23 Containers library [containers]

23.7 Views [views]

23.7.3 Multidimensional access [views.multidim]

23.7.3.3 Class template extents [mdspan.extents]

23.7.3.3.7 Alias template dims [mdspan.extents.dims]

template<size_t Rank, class IndexType = size_t> using dims = see below;
Result: A type E that is a specialization of extents such that E​::​rank() == Rank && E​::​rank() == E​::​rank_dynamic() is true, and E​::​index_type denotes IndexType.