rust/tests/ui/unsafe/union-modification.rs

// run-pass
union Foo {
    bar: i8,
    _blah: isize,
    _zst: (),
}

struct FooHolder {
    inner_foo: Foo
}

fn do_nothing(_x: &mut Foo) {}

pub fn main() {
    let mut foo = Foo { bar: 5 };
    do_nothing(&mut foo);
    foo.bar = 6;
    unsafe { foo.bar += 1; }
    assert_eq!(unsafe { foo.bar }, 7);
    unsafe {
        let Foo { bar: inner } = foo;
        assert_eq!(inner, 7);
    }

    let foo = Foo { bar: 5 };
    let foo = if let 3 = if let true = true { 3 } else { 4 } { foo } else { foo };

    let (_foo2, _random) = (foo, 42);

    let mut foo_holder = FooHolder { inner_foo: Foo { bar: 5 } };
    foo_holder.inner_foo.bar = 4;
    assert_eq!(unsafe { foo_holder.inner_foo.bar }, 4);
    drop(foo_holder);
}