| error[E0384]: cannot assign to immutable argument `_x` | |
| --> $DIR/immutable-arg.rs:2:5 | |
| | | |
| LL | _x = 4; | |
| | ^^^^^^ cannot assign to immutable argument | |
| | | |
| help: consider making this binding mutable | |
| | | |
| LL | fn foo(mut _x: u32) { | |
| | +++ | |
| error: aborting due to 1 previous error | |
| For more information about this error, try `rustc --explain E0384`. |