different kinds: either simple untyped ({\tt void *}) pointers which are simply
stored by the control but not used in any way by it, or typed pointers
({\tt wxClientData *}) which are owned by the control meaning that the typed
different kinds: either simple untyped ({\tt void *}) pointers which are simply
stored by the control but not used in any way by it, or typed pointers
({\tt wxClientData *}) which are owned by the control meaning that the typed