On 30/11/2010 20:47, Andrei Alexandrescu wrote:
Same discussion goes about non-nullable. We don't need the compiler to understand non-nullable types, we need to imbue the compiler with the ability to enforce arbitrary user-defined state invariants, non-null being one of them.
That would be great. That would be *really* great. There are lots of useful invariants one might want to express. (something like Java's wildcards for containers, or numeric ranges, maybe ownership relationships, etc.)
However, just as it would be very useful, wouldn't it be an incredibly compex feature set to implement, at least in a sufficiently generic and useful way? Complex enough for it to be something that could not be worked in anytime soon?
Because the impression I get from Steven and others, is that this issue is quite critical, and makes writing D code unpleasant in many situations (I myself can't agree or disagree, haven't used D2 enough in pratice, but their arguments and experience seem convincing)
-- Bruno Medeiros - Software Engineer
