diff --git a/src/test/ui/async-await/issue-98634.rs b/src/test/ui/async-await/issue-98634.rs new file mode 100644 index 0000000000000..b0d38687f01c4 --- /dev/null +++ b/src/test/ui/async-await/issue-98634.rs @@ -0,0 +1,50 @@ +// edition: 2021 + +use std::{ + future::Future, + pin::Pin, + task::{Context, Poll, Waker}, +}; + +pub struct StructAsync Pin>>> { + pub callback: F, +} + +impl Future for StructAsync +where + F: Fn() -> Pin>>, +{ + type Output = (); + + fn poll(self: Pin<&mut Self>, _cx: &mut Context<'_>) -> Poll { + Poll::Pending + } +} + +async fn callback() {} + +struct Runtime; + +fn waker() -> &'static Waker { + todo!() +} + +impl Runtime { + #[track_caller] + pub fn block_on(&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 `fn() -> impl Future {callback}` to be a fn item that returns `Pin + 'static)>>`, but it returns `impl Future` + //~| ERROR expected `fn() -> impl Future {callback}` to be a fn item that returns `Pin + 'static)>>`, but it returns `impl Future` + //~| ERROR expected `fn() -> impl Future {callback}` to be a fn item that returns `Pin + 'static)>>`, but it returns `impl Future` + }); +} diff --git a/src/test/ui/async-await/issue-98634.stderr b/src/test/ui/async-await/issue-98634.stderr new file mode 100644 index 0000000000000..5160e48d88afd --- /dev/null +++ b/src/test/ui/async-await/issue-98634.stderr @@ -0,0 +1,60 @@ +error[E0271]: expected `fn() -> impl Future {callback}` to be a fn item that returns `Pin + 'static)>>`, but it returns `impl Future` + --> $DIR/issue-98634.rs:45:23 + | +LL | StructAsync { callback }.await; + | ^^^^^^^^ expected struct `Pin`, found opaque type + | +note: while checking the return type of the `async fn` + --> $DIR/issue-98634.rs:24:21 + | +LL | async fn callback() {} + | ^ checked the `Output` of this `async fn`, found opaque type + = note: expected struct `Pin + 'static)>>` + found opaque type `impl Future` +note: required by a bound in `StructAsync` + --> $DIR/issue-98634.rs:9:35 + | +LL | pub struct StructAsync Pin>>> { + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ required by this bound in `StructAsync` + +error[E0271]: expected `fn() -> impl Future {callback}` to be a fn item that returns `Pin + 'static)>>`, but it returns `impl Future` + --> $DIR/issue-98634.rs:45:9 + | +LL | StructAsync { callback }.await; + | ^^^^^^^^^^^^^^^^^^^^^^^^ expected struct `Pin`, found opaque type + | +note: while checking the return type of the `async fn` + --> $DIR/issue-98634.rs:24:21 + | +LL | async fn callback() {} + | ^ checked the `Output` of this `async fn`, found opaque type + = note: expected struct `Pin + 'static)>>` + found opaque type `impl Future` +note: required by a bound in `StructAsync` + --> $DIR/issue-98634.rs:9:35 + | +LL | pub struct StructAsync Pin>>> { + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ required by this bound in `StructAsync` + +error[E0271]: expected `fn() -> impl Future {callback}` to be a fn item that returns `Pin + 'static)>>`, but it returns `impl Future` + --> $DIR/issue-98634.rs:45:33 + | +LL | StructAsync { callback }.await; + | ^^^^^^ expected struct `Pin`, found opaque type + | +note: while checking the return type of the `async fn` + --> $DIR/issue-98634.rs:24:21 + | +LL | async fn callback() {} + | ^ checked the `Output` of this `async fn`, found opaque type + = note: expected struct `Pin + 'static)>>` + found opaque type `impl Future` +note: required by a bound in `StructAsync` + --> $DIR/issue-98634.rs:9:35 + | +LL | pub struct StructAsync Pin>>> { + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ required by this bound in `StructAsync` + +error: aborting due to 3 previous errors + +For more information about this error, try `rustc --explain E0271`.