Zeros implemented with one-liner

zeros.hs

{-# LANGUAGE DeriveAnyClass, DerivingStrategies, DefaultSignatures, TypeApplications, FlexibleContexts, DeriveGeneric #-}
import GHC.Generics
import Generics.OneLiner (nullaryOp, ADTRecord, Constraints)

class Zeros z where
    zero :: z
    default zero :: (ADTRecord z, Constraints z Zeros) => z
    zero = nullaryOp @Zeros zero
    {-# INLINE zero #-}

data B1 = B1 Int
     deriving stock (Show, Read, Eq, Ord, Generic)
     deriving anyclass (Zeros)

instance Zeros Int where zero = 0

test :: B1
test = zero