How can i override a base class's == operator, so the override gets called

Question

With code like the following

public class Task
{
  string Name;
  public static bool operator ==(Task t1, Task t2)
  { return t1.Name = t2.Name && t1.GetType() == t2.GetType(); }
}
public class TaskA : Task
{
   int aThing;
   public static bool operator ==(TaskA t1, TaskA t2)
   { 
      return (Task)t1 == (Task)t2 && t1.GetType() == t2.GetType()
          && t1.aThing == t2.aThing; }
}
public class TaskB : Task  //more of the same

class Stuffin
{
   List<Task> Tasks;

   void CheckIt()
   {
      bool theSame = Tasks[0] == Tasks[1];
   }

I'm trying to make sure that the derived operator (TaskA.==) is called.

I get compilation error when trying the technique here.

I think i'd be able to get it to work correctly if the operator was not static, because i could then override the base class's operator. Is that possible?

Once i get that how would i compare the base properties (i would think the cast to task type [(Task)t1 == (Task)t2] would not work)?

Answer 1

You can't. Operators aren't overridden, they're overloaded. That means the implementation to be used is entirely decided at compile-time.

One thing you can do is override Equals in Task and call it from ==, and then override it again in TaskA. That also makes the "base properties" check easy - just call base.Equals from TaskA.Equals.