rust/tests/ui/async-await/issues/issue-65419/issue-65419-async-fn-resume-after-completion.rs
2023-01-11 09:32:08 +00:00

47 lines
1.3 KiB
Rust

// issue 65419 - Attempting to run an async fn after completion mentions generators when it should
// be talking about `async fn`s instead.
// run-fail
// error-pattern: thread 'main' panicked at '`async fn` resumed after completion'
// edition:2018
// ignore-wasm no panic or subprocess support
// ignore-emscripten no panic or subprocess support
#![feature(generators, generator_trait)]
async fn foo() {
}
fn main() {
let mut future = Box::pin(foo());
executor::block_on(future.as_mut());
executor::block_on(future.as_mut());
}
mod executor {
use core::{
future::Future,
pin::Pin,
task::{Context, Poll, RawWaker, RawWakerVTable, Waker},
};
pub fn block_on<F: Future>(mut future: F) -> F::Output {
let mut future = unsafe { Pin::new_unchecked(&mut future) };
static VTABLE: RawWakerVTable = RawWakerVTable::new(
|_| unimplemented!("clone"),
|_| unimplemented!("wake"),
|_| unimplemented!("wake_by_ref"),
|_| (),
);
let waker = unsafe { Waker::from_raw(RawWaker::new(core::ptr::null(), &VTABLE)) };
let mut context = Context::from_waker(&waker);
loop {
if let Poll::Ready(val) = future.as_mut().poll(&mut context) {
break val;
}
}
}
}