#11732: Deriving Generic1 interacts poorly with TypeInType -------------------------------------+------------------------------------- Reporter: goldfire | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 8.1 Resolution: | Keywords: TypeInType, | Generics Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by goldfire): As I just wrote in the email thread: we can argue that GHC is inferring a `k ~ *` constraint on the `Cat` instance. With that understanding, we're not so poorly off here. Just a reminder to all: we've strayed quite far from the original ticket, which concerns a bespoke instantiation check for `Generic` and `Generic1`. So my "do nothing" comment does not mean we can just close the ticket. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/11732#comment:15 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler