Why is it always necessary to implement IDisposable on an object that has an IDisposable member?

Question

From what I can tell, it is an accepted rule that if you have a class A that has a member m that is IDisposable, A should implement IDisposable and it should call m.Dispose(

Answer 1

If you don't care about the timely release of resources, then indeed there is no point. If you can be sure that the code is only for your consumption and you've got plenty of free memory/resources why not let GC hoover it up when it chooses to. OTOH, if someone else is using your code and creating many instances of (e.g.) MyImage, it's going to be pretty difficult to control memory/resource usage unless it disposes nicely.