c#4.0: int a real subtype of object? covariance, ienumerable and value types

Answer 1

Every value type in .net has a corresponding ("boxed") object type. Non-boxed value types are effectively outside the object type hierarchy, but the compiler will perform a widening from the value type to the boxed class type. It would be helpful to have a "class" Boxed which would support a widening conversions to and from T, but which would be a class type. Internally, I think that's what the compiler's doing implicitly, but I don't know any way to do it explicitly. For any particular type like "integer", there would be no difficulty defining a class which would behave as a Boxed should, but I don't know any way of doing such a thing in generic fashion.