C# polymorphism in Generic types

Question

class Base
{}

class Sub : Base
{}


void AddNewBase(Base t, LinkedList<Base> list){ ... }
...
{

    Sub asub = new Sub();

    LinkedList<Sub> asubList = new LinkedList<Sub>();
    AddNewBase(asub,asubList) // doesn't work
}

basically, I have a custom insert function that takes a new item and a list to put it in, and it does some 'sorting' stuff to find a good place to put it in the list.

problem is, I want to do this based on properties in 'Base' so it would be good to have just one function that could do this for all lists of sub types.

I think what I kind of want is:

static void AddNewBase<T>(T t, LinkedList<T> list){ ... }

but with some way of clarifying T like: 'where T is a sub class of Base'

Answer 1

You can declare Constraints on Type Parameters:

static void AddNewBase<T>(T t, LinkedList<T> list) where T : Base { ... }