say_world()1*4afc5b7bSlinfengasync fn say_world() { 2*4afc5b7bSlinfeng println!("world"); 3*4afc5b7bSlinfeng } 4*4afc5b7bSlinfeng 5*4afc5b7bSlinfeng #[tokio::main(flavor = "current_thread")] main()6*4afc5b7bSlinfengasync fn main() { 7*4afc5b7bSlinfeng // Calling `say_world()` does not execute the body of `say_world()`. 8*4afc5b7bSlinfeng let op = say_world(); 9*4afc5b7bSlinfeng 10*4afc5b7bSlinfeng // This println! comes first 11*4afc5b7bSlinfeng println!("hello"); 12*4afc5b7bSlinfeng 13*4afc5b7bSlinfeng // Calling `.await` on `op` starts executing `say_world`. 14*4afc5b7bSlinfeng op.await; 15*4afc5b7bSlinfeng } 16