//@ edition: 2021 async fn a() -> i32 { 0 } fn foo() -> _ { //~^ ERROR the placeholder `_` is not allowed within types on item signatures for return types [E0121] //~| NOTE not allowed in type signatures //~| HELP replace with an appropriate return type //~| SUGGESTION impl Future a() } fn bar() -> _ { //~^ ERROR the placeholder `_` is not allowed within types on item signatures for return types [E0121] //~| NOTE not allowed in type signatures //~| HELP replace with an appropriate return type //~| SUGGESTION impl Future async { a().await } } fn main() {}