error[E0308]: mismatched types --> $DIR/box-future-wrong-output.rs:20:39 | LL | let _: BoxFuture<'static, bool> = async {}.boxed(); | ------------------------ ^^^^^^^^^^^^^^^^ expected `bool`, found `()` | | | expected due to this | = note: expected struct `Pin + Send + 'static)>>` found struct `Pin + Send>>` error: aborting due to 1 previous error For more information about this error, try `rustc --explain E0308`.