#7401: Can't derive instance for Eq when datatype has no constructor, while it is trivial do do so. ----------------------------------------------+---------------------------- Reporter: jpbernardy | Owner: monoidal Type: feature request | Status: new Priority: normal | Milestone: 7.8.1 Component: Compiler | Version: 7.6.1 Resolution: | Keywords: deriving Operating System: Unknown/Multiple | Architecture: Type of failure: GHC rejects valid program | Unknown/Multiple Test Case: | Difficulty: Unknown Blocking: | Blocked By: | Related Tickets: ----------------------------------------------+---------------------------- Comment (by goldfire): Good point about the fact that H2010 does '''not''' have empty data decls. But, then, GHC's interpretation of H2010 is incorrect, as setting H2010 as the language turns on `EmptyDataDecls`. Personally, I don't love straying from the standard, but it may be best not to unnecessarily break code here by "fixing" this deviation from the standard. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/7401#comment:15 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler