T11339a.hs:5:8: warning: [-Wpartial-type-signatures (in -Wdefault)]
    • Found type wildcard ‘_’ standing for ‘a -> a’
      Where: ‘a’ is a rigid type variable bound by
               the inferred type of bar :: a -> a at T11339a.hs:6:1-10
    • In the type signature: bar :: _