#14292: Coercing between constraints of newtypes -------------------------------------+------------------------------------- Reporter: Iceland_jack | Owner: (none) Type: feature request | Status: new Priority: normal | Milestone: Component: Compiler | Version: 8.2.1 Resolution: | Keywords: 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 AntC): `IncoherentInstances` is a module-wide setting; and nowadays we're supposed to use the more surgical `{-# INCOHERENT #-}` pragma on the instance. Does that also apply for the role mungling? How does the `{-# INCOHERENT #-}` pragma go for `StandaloneDeriving` or `GeneralizedNewtypeDeriving`? It seems to be accepted by GHC OK, does it have the right effect? (It's hard to put together a test case.) -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/14292#comment:3 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler