Hmm, do you have a reference (URL) to the "valid but unspecified state" part? I'm not quite sure what that refers to.
Nevermind, I don't need a reference. I think what you refer to is just a statement that says that you can do whatever you want, but the destructor will run so the object must be in a valid state?
tmp = a a = b b = a
Duh, "b=tmp"...
