Cool, I didn't know that Rust did that (or have forgotten)!

But it sure looks like a map where we throw away the result. What I mean with that is that the loop construct must be served the iterations from an iterator, which may or may not use immutable data. I don't think you can make an immutable while loop, for example?

EDIT: Also, you better have a side-effect in that construct, otherwise it has no effect, right?