mod private {
    /// Yay, type safety.
    #[derive(Debug)]
    pub enum Mark {
        /// Neat-o
        Neat,
        /// Cool
        Cool { a: u32 },
    }
}
pub use private::Mark::*;

enum _Private {
    Fail,
    Aw,
}

// error: enum is private and its variants cannot be re-exported
// pub use _Private::*;

pub fn test(thing: private::Mark) {
    dbg!(thing);
}

fn main() {
    test(Neat);
    test(Cool { a: 3 });
    // test(Mark::Neat);
}