error[E0277]: the trait bound `{coroutine@$DIR/coroutine.rs:20:9: 20:11}: Coroutine<A>` is not satisfied
  --> $DIR/coroutine.rs:20:9
   |
LL |       needs_coroutine(
   |       --------------- required by a bound introduced by this call
LL |           #[coroutine]
LL | /         || {
LL | |
LL | |             yield ();
LL | |         },
   | |_________^ the trait `Coroutine<A>` is not implemented for `{coroutine@$DIR/coroutine.rs:20:9: 20:11}`
   |
note: required by a bound in `needs_coroutine`
  --> $DIR/coroutine.rs:14:28
   |
LL | fn needs_coroutine(_: impl Coroutine<A, Yield = B, Return = C>) {}
   |                            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ required by this bound in `needs_coroutine`

error: aborting due to 1 previous error

For more information about this error, try `rustc --explain E0277`.