Does using let _ = ... have any purpose at all?
I\'ve seen question and answers for What's the _ underscore representative of in Swift References? a
Using let _ = ... specifically tells the compiler that you know that the expression on the right returns a value but that you don't care about it.
In instances where the method has been marked with warn_unused_result, if you don't use the underscore then the compiler will complain with a warning. (Because in some cases it could be an error to not use the return value.)