[mdspan.sub.map.rightpad] (original) (raw)
23 Containers library [containers]
23.7 Views [views]
23.7.3 Multidimensional access [views.multidim]
23.7.3.7 submdspan [mdspan.sub]
23.7.3.7.6 Specializations of submdspan_mapping [mdspan.sub.map]
23.7.3.7.6.6 layout_right_padded specialization of submdspan_mapping [mdspan.sub.map.rightpad]
template<class Extents> template<class... SliceSpecifiers> constexpr auto layout_right_padded::mapping<Extents>::submdspan-mapping-impl( SliceSpecifiers... slices) const -> _see below_;
Returns:
- submdspan_mapping_result{*this, 0}, if rank_ == 0 is true;
- otherwise,submdspan_mapping_result{layout_right::mapping(sub_ext), offset},
if rank_ == 1 is true orSubExtents::rank() == 0 is true; - otherwise,submdspan_mapping_result{layout_right::mapping(sub_ext), offset}, if
- SubExtents::rank() == 1 is true and
- for k equal to rank_ - 1, is a unit-stride slice for mapping;
- otherwise,submdspan_mapping_result{layout_right_padded<S_static>::mapping(sub_ext, stride(rank_ - u - 2)), offset} if for a value ufor which rank_ - u - 2is the largest value p smaller than rank_ - 1for which is a unit-stride slice for mapping, the following conditions are met:
- for k equal to rank_ - 1, is a unit-stride slice for mapping; and
- for each k in the range [rank_ - SubExtents::rank() - u + 1, rank_ - u - 1)),is_convertible_v<, full_extent_t> is true; and
- for k equal to rank_ - SubExtents::rank() - u,
is a unit-stride slice for mapping;
and where S_static is: - dynamic_extentif static-padding-stride is dynamic_extent or for any k in the range [rank_ - u - 1, rank_ - 1)static_extent(k) is dynamic_extent,
- otherwise, the product of static-padding-stride and all values static_extent(k)with k in the range [rank_ - u - 1, rank_ - 1);
- otherwise,submdspan_mapping_result{layout_stride::mapping(sub_ext, sub_strides), offset}