Generics.Deriving.Show

For example, with this type:

newtype TestShow = TestShow Bool
  deriving (GShow) via (Default Bool)

gshow for TestShow would produce the same string as gshow for Bool.

In this example, TestShow requires no Generic instance, as the constraint on gshowsPrec from Default Bool is Generic Bool.

In general, when using a newtype wrapper, the instance can be derived via the wrapped type, as here (via Default Bool rather than Default TestShow).