Tuples & sets

Tuples: a fixed little bundle

A tuple is like a list, but frozen in length and (usually) meant to hold a few different things together — think of a GPS fix as (lat, lng). Once built, you can't append to it or reassign a slot.

fix = (37.77, -122.42)
lat, lng = fix   # unpacking — pull both values out in one line

That unpacking trick — lat, lng = fix — has no direct one-liner in Swift; the closest is destructuring a tuple in a let (lat, lng) = fix.