| // A callee may not read the destination of our `&mut` without |
| // us noticing. |
| |
| #[rustfmt::skip] // rustfmt bug: https://github.com/rust-lang/rustfmt/issues/5391 |
| fn main() { |
| let mut x = 15; |
| let xraw = &mut x as *mut _; |
| let xref = unsafe { &mut *xraw }; // derived from raw, so using raw is still ok... |
| callee(xraw); |
| let _val = *xref; // ...but any use of raw will invalidate our ref. |
| //~^ ERROR: /read access .* tag does not exist in the borrow stack/ |
| } |
| |
| fn callee(xraw: *mut i32) { |
| // We are a bit sneaky: We first create a shared ref, exploiting the reborrowing rules, |
| // and then we read through that. |
| let shr = unsafe { &*xraw }; |
| let _val = *shr; |
| } |
