copy_if

Header: <Kokkos_StdAlgorithms.hpp>

Description

Copies the elements for which a predicate returns true from source range or View to another range or View

Interface

Warning

This is currently inside the Kokkos::Experimental namespace.

Overload set accepting execution space

template <
  class ExecutionSpace, class InputIteratorType,
  class OutputIteratorType, class UnaryPredicateType>
OutputIteratorType copy_if(const ExecutionSpace& exespace,                   (1)
                           InputIteratorType first_from,
                           InputIteratorType last_from,
                           OutputIteratorType first_to,
                           UnaryPredicateType pred);

template <
  class ExecutionSpace, class InputIteratorType,
  class OutputIteratorType, class UnaryPredicateType>
OutputIteratorType copy_if(const std::string& label,
                           const ExecutionSpace& exespace,                   (2)
                           InputIteratorType first_from,
                           InputIteratorType last_from,
                           OutputIteratorType first_to,
                           UnaryPredicateType pred);

template <
  class ExecutionSpace,
  class DataType1, class... Properties1,
  class DataType2, class... Properties2,
  class UnaryPredicateType
>
auto copy_if(const ExecutionSpace& exespace,                                 (3)
             const Kokkos::View<DataType1, Properties1...>& view_from,
             const Kokkos::View<DataType2, Properties2...>& view_to,
             UnaryPredicateType pred);

template <
  class ExecutionSpace,
  class DataType1, class... Properties1,
  class DataType2, class... Properties2,
  class UnaryPredicateType
>
auto copy_if(const std::string& label, const ExecutionSpace& exespace,       (4)
             const Kokkos::View<DataType1, Properties1...>& view_from,
             const Kokkos::View<DataType2, Properties2...>& view_to,
             UnaryPredicateType pred);

Overload set accepting a team handle

New in version 4.2.

template <
  class TeamHandleType, class InputIteratorType,
  class OutputIteratorType, class UnaryPredicateType>
KOKKOS_FUNCTION
OutputIteratorType copy_if(const TeamHandleType& teamHandle,                 (5)
                           InputIteratorType first_from,
                           InputIteratorType last_from,
                           OutputIteratorType first_to,
                           UnaryPredicateType pred);

template <
  class TeamHandleType,
  class DataType1, class... Properties1,
  class DataType2, class... Properties2,
  class UnaryPredicateType>
KOKKOS_FUNCTION
auto copy_if(const TeamHandleType& teamHandle,                              (6)
             const Kokkos::View<DataType1, Properties1...>& view_from,
             const Kokkos::View<DataType2, Properties2...>& view_to,
             UnaryPredicateType pred);

Parameters and Requirements

• exespace, teamHandle, first_from, last_from, first_to, view_from, view_to: same as in copy

• label:

  • for 1, the default string is: “Kokkos::copy_if_iterator_api_default”

  • for 3, the default string is: “Kokkos::copy_if_view_api_default”

• pred: unary predicate which returns true for the required element to copy

  • pred(v) must be valid to be called from the execution space passed or the execution space associated with the team handle, and convertible to bool for every argument v of type (possible const) value_type, where value_type is the value type of InputIteratorType or of view_from, and must not modify v.

  • must conform to:

  struct Predicate
  {
     KOKKOS_INLINE_FUNCTION
     bool operator()(const value_type & v) const { return /* ... */; }
  
     // or, also valid
  
     KOKKOS_INLINE_FUNCTION
     bool operator()(value_type v) const { return /* ... */; }
  };
  

Return Value

Iterator to the destination element after the last element copied.