Question

I’m trying to create a class that accepts two generic types (IQueue, IItem) for example:

public class Coordinator<T,K>
    where T : IQueue<K>
    where K : IItem
{
    private T<K> collection = new T<K>();
}

Where:

public interface IQueue<T> where T : IItem
{
}

public class MyQueue<T> : IQueue<T>
    where T : IItem
{
}

But the compiler does not like:

private T<K> collection = new T<K>();

Is this at all possible?

Thanks!

Answer 1

I think you need to do the following:

public interface IQueue<T> where T : IItem
{
}

public class MyQueue<T> : IQueue<T>
    where T : IItem
{
}

Because you are saying: The coordinator gets an IQueue, but you are trying to construct a MyQueue with more specific information.

Using the already discussed Activator, you can do this without compiler errors:

class Coordinator <T,K>
    where T : IQueue<K>
    where K : IItem
{
    private T collection = (T)Activator.CreateInstance(typeof(T));
}