate>
::cuda::std::pair<OutputIterator1, OutputIterator2> thrust::partition_copy(
InputIterator first,
InputIterator last,
OutputIterator1 out_true,
OutputIterator2 out_false,
Predicate pred
)#

partition_copy differs from partition only in that the reordered sequence is written to different output sequences, rather than in place.

partition_copy copies the elements [first, last) based on the function object pred. All of the elements that satisfy pred are copied to the range beginning at out_true and all the elements that fail to satisfy it are copied to the range beginning at out_false.

The following code snippet demonstrates how to use partition_copy to separate a sequence into two output sequences of even and odd numbers.

#include <thrust/partition.h>
...
struct is_even
{
  __host__ __device__
  bool operator()(const int &x)
  {
    return (x % 2) == 0;
  }
};
...
int A[] = {1, 2, 3, 4, 5, 6, 7, 8, 9, 10};
int result[10];
const int N = sizeof(A)/sizeof(int);
int *evens = result;
int *odds  = result + 5;
thrust::partition_copy(A, A + N, evens, odds, is_even());
// A remains {1, 2, 3, 4, 5, 6, 7, 8, 9, 10}
// result is now {2, 4, 6, 8, 10, 1, 3, 5, 7, 9}
// evens points to {2, 4, 6, 8, 10}
// odds points to {1, 3, 5, 7, 9}

Added in version 2.2.0.

See also

http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2008/n2569.pdf

See also

stable_partition_copy

See also

partition

Note

The relative order of elements in the two reordered sequences is not necessarily the same as it was in the original sequence. A different algorithm, stable_partition_copy, does guarantee to preserve the relative order.

Parameters:

  • first – The beginning of the sequence to reorder.

  • last – The end of the sequence to reorder.

  • out_true – The destination of the resulting sequence of elements which satisfy pred.

  • out_false – The destination of the resulting sequence of elements which fail to satisfy pred.

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

Template Parameters:

  • InputIterator – is a model of Input Iterator, and InputIterator's value_type is convertible to Predicate's argument type and InputIterator's value_type is convertible to OutputIterator1 and OutputIterator2's value_types.

  • OutputIterator1 – is a model of Output Iterator.

  • OutputIterator2 – is a model of Output Iterator.

  • Predicate – is a model of Predicate.

Returns:

A pair p such that p.first is the end of the output range beginning at out_true and p.second is the end of the output range beginning at out_false.

Pre:

The input range shall not overlap with either output range.

partition_copy(exec, first, last, stencil, out_true, out_false, pred)#

template<typename DerivedPolicy, typename InputIterator1, typename InputIterator2, typename OutputIterator1, typename OutputIterator2, typename Predicate>
::cuda::std::pair<OutputIterator1, OutputIterator2> thrust::partition_copy(
const thrust::detail::execution_policy_base<DerivedPolicy> &exec,
InputIterator1 first,
InputIterator1 last,
InputIterator2 stencil,
OutputIterator1 out_true,
OutputIterator2 out_false,
Predicate pred
)#

partition_copy differs from partition only in that the reordered sequence is written to different output sequences, rather than in place.

partition_copy copies the elements [first, last) based on the function object pred which is applied to a range of stencil elements. All of the elements whose corresponding stencil element satisfies pred are copied to the range beginning at out_true and all the elements whose stencil element fails to satisfy it are copied to the range beginning at out_false.

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

The following code snippet demonstrates how to use partition_copy to separate a sequence into two output sequences of even and odd numbers using the thrust::host execution policy for parallelization.

#include <thrust/partition.h>
#include <thrust/functional.h>
#include <thrust/execution_policy.h>
...
int A[] = {1, 2, 3, 4, 5, 6, 7, 8, 9, 10};
int S[] = {0, 1, 0, 1, 0, 1, 0, 1, 0,  1};
int result[10];
const int N = sizeof(A)/sizeof(int);
int *evens = result;
int *odds  = result + 5;
thrust::stable_partition_copy(thrust::host, A, A + N, S, evens, odds, ::cuda::std::identity{});
// A remains {1, 2, 3, 4, 5, 6, 7, 8, 9, 10}
// S remains {0, 1, 0, 1, 0, 1, 0, 1, 0,  1}
// result is now {2, 4, 6, 8, 10, 1, 3, 5, 7, 9}
// evens points to {2, 4, 6, 8, 10}
// odds points to {1, 3, 5, 7, 9}

Added in version 2.2.0.

See also

http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2008/n2569.pdf

See also

stable_partition_copy

See also

partition

Note

The relative order of elements in the two reordered sequences is not necessarily the same as it was in the original sequence. A different algorithm, stable_partition_copy, does guarantee to preserve the relative order.

Parameters:

  • exec – The execution policy to use for parallelization.

  • first – The beginning of the sequence to reorder.

  • last – The end of the sequence to reorder.

  • stencil – The beginning of the stencil sequence.

  • out_true – The destination of the resulting sequence of elements which satisfy pred.

  • out_false – The destination of the resulting sequence of elements which fail to satisfy pred.

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

Template Parameters:

  • DerivedPolicy – The name of the derived execution policy.

  • InputIterator1 – is a model of Input Iterator, and InputIterator's value_type is convertible to OutputIterator1 and OutputIterator2's value_types.

  • InputIterator2 – is a model of Input Iterator, and InputIterator2's value_type is convertible to Predicate's argument type.

  • OutputIterator1 – is a model of Output Iterator.

  • OutputIterator2 – is a model of Output Iterator.

  • Predicate – is a model of Predicate.

Returns:

A pair p such that p.first is the end of the output range beginning at out_true and p.second is the end of the output range beginning at out_false.

Pre:

The input ranges shall not overlap with either output range.

partition_copy(first, last, stencil, out_true, out_false, pred)#

template<typename InputIterator1, typename InputIterator2, typename OutputIterator1, typename OutputIterator2, typename Predicate>
::cuda::std::pair<OutputIterator1, OutputIterator2> thrust::partition_copy(
InputIterator1 first,
InputIterator1 last,
InputIterator2 stencil,
OutputIterator1 out_true,
OutputIterator2 out_false,
Predicate pred
)#

partition_copy differs from partition only in that the reordered sequence is written to different output sequences, rather than in place.

partition_copy copies the elements [first, last) based on the function object pred which is applied to a range of stencil elements. All of the elements whose corresponding stencil element satisfies pred are copied to the range beginning at out_true and all the elements whose stencil element fails to satisfy it are copied to the range beginning at out_false.

The following code snippet demonstrates how to use partition_copy to separate a sequence into two output sequences of even and odd numbers.

#include <thrust/partition.h>
#include <thrust/functional.h>
...
int A[] = {1, 2, 3, 4, 5, 6, 7, 8, 9, 10};
int S[] = {0, 1, 0, 1, 0, 1, 0, 1, 0,  1};
int result[10];
const int N = sizeof(A)/sizeof(int);
int *evens = result;
int *odds  = result + 5;
thrust::stable_partition_copy(A, A + N, S, evens, odds, ::cuda::std::identity{});
// A remains {1, 2, 3, 4, 5, 6, 7, 8, 9, 10}
// S remains {0, 1, 0, 1, 0, 1, 0, 1, 0,  1}
// result is now {2, 4, 6, 8, 10, 1, 3, 5, 7, 9}
// evens points to {2, 4, 6, 8, 10}
// odds points to {1, 3, 5, 7, 9}

Added in version 2.2.0.

See also

http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2008/n2569.pdf

See also

stable_partition_copy

See also

partition

Note

The relative order of elements in the two reordered sequences is not necessarily the same as it was in the original sequence. A different algorithm, stable_partition_copy, does guarantee to preserve the relative order.

Parameters:

  • first – The beginning of the sequence to reorder.

  • last – The end of the sequence to reorder.

  • stencil – The beginning of the stencil sequence.

  • out_true – The destination of the resulting sequence of elements which satisfy pred.

  • out_false – The destination of the resulting sequence of elements which fail to satisfy pred.

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

Template Parameters:

  • InputIterator1 – is a model of Input Iterator, and InputIterator's value_type is convertible to OutputIterator1 and OutputIterator2's value_types.

  • InputIterator2 – is a model of Input Iterator, and InputIterator2's value_type is convertible to Predicate's argument type.

  • OutputIterator1 – is a model of Output Iterator.

  • OutputIterator2 – is a model of Output Iterator.

  • Predicate – is a model of Predicate.

Returns:

A pair p such that p.first is the end of the output range beginning at out_true and p.second is the end of the output range beginning at out_false.

Pre:

The input ranges shall not overlap with either output range.