Providing a default value for an Optional in Swift?

Question

The idiom for dealing with optionals in Swift seems excessively verbose, if all you want to do is provide a default value in the case where it\'s nil:

if let         


        

Answer 1

The following seems to work

extension Optional {
    func getOrElse(defaultValue: T) -> T {
        if let value = self? {
            return value as T
        } else {
            return defaultValue
        }
    }
}

however the need to cast value as T is an ugly hack. Ideally, there should be a way to assert that T is the same as the type contained in the Optional. As it stands, type inferencing sets T based on the parameter given to getOrElse, and then fails at runtime if this does not match the Optional and the Optional is non-nil:

let x: Int?

let y = x.getOrElse(1.414) // y inferred as Double, assigned 1.414

let a: Int? = 5

let b: Double = a.getOrElse(3.14) // Runtime failure casting 5 to Double