struct Circle {
    radius: f32;
}

struct Rect {
    width: f32;
    height: f32;
}

union Shape {
    circle: Circle;
    rect: Rect;
}

test "union_init" {
    var c = Circle{ radius: 10.0 };
    var s = Shape{ circle: c };
    assert(s.circle.radius == 10.0, "s.circle.radius != 10.0");

    var s2 = Shape{};
    s2.rect = Rect{ width: 5.0, height: 5.0 };
    assert(s2.rect.width == 5.0, "s2.rect.width != 5.0");
}