tests/ui/return/suggest-a-value.rs - rust-lang/rust - Git at Google

 fn test() -> (i32,) {
     return;
     //~^ ERROR `return;` in a function whose return type is not `()`
 }

 fn main() {}
	fn test() -> (i32,) {
	return;
	//~^ ERROR `return;` in a function whose return type is not `()`
	}

	fn main() {}