Generics.Deriving.Semigroup

Semigroups often have many sensible implementations of Data.Semigroup.<> / gsappend, and therefore no sensible default. Indeed, there is no GSemigroup' instance for representations of sum types.

In other cases, one may wish to use the existing wrapper newtypes in base, such as the following (using First):

newtype FirstSemigroup = FirstSemigroup Bool
  deriving stock (Eq, Show)
  deriving (GSemigroup) via (First Bool)