Question

I have

public abstract class DataClass
{
    public static bool operator ==(DataClass left, DataClass right)
    {
        return left.Equals(right);
    }
}

and this is what happens

object left = new DataClass();
object right = new DataClass();
bool expected = true;
bool actual;
actual = ((DataClass)left) == ((DataClass)right);
Assert.AreEqual(expected, actual); // passes
actual = left == right;
Assert.AreEqual(expected, actual); // fails

How to make it call the right implementation, without casting it explicitly?

Answer 1

static methods are not subject to polymorphic behavior (i.e. they cannot be overriden). The cast is required.

For a possible workaround see this related question: Override a static method

Most likely you will have to resort to creating an instance method or overriding Equals instead.