Designing an interface where only some implementations require IDisposable [closed]

Question

You are designing an interface IFoo

public interface IFoo
{
   void Bar();
}

Let's say there are five implementations of this interface. Two of those implementations should also implement IDisposable as they use unmanaged resources. From a caller's perspective, it would be easiest if IFoo implemented IDisposable so any IFoo can be wrapped in a using block, but of course some of the implementations would then be littered with empty Dispose() methods. Just curious are there other ways of doing this?

Answer 1

I suspect I'd simply demand IDisposable() - a no-op Dispose() isn't a big overhead.

If you can't be sure whether it is disposable, the following is pretty effective:

var mightBeDisposable = GetBlah();
using(mightBeDisposable as IDisposable)
{
   // etc
}