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// edition: 2021
use std::{
future::Future,
pin::Pin,
task::{Context, Poll, Waker},
};
pub struct StructAsync<F: Fn() -> Pin<Box<dyn Future<Output = ()>>>> {
pub callback: F,
}
impl<F> Future for StructAsync<F>
where
F: Fn() -> Pin<Box<dyn Future<Output = ()>>>,
{
type Output = ();
fn poll(self: Pin<&mut Self>, _cx: &mut Context<'_>) -> Poll<Self::Output> {
Poll::Pending
}
}
async fn callback() {}
struct Runtime;
fn waker() -> &'static Waker {
todo!()
}
impl Runtime {
#[track_caller]
pub fn block_on<F: Future>(&self, mut future: F) -> F::Output {
loop {
unsafe {
Pin::new_unchecked(&mut future).poll(&mut Context::from_waker(waker()));
}
}
}
}
fn main() {
Runtime.block_on(async {
StructAsync { callback }.await;
//~^ ERROR expected `callback` to be a fn item that returns `Pin<Box<dyn Future<Output = ()>>>`, but it returns `impl Future<Output = ()>`
//~| ERROR expected `callback` to be a fn item that returns `Pin<Box<dyn Future<Output = ()>>>`, but it returns `impl Future<Output = ()>`
//~| ERROR expected `callback` to be a fn item that returns `Pin<Box<dyn Future<Output = ()>>>`, but it returns `impl Future<Output = ()>`
});
}
|
