-// Copyright 2018 The Rust Project Developers. See the COPYRIGHT
-// file at the top-level directory of this distribution and at
-// http://rust-lang.org/COPYRIGHT.
-//
-// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
-// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
-// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
-// option. This file may not be copied, modified, or distributed
-// except according to those terms.
-
// edition:2018
-#![feature(futures_api)]
+struct S;
+
+impl S {
+ async fn foo() {} //~ ERROR async fn is unstable
+}
+
+trait T {
+ async fn foo(); //~ ERROR trait fns cannot be declared `async`
+ //~^ ERROR async fn is unstable
+}
async fn foo() {} //~ ERROR async fn is unstable