error[E0499]: cannot borrow `*x` as mutable more than once at a time --> $DIR/borrowck-borrow-mut-object-twice.rs:13:5 | LL | let y = x.f1(); | - first mutable borrow occurs here LL | x.f2(); | ^ second mutable borrow occurs here LL | y.use_ref(); | - first borrow later used here error: aborting due to previous error For more information about this error, try `rustc --explain E0499`.