[lucozade]

It depends on what mistake you mean.

Having errors on return has merits. Particularly it make error handling more deterministic. What it tends to do though, in languages like C and Go, is be very verbose.

Rust largely mitigates that through judicious usage of some of its higher levels features. Specifically its try! macro wrap up the common case of passing errors up the call stack quite neatly. With that and the pervasive RAII, Rust does a pretty good job of making error management quite unobtrusive.

It also has quite a nice way of converting errors types using traits that, in my opinion at least, handles typed error propagation better than most exception mechanisms I am familiar with.

From a personal pov, I like the determinism and I like the type conversion. I probably prefer D's scope mechanism to RAII in general as I like thinks to be as explicit as possibly but without being too verbose. But I think Rust seems to have hit quite a nice balance.