//@ edition: 2018 #![feature(async_drop)] //~^ WARN the feature `async_drop` is incomplete use std::future::AsyncDrop; use std::pin::Pin; struct Foo; impl AsyncDrop for &Foo { //~^ ERROR the `AsyncDrop` trait may only be implemented for async fn drop(self: Pin<&mut Self>) {} } impl AsyncDrop for Pin { //~^ ERROR the `AsyncDrop` trait may only be implemented for async fn drop(self: Pin<&mut Self>) {} } fn main() {}