My point is that whether it's "A() error" or "A() (int, error)", whether it calls one function or three, what it's doing with the error is throwing it up the li

My point is that whether it's "A() error" or "A() (int, error)", whether it calls one function or three, what it's doing with the error is throwing it up the line, rather than handling it locally. Exactly as if it had said "throw err". So yeah, your version is what I'd shorten it to in practise, it just wasn't quite so illustrative.