> On Aug 2, 2016, at 4:03 AM, Tino Heth via swift-users <swift-users@swift.org> > wrote: > > There is no fundamental reason to disallow struct inheritance, and I started > a pitch where afair one member of core agreed it would be useful — I hope > there is time to add it in the next year. > There is, however, a fundamental problem with struct polymorphism: > As soon as you add members, you loose compatibility (a Point3D: Point2D can't > be stored or passed where its parent is expected), and when you cross module > borders, there might be issues as well. > Struct and class have to behave different in inheritance, and to disallow > struct subtyping completely is just the easiest solution. > Imho it's definitely not the best solution, as it forces you to use classes > whenever you want to use inheritance (I don't think that composition is > superior in general). > It could be even possible to create structs that inherit from classes and > vice versa.
I thought the problem with struct polymorphism (specifically the stack size issue) *was* the fundamental reason we can’t have “substructs”. - Dave Sweeris _______________________________________________ swift-users mailing list swift-users@swift.org https://lists.swift.org/mailman/listinfo/swift-users
