#[repr(C)] union Bar { a: &'static u8, b: usize, } const fn bar() -> u8 { unsafe { // This will error as long as this test is run on a system whose // pointers need more than 8 bits. Bar { a: &42 }.b as u8 } } fn main() { // This will compile, but then hard-abort at runtime. // FIXME(oli-obk): this should instead panic (not hard-abort) at runtime. let x: &'static u8 = &(bar() + 1); //~^ ERROR temporary value dropped while borrowed let y = *x; unreachable!(); }