rust/tests/ui/consts/qualif-union.rs
2023-01-11 09:32:08 +00:00

34 lines
978 B
Rust

// Checks that unions use type based qualification. Regression test for issue #90268.
use std::cell::Cell;
use std::mem::ManuallyDrop;
union U { i: u32, c: ManuallyDrop<Cell<u32>> }
const C1: ManuallyDrop<Cell<u32>> = {
unsafe { U { c: ManuallyDrop::new(Cell::new(0)) }.c }
};
const C2: ManuallyDrop<Cell<u32>> = {
unsafe { U { i : 0 }.c }
};
const C3: ManuallyDrop<Cell<u32>> = {
let mut u = U { i: 0 };
u.i = 1;
unsafe { u.c }
};
const C4: U = U { i: 0 };
const C5: [U; 1] = [U {i : 0}; 1];
fn main() {
// Interior mutability should prevent promotion.
let _: &'static _ = &C1; //~ ERROR temporary value dropped while borrowed
let _: &'static _ = &C2; //~ ERROR temporary value dropped while borrowed
let _: &'static _ = &C3; //~ ERROR temporary value dropped while borrowed
let _: &'static _ = &C4; //~ ERROR temporary value dropped while borrowed
let _: &'static _ = &C5; //~ ERROR temporary value dropped while borrowed
}