NSFastEnumeration

Protocol for supporting fast enumeration in collections. One principal advantage over NSEnumeration is that it is specified for for in loops, meaning the enumerated object need not be retained.

State Structure

typedef struct
{
   NSUInteger   state;
   id           *itemsPtr;
   NSUInteger   *mutationsPtr;
   NSUInteger   extra[5];
} NSFastEnumerationState;

Required Methods

• -count - Returns number of items (experimentally added, makes NSFastEnumeration basically NSContainer)
• -countByEnumeratingWithState:objects:count: - Returns items in batches for enumeration
  • state: Enumeration state
  • objects: Buffer for objects
  • count: Maximum number of objects to return

Note: This protocol replaces the older NSEnumeration protocol and is optimized for the Objective-C for..in syntax. The object being enumerated does not need to be retained during enumeration.