You may wish to have a look at my proposal for partial initializers.  It went 
dormant as I think everyone was burned out on talking about initializers at the 
time.  

https://github.com/anandabits/swift-evolution/blob/partial-initializers/proposals/NNNN-partial-initializers.md

Sent from my iPad

> On Apr 27, 2016, at 4:52 PM, Shannon Potter via swift-evolution 
> <[email protected]> wrote:
> 
> Consider a relatively-common init pattern:
> 
> class SomeViewController: UIViewController {
> 
>   // MARK: Properties
> 
>   private var videoPlayer: AVPlayer
>   private var videoPlayerLayer: AVPlayerLayer
> 
>   // MARK: - Object Lifecycle
> 
>   override init(nibName: String?, bundle nibBundle: NSBundle?) {
>       super.init(nibName: nibName, bundle: nibBundle)
> 
>       commonInitialization()
>   }
> 
>   required init?(coder decoder: NSCoder) {
>       super.init(coder: decoder)
> 
>       commonInitialization()
>   }
> 
>   private func commonInitialization() {
>       videoPlayer = AVPlayer(...)
>       videoPlayerLayer = AVPlayerLayer(player: videoPlayer)
>   }
> 
> }
> 
> This does not work. Both properties are non-optional, and the compiler 
> complains that they are not initialized in either init method. It seems 
> rather common to want a single point of contact regarding object 
> initialization, regardless of the path taken to initialize that object. 
> Ideally, objects could all be funneled to one designated initializer, but 
> this isn’t always the case.
> 
> What are people’s thoughts about either a specialized function that is always 
> called at the very end of each object’s lifecycle OR some sort of attribute 
> for a function that hints that the compiler should follow it if called in an 
> init function to check for property initialization?
> 
> func commonInit() {
> 
> }
> 
> or
> 
> @extend_init private func commonInitialization() {
> 
> }
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