An example to generate Out class for Person, Name and Address. Out class has to provide a default implementation for the function it declears.

data Person = Person Names Address 
            | Student Names Address 
              deriving (Show, Generic, Eq, Ord , Data,Typeable)
data Names  = Names String 
              deriving (Show, Generic, Eq, Ord, Data, Typeable)
data Address = Address Gate
              deriving (Show, Generic, Eq, Ord, Typeable, Data)

type Gate = PF

data PF = PF String deriving (Data, Typeable, Generic, Ord,Eq,Show)

For generating 4 empty instances

instance Out Person
instnace Out Nmads
instance Out Address
instance Out Gate

you just write:

instances ''Out ''Person

It will generate all instances that form Person and including Person.

If you use :set -ddump-splices, you will get

 instances ''Out  ''Person
 ======>
 ~\Test.hs:13:1-18
   instance Out Names
   instance Out Gate
   instance Out Address
   instance Out Person
Ok, modules loaded: CompositeDataInstancesGen, Main.

You can also use instnaceList to generate a list of class.