extern crate ambassador; use ambassador::{delegatable_trait, Delegate}; #[delegatable_trait] pub trait Shout { fn shout(&self, input: &str) -> String; } pub struct Cat; impl Shout for Cat { fn shout(&self, input: &str) -> String { format!("{} - meow!", input) } } pub struct Dog; impl Shout for Dog { fn shout(&self, input: &str) -> String { format!("{} - wuff!", input) } } #[derive(Delegate)] #[delegate(Shout, where = "A: Shout, B: Shout")] pub enum Either { Left(A), Right(B), } pub fn main() { let foo_animal = Either::Left::(Cat); println!("{}", foo_animal.shout("BAR")); let bar_animal = Either::Right::(Dog); println!("{}", bar_animal.shout("BAR")); }