Compiler's wrong code interpretation causes loop of error messages

[sjvolkmann]

This is how it looks like in latest Xcode 15.0 beta 5:

And this is the code that causes this error:

@State private var version: String = "Sample App" + Bundle.main.object(forInfoDictionaryKey: "CFBundleShortVersionString") as! String

This will Xcode let show an error and a warning which both say the exact opposite: "Insert ' as! String'" and "Remove 'as! String'". The solution is easy as follows.

@State private var version: String = "Sample App" + (Bundle.main.object(forInfoDictionaryKey: "CFBundleShortVersionString") as! String)

The problem is that there needs a cast to String first for the Bundle.main.object(forInfoDictionaryKey: "CFBundleShortVersionString" before joining the two. However, the compiler does understand the code as it would be like this:

@State private var version: String = ("Sample App" + Bundle.main.object(forInfoDictionaryKey: "CFBundleShortVersionString")) as! String

This does explain the error and the warning, the error because the cast is still required for the latter and the warning because the code inside the brackets is already a String.

I don't know if this is an issue that would be worth its effort because it goes much into detail. However, I do think this is a very common because fundamental error message. As of now the error and warning together doesn't make much sense.