trait Base {
    type Item;
    type Item2;
}

trait Service {
    type R;
    type E;
    type C: Base<Item = Self::R, Item2 = Self::E>;
}

fn create() -> impl Service {
    struct BaseImpl {}
    impl Base for BaseImpl {
        type Item = u64;
        type Item2 = String;
    }

    struct ServiceImpl {}
    impl Service for ServiceImpl {
        type R = u64;
        type E = String;
        type C = BaseImpl;
    }

    ServiceImpl {}
}

fn create_config() -> impl Service {
    let mut srv = create();
    srv
}

struct S1<T: Service> {
    service: T,
}

fn new_service() -> S1<impl Service> {
    S1 {
            service: create_config(),
    }
}

impl<S: Service> S1<S> {
    fn new() -> S1<impl Service> {
        S1 {
            service: create_config(),
        }
    }
}

fn main() {
    //let s = S1::new();
    let s = new_service();
}