Dynamic method invocation in Rust

main.rs

#![feature(plugin)]
#![plugin(dynamic_gen)]

extern crate dynamic;
use dynamic::Object;

#[protocol]
trait Pet {
    fn speak(&self) -> String;
}

#[dynamic]
#[conform(Pet)]
struct Dog {
    name: &'static str,
}

impl Pet for Dog {
    fn speak(&self) -> String {
        format!("{}: Woof!", self.name)
    }
}

#[dynamic]
#[conform(Pet)]
struct Cat {
    name: &'static str,
}

impl Pet for Cat {
    fn speak(&self) -> String {
        if self.name == "Garfield" {
            format!("{}: Lasagna !", self.name)
        } else {
            format!("{}: Meow!", self.name)
        }
    }
}

fn main() {
    let pets: Vec<Box<Object>> = vec![
        Box::new(Cat{ name: "Nermal" }),
        Box::new(Dog{ name: "Odie" }),
        Box::new(Cat{ name: "Garfield" }),
    ];

    for pet in pets {
        println!("{}", Pet::proxy(&*pet).speak());
    }
}