TypeFun.Data.Maybe
type family MaybeCase (a :: Maybe k) (nothing :: r) (just :: k -> r) :: r where ...
type family NothingToConstr (a :: Maybe k) (c :: Constraint) :: Constraint where ...
type family JustToConstr (a :: Maybe k) (c :: Constraint) :: Constraint where ...
type family CatMaybes (l :: [Maybe k]) :: [k] where ...
type family FromJust (a :: Maybe k) :: k where ...