1 error: future cannot be sent between threads safely
2 --> $DIR/issue-70818.rs:4:38
4 LL | fn foo<T: Send, U>(ty: T, ty1: U) -> impl Future<Output = (T, U)> + Send {
5 | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ future created by async block is not `Send`
7 note: captured value is not `Send`
8 --> $DIR/issue-70818.rs:6:18
10 LL | async { (ty, ty1) }
11 | ^^^ has type `U` which is not `Send`
12 help: consider restricting type parameter `U`
14 LL | fn foo<T: Send, U: std::marker::Send>(ty: T, ty1: U) -> impl Future<Output = (T, U)> + Send {
17 error: aborting due to previous error