Question

I have a base class that inherits List<> which has multiple classes derived from it.

I want to create a method that can add items to any class that has inherited from this base class, is this possible ?

pseudo code:

public class BaseList<T> : List<T> where T: baseItem { }  public BaseList<T> AddItems<T>(int someArg) where T: new(), baseItem {  BaseList<T> temp = new BaseList<T>(); temp.add(new T()); temp.add(new T()); return temp; }   public class MyDerived: BaseList<SomeClass> { } 

Then to call this code:

MyDerived temp = (MyDerived)AddItems(); 

is something like this possible ? I can’t figure out the correct syntax

Answer 1

Do you really need to derive from List<T> instead of using composition?

It sounds like you want a static method in a non-generic type:

public static TList CreateList<TList,TItem>(int someArg)     where TList : BaseList<TItem>, new()     where TItem : baseItem, new() {     TList temp = new TList();     temp.Add(new TItem());     temp.Add(new TItem());     return temp; } 

It doesn’t seem particularly nice though… perhaps if you explained the purpose of this, we could come up with a better idea.