Why can’t I inherit static classes?

by

Citation from here:

This is actually by design. There seems to be no good reason to inherit a static class. It has public static members that you can always access via the class name itself. The only reasons I have seen for inheriting static stuff have been bad ones, such as saving a couple of characters of typing.

There may be reason to consider mechanisms to bring static members directly into scope (and we will in fact consider this after the Orcas product cycle), but static class inheritance is not the way to go: It is the wrong mechanism to use, and works only for static members that happen to reside in a static class.

(Mads Torgersen, C# Language PM)

Other opinions from channel9

Inheritance in .NET works only on instance base. Static methods are defined on the type level not on the instance level. That is why overriding doesn’t work with static methods/properties/events…

Static methods are only held once in memory. There is no virtual table etc. that is created for them.

If you invoke an instance method in .NET, you always give it the current instance. This is hidden by the .NET runtime, but it happens. Each instance method has as first argument a pointer (reference) to the object that the method is run on. This doesn’t happen with static methods (as they are defined on type level). How should the compiler decide to select the method to invoke?

(littleguru)

And as a valuable idea, littleguru has a partial “workaround” for this issue: the Singleton pattern.

More Related Contents:

  1. What’s the correct alternative to static method inheritance?
  2. C# static member “inheritance” – why does this exist at all?
  3. Why not inherit from List?
  4. Lifetime of ASP.NET Static Variable
  5. Is the order of static class initialization in C# deterministic?
  6. Are static class instances unique to a request or a server in ASP.NET?
  7. Get all derived types of a type
  8. Should C# have multiple inheritance? [closed]
  9. Are static methods thread safe
  10. How to access Winform textbox control from another class?
  11. Static Indexers?
  12. Should C# methods that *can* be static be static? [closed]
  13. Inheritance with base class constructor with parameters [duplicate]
  14. Overloading and overriding
  15. Convert base class to derived class [duplicate]
  16. How do I override List’s Add method in C#?
  17. Are static variables in a base class shared by all derived classes?
  18. How to hide an inherited property in a class without modifying the inherited class (base class)?
  19. Use dependency injection in static class
  20. In C#, is it possible to cast a List to List?
  21. Why aren’t generic type constraints inheritable/hierarchically enforced
  22. How to access page controls inside a static web method? [duplicate]
  23. How can I get the value of a session variable inside a static method?
  24. How to implement virtual static properties?
  25. Why can’t my public class extend an internal class?
  26. Why must an C# interface method implemented in a class be public?
  27. Are static members of a generic class tied to the specific instance?
  28. Force base method call
  29. Order of static constructors/initializers in C#
  30. Why static fields initialization occurs before the static constructor?

Leave a Comment