> On Apr 17, 2017, at 10:11 PM, Rick Mann <rm...@latencyzero.com> wrote: > >> >> On Apr 17, 2017, at 08:54 , Joe Groff <jgr...@apple.com> wrote: >> >> >>> On Apr 14, 2017, at 7:41 PM, Rick Mann via swift-users >>> <swift-users@swift.org> wrote: >>> >>> I'm refactoring some Objective-C code to inherit from a new Swift super >>> class. This has been going okay, and I've been cleaning up build errors as >>> I spot them (some auxiliary enums caused enum name changes, etc.). >>> >>> But my last error seems to be that I can't subclass the Swift class: >>> "Cannot subclass a class with objc_subclassing_restricted attribute". I >>> didn't notice it before, and all the online references that say you can't >>> subclass a Swift class point to a Swift document that no longer mentions >>> that. They also don't say what they mean by "Swift" class (e.g. is it not >>> marked with @objc?). >>> >>> In any case, my Swift class looks like: >>> >>> @objc >>> class >>> Camera : NSObject >>> { >>> ... >>> } >>> >>> And my ObjC class looks like: >>> >>> @interface >>> MCPCamera : Camera >>> >>> ... >>> >>> @end >>> >>> I feel like this is a reasonable thing to try to do. Is it just not >>> possible? >> >> Subclassing Swift classes from Objective-C is not supported. If the >> documentation no longer mentions that restriction, we should fix that. Where >> is that document that you're referring to? > > This is one document that doesn't clearly state it: > > > https://developer.apple.com/library/content/documentation/Swift/Conceptual/BuildingCocoaApps/MixandMatch.html#//apple_ref/doc/uid/TP40014216-CH10-ID136 > > It has nice sections like "Using Swift from Objective-C," and "Declaring a > Swift Protocol That Can Be Adopted by an Objective-C Class," and "Adopting a > Swift Protocol in an Objective-C Implementation," but no "Inheriting a Swift > Class in Objective-C" (the discussion in such a section should explain that > it can't be done and why). Searching the document for "derive", "inherit", > "subclass" doesn't turn up any indication this can't be done. > > Given that you can do all the other things, and there's such a thing as > marking a Swift class as @objc, and you can subclass in Swift, it's quite > unintuitive that you cannot go the other way.
Thanks. I'll file a bug with our documentation team to try to clarify that. -Joe _______________________________________________ swift-users mailing list swift-users@swift.org https://lists.swift.org/mailman/listinfo/swift-users