Execution

Just for feedback
Oh, you might be interested in this: https://groups.google.com/forum/#!msg/scala-user/FyQK3-cqfaY/fXLHr8QsW_0J

It looks like default values are compiled as extra methods, presumably on the class which contains the original method.

Speculation: presumably it wouldn't be impossible for such a method to have the same type parameters and type class constraints as the original method, but it's also easy to imagine why the implementation might not handle it.