In Rust you can write ```f: fn(i32) -> i32```. Ocaml's syntax is more consistent, I agree, but its colon operator has different precedence than in Rust, so I a

In Rust you can write ```f: fn(i32) -> i32```. Ocaml's syntax is more consistent, I agree, but its colon operator has different precedence than in Rust, so I am not sure its rational applies to Rust.