| //@ edition:2015 | 
 | async fn foo() { | 
 | //~^ ERROR `async fn` is not permitted in Rust 2015 | 
 | //~| NOTE to use `async fn`, switch to Rust 2018 or later | 
 | //~| HELP pass `--edition 2024` to `rustc` | 
 | //~| NOTE for more on editions, read https://doc.rust-lang.org/edition-guide | 
 |  | 
 |     let x = async {}; | 
 |     //~^ ERROR cannot find struct, variant or union type `async` in this scope | 
 |     //~| NOTE `async` blocks are only allowed in Rust 2018 or later | 
 |     let y = async { //~ NOTE `async` blocks are only allowed in Rust 2018 or later | 
 |         let x = 42; | 
 |         //~^ ERROR expected identifier, found keyword `let` | 
 |         //~| NOTE expected identifier, found keyword | 
 |         //~| HELP pass `--edition 2024` to `rustc` | 
 |         //~| NOTE for more on editions, read https://doc.rust-lang.org/edition-guide | 
 |         42 | 
 |     }; | 
 |     let z = async { //~ NOTE `async` blocks are only allowed in Rust 2018 or later | 
 |         42 | 
 |         //~^ ERROR expected identifier, found `42` | 
 |         //~| NOTE expected identifier | 
 |         //~| HELP pass `--edition 2024` to `rustc` | 
 |         //~| NOTE for more on editions, read https://doc.rust-lang.org/edition-guide | 
 |     }; | 
 |     y.await; | 
 |     z.await; | 
 |     x | 
 | } | 
 |  | 
 | fn main() {} |