GeneralizedNewtypeDeriving: "deriving ALL"

I've found I've wanted to do:

newtype X1 = X1 ( X ) deriving ( ALL ); newtype X2 = X2 ( X ) deriving ( ALL );

When I want X1, X2 to behave like X, but I might later want to add them to different instances, i.e.

class Silly a

double :: a -> a

instance Silly X1 where

double x = 2 * x

instance Silly X2 where

double x = 3 * x -- Silly double

Currently, it seems to be the only way to do this is to dig into the source of X and find every instance it has. It would be nice to be able to simply to "deriving ALL" to make XN in "newtype XN = XN X" behave exactly the same as X.

Trac metadata

Trac field	Value
Version	7.4.1
Type	FeatureRequest
TypeOfFailure	OtherFailure
Priority	normal
Resolution	Unresolved
Component	Compiler
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