Inherits from
Available in OS X v10.0 and later.
Declared in


The abstract superclass for Libkern iterators.

OSIterator is the abstract superclass for all Libkern C++ object iterators. It defines the basic interface for iterating and resetting. See OSCollection and OSCollectionIterator for more information.

With very few exceptions in the I/O Kit, all Libkern-based C++ classes, functions, and macros are unsafe to use in a primary interrupt context. Consult the I/O Kit documentation related to primary interrupts for more information.

OSIterator provides no concurrency protection.



Instance Methods


Advances to and returns the next object in the iteration.

virtual OSObject *getNextObject() = 0;
Return Value

The next object in the iteration context, NULL if there is no next object or if the iterator is no longer valid.


The returned object will be released if removed from the collection; if you plan to store the reference, you should call retain on that object.

Subclasses must implement this pure virtual function to check for validity with isValid, and then to advance the iteration context to the next object (if any) and return that next object, or NULL if there is none.


Check that the collection hasn't been modified during iteration.

virtual bool isValid() = 0;
Return Value

true if the iterator is valid for continued use, false otherwise (typically because the collection being iterated has been modified).


Subclasses must implement this pure virtual member function.


Resets the iterator to the beginning of the collection, as if it had just been created.

virtual void reset() = 0;

Subclasses must implement this pure virtual member function.