#12702: Don't warn about redundant constraints for necessary -------------------------------------+------------------------------------- Reporter: crockeea | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 8.0.1 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 simonpj):
So: if the constraint is required to make foo compile, then it is most certainly not redundant, and there shouldn't be a warning suggesting its removal.
Correct. But I can't reproduce this error either with HEAD or with the 8.0 branch (which has zillions of bugs fixed wrt 8.0.1). Could you see if you get the warning with either of those? You'll need to ask for `-Wredundant-constraints` explicitly, because it's no longer in `-Wall`. Thanks -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/12702#comment:1 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler