Generics question - enumerating ICollection<T> as ICollection<Base> where T : Base

[emma_middlebrook]

Hi

Hopefully the title is quite accurate but here's some more information.

I have a load of ICollection<references hanging off a class e.g.
ICollection<X>, ICollection<Yetc etc.

Each of the collection's types are all derived from a base class Base
i.e X : Base, Y : Base etc etc.

How can I automatically use all those collections as ICollection<T>?

This is the best I could come up with (using a wrapper class for
enumerating) but I was hoping there was something much more direct:

class BaseEnumerable<T: IEnumerable<Basewhere T : Base
{
ICollection<T_collection;

public BaseEnumerable(ICollection<Tcollection)
{
_collection = collection;
}

public IEnumerator<BaseGetEnumerator()
{
foreach(T t in _collection)
{
yield return t as Base;
}
}

IEnumerator IEnumerable.GetEnumerator()
{
return GetEnumerator();
}
}

Any help appreciated!

Thanks,

Emma.