concrete functor and monad transformers

#82Proposal: Add Elevator modifier to lift over transformers

This would be the place any transformer library can attach their lifting instance, which can then be derived via the newtype Elevator (British English: lift) (MonadTransformer = (Type -> Type) -> (Type -> Type))

type    Elevator :: MonadTransformer -> MonadTransformer
newtype Elevator trans m a = Elevator (trans m a)
 newtype (Functor, Applicative, Monad, MonadTrans)

type    ContT :: Type -> MonadTransformer
newtype ContT r m a = ..
 deriving (MonadIO, MonadState s)
 via Elevator (ContT r) m

has instances

instance (MonadTrans trans, MonadIO m) => MonadIO (Elevator trans m) where
 liftIO :: IO ~> Elevator trans m
 liftIO = lift . liftIO

-- ?
instance (MonadTrans trans, MonadFail m) => MonadFail (Elevator trans m) where
 fail :: String -> Elevator trans m a
 fail = lift . fail

instance (MonadTrans trans, MonadState s m) => MonadState s (Elevator trans m) where
 get :: Elevator trans m s
 get = lift get

 put :: s -> Elevator trans m ()
 put = lift . put

 state :: (s -> (a, s)) -> Elevator trans m a
 state = lift . state

I haven't been able to work out how to derive other classes like MonadReader/MonadWriter/MonadError which use map*T/liftListen/liftPass/liftCatch functions to define local/listen/pass/catchError.