I'm not sure I totally agree. Well I do agree that I tailored the question to suit my point! But to your reply, I think you've changed the semantics of my meani

I'm not sure I totally agree. Well I do agree that I tailored the question to suit my point! But to your reply, I think you've changed the semantics of my meaning. My questions were more from the perspective of the caller, and even then it was a bit abstracted from the actual type and implementation ... just more of a conversational "Does it? Maybe!" You're rephrasing is still looking at it from the caller, but now takes into account the language semantics (which mine conveniently didn't :) ). I would rephrase your questions, and look at them from the callee's perspective: "Will I get an argument? Maybe!" And really, shouldn't we be saying that the function takes Just a to ... and takes Nothing to ... ? Perhaps this has stretched as far as it might go. Maybe?