type Counter {
    value: i32,
    fn read(self: ref<Self>) -> i32 {
        return self.value
    }
}

interface Readable<T: Type> {
    fn read(self: ref<T>) -> i32
}

fn readValue<T: Readable<T>>(value: ref<T>) -> i32 {
    return T.read(value)
}

pub fn main() -> Void {
    let counter: Counter = Counter { value: 42 }
    expect (readValue<Counter>(&counter) == 42)
}