To me, these sorts of examples always seem contrived. To the first order, I've never had a real hash table problem that was on machine word keys.

I've nearly always had a variable length string or other complex structure that was being hashed, not their handles.

Back in my early career in C, this would be a generic API to hash and store void pointers, but the pointers were not being hashed. The domain-specific hash function needed to downcast and perform the appropriate remote memory access to fetch the variable-length material that was actually being hashed.