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