error[E0392]: lifetime parameter `'a` is never used --> $DIR/variance-unused-region-param.rs:3:19 | LL | struct SomeStruct<'a> { x: u32 } | ^^ unused lifetime parameter | = help: consider removing `'a`, referring to it in a field, or using a marker such as `PhantomData` error[E0392]: lifetime parameter `'a` is never used --> $DIR/variance-unused-region-param.rs:4:15 | LL | enum SomeEnum<'a> { Nothing } | ^^ unused lifetime parameter | = help: consider removing `'a`, referring to it in a field, or using a marker such as `PhantomData` error: aborting due to 2 previous errors For more information about this error, try `rustc --explain E0392`.