error[E0261]: use of undeclared lifetime name `'missing` --> $DIR/missing-lt-outlives-in-rpitit-114274.rs:8:55 | LL | fn iter(&self) -> impl Iterator>; | ^^^^^^^^ undeclared lifetime | = note: for more information on higher-ranked polymorphism, visit https://doc.rust-lang.org/nomicon/hrtb.html help: consider making the bound lifetime-generic with a new `'missing` lifetime | LL | fn iter(&self) -> impl for<'missing> Iterator>; | +++++++++++++ help: consider introducing lifetime `'missing` here | LL | fn iter<'missing>(&self) -> impl Iterator>; | ++++++++++ help: consider introducing lifetime `'missing` here | LL | trait Iterable<'missing> { | ++++++++++ error: aborting due to previous error For more information about this error, try `rustc --explain E0261`.