System Initiative

use std::{ convert::Infallible, future::Future, pin::Pin, task::{ Context, Poll, }, }; use pin_project_lite::pin_project; use tokio::time::Sleep; pin_project! { pub struct ResponseFuture<T> { #[pin] pub(crate) response: T, #[pin] pub(crate) sleep: Sleep, } } impl<F, T> Future for ResponseFuture<F> where F: Future<Output = Result<T, Infallible>>, { type Output = Result<T, Infallible>; fn poll(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Self::Output> { let this = self.project(); // First, try polling the wait/sleep if this.sleep.poll(cx).is_pending() { return Poll::Pending; } // Now poll the response future this.response.poll(cx) } }