Objc.class-cluster

class Cluster

In a class cluster, only the abstract superclass is public. Allocating an instance actually creates

An object of a private subclass. As such, subclassing always happens in an abstract class and

Requires all methods to be implemented. See also the class cluster documentation.

"Class clusters is a design pattern, the Foundation framework makes extensive use of.

Class clusters Group A number of private concrete subclasses under a public abstract superclass.

The grouping of classes in this simplifies, the publicly visible architecture of an object-oriented

Framework without reducing its functional richness. Class clusters is based on the

Abstract Factory design pattern. "

Q: How do I subclass (Subclass) class cluster?

What does q:primitive methods mean?

Objc.primitive-methods

Reference

1. Class clusters-concepts in OBJECTIVE-C programming

https://developer.apple.com/library/ios/documentation/General/Conceptual/CocoaEncyclopedia/ClassClusters/ Classclusters.html

2. Abstract Factory (Todo)

Objc.class-cluster