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

My hybrid solution that seems to work.

public class Task
{
  string Name;
  public static bool operator ==(Task t1, Task t2)
  { 
    if ((object)t1 == null || (object)t2 == null)
    {
      return (object)t1 == null && (object)t2 == null;
    }

    return t1.Name == t2.Name && t1.GetType() == t2.GetType(); }
  public virtual bool Equals(Task t2)
  {
     return this == t2;
  }
}

public class TaskA : Task
{
  int aThing;
  public static bool operator ==(TaskA t1, TaskA t2)
  { 
    if ((object)t1 == null || (object)t2 == null)
    {
      return (object)t1 == null && (object)t2 == null;
    }

    return (Task)t1 == (Task)t2 && t1.aThing == t2.aThing;
  }
  public override bool Equals(Task t2)
  {
    return this == t2 as TaskA;
  }
}