<i>Having type annotations that are ignored at runtime would cause problems when you interact with code without type annotations, no?</i><p>I seem to be doing this a lot in this thread, but...<p>This is your obligatory reminder that several statically-typed languages actually run on dynamic-language runtimes, because programmers don&#x27;t like to think about the cost of polymorphism&#x2F;generics, but implementers have to think about that.