[GHC] #11793: Confusing type error from constrained class method

[GHC]

#11793: Confusing type error from constrained class method
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        Reporter:  gridaphobe        |                Owner:
            Type:  bug               |               Status:  new
        Priority:  normal            |            Milestone:  8.0.1
       Component:  Compiler          |              Version:  8.0.1-rc2
      Resolution:                    |             Keywords:  error-message
Operating System:  Unknown/Multiple  |         Architecture:
 Type of failure:  Incorrect         |  Unknown/Multiple
  warning at compile-time            |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):
       Wiki Page:                    |
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Comment (by Simon Peyton Jones <simonpj@…>):

 In [changeset:"e24b3b1eeba91bd5b127261652b48eae2d4751b1/ghc"
 e24b3b1e/ghc]:
 {{{
 #!CommitTicketReference repository="ghc"
 revision="e24b3b1eeba91bd5b127261652b48eae2d4751b1"
 Adjust error check for class method types

 Fixes Trac #11793.  Nothing deep here.
 }}}

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Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/11793#comment:4>
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