error[E0277]: the trait bound `isize: HasState` is not satisfied
  --> $DIR/issue-18611.rs:1:1
   |
LL | / fn add_state(op: <isize as HasState>::State) {
LL | |
LL | | }
   | |_^ the trait `HasState` is not implemented for `isize`

error: aborting due to previous error

For more information about this error, try `rustc --explain E0277`.