Change type to non-optional after get rid of nils by applying filter

Here's a way without force-unwrapping that is still mostly readable:

let result = elements.compactMap { $0 as? (Int, Int?) }

Printing out result shows that it works:

[(1, Optional(2)), (2, Optional(1)), (3, nil), (5, Optional(6)), (6, Optional(5))]

The only way without force unwrapping (!) I could think of is:

let result = elements.compactMap { (x, y) in { ($0, y) } }

But that sacrifices readability. I would just keep the force unwrapping to be honest. It's not an "absolute evil" thing. Sometimes you need it.