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slot-makunbound [Function]

slot-makunbound instance slot-name => instance

Arguments and Values::

instance - instance.

Slot-name--a symbol.

Description::

The function slot-makunbound restores a slot of the name slot-name in an instance to the unbound state.

Exceptional Situations::

If no slot of the name slot-name exists in the instance, slot-missing is called as follows:

     (slot-missing (class-of instance)
                   instance
                   slot-name
                   'slot-makunbound)
     

(Any values returned by slot-missing in this case are ignored by slot-makunbound.)

The specific behavior depends on instance's metaclass. An error is never signaled if instance has metaclass standard-class. An error is always signaled if instance has metaclass built-in-class. The consequences are undefined if instance has any other metaclass-an error might or might not be signaled in this situation. Note in particular that the behavior for conditions and structures is not specified.

See Also::

slot-boundp , slot-missing

Notes::

Although no implementation is required to do so, implementors are strongly encouraged to implement the function slot-makunbound using the function slot-makunbound-using-class described in the Metaobject Protocol.