Incoherence in gsolomap

GF.hs

{-# LANGUAGE DeriveGeneric #-}
module Main where

import Generic.Functor
import GHC.Generics (Generic)

data T a b = C Int a b
  deriving (Show, Generic)

fmapT :: (b -> b') -> T a b -> T a b'
fmapT = gsolomap

firstT :: (a -> a') -> T a b -> T a' b
firstT = gsolomap

bothT :: (a -> a') -> T a a -> T a' a'
bothT = gsolomap

watT ::
  (a -> a') ->
  T (a , a ) ((a  -> a') -> Maybe a ) ->
  T (a', a') ((a' -> a ) -> Maybe a') 
watT = gsolomap

main :: IO ()
main = do
  print (fmapT    ((+1) :: Int -> Int) (C 0 0 0 :: T Int Int))
  print (gsolomap ((+1) :: Int -> Int) (C 0 0 0 :: T Int Int) :: T Int Int)
  -- NB: Type annotations are needed on both the input and output T Int Int.
  putStrLn "We are not the same."