feat: impl better help for `.poll()` not found on `impl Future`

2 files changed, 24 insertions, 0 deletions

diff --git a/tests/ui/async-await/issue-108572.rs b/tests/ui/async-await/issue-108572.rs
new file mode 100644
index 00000000000..efcb8b8ebab
--- /dev/null
+++ b/tests/ui/async-await/issue-108572.rs
@@ -0,0 +1,12 @@
+// edition: 2021
+
+use std::future::Future;
+fn foo() -> impl Future<Output=()> {
+    async { }
+}
+
+fn main() {
+    let fut = foo();
+    fut.poll();
+    //~^ ERROR no method named `poll` found for opaque type `impl Future<Output = ()>` in the current scope [E0599]
+}
diff --git a/tests/ui/async-await/issue-108572.stderr b/tests/ui/async-await/issue-108572.stderr
new file mode 100644
index 00000000000..0dbcf4d660a
--- /dev/null
+++ b/tests/ui/async-await/issue-108572.stderr
@@ -0,0 +1,12 @@
+error[E0599]: no method named `poll` found for opaque type `impl Future<Output = ()>` in the current scope
+  --> $DIR/issue-108572.rs:10:9
+   |
+LL |     fut.poll();
+   |         ^^^^ method not found in `impl Future<Output = ()>`
+   |
+   = help: method `poll` found on `Pin<&mut impl Future<Output = ()>>`, see documentation for `std::pin::Pin`
+   = help: self type must be pinned to call `Future::poll`, see https://rust-lang.github.io/async-book/04_pinning/01_chapter.html#pinning-in-practice
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0599`.