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

30 lines
812 B
Rust

// revisions: mirunsafeck thirunsafeck
// [thirunsafeck]compile-flags: -Z thir-unsafeck
use std::ops::AddAssign;
use std::mem::ManuallyDrop;
struct NonCopy;
impl AddAssign for NonCopy {
fn add_assign(&mut self, _: Self) {}
}
union Foo {
a: u8, // non-dropping
b: ManuallyDrop<NonCopy>,
}
fn main() {
let mut foo = Foo { a: 42 };
foo.a += 5; //~ ERROR access to union field is unsafe
*foo.b += NonCopy; //~ ERROR access to union field is unsafe
*foo.b = NonCopy; //~ ERROR access to union field is unsafe
foo.b = ManuallyDrop::new(NonCopy);
foo.a; //~ ERROR access to union field is unsafe
let foo = Foo { a: 42 };
foo.b; //~ ERROR access to union field is unsafe
let mut foo = Foo { a: 42 };
foo.b = foo.b;
//~^ ERROR access to union field is unsafe
}