[Cs3] nested class issues

[Mikhail Nesterenko]

CS3 students,

This is to follow up on yesterday's discussion on nested
classes. First, the proper name for the outer class is _the enclosing
class_. I changed the slides and the example to reflect that.

One may not (out-of-line) define the member functions of the inner
class inside the enclosing class. That is, inner class member
functions may be defined inside the inner class (inline definition) or
completely outside (out-of-line definition). That's just how things
are in the standard.

Inner class itself may be forward declared, and then defined
out-of-line, but it may not be forward declared with an elaborated
type specifier. Again, that's just how things are.

thanks,
-- 
Mikhail