NSMutableSet
A dynamic unordered collection of unique objects.
Declaration
class NSMutableSetOverview
You can use this type in Swift instead of a Set in cases that require reference semantics.
The NSMutableSet class declares the programmatic interface to a mutable, unordered collection of distinct objects.
The NSCountedSet class, which is a concrete subclass of NSMutableSet, supports mutable sets that can contain multiple instances of the same element. The NSSet class supports creating and managing immutable sets.
NSMutableSet is “toll-free bridged” with its Core Foundation counterpart, CFMutableSet. See Toll-Free Bridging for more information.
Subclassing Notes
There should be little need of subclassing. If you need to customize behavior, it is often better to consider composition instead of subclassing.
Methods to Override
In a subclass, you must override both of its primitive methods:
You must also override the primitive methods of the NSSet class.