Scieneer Common Lisp 1.3.9 online documentation ext:weak-pointer-value weak-pointer [Function] If weak-pointer is valid, returns the value of weak-pointer and t. If the referent of weak-pointer has been garbage collected, returns the values nil and nil.
(setf (ext:weak-pointer-value weak-pointer) object) [Function] Updates weak-pointer to point to a new object.