#12142: -Wredundant-constraints warns about constraints introduced via type synonyms. -------------------------------------+------------------------------------- Reporter: scshunt | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 8.0.1 Resolution: | Keywords: Operating System: Linux | Architecture: Type of failure: Incorrect | Unknown/Multiple warning at compile-time | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by simonpj): I can see that's annoying, but it's hard to avoid. And it does tell you something useful, namely that `l` is less polymorphic, and therefore less usable, than it could be. It's tantalising -- `-Wredundant-constraints` really is jolly useful but it is also sometimes annoying. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/12142#comment:1 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler