error[E0700]: hidden type for `impl Iterator` captures lifetime that does not appear in bounds --> $DIR/static-return-lifetime-infered.rs:7:9 | LL | fn iter_values_anon(&self) -> impl Iterator { | ----- ----------------------- opaque type defined here | | | hidden type `Map, {closure@$DIR/static-return-lifetime-infered.rs:7:27: 7:30}>` captures the anonymous lifetime defined here LL | self.x.iter().map(|a| a.0) | ^^^^^^^^^^^^^^^^^^^^^^^^^^ | help: to declare that `impl Iterator` captures `'_`, you can add an explicit `'_` lifetime bound | LL | fn iter_values_anon(&self) -> impl Iterator + '_ { | ++++ error[E0700]: hidden type for `impl Iterator` captures lifetime that does not appear in bounds --> $DIR/static-return-lifetime-infered.rs:11:9 | LL | fn iter_values<'a>(&'a self) -> impl Iterator { | -- ----------------------- opaque type defined here | | | hidden type `Map, {closure@$DIR/static-return-lifetime-infered.rs:11:27: 11:30}>` captures the lifetime `'a` as defined here LL | self.x.iter().map(|a| a.0) | ^^^^^^^^^^^^^^^^^^^^^^^^^^ | help: to declare that `impl Iterator` captures `'a`, you can add an explicit `'a` lifetime bound | LL | fn iter_values<'a>(&'a self) -> impl Iterator + 'a { | ++++ error: aborting due to 2 previous errors For more information about this error, try `rustc --explain E0700`.