Only prevent field projections into opaque types, not types containing opaque types

1 files changed, 27 insertions, 0 deletions

diff --git a/tests/ui/impl-trait/opaque-cast-field-access-in-future.rs b/tests/ui/impl-trait/opaque-cast-field-access-in-future.rs
new file mode 100644
index 00000000000..3e3bc09a62a
--- /dev/null
+++ b/tests/ui/impl-trait/opaque-cast-field-access-in-future.rs
@@ -0,0 +1,27 @@
+// edition: 2021
+
+use std::future::Future;
+
+async fn bop() {
+    fold(run(), |mut foo| async move {
+        &mut foo.bar;
+    })
+}
+
+fn fold<Fut, F, U>(_: Foo<U>, f: F)
+where
+    F: FnMut(Foo<U>) -> Fut,
+{
+    loop {}
+}
+
+struct Foo<F> {
+    bar: Vec<F>,
+}
+
+fn run() -> Foo<impl Future<Output = ()>> {
+    //~^ ERROR type annotations needed
+    loop {}
+}
+
+fn main() {}