Suppose there were no question-mark optional syntax and no standard Optional. If you had to design a type in Swift that expresses 'a value or nothing,' how would you define it?
Define a generic enum Maybe<Wrapped> with two cases, .none for no value and .some(Wrapped) for a value, and extract with switch pattern matching. The standard Optional has exactly this structure.
SwiftMultiple choiceBasics
What does this code print? …
#map #flatmap
SwiftShort answerIntro
Why does Swift have optionals?
#optional #enum
SwiftShort answerBasics
Extend Array with a myCompactMap that behaves like the standard library's compactMap. How…
#optional #generics
SwiftShort answerBasics
Extend Optional so that any optional can be asked for its nil status, like…
#optional #enum