#![deny(unreachable_code)] use futures::{executor::block_on, try_join}; // TODO: This abuses https://github.com/rust-lang/rust/issues/58733 in order to // test behavior of the `try_join!` macro with the never type before it is // stabilized. Once `!` is again stabilized this can be removed and replaced // with direct use of `!` below where `Never` is used. trait MyTrait { type Output; } impl MyTrait for fn() -> T { type Output = T; } type Never = ! as MyTrait>::Output; #[test] fn try_join_never_error() { block_on(async { let future1 = async { Ok::<(), Never>(()) }; let future2 = async { Ok::<(), Never>(()) }; try_join!(future1, future2) }) .unwrap(); } #[test] fn try_join_never_ok() { block_on(async { let future1 = async { Err::(()) }; let future2 = async { Err::(()) }; try_join!(future1, future2) }) .unwrap_err(); }