[GHC] #12980: Unlifted class method rejected

[GHC]

#12980: Unlifted class method rejected
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        Reporter:  goldfire          |                Owner:  goldfire
            Type:  bug               |               Status:  new
        Priority:  normal            |            Milestone:
       Component:  Compiler          |              Version:  8.1
      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:                    |
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Comment (by simonpj):

 Certainly should be ok for multi-method classes.  I'm not quite sure about
 the single-method case, because of the interaction with newtypes -- but I
 think there's a case for using data types in the single-method case too.

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Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/12980#comment:1>
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