error[E0053]: method `foo` has an incompatible type for trait
  --> $DIR/async-example-desugared-boxed-in-trait.rs:15:28
   |
LL |     async fn foo(&self) -> i32 {
   |                            ^^^ expected struct `Pin`, found opaque type
   |
note: type in trait
  --> $DIR/async-example-desugared-boxed-in-trait.rs:11:22
   |
LL |     fn foo(&self) -> Pin<Box<dyn Future<Output = i32> + '_>>;
   |                      ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
   = note: expected fn pointer `fn(&i32) -> Pin<Box<dyn Future<Output = i32>>>`
              found fn pointer `fn(&i32) -> impl Future<Output = i32>`

error: aborting due to previous error

For more information about this error, try `rustc --explain E0053`.