is_sorted#

Header File: Kokkos_StdAlgorithms.hpp

namespace Kokkos{
namespace Experimental{

//
// overload set accepting iterators
//
template <class ExecutionSpace, class IteratorType>
bool is_sorted(const ExecutionSpace& exespace,                              (1)
               IteratorType first, IteratorType last);

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

template <class ExecutionSpace, class IteratorType, class ComparatorType>
bool is_sorted(const ExecutionSpace& exespace,                              (3)
               IteratorType first, IteratorType last,
               ComparatorType comp);

template <class ExecutionSpace, class IteratorType, class ComparatorType>
bool is_sorted(const std::string& label, const ExecutionSpace& exespace,    (4)
               IteratorType first, IteratorType last,
			   ComparatorType comp);

//
// overload set accepting views
//
template <class ExecutionSpace, class DataType, class... Properties>
bool is_sorted(const ExecutionSpace& exespace,                              (5)
               const ::Kokkos::View<DataType, Properties...>& view);

template <class ExecutionSpace, class DataType, class... Properties>
bool is_sorted(const std::string& label, const ExecutionSpace& exespace,    (6)
               const ::Kokkos::View<DataType, Properties...>& view);

template <
  class ExecutionSpace,
  class DataType, class... Properties, class ComparatorType>
bool is_sorted(const ExecutionSpace& exespace,                              (7)
               const ::Kokkos::View<DataType, Properties...>& view,
               ComparatorType comp);

template <
  class ExecutionSpace,
  class DataType, class... Properties, class ComparatorType>
bool is_sorted(const std::string& label, const ExecutionSpace& exespace,    (8)
               const ::Kokkos::View<DataType, Properties...>& view,
               ComparatorType comp);

} //end namespace Experimental
} //end namespace Kokkos

Description#

  • (1,2,5,6): checks if the elements in the range [first, last) (1,2) or in view (5,6) are sorted in non-descending order using operator< to compare two elements.

  • (3,4,7,8): checks if the elements in the range [first, last) (3,4) or in view (7,8) are sorted in non-descending order using the binary functor comp to compare two elements.

Parameters and Requirements#

  • exespace:

    • execution space instance

  • label:

    • used to name the implementation kernels for debugging purposes

    • for 1,3 the default string is: “Kokkos::is_sorted_iterator_api_default”

    • for 5,7 the default string is: “Kokkos::is_sorted_view_api_default”

  • first, last:

    • range of elements to examine

    • must be random access iterators

    • must represent a valid range, i.e., last >= first (checked in debug mode)

    • must be accessible from exespace

  • view:

    • Kokkos view to examine

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

    • must be accessible from exespace

  • comp:

    • binary functor returning true if the first argument is less than the second argument; comp(a,b) must be valid to be called from the execution space passed, and convertible to bool for every pair of arguments a,b of type value_type, where value_type is the value type of IteratorType (for 1,2,3,4) or the value type of view (for 5,6,7,8) and must not modify a,b.

    • must conform to:

    struct Comparator
    {
       KOKKOS_INLINE_FUNCTION
       bool operator()(const value_type & a, const value_type & b) const {
         return /* true if a is less than b, based on your logic of "less than" */;
       }
    };
    

Return#

True if the elements are sorted in descending order.