static void Operators()
{
Console.WriteLine("Operators");
var o1 = new OpClass(10);
var o2 = new OpClass(100);
(o1 + o2).f();
fo(++o1);
o1.f();
fo(o2++);
o2.f();
int i = o1;
int j = (int)o2;
double d = (double)o1;
double f = o2;
}
static void fo(OpClass o)
{
o.f();
}