// This attempts to modify `x.1` via a pointer derived from `addr_of_mut!(x.0)`. // According to Miri, that is UB. However, T-opsem has not finalized that // decision and as such we cannot rely on it in optimizations. Consequently, // DataflowConstProp must treat the `addr_of_mut!(x.0)` as potentially being // used to modify `x.1` - if it did not, then it might incorrectly assume that it // can infer the value of `x.1` at the end of this function. // unit-test: DataflowConstProp // EMIT_MIR sibling_ptr.main.DataflowConstProp.diff fn main() { let mut x: (u8, u8) = (0, 0); unsafe { let p = std::ptr::addr_of_mut!(x.0); *p.add(1) = 1; } let x1 = x.1; // should not be propagated }