error[E0641]: cannot cast to a pointer of an unknown kind --> $DIR/order-dependent-cast-inference.rs:5:22 | LL | let mut y = 0 as *const _; | ^^^^^^^^ needs more type information | = note: the type information given here is insufficient to check whether the pointer cast is valid error: aborting due to previous error For more information about this error, try `rustc --explain E0641`.