From 5ba643c001a55f70c4a44690e040cdfab873ba56 Mon Sep 17 00:00:00 2001
From: David Tolnay <dtolnay@gmail.com>
Date: Fri, 22 Sep 2023 19:14:34 -0700
Subject: [PATCH] Test dyn Trait containing async fn

---
 tests/ui/no-attribute-macro.rs     |  4 +++-
 tests/ui/no-attribute-macro.stderr | 15 +++++++++++++++
 2 files changed, 18 insertions(+), 1 deletion(-)

diff --git a/tests/ui/no-attribute-macro.rs b/tests/ui/no-attribute-macro.rs
index 965a485..c0fb431 100644
--- a/tests/ui/no-attribute-macro.rs
+++ b/tests/ui/no-attribute-macro.rs
@@ -8,4 +8,6 @@ impl Trait for Struct {
     async fn method(&self) {}
 }
 
-fn main() {}
+fn main() {
+    let _: &dyn Trait;
+}
diff --git a/tests/ui/no-attribute-macro.stderr b/tests/ui/no-attribute-macro.stderr
index 3085e6d..c7f2502 100644
--- a/tests/ui/no-attribute-macro.stderr
+++ b/tests/ui/no-attribute-macro.stderr
@@ -23,3 +23,18 @@ error[E0706]: functions in traits cannot be declared `async`
   = note: consider using the `async-trait` crate: https://crates.io/crates/async-trait
   = note: see issue #91611 <https://github.com/rust-lang/rust/issues/91611> for more information
   = help: add `#![feature(async_fn_in_trait)]` to the crate attributes to enable
+
+error[E0038]: the trait `Trait` cannot be made into an object
+  --> tests/ui/no-attribute-macro.rs:12:12
+   |
+12 |     let _: &dyn Trait;
+   |            ^^^^^^^^^^ `Trait` cannot be made into an object
+   |
+note: for a trait to be "object safe" it needs to allow building a vtable to allow the call to be resolvable dynamically; for more information visit <https://doc.rust-lang.org/reference/items/traits.html#object-safety>
+  --> tests/ui/no-attribute-macro.rs:2:14
+   |
+1  | pub trait Trait {
+   |           ----- this trait cannot be made into an object...
+2  |     async fn method(&self);
+   |              ^^^^^^ ...because method `method` is `async`
+   = help: consider moving `method` to another trait