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Similar in spirit to this question, except, instead of limiting a protocol to only classes, I want to be able to define a protocol that can only be adopted by enums, structs etc.. Is this possible?

Community
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vopilif
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1 Answers1

6

I couldn't find the answer, but through playing around, I've come to the conclusion that you can't. Being that to restrict a protocol to just classes, you precede it with class like 

protocol SomeProto: class {
    func structYourStuff() -> Void
}

Making the assumption that this would be consistent among other types, I tried

protocol SomeProto: struct {
    func structYourStuff() -> Void
}

But Xcode gave me five different errors on one line, which brings me to the conclusion that you can't. I could be completely wrong though, I only started learning Swift about a week ago

Chris
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    Exactly, we cannot do this. IMHO, it would be a useful extension to the language. – CouchDeveloper Nov 10 '15 at 07:30
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    @CouchDeveloper You got me thinking, perhaps there's some way to build out close functionality since we have the flexibility of custom operators. I can't think of how that would work though. – Chris Nov 10 '15 at 07:38