#7401: Can't derive instance for Eq when datatype has no constructor, while it is trivial do do so. -------------------------------------+------------------------------------- Reporter: jpbernardy | Owner: osa1 Type: feature request | Status: new Priority: normal | Milestone: 7.12.1 Component: Compiler | Version: 7.6.1 Resolution: | Keywords: deriving, Operating System: Unknown/Multiple | newcomer Type of failure: GHC rejects | Architecture: valid program | Unknown/Multiple Blocked By: | Test Case: Related Tickets: | Blocking: | Differential Revisions: Phab:D978 -------------------------------------+------------------------------------- Comment (by rwbarton): Indeed. I for one think it should be changed to use an empty case. This ticket might not be the right place to discuss it though, since in any case standalone deriving and ordinary deriving should not produce two different instances. I only skimmed over the patch on Phab, but I assume the same code is used to actually generate the instances in those two cases, right? -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/7401#comment:36 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler