$ rustc --explain E0760

`async fn`/`impl trait` return type cannot contain a projection or `Self` that references lifetimes from a parent scope.


Erroneous code example:

```

struct S<'a>(&'a i32);

impl<'a> S<'a> {

    async fn new(i: &'a i32) -> Self {

        S(&22)

    }

}

```


To fix this error we need to spell out `Self` to `S<'a>`:

```

struct S<'a>(&'a i32);

impl<'a> S<'a> {

    async fn new(i: &'a i32) -> S<'a> {

        S(&22)

    }

}

```


This will be allowed at some point in the future,

but the implementation is not yet complete.

See the [issue-61949] for this limitation.


[issue-61949]: https://github.com/rust-lang/rust/issues/61949



lifetime 딸린 Self는 async에서는 못쓴대 장난까냐 ㅡㅡ


그래도 그나마 지들 잘못된 줄은 알고 있음