Quick tip: dispatch_once singleton model in Swift

From my short experience with iOS8 Swift there are three approaches to implement the Singleton pattern that support lazy initialisation and thread safety. Global constant Nested struct dispatch_once Download the Source Files for example These approaches might change or become redundant as the language matures. Global constant 1234567private let _SingletonSharedInstance = Singleton() class Singleton  {     class var sharedInstance : Singleton {         return _SingletonSharedInstance     } } We use a global constant because class ...