// Some optimizations remove ZST accesses, thus masking this UB. // compile-flags: -Zmir-opt-level=0 // error-pattern: memory access failed: 0x0 is not a valid pointer #[allow(deref_nullptr)] fn main() { // Not using the () type here, as writes of that type do not even have MIR generated. // Also not assigning directly as that's array initialization, not assignment. let zst_val = [1u8; 0]; unsafe { std::ptr::null_mut::<[u8; 0]>().write(zst_val) }; }