error[E0641]: cannot cast to a pointer of an unknown kind --> $DIR/issue-99122.rs:5:27 | LL | let pointer = 1u32 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 1 previous error For more information about this error, try `rustc --explain E0641`.