count#

Header: <Kokkos_StdAlgorithms.hpp>

Description#

Returns the number of elements in a range or in rank-1 View that are equal to a target value.

Interface#

Warning

This is currently inside the Kokkos::Experimental namespace.

Overload set accepting execution space#

template <class ExecutionSpace, class IteratorType, class T>
typename IteratorType::difference_type count(const ExecutionSpace& exespace,
                                             IteratorType first,
                                             IteratorType last,                      (1)
                                             const T& value);

template <class ExecutionSpace, class IteratorType, class T>
typename IteratorType::difference_type count(const std::string& label,
                                             const ExecutionSpace& exespace,
                                             IteratorType first,
                                             IteratorType last,                      (2)
                                             const T& value);

template <class ExecutionSpace, class DataType, class... Properties, class T>
auto count(const ExecutionSpace& exespace,                                           (3)
           const ::Kokkos::View<DataType, Properties...>& view, const T& value);

template <class ExecutionSpace, class DataType, class... Properties, class T>
auto count(const std::string& label, const ExecutionSpace& exespace,                 (4)
           const ::Kokkos::View<DataType, Properties...>& view,
           const T& value);

Overload set accepting a team handle#

New in version 4.2.

template <class TeamHandleType, class IteratorType, class T>
KOKKOS_FUNCTION
typename IteratorType::difference_type count(const TeamHandleType& teamHandle,
                                             IteratorType first,
                                             IteratorType last,                      (5)
                                             const T& value);

template <class TeamHandleType, class DataType, class... Properties, class T>
KOKKOS_FUNCTION
auto count(const TeamHandleType& teamHandle,                                         (6)
           const ::Kokkos::View<DataType, Properties...>& view,
           const T& value);

Parameters and Requirements#

  • exespace: execution space instance

  • teamHandle: team handle instance given inside a parallel region when using a TeamPolicy

  • label: string forwarded to internal parallel kernels for debugging purposes

    • 1: The default string is “Kokkos::count_iterator_api_default”.

    • 3: The default string is “Kokkos::count_view_api_default”.

    • NOTE: overloads accepting a team handle do not use a label internally

  • first, last: range of elements to search in

    • must be random access iterators, e.g., returned from Kokkos::Experimental::(c)begin/(c)end

    • must represent a valid range, i.e., last >= first

    • must be accessible from exespace or from the execution space associated with the team handle

  • view:

    • must be rank-1, and have LayoutLeft, LayoutRight, or LayoutStride

    • must be accessible from exespace or from the execution space associated with the team handle

Return Value#

Returns the number of elements in the range first, last or in view that are equal to value.