CFMutableSet manages dynamic sets. The basic interface for managing sets is provided by CFSet. CFMutableSet adds functions to modify the contents of a set.
CFMutableSet is “toll-free bridged” with its Cocoa Foundation counterpart,
NSMutableSet. What this means is that the Core Foundation type is interchangeable in function or method calls with the bridged Foundation object. This means that in a method where you see an
NSMutableSet * parameter, you can pass in a
CFMutableSetRef, and in a function where you see a
CFMutableSetRef parameter, you can pass in an NSMutableSet instance. This also applies to concrete subclasses of NSMutableSet. See Toll-Free Bridged Types for more information on toll-free bridging.