Is C# 4.0 Tuple covariant

Question

(I would check this out for myself, but I don\'t have VS2010 (yet))

Say I have 2 base interfaces:

IBaseModelInterface
IBaseViewInterface

Answer 1

You can inherit from tuple for create your own Covariant Tuple. This way you avoid to have to rewrite your own equalities logic.

public interface ICovariantTuple
{
    T1 Item1 { get; }
}
public class CovariantTuple : Tuple, ICovariantTuple
{
    public CovariantTuple(T1 item1) : base(item1) { }
}

public interface ICovariantTuple
{
    T1 Item1 { get; }
    T2 Item2 { get; }
}
public class CovariantTuple : Tuple, ICovariantTuple
{
    public CovariantTuple(T1 item1, T2 item2) : base(item1, item2) { }
}

etc.... for 3, 4, 5, 6, 7, 8 items

Compile Fail

Tuple item = new Tuple(null);

Compile Success

ICovariantTuple item = new CovariantTuple(null);

There is no base Tuple after 8 items, but it should be enough.