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#![feature(async_fn_traits, async_trait_bounds)]
use std::future::Future;
use std::pin::pin;
use std::task::*;
pub fn block_on<T>(fut: impl Future<Output = T>) -> T {
let mut fut = pin!(fut);
let ctx = &mut Context::from_waker(Waker::noop());
loop {
match fut.as_mut().poll(ctx) {
Poll::Pending => {}
Poll::Ready(t) => break t,
}
}
}
async fn call_once(f: impl async FnOnce(DropMe)) {
f(DropMe("world")).await;
}
#[derive(Debug)]
struct DropMe(&'static str);
impl Drop for DropMe {
fn drop(&mut self) {
println!("{}", self.0);
}
}
pub fn main() {
block_on(async {
let b = DropMe("hello");
let async_closure = async move |a: DropMe| {
println!("{a:?} {b:?}");
};
call_once(async_closure).await;
});
}
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