Intel® oneAPI DPC++/C++ Compiler Developer Guide and Reference

ID 767253
Date 3/22/2024
Public

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index_d template function

Syntax

template<int DimensionT, typename ObjT>
auto index_d(const ObjT &a_obj)

Description

The template function offers a consistent way to determine the index of a dimension for a multi-dimensional object. It can avoid extracting an entire n_index_t<…> when only the extent of a single dimension is needed.

Template Argument Description
int DimensionT

0 based index starting at the leftmost dimension indicating which n-dimensions to query the index of.

Requirements: DimensionT >=0 and DimensionT < ObjT::rank

typename ObjT

The type of n-dimensional object from which to retrieve the extent.

Requirements: ObtT is one of:

n_index_t<…>

n_index_generator<…>

Returns

The correctly typed index corresponding to the requested DimensionT of a_obj.

Example

template <typename IndicesT>
void foo(const IndicesT & a_pos)
{
    int z = index_d<0>(a_pos);
    int y = index_d<1>(a_pos);
    int x = index_d<2>(a_pos);
    /…
}