I will point out one drawback: I believe users will be confused about
#9858: Typeable instances should be kind-aware -------------------------------------+------------------------------------- Reporter: dreixel | Owner: dreixel Type: bug | Status: new Priority: highest | Milestone: 7.10.1 Component: Compiler | Version: 7.9 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: Type of failure: None/Unknown | Unknown/Multiple Blocked By: | Test Case: Related Tickets: | Blocking: | Differential Revisions: -------------------------------------+------------------------------------- Comment (by crockeea): Replying to [comment:21 goldfire]: the need for `Typeable` constraints. After all, if ''every'' type is `Typeable`, then why include the constraint? We cognoscenti know that the `Typeable` constraint is just implicitly passing the runtime witness, but we'll have to be careful to explain this to those who think that class constraints are all about logical statements, not implicit type-determined parameters. After using Haskell for several years, that ''still'' trips me up. If you are able to make everything `Typeable`, might there be a way to make the `Typeable` constraint implicit, at least when it's needed? -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/9858#comment:22 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler