[GHC] #8631: Need ImpredicativeTypes for GeneralizedNewtypeDeriving?

[GHC]

#8631: Need ImpredicativeTypes for GeneralizedNewtypeDeriving?
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        Reporter:  goldfire          |            Owner:
            Type:  bug               |           Status:  new
        Priority:  normal            |        Milestone:
       Component:  Compiler          |          Version:  7.7
      Resolution:                    |         Keywords:
Operating System:  Unknown/Multiple  |     Architecture:  Unknown/Multiple
 Type of failure:  None/Unknown      |       Difficulty:  Unknown
       Test Case:                    |       Blocked By:
        Blocking:                    |  Related Tickets:
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Comment (by Richard Eisenberg <eir@…>):

 In [changeset:"674c969c240632da70ed2928fa30c20a9a52e5dc/ghc"]:
 {{{
 #!CommitTicketReference repository="ghc"
 revision="674c969c240632da70ed2928fa30c20a9a52e5dc"
 Fix #8631.

 This patch allows turning on ImpredicativeTypes while type-checking
 the code generated by GeneralizedNewtypeDeriving. It does this
 by adding a field ib_extensions to InstBindings, informing the
 type-checker what extensions should be enabled while type-checking
 the instance.
 }}}

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Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8631#comment:10>
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