[GHC] #8813: further support deriving instances Typeable1, Typeable2, etc

[GHC]

#8813: further support deriving instances Typeable1, Typeable2, etc
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        Reporter:  maeder                     |            Owner:
            Type:  task                       |           Status:  closed
        Priority:  normal                     |        Milestone:
       Component:  Compiler                   |          Version:
      Resolution:  wontfix                    |  7.8.1-rc1
Operating System:  Unknown/Multiple           |         Keywords:
 Type of failure:  GHC rejects valid program  |     Architecture:
       Test Case:                             |  Unknown/Multiple
        Blocking:                             |       Difficulty:  Unknown
                                              |       Blocked By:
                                              |  Related Tickets:
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Comment (by maeder):

 An (derived) instance of Data.!OldTypeable.Typeable cannot be used for a
 context based on Data.Typeable.
 Therefore Data.!OldTypeable is pretty useless.

 Is it no option (i.e. better) to make Typeable{1,..,7} behave like
 Typeable (with a warning)?

--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8813#comment:2>
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