counter.rs

struct X {
    counter: u32
}

impl X {
    fn handler(&self, _: &mut Request) -> IronResult<Response> {
        self.counter += 1;
        Ok(Response::with((iron::status::Ok, "Hello World")))
    }
}

fn main() {
    let x = X::new();

    Iron::new(x.handler).http("localhost:9666").unwrap();
}