static void TestBox() {
ArrayList c = new ArrayList();
SomeValue x = new SomeValue();
x.x = 1;
// box
c.Add(x);
x.x = 2;
// box
c.Add(x);
// unbox
SomeValue y = (SomeValue)c[0];
// box while calling GetType
x.GetType();
// not box while calling ToString. However, Base.ToString cause boxing
x.ToString();
// box, interface is reference type
IComparable v = x;
}