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

[emma_middlebrook]

Hi

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

I have a load of ICollection<ref erences hanging off a class e.g.
ICollection<X>, ICollection<Yet c 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<Bas ewhere T : Base
{
ICollection<T_c ollection;

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

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

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

Any help appreciated!

Thanks,

Emma.