[GHC] #12185: Can't call rank-2 function with type family constraint

[GHC]

#12185: Can't call rank-2 function with type family constraint
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        Reporter:  crockeea          |                Owner:
            Type:  bug               |               Status:  closed
        Priority:  normal            |            Milestone:
       Component:  Compiler (Type    |              Version:  8.0.1
  checker)                           |
      Resolution:  duplicate         |             Keywords:
Operating System:  Unknown/Multiple  |         Architecture:
                                     |  Unknown/Multiple
 Type of failure:  GHC rejects       |            Test Case:
  valid program                      |  typecheck/should_compile/T12185
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):
       Wiki Page:                    |
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Changes (by simonpj):

 * testcase:   => typecheck/should_compile/T12185


Comment:

 I've added a regression test though

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Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/12185#comment:3>
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