error[E0506]: cannot assign to `*refr` because it is borrowed --> $DIR/issue-40288.rs:16:5 | LL | save_ref(&*refr, &mut out); | ------ `*refr` is borrowed here ... LL | *refr = 3; | ^^^^^^^^^ `*refr` is assigned to here but it was already borrowed ... LL | println!("{:?}", out[0]); | ------ borrow later used here error: aborting due to 1 previous error For more information about this error, try `rustc --explain E0506`.