Size of StaticArray type

Using ArrayInterface v5.05 and StaticArrays v1.42:

julia> import ArrayInterface as Arr

julia> using StaticArrays

julia> Arr.known_size(SArray{Tuple{2,3}})
(6,)

julia> Arr.size(StaticArray{Tuple{2,3}})
(static(6),)

Are those the intended results? I expected (2, 3) and (static(2), static(3)), respectively. (Though, things work fine for instances of StaticArrays.)

I think what is happening is that IteratorSize(::Type{<:StaticArray}) is defaulting to HasLength() while it might better off be HasShape{N}(), so the wrong method gets called at some point. If that's the case, perhaps its also worth opening a bug report on StaticArrays.

Also, should ArrayInterface.size produce an error if given a Type as an argument? What should be the behavior if one of the dimensions is unknown?

Reproduce the Julia examples using ArrayInterface.known_size, ArrayInterface.size, StaticArray, and StaticArrays, then inspect the IteratorSize-related dispatch involved in those entry points. Done means the expected behavior for type-level dimensions and unknown dimensions is decided, documented by regression tests, and any needed StaticArrays report is filed.