error[E0637]: `&` without an explicit lifetime name cannot be used here --> $DIR/where-clause-trait-impl-region-2018.rs:11:17 | LL | T: WithType<&u32> | ^ explicit lifetime name needed here | help: consider introducing a higher-ranked lifetime here | LL | T: for<'a> WithType<&'a u32> | +++++++ ++ error: aborting due to 1 previous error For more information about this error, try `rustc --explain E0637`.