> Without the let, I'd have to do a match statement followed by an unwrap just to check if a field in an enum is set.

You... would not?

An `if let` trivially desugars to a `match`.

    if let <pat> = <expr> {
        ...
    }

becomes

    match <expr> {
        <pat> => {
            ...
        }
        _ => {}
    }