I'm trying to find a situation where this could cause confusion to see if we should be advocating for * to return true like in the availability or to search for a different solution. What makes this confusing in my head is that if you do have a condition triggering the wildcard it means the condition has nothing to do with your platform, so whether it returns true or false should, in practice, be irrelevant. As mentioned before it really has no purpose besides allowing other platforms to compile.
I guess the only situation where the wildcard wouldn't be completely useless is if you're doing something like this:
if #available(iOS 13, *) {
#if iOS
// some iOS 13 code
#elseif macOS
// some macOS code
#endif
}
This will work as designed, and in the case of unavailability it could cause some confusion indeed. But is this right? Why is the macOS code inside the expression if the statement doesn't explicitly define a version for it? I think someone who really needed this would write it like this:
if #available(iOS 13, *) {
#if iOS
// some iOS 13 code
#endif
}
#if macOS
// some macOS code
#endif
This then goes back to the original point: The expression has now nothing to do with macOS, so we can't get confused because what it does just doesn't matter. Can you think of any legitimate reason to use the wildcard?