【Rust日报】2023-01-18 希望你能早点学到的 Rust 技巧

#[tokio::main]
async fn main() {
    let mut service_map = ServiceMap::default();
    service_map.register(Foo {});
    service_map.register(Bar {});

    // prints: "got i64: 123"
    service_map.call(123i64).await;

    // prints: Point(123.0, 456.0)
    service_map.call((123.0f64, 456.0f64)).await;

    // prints nothing, since no service has been registered for `Request = &str`
    service_map.call("str").await;
}

struct Foo {}

impl Service<i64> for Foo {
    type Response = String;
    type Future = Ready<String>;

    fn call(&mut self, req: i64) -> Ready<String> {
        ready(format!("got i64: {req:?}"))
    }
}

#[derive(Debug)]
struct Point(f64, f64);

struct Bar {}

impl Service<(f64, f64)> for Bar {
    type Response = Point;
    type Future = Ready<Point>;

    fn call(&mut self, req: (f64, f64)) -> Ready<Point> {
        ready(Point(req.0, req.1))
    }
}