- class GFunctor f where
- gmap :: (a -> b) -> f a -> f b

- gmapdefault :: (Generic1 f, GFunctor' (Rep1 f)) => (a -> b) -> f a -> f b

- class GFunctor f where
- gmap :: (a -> b) -> f a -> f b

- gmapdefault :: (Generic1 f, GFunctor' (Rep1 f)) => (a -> b) -> f a -> f b