error[E0277]: `()` is not a future --> $DIR/unnecessary-await.rs:9:11 | LL | boo().await; | ----- ^^^^^ `()` is not a future | | | this call returns `()` | = help: the trait `Future` is not implemented for `()` = note: () must be a future or must implement `IntoFuture` to be awaited = note: required for `()` to implement `IntoFuture` help: remove the `.await` | LL - boo().await; LL + boo(); | help: alternatively, consider making `fn boo` asynchronous | LL | async fn boo() {} | +++++ error[E0277]: `()` is not a future --> $DIR/unnecessary-await.rs:28:10 | LL | e!().await; | -^^^^^ | || | |`()` is not a future | help: remove the `.await` | = help: the trait `Future` is not implemented for `()` = note: () must be a future or must implement `IntoFuture` to be awaited = note: required for `()` to implement `IntoFuture` error[E0277]: `()` is not a future --> $DIR/unnecessary-await.rs:22:15 | LL | $expr.await | ^^^^^ | | | `()` is not a future | remove the `.await` ... LL | f!(()); | ------ in this macro invocation | = help: the trait `Future` is not implemented for `()` = note: () must be a future or must implement `IntoFuture` to be awaited = note: required for `()` to implement `IntoFuture` = note: this error originates in the macro `f` (in Nightly builds, run with -Z macro-backtrace for more info) error[E0277]: `()` is not a future --> $DIR/unnecessary-await.rs:36:20 | LL | for x in [] {}.await | -^^^^^ | || | |`()` is not a future | help: remove the `.await` | = help: the trait `Future` is not implemented for `()` = note: () must be a future or must implement `IntoFuture` to be awaited = note: required for `()` to implement `IntoFuture` error: aborting due to 4 previous errors For more information about this error, try `rustc --explain E0277`.