23 Containers library [containers]

The submdspan facilities create a new mdspan viewing a subset of elements of an existing input mdspan.

The subset viewed by the created mdspan is determined by the SliceSpecifier arguments.

For each function defined in [mdspan.sub] that takes a parameter pack named slices as an argument:

• (2.1)
  let index_type be
  • (2.1.1)
    M​::​index_type if the function is a member of a class M,
  • (2.1.2)
    otherwise, remove_reference_t<decltype(src)>​::​index_type if the function has a parameter named src,
  • (2.1.3)
    otherwise, the same type as the function's template argument IndexType;
• (2.2)
  let rank be the number of elements in slices;
• (2.3)
  let $s_k$ be the $k^{\text{th}}$ element of slices;
• (2.4)
  let $S_k$ be the type of $s_k$; and
• (2.5)
  let map-rank be an array<size_t, rank> such that for each k in the range [0, rank), map-rank[k] equals:
  • (2.5.1)
    dynamic_extent if $S_k$ models convertible_to<index_type>,
  • (2.5.2)
    otherwise, the number of types $S_j$ with $j<k$ that do not model convertible_to<index_type>.