error[E0107]: struct takes 0 lifetime arguments but 1 lifetime argument was supplied --> $DIR/issue-18423.rs:4:8 | LL | x: Box<'a, isize> | ^^^ -- help: remove the lifetime argument | | | expected 0 lifetime arguments error: aborting due to 1 previous error For more information about this error, try `rustc --explain E0107`.