Data.Concurrent.Deque.Reference.DequeInstance

By convention, every provider of the Data.Concurrent.Deque.Class interface optionally provides a module that provides the relevant instances of the Deque type class, covering the [maximum] portion of the configuration space that the implementation is able to handle.

This is kept in a separate package because importing instances is unconditional and the user may well want to assemble their own combination of Deque instances to cover the configuration space.