From: "Matt Doyle" <mdoyle@a-m-c.com>
From: "michael toksvig" <michaeltoksvig@yahoo.com>
add two numbers in the 1-10 range, and you invariably end=20 up with a number=20 in the 2-20 range
Yep. However, when considering constrained ranges, I find it surprising that the result would be *permitted* to exceed the constraints of the inputs.
IOW, I'd have expect the result to be constrained to be 2-10. Yes, that means that combinations exist that violate that constraint, but at least it wouldn't surprise me.
YES, that's exactly the point I was trying to make earlier - you just = did a much better job of explaining it :)
Thanks, if in fact I was addressing your concern.
IMO, the constraints and/or policies set forth when the type was defined = must apply for the lifetime of the type.
To be certain we're talking about the same thing, Michael and I have been discussing the result of a computation. Built-in types regularly undergo promotions when participating in such expressions, so the question is whether something similar should happen for a checked integral class and what form it should take. Michael was positing that the result type should account for the full range of values possible from the computation. I argued against that. I should also point out that built-in types don't behave that way; they can overflow silently, but they don't magically gain range. (The analogy isn't strong, but has some bearing, I think.) -- Rob Stewart stewart@sig.com Software Engineer http://www.sig.com Susquehanna International Group, LLP using std::disclaimer;