Personally I think that the suggested new operators are more ugly than UNDEFINED and zero_type squared.
/ Per Hedbor ()
Previous text:
2003-01-23 00:34: Subject: Re: zero_type() & UNDEFINED and _typeof()
I said that UNDEFINED is useful considering the current situation when this kludge exists. The kludge itself is unfortunate, though, and UNDEFINED (and the other zero types) could be removed if a new existence operator is added.
/ Martin Stjernholm, Roxen IS