Retreats the iterator to the previous item and returns TRUE . Advances the iterator n positions and returns TRUE . When the end of the collection is reached, returns nil and the position of the iterator will be undefined. Returns a pointer to the collection over which this iterator is iterating. If no item is found, returns nil and the position of the iterator will be undefined.
Equality is measured by the class-defined equality operator for type T .
If no item is found, returns nil and the position of the iterator will be undefined. Returns a pointer to the object at the iterator's current position. The results are undefined if the iterator is no longer valid. Removes and returns the object at the iterator's current position from the iterator's associated collection. Afterwards, the iterator will be positioned at the element immediately before the removed element.