// Basic test for liveness constraints: the region (`R1`) that appears // in the type of `p` includes the points after `&v[0]` up to (but not // including) the call to `use_x`. The `else` branch is not included. // check-pass #![allow(warnings)] #![feature(dropck_eyepatch)] fn use_x(_: usize) -> bool { true } fn main() { let mut v = [1, 2, 3]; let p: WrapMayDangle<& /* R4 */ usize> = WrapMayDangle { value: &v[0] }; if true { // `p` will get dropped at end of this block. However, because of // the `#[may_dangle]` attribute, we do not need to consider R4 // live after this point. use_x(*p.value); } else { v[0] += 1; use_x(22); } v[0] += 1; } struct WrapMayDangle { value: T } unsafe impl<#[may_dangle] T> Drop for WrapMayDangle { fn drop(&mut self) { } }