tests/rustdoc/edition-flag.rs - third_party/github.com/rust-lang/rust - Git at Google

 //@ compile-flags:--test
 //@ edition:2018

 /// ```rust
 /// fn main() {
 ///     let _ = async { };
 /// }
 /// ```
 fn main() {
     let _ = async { };
 }
	//@ compile-flags:--test
	//@ edition:2018

	/// ```rust
	/// fn main() {
	/// let _ = async { };
	/// }
	/// ```
	fn main() {
	let _ = async { };
	}