[GHC] #15558: Locally handling an empty constraint

[GHC]

#15558: Locally handling an empty constraint
-------------------------------------+-------------------------------------
        Reporter:  Ericson2314       |                Owner:  (none)
            Type:  task              |               Status:  closed
        Priority:  normal            |            Milestone:  ⊥
       Component:  Compiler          |              Version:  8.0.1
      Resolution:  fixed             |             Keywords:
Operating System:  Unknown/Multiple  |         Architecture:
 Type of failure:  Incorrect         |  Unknown/Multiple
  error/warning at compile-time      |            Test Case:  gadt/T15558
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):
       Wiki Page:                    |
-------------------------------------+-------------------------------------

Comment (by simonpj):

 > Is writing the code with the "type warning" the best one can do?

 I don't know. I'd love to improve it further.  The patch does the best I
 can within the current setup -- but doubtless one could do better.

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/15558#comment:12>
GHC <http://www.haskell.org/ghc/>
The Glasgow Haskell Compiler