[GHC] #9858: Typeable instances should be kind-aware

[GHC]

#9858: Typeable instances should be kind-aware
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        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:
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Comment (by dfeuer):

 Replying to [comment:30 simonpj]:

 > The "right" solution is, I think, at the bottom of comment:20.  But NB
 that solution will mean that all these standalone derived instances would
 become illegal, so there is a backward compatibility cost.  The drastic
 solution does not have this problem.

 Wouldn't it be (sufficiently) correct to simply ignore all `Typeable`
 instance declarations (`deriving`, standalone `deriving`, and otherwise),
 issuing a warning to that effect, instead of rejecting them outright?

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Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/9858#comment:39>
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