NSString is really a container class for different types of string objects. Generally an NSString constructor does return an object that is actually of type NSCFString, which is a thin wrapper around the Core Foundation CFString struct.
I don’t believe that this pattern can be directly supported in Swift, because initialisers do not return a value as they do in Objective C – so you do not get an opportunity to return an alternate object instance. You can use a type method as an object factory – a fairly contrived example is … Read more
I don’t know what is in the CDP that Steve referenced but basically the Objective-C Class Cluster is a construct that supports implementing the abstract Factory pattern. The idea is simple: You want to provide a Factory (Cluster) interface that, with minimal description, manufactures and returns a specific concrete instance of a Factory Object that … Read more