testsuite/tests/typecheck/should_fail/tcfail181.hs

   1 -- GHC 6.7 at one point said wog's type was:
   2 --
   3 --    wog :: forall t e (m :: * -> *).
   4 --           (Monad GHC.Prim.Any1, Monad m) =>
   5 --           t -> Something (m Bool) e
   6 --
   7 -- The stupid 'GHC.Prim.Any1' arose because of type ambiguity
   8 -- which should be reported, and wasn't.
   9
  10 module ShouldFail where
  11
  12 data Something d e = Something{ bar::  d, initializer::e   }
  13
  14 foo :: (Monad m) => Something (m Bool) n
  15 foo = undefined
  16
  17 wog x = foo{bar = return True}
  18