Yes. I knew this as list fusion. Note that Rust doesn't need to do this because of the way `iter_into()` and mapping works. List fusion boils down to removin

Yes. I knew this as list fusion. Note that Rust doesn't need to do this because of the way `iter_into()` and mapping works. List fusion boils down to removing interior `.collect().iter_into()`. There is something to be said for designing APIs so that you don't need such rewrite rules, though, of course, the need comes up eventually anyways, so rewrite rules end up being kinda necessary.