error: future cannot be sent between threads safely --> $DIR/unsend-future.rs:20:21 | LL | require_handler(handler) | ^^^^^^^ future returned by `handler` is not `Send` | = help: within `impl Future`, the trait `Send` is not implemented for `*const i32` note: future is not `Send` as this value is used across an await --> $DIR/unsend-future.rs:15:14 | LL | let a = &1 as *const i32; | - has type `*const i32` which is not `Send` LL | async {}.await; | ^^^^^ await occurs here, with `a` maybe used later note: required by a bound in `require_handler` --> $DIR/unsend-future.rs:11:23 | LL | fn require_handler(h: H) {} | ^^^^^^^ required by this bound in `require_handler` error: aborting due to previous error