Error code E0760

Note: this error code is no longer emitted by the compiler.

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>:

#![allow(unused)] fn main() { 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.