We should also consider whether writing class var with a property wrapper gives you a static stored property or an error. Error is certainly more conservative.

The error would make sense then and match the current behavior when writing class var str = "string".
For me it was really a surprise, because I was replacing the following (working) code:

private static var _bool = Wrap(wrappedValue: true)
static var bool: Bool { return _bool.wrappedValue }

with above's version using @propertyWrapper.

Just to be clear - is the bug that we're generating the wrong diagnostic or that we're generating a diagnostic instead of allowing it to compile? At the moment, we're calling to getCorrectStaticSpellingForDecl() when getting the spelling for the backing property's pattern binding and since our context is a class, we're returning class instead of static.

We shouldn't generate any diagnostic at all in the static case. It's not the spelling that matters so much as the non-final-ity; generating the backing property as class final rather than static would also be fine. (But matching how the regular property is written would also make sense.)

I totally forgot that we can use static wrappers (duh!!). Here's a fix: #27198

Right, but at that point we have the question about how class var should behave, and also class final var.

With my patch, it mimics the original property (and context):

1. class var inside final class - ok

2. class var inside non-final class - error

3. static var inside class - ok

Wow, that was quick, thank you @theblixguy!
IMHO, what you describe is fine. What about final class var in non-final class (which would be the same as static just written differently)?

You'll get an error -the backing variable is using the same static spelling as the original variable.

Ah, my bad. I thought that final class var would work today (and is treated the same as static var). But that is already giving an error - in which case it makes sense to also generate an error now of course. Thanks for clarifying.

Fixed on master. Please verify using the next available master snapshot!

@swift-ci create