Question

I have the following structure:

abstract class Base {         public abstract List<...> Get(); //What should be the generic type? }  class SubOne : Base {     public override List<SubOne> Get() {      } }  class SubTwo : Base {     public override List<SubTwo> Get() {      } } 

I want to create an abstract method that returns whatever class the concrete sub class is. So, as you can see from the example, the method in SubOne should return List<SubOne> whereas the method in SubTwo should return List<SubTwo>.

What type do I specify in the signature declared in the Base class ?

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[UPDATE]

Thank you for the posted answers.

The solution is to make the abstract class generic, like such:

abstract class Base<T> {         public abstract List<T> Get(); }  class SubOne : Base<SubOne> {     public override List<SubOne> Get() {      } }  class SubTwo : Base<SubTwo> {     public override List<SubTwo> Get() {      } }  

Answer 1

Your abstract class should be generic.

abstract class Base<T> {         public abstract List<T> Get();  }  class SubOne : Base<SubOne> {     public override List<SubOne> Get() {      } }  class SubTwo : Base<SubTwo> {     public override List<SubTwo> Get() {     } } 

If you need to refer to the abstract class without the generic type argument, use an interface:

interface IBase {         //common functions }  abstract class Base<T> : IBase {         public abstract List<T> Get();  }