array-displacement

(array-displacement array)

Returns two values: the array array was displaced to with make-array :displaced-to, and the :displaced-index-offset it was created with. For a non-displaced array the values are nil and 0. The second value is only observable through a multiple-value consumer such as multiple-value-bind; the function object #'array-displacement answers the same two values. A string view (a :displaced-to over a string) reports its target string the same way.