Void
From Erights
The void guard, present in the universal environment, coerces all inputs to null.
It specifies that a given data flow path (particularly, a method return value) carries no information and is not used.
In E syntactic versions prior to 0.9 (before the “easy-return” syntactic feature), the default result guard for methods was void rather than any; thus the method body's return value was null unless a guard was specified.
? void # value: void
? void.coerce(def obj {}, throw) # value: null