Casting an NSError return to a CFErrorRef return

Question

I have a function that returns an NSError object by reference:

NSData *foo(NSData *foo, NSError *__autoreleasing *outError);

This function uses an API that takes a pointer to storage for a CFErrorRef. I'd like to just pass outError to the underlying function directly, but I can't figure out the correct combination of declaration keywords and cast keywords to make clang agree with that plan. Is there one?

Answer 1

If you look at the clang notes for __autoreleasing it mentions that the magic happens at assignment time, which means that automatic casting can't help here. You need to actually make the assignment using a temporary variable as mentioned in the comments on the original post.