On Wed, 1 Dec 2010 03:22:39 -0800 Jonathan M Davis <jmdavisp...@gmx.com> wrote:
> > What would be the consequences if D had no const, only immutable (that, > > IIUC, removes the latter non-guarantee)? > > The biggest problem would be that no function could then work on both a > mutable > and an immutable value (unless it could be copied by value). With const, you > can > pass both mutable and immutable stuff to it. Without const, any and all > functions > which would want to deal with both would have to be duplicated. That includes > stuff like member functions. Right, but isn't this the main point of Unqual!? (Would unqualify immutable as well, no?). > And of course, as C++ shows, there are plenty of cases where having const but > no > immutable can be quite valuable. Just the fact that you can pass an object to > a > function and know with reasonable certainty (and more certainty in D than > C++) > than that object won't be altered can be extremely valuable. Sure, many > languages get by without const, but I think that they're definitely worse off > for > it. And with immutable added to the mix, I think that const is that much more > important. For this case, I prefere the "in" qualifier. (And imo value parameters should be "in" by default). Unless I miss important use cases, seems I would be happy with "immutable" and "in". denis -- -- -- -- -- -- -- vit esse estrany ☣ spir.wikidot.com
