Paul "LeoNerd" Evans wrote: >imagine that Future::AsyncAwait is going to need to know, when >suspending one of these new CVs, that the @_ suppression is in effect. Yes, that's a good point. @_ suppression is technically part of the internal implementation, and so shouldn't be promoted as something for general users to introspect. But it is of a different character from the sub body, and there's legitimate reason for modules like yours to look at it. Presumably you'd be able to look at the same flag, probably one of the CvFLAGS(), that the core looks at in deciding whether to set up @_. And we should be clear that what you're introspecting here is whether @_ gets set up, *not* whether the sub has a signature. -zefram