A channel reference, holding a type list of all channels supported by the underlying actor.
Typed channels atop untyped actors.
This exception is used to signal errors when trying to
ActorRef into a ChannelRef: if the actor finds the requested channel types
incompatible with its selfChannel, it will return errors in the same format
as would occur during compilation of a
This type is used to stand in for the unknown reply types of the fabricated sender references; users don’t need to write it down, and if they do, they know that they’re cheating (since these ref types must not escape their defining actor context).