Non-frozen enums in Swift

Using Swift
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As I understand it, as a user of Swift, I can't define a non-frozen enum in Swift?

Presumably there's a reason for that? It would seem beneficial if we could as we could then avoid breaking changes in library APIs when adding new cases to the enum.

Currently a user of my library gets frozen enums which I may intend to add new values to in the future. They have to write exhaustive switch statements, which might take the form a listing our each possible case, with no default case, so adding a new value will break compilation.

In ObjC, or Apple's code, enums can be defined as non-frozen to avoid this issue.

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You’d need to use library evolution support.

See some background here:

(There are several caveats though - one of the biggest ones that this is not yet fully supported cross platform yet)

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Ahh nice, my sample library/app I was playing around with this in didn't have that enabled of course, but the production library should be able to

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You might also want to check out eg.

And

For at least two of the current caveats.

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Thanks sharing! SPM and/or Linux aren't currently a concern and our current approach isn't affected by the second one I don't think (but either might apply to others reading of course!).

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If you want to do proper library evolution tied to versions of your library, I think the second one would be something that would impact.

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That’d be much more lightweight for some use cases, thanks for the pointer.