Derive Macro Tagged 

#[derive(Tagged)]
{
    // Attributes available to this derive:
    #[tags]
}

use object_rainbow::Tagged;

#[derive(Tagged)]
struct Three<A, B, C> {
    a: A,
    #[tags(skip)]
    b: B,
    c: C,
}

object_rainbow::assert_impl!(
    impl<A, B, C> Tagged for Three<A, B, C>
    where
        A: Tagged,
        C: Tagged,
    {}
);