error[E0596]: cannot borrow `x` as mutable, as it is not declared as mutable --> $DIR/borrowck-auto-mut-ref-to-immut-var.rs:25:5 | LL | let x = Foo { x: 3 }; | - help: consider changing this to be mutable: `mut x` LL | x.printme(); //~ ERROR cannot borrow | ^ cannot borrow as mutable error: aborting due to previous error For more information about this error, try `rustc --explain E0596`.