5 public int ID { get; set; }
10 public readonly int ID;
17 public static explicit operator C (S x)
19 throw new ApplicationException ("wrong conversion");
22 public static explicit operator C (S? x)
24 return new C (x.HasValue ? x.Value.ID : 5);
30 public static int Main ()
38 s = new S () { ID = 10 };