error[E0507]: cannot move out of dereference of `Ref<'_, TheDarkKnight>` --> $DIR/E0507.rs:12:5 | LL | x.borrow().nothing_is_true(); | ^^^^^^^^^^^----------------- | | | | | value moved due to this method call | move occurs because value has type `TheDarkKnight`, which does not implement the `Copy` trait | note: `TheDarkKnight::nothing_is_true` takes ownership of the receiver `self`, which moves value --> $DIR/E0507.rs:6:24 | LL | fn nothing_is_true(self) {} | ^^^^ error: aborting due to previous error For more information about this error, try `rustc --explain E0507`.