Does guard make a copy of variables in swift

Question

In swift you can unwrap optional values with a guard statement

guard let foo = foo else { return nil }

Is this statement making a copy of foo? In other words, could this statement be potentially expensive if foo is very large?

Answer 1

Actually this depends on type of foo e.x class type won't create a copy unlike struct type

guard isn't a magic keyword it simply if not presented in 1 word