[GHC] #3087: Derived instances of Data lack dataCast1 and dataCast2

[GHC]

#3087: Derived instances of Data lack dataCast1 and dataCast2
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    Reporter:  dreixel           |        Owner:  simonpj         
        Type:  bug               |       Status:  closed          
    Priority:  normal            |    Milestone:                  
   Component:  Compiler          |      Version:  6.10.1          
    Severity:  normal            |   Resolution:  fixed           
    Keywords:                    |   Difficulty:  Unknown         
    Testcase:                    |           Os:  Unknown/Multiple
Architecture:  Unknown/Multiple  |  
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Changes (by simonpj):

  * status:  new => closed
  * resolution:  => fixed

Comment:

 Fixed by
 {{{
 Fri Mar 13 13:44:36 GMT 2009  simonpj at microsoft.com
   * Fix Trac #3087: derived Data now defines dataCast1/2

   This patch generates code in deriving(Data) for dataCast1 or 2 as
   appropriate.

   While I was there I did some refactoring (of course), pulling out
   the TcDeriv.inferConstraints as a separate function.
 }}}
 I don't think it's worth merging this to 6.10.2, even though it's a
 bugfix,
 because it modifies code that I added in the HEAD only (for deriving
 Functor)
 so the merge will be sligtly awkward.  And there's an easy workaround.

-- 
Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/3087#comment:2>
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