dual type operator

Hypothetical operator that allows computing the dual of a type.

For example given a type:

data Either a b = Left a | Right b

You might want to be able to express Dual (Either a b) which should be isomorphic to:

data DualEither a b = DualEither {left :: a, right :: b}

One might want this for co-completeness checking.

Maybe you kind of get for free in certain linear logic like type systems (literally the dual relationship?)?