|  | error[E0133]: borrow of layout constrained field with interior mutability is unsafe and requires unsafe function or block | 
|  | --> $DIR/ranged_ints3_const.rs:12:13 | 
|  | | | 
|  | LL |     let y = &x.0; | 
|  | |             ^^^^ borrow of layout constrained field with interior mutability | 
|  | | | 
|  | = note: references to fields of layout constrained fields lose the constraints. Coupled with interior mutability, the field can be changed to invalid values | 
|  |  | 
|  | error: aborting due to 1 previous error | 
|  |  | 
|  | For more information about this error, try `rustc --explain E0133`. |