According to the documentation (scroll down to Tuples), there are three ways to do it.
Given
var answer: (number: Int, good: Bool) = (100, true)
Method 1
Put the element variable name within a tuple.
let (firstElement, _) = answer
let (_, secondElement) = answer
or
let (firstElement, secondElement) = answer
Method 2
Use the index.
let firstElement = answer.0
let secondElement = answer.1
Method 3
Use the names. This only works, of course, if the elements were named in the Tuple declaration.
let firstElement = answer.number
let secondElement = answer.good