使用Swift 3初始化一个空的NSZone结构

Question

In Swift 2, I was able to initialize an empty NSZone struct like so:

let z = NSZone() // ObjectiveC.NSZone

I used this to stub test calls that required NSZone . With Swift 3, the interface was changed so that the initializer is no longer available:

Swift 2.3:

public struct NSZone : NilLiteralConvertible {
    public init()
    /// Create an instance initialized with `nil`.
    public init(nilLiteral: ())
}

Swift 3:

public struct NSZone {
}

Is Apple pushing to use an optional NSZone instead of the old NSZone() initializer which initialized NSZone with a nil value?

Try to extend NSZone to add an initializer results in an error:

extension NSZone {
    init() { } // Return from initializer without initializing all stored properties
}

Answer 1

Per the Swift open source project's design doc for importing ObjC API into Swift 3:

Nullable NSZone parameters are given a default value of nil . Zones are essentially unused in Swift and should always be nil .

If you're testing any calls that require a zone, you should be passing nil anyway.