1 async fn say_world() { 2 println!("world"); 3 } 4 5 #[tokio::main(flavor = "current_thread")] 6 async fn main() { 7 // Calling `say_world()` does not execute the body of `say_world()`. 8 let op = say_world(); 9 10 // This println! comes first 11 println!("hello"); 12 13 // Calling `.await` on `op` starts executing `say_world`. 14 op.await; 15 } 16