Covariance with C#

Question

I met some interesting covariance problem in my c# code.

I have a generic Matrix class, and it\'s been instantiated for example Matrix

Answer 1

Recently I've come across such limitation and I implemented a variation of Visitor Pattern (may be abuse of it). But that helped me to solve the problem.

I'm no architect, just a developer. So pardon me if am abusing the design pattern, but sure this will help.

With provided information I created mocks of your classes and applied visitor pattern as follows.

public class Matrix
{
    public T Obj { get; set; }
}

public interface INonGenericWrapper
{
    void Wrap();
    void Accept(IVisitor visitor);
}

public class Wrapper : INonGenericWrapper
{
    public Matrix Matrix { get; private set; }

    public void Wrap()
    {
        //Your domain specific method
    }

    public void Accept(IVisitor visitor)
    {
        visitor.Visit(this);
    }
}

public interface IVisitor
{
    void Visit(T element);
}

public class SerializationVisitor : IVisitor
{
    public void Visit(T element)
    {
        new Serializer().Serialize(element);
    }
}

public class Serializer
{
    public Stream Serialize(T objectToSerialize)
    {
        Console.WriteLine("Serializing {0}", objectToSerialize);
        //Your serialization logic here
        return null;
    }
}

How to use:

List wrappers = new List();
wrappers.Add(new Wrapper