error[E0621]: explicit lifetime required in the type of `x` --> $DIR/issue-3154.rs:6:5 | LL | fn thing<'a,Q>(x: &Q) -> Thing<'a,Q> { | -- help: add explicit lifetime `'a` to the type of `x`: `&'a Q` LL | Thing { x: x } | ^^^^^^^^^^^^^^ lifetime `'a` required error: aborting due to 1 previous error For more information about this error, try `rustc --explain E0621`.