Pros and cons of using nested C++ classes and enumerations?

Question

What are the pros and cons of using nested public C++ classes and enumerations? For example, suppose you have a class called printer, and this class also store

Answer 1

Only problem with nested classes that I bumped into yet was that C++ does not let us refer to the object of the enclosing class, in the nested class functions. We cannot say "Enclosing::this"

(But maybe there's a way?)