If a class partially implemented a protocol, it also would not be instantiatable, but a subclass can supply the missing method(s). Doesn’t the compiler already handle that? How are abstract classes harder?
C. Keith Ray https://leanpub.com/wepntk <- buy my book? http://agilesolutionspace.blogspot.com/ twitter: @ckeithray http://www.thirdfoundationsw.com/keith_ray_resume_2014_long.pdf > On Nov 2, 2017, at 2:22 PM, Slava Pestov <[email protected]> wrote: > > Abstract methods and classes seem like they will introduce a fair amount of > complexity in the type checker, particularly around metatypes and > constructors, because now we have this new concept of a class that cannot be > directly instantiated. I’m not sure the cost is worth the benefit. > > Slava > >> On Nov 2, 2017, at 12:45 PM, C. Keith Ray via swift-evolution >> <[email protected]> wrote: >> >> How many "subclass must override" assertions or comments in base class >> methods do we need to see, to want to add "abstract" to the Swift language? >> 5? 50? 500? >> >> It's a not uncommon idiom in Objective-C. >> >> I'm about to port a substantial amount of C++ code to swift, and compiler >> help to enforce abstract classes would be very useful. >> >> >> -- >> C. Keith Ray >> Senior Software Engineer / Trainer / Agile Coach >> * http://www.thirdfoundationsw.com/keith_ray_resume_2014_long.pdf >> >> >> >> _______________________________________________ >> swift-evolution mailing list >> [email protected] >> https://lists.swift.org/mailman/listinfo/swift-evolution >
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