Like it has been written here Qt up to now has 8 specilized smart pointer classes. It looks like it is all you will ever need. However, in order to use any of these smart pointers your class must be derived from QObject which is not always convenient. Is there other implementations of smart pointers in Qt which work with arbitrary classes?
Many Qt classes are derived from QObject, and while some of the built in smart pointer classes are related to QObject (or QSharedData), the QSharedPointer and QScopedPointer templates appear to allow pointers to anything.