[Manishearth]

I think they were talking about the compiler-enforced exhaustive match, not must_use.

The fact that you must acknowledge the existence of the error value before accessing the meaty success value (either with a match, an unwrap, or a try) is a great feature in Rust.

must_use forcing you to handle errors for things you don't need the meaty success value of is just icing on the cake.