I'm working my way thru Beginning Mac OS X Snow Leopard Programming and have a problem but there doesn't seem to be a forum for that book yet. Since you are the same authors, here goes:

In Chapter 6 the code for AddressBook.h has the AddressBook struct line:

Person *persons[];

This line produces a compile error "Flexible array member not at end of struct"

The downloaded code for the AddressBook.h file uses the line

Person **persons;

which compiles fine. The double * would seem to indicate a pointer to a pointer. Would you comment?