#![feature(async_await)]
use std::future::Future;
use std::task::{Context, Poll};
use std::pin::Pin;

struct Five;

impl Future for Five {
    type Output = i32;

    fn poll(self: Pin<&mut Self>, _cx: &mut Context) -> Poll<Self::Output> {
        Poll::Ready(5)
    }
}

fn returns_five() -> impl Future<Output=i32> {
    Five
}

async fn testing() {
    returns_five().await;
}