error[E0107]: this struct takes 0 lifetime arguments but 1 lifetime argument was supplied
  --> $DIR/issue-18423.rs:4:8
   |
LL |     x: Box<'a, isize>
   |        ^^^ -- help: remove this lifetime argument
   |        |
   |        expected 0 lifetime arguments

error: aborting due to previous error

For more information about this error, try `rustc --explain E0107`.