error[E0594]: cannot assign to `fancy_ref.num` which is behind a `&` reference --> $DIR/issue-47388.rs:9:5 | LL | let fancy_ref = &(&mut fancy); | ------------- help: consider changing this to be a mutable reference: `&mut (&mut fancy)` LL | fancy_ref.num = 6; | ^^^^^^^^^^^^^^^^^ `fancy_ref` is a `&` reference, so the data it refers to cannot be written error: aborting due to previous error