{-# language ImpredicativeTypes #-}
module M where

class C m

foo :: forall m. C m => Int -> m Char
foo _ = undefined

tgt :: Int -> forall m. C m => m Char
tgt x = foo x

hm :: Functor f => f Int -> f (forall m. C m => m Char)
hm = fmap tgt

hm2 :: Functor f => f Int -> f (forall m. C m => m Char)
hm2 = fmap (\x -> foo x)