1 files changed, 57 insertions, 0 deletions
diff --git a/src/test/ui/async-await/async-fn-send-uses-nonsend.rs b/src/test/ui/async-await/async-fn-send-uses-nonsend.rs
new file mode 100644
index 000000000..35d9cb155
--- /dev/null
+++ b/src/test/ui/async-await/async-fn-send-uses-nonsend.rs
@@ -0,0 +1,57 @@
+// build-pass (FIXME(62277): could be check-pass?)
+// edition:2018
+// compile-flags: --crate-type lib
+
+use std::{
+    cell::RefCell,
+    fmt::Debug,
+    rc::Rc,
+};
+
+fn non_sync() -> impl Debug { RefCell::new(()) }
+
+fn non_send() -> impl Debug { Rc::new(()) }
+
+fn take_ref<T>(_: &T) {}
+
+async fn fut() {}
+
+async fn fut_arg<T>(_: T) {}
+
+async fn still_send() {
+    fut().await;
+    println!("{:?} {:?}", non_send(), non_sync());
+    fut().await;
+    drop(non_send());
+    drop(non_sync());
+    fut().await;
+    fut_arg(non_sync()).await;
+
+    // Note: all temporaries in `if let` and `match` scrutinee
+    // are dropped at the *end* of the blocks, so using `non_send()`
+    // in either of those positions with an await in the middle will
+    // cause a `!Send` future. It might be nice in the future to allow
+    // this for `Copy` types, since they can be "dropped" early without
+    // affecting the end user.
+    if let Some(_) = Some(non_sync()) {
+        fut().await;
+    }
+    match Some(non_sync()) {
+        Some(_) => fut().await,
+        None => fut().await,
+    }
+
+    let _ = non_send();
+    fut().await;
+
+    {
+        let _x = non_send();
+    }
+    fut().await;
+}
+
+fn assert_send(_: impl Send) {}
+
+pub fn pass_assert() {
+    assert_send(still_send());
+}