Make enum auto castable

[Mike B Johnson via Digitalmars-d-learn]

I am dealing with some COM stuff and some functions use VARIANT, 
which can hold an enum.

Instead of having to manually convert the enum(and for that 
matter, other things) to VARIANT, is it possible to have them 
automatically converted?

This is because an enum is always convertible to a VARIANT but 
not the other way around. So, when a enum is passed to a function 
accepting a VARIANT, it should just work. Overloading is not an 
option.