> It's called the "if" clause. "If" is often a statement, not an expression, so they aren't equivalent in a lot of cases. I'm not sure if this is the case in S

> It's called the "if" clause. "If" is often a statement, not an expression, so they aren't equivalent in a lot of cases. I'm not sure if this is the case in Swift, but I'm fairly certain that Swift's '?' operator also does unwrapping and propagation, similar to '?' in Rust.