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

[GHC]

#9858: Typeable instances should be kind-aware
-------------------------------------+-------------------------------------
        Reporter:  dreixel           |                   Owner:
            Type:  bug               |                  Status:  new
        Priority:  normal            |               Milestone:  7.12.1
       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:  Phab:D652
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Comment (by shachaf):

 This doesn't seem to be completely fixed:

 {{{
 λ> type A = (() :: *)
 λ> type B = (() :: Constraint)
 λ> typeRep (Proxy :: Proxy A) == typeRep (Proxy :: Proxy B)
 True
 λ> typeRep (Proxy :: Proxy (Proxy A)) == typeRep (Proxy :: Proxy (Proxy
 B))
 False
 }}}

 Though I can't think of a way to write `unsafeCoerce` in this case.

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Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/9858#comment:73>
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