abstract class $NIL < $IS_NIL
****
Inidicates that the subtype provides a nil value
_
Designer's Note:The advantage of T over SAME is that in parametrized classes typecase e when $NILthen .... e.nil e.nil is now known to be of type T, whereas if it were SAME, you would need at least an extra level of typecase


Ancestors
$IS_NIL

Descendants
$NUMBER{_} FLT INT FLTD



Public


Features
nil:SAME;