[mdspan.sub.map.leftpad]

🔗

template<class Extents>
template<class... SliceSpecifiers>
constexpr auto layout_left_padded::mapping<Extents>::submdspan-mapping-impl(
    SliceSpecifiers... slices) const -> see below;

Returns:

(1.1)
submdspan_mapping_result{*this, 0}, if Extents::rank() == 0 is true;
(1.2)
otherwise, submdspan_mapping_result{layout_left::mapping(sub_ext), offset}, if rank_ == 1 is true or SubExtents::rank() == 0 is true;
(1.3)
otherwise, submdspan_mapping_result{layout_left::mapping(sub_ext), offset}, if
- (1.3.1)
  SubExtents::rank() == 1 is true and
- (1.3.2)
  $S_{0}$ is a unit-stride slice for mapping;
(1.4)
otherwise, submdspan_mapping_result{layout_left_padded<S_static>::mapping(sub_ext, stride(u + 1)), offset} if for a value u for which u + 1 is the smallest value p larger than zero for which $S_{p}$ is a unit-stride slice for mapping, the following conditions are met:
- (1.4.1)
  $S_{0}$ is a unit-stride slice for mapping; and
- (1.4.2)
  for each k in the range [u + 1, u + SubExtents::rank() - 1), is_convertible_v< $S_{k}$ , full_extent_t> is true; and
- (1.4.3)
  for k equal to u + SubExtents::rank() - 1, $S_{k}$ is a unit-stride slice for mapping;
where S_static is:
- (1.4.4)
  dynamic_extent, if static-padding-stride is dynamic_extent or static_extent(k) is dynamic_extent for any k in the range [1, u + 1),
- (1.4.5)
  otherwise, the product of static-padding-stride and all values static_extent(k) for k in the range [1, u + 1);
(1.5)
otherwise, submdspan_mapping_result{layout_stride::mapping(sub_ext, sub_strides), offset}

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]

23.7.3.7.6.5 layout_left_padded specialization of submdspan_mapping [mdspan.sub.map.leftpad]