[GHC] #14840: QuantifiedConstraints: Can't define class alias

[GHC]

#14840: QuantifiedConstraints: Can't define class alias
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        Reporter:  Iceland_jack      |                Owner:  (none)
            Type:  bug               |               Status:  closed
        Priority:  normal            |            Milestone:
       Component:  Compiler          |              Version:  8.5
      Resolution:  fixed             |             Keywords:
                                     |  QuantifiedConstraints wipT2893
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):

 Given this [wiki:QuantifiedConstraints interesting collection of tickets
 on quantified constraints] it'd be great if someone (Iceland Jack?  Ryan?)
 wanted to write a blog post or even a paper about what you can and cannot
 do; and why.   These examples make my head hurt!

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/14840#comment:6>
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