error[E0309]: the parameter type `T` may not live long enough --> $DIR/regions-struct-not-wf.rs:13:16 | LL | impl<'a, T> Trait<'a, T> for usize { | -- the parameter type `T` must be valid for the lifetime `'a` as defined here... LL | type Out = &'a T; | ^^^^^ ...so that the reference type `&'a T` does not outlive the data it points at | help: consider adding an explicit lifetime bound | LL | impl<'a, T: 'a> Trait<'a, T> for usize { | ++++ error[E0309]: the parameter type `T` may not live long enough --> $DIR/regions-struct-not-wf.rs:21:16 | LL | impl<'a, T> Trait<'a, T> for u32 { | -- the parameter type `T` must be valid for the lifetime `'a` as defined here... LL | type Out = RefOk<'a, T>; | ^^^^^^^^^^^^ ...so that the type `T` will meet its required lifetime bounds... | note: ...that is required by this bound --> $DIR/regions-struct-not-wf.rs:16:20 | LL | struct RefOk<'a, T:'a> { | ^^ help: consider adding an explicit lifetime bound | LL | impl<'a, T: 'a> Trait<'a, T> for u32 { | ++++ error[E0491]: in type `&'a &'b T`, reference has a longer lifetime than the data it references --> $DIR/regions-struct-not-wf.rs:25:16 | LL | type Out = &'a &'b T; | ^^^^^^^^^ | note: the pointer is valid for the lifetime `'a` as defined here --> $DIR/regions-struct-not-wf.rs:24:6 | LL | impl<'a, 'b, T> Trait1<'a, 'b, T> for u32 { | ^^ note: but the referenced data is only valid for the lifetime `'b` as defined here --> $DIR/regions-struct-not-wf.rs:24:10 | LL | impl<'a, 'b, T> Trait1<'a, 'b, T> for u32 { | ^^ error: aborting due to 3 previous errors Some errors have detailed explanations: E0309, E0491. For more information about an error, try `rustc --explain E0309`.