Support objects with implicit operator casting

I make extensive use of the Whole Value pattern in my code which requires hidding a simpletype (such as string) behind a class. To make the WholeValue work smoothly you need to use implicit implicit operator casting.

NHibernate is OK going in the database but bombs out coming back out. There is a work around (to manipulate the wrapped simpletype directly) but this is causing some nasty side-effects as any integrity code is bypassed.