Yes, those are phantom types. Many languages allow phantom types --- basically any language that has type parameters. So Haskell as we've seen, Scala as you poi

Yes, those are phantom types. Many languages allow phantom types --- basically any language that has type parameters. So Haskell as we've seen, Scala as you point out, ML, Rust, etc. That's not the interesting part, though. It's the linear types that are giving the guarantees here, and linear type systems are rare.