Question

Consider this code sample:

public class Human {    
    public string Value { get; set;}
}
public class Car { 

    public static explicit operator Human (Car c) { 

        Human h = new Human();

        h.Value = "Value from Car";
        return h;
    }
}

public class Program { 
public static void Mani() { 
        Car c = new Car();

        Human h = (Human)c;
        Console.WriteLine("h.Value = {0}", h.Value);
        Console.WriteLine(c is Human);
}
}

Up I provide a possibility of an explicit cast from Car to Human, though Car and Human hierarchically are not related! The above code simply means that “Car is convertible to human”

However, if you run the snippet you will find the expression c is Human evaluates to false! I used to believe that the is operator is kinda expensive cause it attempts to do an actual cast that might result in an InvalidCastException. If the operator is trying to cast, then the cast should succeed as there’s an operator logic that should perform the cast!
What does “is” test?
Does test a hierarchical “is-a” relationship?

Does test whether a variable type “is convertible to” a type?

Answer 1

The is operator tests for an actual type relation, not for ‘can cast’. Rightfully so.

As for the ‘how does it do it’ part: I don’t know but I assume there are more efficient ways (reflection) to test for family ties than letting it come to an exception.