Implement projection and shim for AFIDT

1 files changed, 23 insertions, 0 deletions

diff --git a/tests/ui/async-await/dyn/wrong-size.rs b/tests/ui/async-await/dyn/wrong-size.rs
new file mode 100644
index 00000000000..ac15dd26067
--- /dev/null
+++ b/tests/ui/async-await/dyn/wrong-size.rs
@@ -0,0 +1,23 @@
+//@ edition: 2021
+
+#![feature(async_fn_in_dyn_trait)]
+//~^ WARN the feature `async_fn_in_dyn_trait` is incomplete
+
+use std::future::Future;
+
+trait AsyncTrait {
+    async fn async_dispatch(&self);
+}
+
+impl AsyncTrait for &'static str {
+    fn async_dispatch(&self) -> impl Future<Output = ()> {
+        async move {
+            // The implementor must box the future...
+        }
+    }
+}
+
+fn main() {
+    let x: &dyn AsyncTrait = &"hello, world!";
+    //~^ ERROR `impl Future<Output = ()>` needs to have the same ABI as a pointer
+}