<html><head><meta http-equiv="Content-Type" content="text/html charset=us-ascii"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" class="">An equivalent of "NS_REQUIRES_SUPER" (hopefully with a better name ;-) has been requested several times, but never got the momentum it deserves.<div class="">Considering the current confusion (especially in UIKit), it would be really nice to have some help from the compiler, and I wonder how composition and protocols would be helpful here at all.</div><div class=""><br class=""></div><div class="">I guess the problem is that there are to many options for this feature without an obvious favorite: Not only for the keywords, but also for the exact semantic.</div><div class=""><br class=""></div><div class="">Additionally, there are imho already to many access levels (private, fileprivate, internal, public, <i class="">extendable?</i>, open), so I hope we'll someday find a solution that is powerful enough to replace the special willSet/didSet treatment for properties as well.</div><div class=""><br class=""></div><div class="">So unless somebody has a real flash of genius, I guess it's better to delay discussion until there is a chance for new proposals to be accepted.</div><div class=""><br class=""></div><div class="">Tino</div></body></html>