error[E0283]: type annotations needed: cannot satisfy `&'a (): Foo` --> $DIR/issue-34979.rs:6:13 | LL | &'a (): Foo, | ^^^ | = note: cannot satisfy `&'a (): Foo` = help: the trait `Foo` is implemented for `&'a T` error: aborting due to previous error For more information about this error, try `rustc --explain E0283`.