[GHC] #12507: Can't deduce implicit parameter

[GHC]

#12507: Can't deduce implicit parameter
-------------------------------------+-------------------------------------
        Reporter:  Iceland_jack      |                Owner:
            Type:  bug               |               Status:  closed
        Priority:  normal            |            Milestone:
       Component:  Compiler          |              Version:  8.0.1
      Resolution:  fixed             |             Keywords:
Operating System:  Unknown/Multiple  |         Architecture:
                                     |  Unknown/Multiple
 Type of failure:  None/Unknown      |            Test Case:
                                     |  typecheck/should_compile/T12507
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):
       Wiki Page:                    |
-------------------------------------+-------------------------------------
Changes (by simonpj):

 * testcase:   => typecheck/should_compile/T12507


--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/12507#comment:4>
GHC <http://www.haskell.org/ghc/>
The Glasgow Haskell Compiler