error[E0706]: trait fns cannot be declared `async`
  --> $DIR/feature-gate-async-await.rs:10:5
   |
LL |     async fn foo();
   |     ^^^^^^^^^^^^^^^

error[E0658]: async fn is unstable
  --> $DIR/feature-gate-async-await.rs:6:5
   |
LL |     async fn foo() {}
   |     ^^^^^^^^^^^^^^^^^
   |
   = note: for more information, see https://github.com/rust-lang/rust/issues/50547
   = help: add `#![feature(async_await)]` to the crate attributes to enable

error[E0658]: async fn is unstable
  --> $DIR/feature-gate-async-await.rs:10:5
   |
LL |     async fn foo();
   |     ^^^^^^^^^^^^^^^
   |
   = note: for more information, see https://github.com/rust-lang/rust/issues/50547
   = help: add `#![feature(async_await)]` to the crate attributes to enable

error[E0658]: async fn is unstable
  --> $DIR/feature-gate-async-await.rs:14:1
   |
LL | async fn foo() {}
   | ^^^^^^^^^^^^^^^^^
   |
   = note: for more information, see https://github.com/rust-lang/rust/issues/50547
   = help: add `#![feature(async_await)]` to the crate attributes to enable

error[E0658]: async blocks are unstable
  --> $DIR/feature-gate-async-await.rs:17:13
   |
LL |     let _ = async {};
   |             ^^^^^^^^
   |
   = note: for more information, see https://github.com/rust-lang/rust/issues/50547
   = help: add `#![feature(async_await)]` to the crate attributes to enable

error: aborting due to 5 previous errors

For more information about this error, try `rustc --explain E0658`.