iv class="comment-context-intro">Selected text:</div><div class="comment-context-value">&amp;quot;Rust won&amp;#39;t like this. Our structs generally don&amp;#39;t contain borrow references. Missile&amp;#39;s Plane targetPlane; should probably be a target_plane_index: u64; instead. And, to prevent other borrowing errors, we turn that missile parameter into some indices:<br><br>fn act(world: &amp;amp;mut World, plane_index: u64, missile_index: u64) {<br>  let target_plane_index = missile.target_plane_index;<