How do you compare an oxygene class reference to classes?

Given the following code:

type
  Class1 = public class
  end;

  Class1Class = class of Class1;

  Class2 = public class (Class1)
  end;

  Class3 = public class (Class1)
  end;

  Class4 = public class
  public
    method DoSomething(c: Class1Class): Integer;
  end;

implementation

method Class4.DoSomething(c: Class1Class): Integer;
begin
  if c = Class2 then
    result := 0
  else if c = Class3 then
    result := 1
  else
    result := 2;
end;

How should DoSomething actually be written, as the equality comparisons throw the compiler error: Type mismatch, cannot find operator to evaluate "class of Class1" = "<type>"

Using is compiles, but in actuality the first conditional always evaluates to true no matter if Class2 or Class3 is passed in.

The goal is to write this in a cross-platform ways without using code specific to any one of the platforms Oxygene supports.

You must create class references for each class used in the conditionals and use the is operator.

type
  Class1 = public class
  end;

  Class1Class = class of Class1;

  Class2 = public class (Class1)
  end;

  Class3 = public class (Class1)
  end;

  Class4 = public class
  public
    method DoSomething(c: Class1Class): Integer;
  end;

  Class2Class = class of Class2;
  Class3Class = class of Class3;

implementation


method Class4.DoSomething(c: Class1Class): Integer;
begin
  if c is Class2Class then
    result := 0
  else if c is Class3Class then
    result := 1
  else
    result := 2;
end;