How do I check for nulls in an ‘==’ operator overload without infinite recursion?

by

Use ReferenceEquals:

Foo foo1 = null;
Foo foo2 = new Foo();
Assert.IsFalse(foo1 == foo2);

public static bool operator ==(Foo foo1, Foo foo2) {
    if (object.ReferenceEquals(null, foo1))
        return object.ReferenceEquals(null, foo2);
    return foo1.Equals(foo2);
}

More Related Contents:

  1. What is “Best Practice” For Comparing Two Instances of a Reference Type?
  2. C# operator overload for `+=`?
  3. Operator overloading ==, !=, Equals
  4. Equivalent to ‘app.config’ for a library (DLL)
  5. Datetime – Get next tuesday
  6. Does .NET have a way to check if List a contains all items in List b?
  7. Will code in a Finally statement fire if I return a value in a Try block?
  8. How to “flatten” or “index” 3D-array in 1D array?
  9. ShellExecute equivalent in .NET
  10. Casting List – covariance/contravariance problem
  11. How to store/retrieve RSA public/private key
  12. Read from word document line by line
  13. Why SortedSet.GetViewBetween isn’t O(log N)?
  14. Good introduction to the .NET Reactive Framework [closed]
  15. Can I set LARGEADDRESSAWARE from within Visual Studio?
  16. Generic List – moving an item within the list
  17. Implementing the Producer/Consumer Pattern in C#
  18. MVC 4 how pass data correctly from controller to view
  19. How to Start a Process Unelevated
  20. Any trick to use opacity on a panel in Visual Studio Window Form?
  21. C#, FindControl [duplicate]
  22. How to create an extension method for ToString?
  23. Warm-up when calling methods in C#
  24. How to create a User Control with rounded corners?
  25. Keep Getting ‘The LINQ expression node type ‘Invoke’ is not supported in LINQ to Entities’ Exception
  26. View Models and dependency injection
  27. How do I get a return value from Task.WaitAll() in a console app?
  28. Overloading operator== versus Equals()
  29. Is int? thread safe?
  30. How to empty/flush Windows READ disk cache in C#?

Leave a Comment