Thanks for the pointer.  I must admit that thread somehow happened to sneak out from under my radar :)

Personally, I would consider it more "natural" if an if-construct without an else clause (when used in an "expression context") would sematically behave more like a ternary cond ? ... : undef (instead of cond ? ... : cond), but if you look at it from the perspective of what is evaluated last, it's of course perfectly clear why things behave as they do.

(Yes, I'm aware that if-constructs in Perl - unlike in some other languages - don't evaluate to anything itself (as a whole), i.e. they are not expressions — so no need to comment on that.)