public static Ite <C> Is <A, B, C>(this A a, Func <B, C> f)
where B : A
{
return(a is B?Ite.ProduceThen(f((B)a)) : Ite.ProduceElse <C>());
}
public static Ite <C> Is <A, B, C>(this A a, Func <B, C> f)
where B : A
{
return(a is B?Ite.ProduceThen(f((B)a)) : Ite.ProduceElse <C>());
}