Iterators

Kokkos::Experimental::{begin, cbegin, end, cend}

Header File: Kokkos_Core.hpp

template <class DataType, class... Properties>
KOKKOS_INLINE_FUNCTION auto begin(const Kokkos::View<DataType, Properties...>& view);  (1)

template <class DataType, class... Properties>
KOKKOS_INLINE_FUNCTION auto cbegin(const Kokkos::View<DataType, Properties...>& view); (2)

template <class DataType, class... Properties>
KOKKOS_INLINE_FUNCTION auto end(const Kokkos::View<DataType, Properties...>& view);    (3)

template <class DataType, class... Properties>
KOKKOS_INLINE_FUNCTION auto cend(const Kokkos::View<DataType, Properties...>& view);   (4)

Description

• (1,2) return a Kokkos iterator to the beginning of view
• (3,4) return a Kokkos iterator to the element past the end of view

Notes

• for performance reasons, these functions currently return a random access iterator

• cbegin, cend ensure that the dereferenced iterator is const-qualified.

• view is taken as const because, within each function, we are not changing the view itself: the returned iterator operates on the view without changing its structure.

• dereferencing an iterator must be done within an execution space where view is accessible

Parameters and Requirements

• view: must be a rank-1 view with LayoutLeft, LayoutRight, or LayoutStride

Example

namespace KE = Kokkos::Experimental;
using view_type = Kokkos::View<int*>;
view_type a("a", 15);

auto it = KE::begin(a);
// if dereferenced (within a proper execution space), can modify the content of `a`

auto itc = KE::cbegin(a);
// if dereferenced (within a proper execution space), can only read the content of `a`