// Note: it would be nice to give fewer warnings in these cases. fn mutate_by_mut_ref(&x: uint) { x = 0u; } fn mutate_by_ref(&&x: uint) { //!^ WARNING unused variable: `x` x = 0u; //! ERROR assigning to argument } fn mutate_by_val(++x: uint) { //!^ WARNING unused variable: `x` x = 0u; //! ERROR assigning to argument } fn mutate_by_copy(+x: uint) { //!^ WARNING unused variable: `x` x = 0u; //! ERROR assigning to argument //!^ WARNING value assigned to `x` is never read } fn mutate_by_move(-x: uint) { //!^ WARNING unused variable: `x` x = 0u; //! ERROR assigning to argument //!^ WARNING value assigned to `x` is never read } fn main() { }