CCN5193 exception
When you specify a friend within a class, you must use the class
name instead of the type-definition name. Without modification,
the code in Figure 1 would result in the following
error message:
CCN5193: A typedef name cannot be used in this context class A { };
typedef A B;
class C {
friend class B; 1
};
Note: Do not use the type-definition name; instead,
use the name of the class:
friend class A;