It should copy Zig's '= undefined;' instead of D's '= void;' The latter is very confusing: why have a keyword that means nothing, but also anything? This is a pretty common flaw within D, see also: static.
> why have a keyword that means nothing, but also anything?
googling void: "A void is a space containing nothing, a feeling of utter emptiness, or a legal nullity, representing a state of absolute vacancy or lack."
Sounds perfect!