You're mixing up a thing you can do with a way that you can do something. You can write Rust code with the same observable behavior as Duff's device in C.

Also, Duff’s device is pretty terrible and a modern compiler will output much better code.

> You're mixing up a thing you can do with a way that you can do something.

I don't think they are.

> You can write Rust code with the same observable behavior as Duff's device in C.

Yes, turing complete languages can do that.

A good example of cool tricks to impress fellow hackers that have no place in code bases that should meet certain quality levels of long term maintenance.