unique

Header: Kokkos_StdAlgorithms.hpp

Description

Eliminates all except the first element from every consecutive group of equivalent elements in a range or in a View and returns an iterator to the element after the new logical end of the range. Equivalence is checked using operator== and the binary predicate pred.

Interface

Warning

This is currently inside the Kokkos::Experimental namespace.

Overload set accepting execution space

template <class ExecutionSpace, class IteratorType>
IteratorType unique(const ExecutionSpace& exespace,                       (1)
                    IteratorType first, IteratorType last);

template <class ExecutionSpace, class IteratorType>
IteratorType unique(const std::string& label,                             (2)
                    const ExecutionSpace& exespace,
                    IteratorType first, IteratorType last);

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

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

template <class ExecutionSpace, class IteratorType, class BinaryPredicate>
IteratorType unique(const ExecutionSpace& exespace,                       (5)
                    IteratorType first, IteratorType last,
                    BinaryPredicate pred);

template <class ExecutionSpace, class IteratorType, class BinaryPredicate>
IteratorType unique(const std::string& label,                             (6)
                    const ExecutionSpace& exespace,
                    IteratorType first, IteratorType last,
                    BinaryPredicate pred);

template <
  class ExecutionSpace,
  class DataType, class... Properties,
  class BinaryPredicate>
auto unique(const ExecutionSpace& exespace,                               (7)
            const Kokkos::View<DataType, Properties...>& view,
            BinaryPredicate pred);

template <
  class ExecutionSpace,
  class DataType, class... Properties,
  class BinaryPredicate>
auto unique(const std::string& label,                                     (8)
            const ExecutionSpace& exespace,
            const Kokkos::View<DataType, Properties...>& view,
            BinaryPredicate pred);

Overload set accepting a team handle

New in version 4.2.

template <class TeamHandleType, class IteratorType>
KOKKOS_FUNCTION
IteratorType unique(const TeamHandleType& teamHandle,                     (9)
                    IteratorType first, IteratorType last);

template <class TeamHandleType, class DataType, class... Properties>
KOKKOS_FUNCTION
auto unique(const TeamHandleType& teamHandle,                             (10)
            const Kokkos::View<DataType, Properties...>& view);

template <class TeamHandleType, class IteratorType, class BinaryPredicate>
KOKKOS_FUNCTION
IteratorType unique(const TeamHandleType& teamHandle,                     (11)
                    IteratorType first, IteratorType last,
                    BinaryPredicate pred);

template <
    class TeamHandleType,
    class DataType, class... Properties,
    class BinaryPredicate>
KOKKOS_FUNCTION
auto unique(const TeamHandleType& teamHandle,                             (12)
            const Kokkos::View<DataType, Properties...>& view,
            BinaryPredicate pred);

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, 5: The default string is “Kokkos::unique_iterator_api_default”.

  • 3, 7: The default string is “Kokkos::unique_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

• pred:

  • unary predicate returning true for the required element to replace; pred(v) must be valid to be called from the execution space passed, and convertible to bool for every argument v of type (possible const) value_type, where value_type is the value type of IteratorType (for 1,2,5,6,9,11) or the value type of view (for 3,4,7,8,10,12), 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 element after the new logical end of the range.