error: future cannot be sent between threads safely --> $DIR/async-fn-nonsend.rs:72:17 | LL | assert_send(non_send_temporary_in_match()); | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ future returned by `non_send_temporary_in_match` is not `Send` | = help: within `impl Future`, the trait `Send` is not implemented for `Rc<()>` note: future is not `Send` as this value is used across an await --> $DIR/async-fn-nonsend.rs:36:26 | LL | match Some(non_send()) { | ---------------- has type `Option` which is not `Send` LL | Some(_) => fut().await, | ^^^^^ await occurs here, with `Some(non_send())` maybe used later note: required by a bound in `assert_send` --> $DIR/async-fn-nonsend.rs:67:24 | LL | fn assert_send(_: impl Send) {} | ^^^^ required by this bound in `assert_send` error: future cannot be sent between threads safely --> $DIR/async-fn-nonsend.rs:74:17 | LL | assert_send(non_sync_with_method_call()); | ^^^^^^^^^^^^^^^^^^^^^^^^^^^ future returned by `non_sync_with_method_call` is not `Send` | = help: within `impl Future`, the trait `Send` is not implemented for `dyn std::fmt::Write` note: future is not `Send` as this value is used across an await --> $DIR/async-fn-nonsend.rs:49:15 | LL | let f: &mut std::fmt::Formatter = &mut get_formatter(); | --------------- has type `Formatter<'_>` which is not `Send` ... LL | fut().await; | ^^^^^ await occurs here, with `get_formatter()` maybe used later note: required by a bound in `assert_send` --> $DIR/async-fn-nonsend.rs:67:24 | LL | fn assert_send(_: impl Send) {} | ^^^^ required by this bound in `assert_send` error: aborting due to 2 previous errors