error[E0495]: cannot infer an appropriate lifetime for lifetime parameter `'b` due to conflicting requirements --> $DIR/impl-of-supertrait-has-wrong-lifetime-parameters.rs:24:28 | LL | impl<'a,'b> T2<'a, 'b> for S<'a, 'b> { | ^^^^^^^^^ | note: first, the lifetime cannot outlive the lifetime `'a` as defined here... --> $DIR/impl-of-supertrait-has-wrong-lifetime-parameters.rs:24:6 | LL | impl<'a,'b> T2<'a, 'b> for S<'a, 'b> { | ^^ note: ...but the lifetime must also be valid for the lifetime `'b` as defined here... --> $DIR/impl-of-supertrait-has-wrong-lifetime-parameters.rs:24:9 | LL | impl<'a,'b> T2<'a, 'b> for S<'a, 'b> { | ^^ note: ...so that the types are compatible --> $DIR/impl-of-supertrait-has-wrong-lifetime-parameters.rs:24:28 | LL | impl<'a,'b> T2<'a, 'b> for S<'a, 'b> { | ^^^^^^^^^ = note: expected `T1<'a>` found `T1<'_>` error: aborting due to previous error For more information about this error, try `rustc --explain E0495`.