Re: Why no access specifiers for friends?

Jiang wrote:


We already do. For example, this program declares main() a "protected"
friend of class A:

     class A
     {
     protected:
         static void protectedMethod() {}

     private:
         static void privateMethod() {}
     };

     class B : public A
     {
         friend int main();
     };

     int main()
     {
         A::protectedMethod(); // OK
         A::privateMethod(); // Error
     }

In other words, just declare a useless subclass of the target class and
have the subclass nominate the "protected" friend. In practical terms,
this kind of nuanced access control simply is not worth the trouble.
Either a class (or a function) implements an interface - or it is (at
least, a potential) client of that inteface. In other words, all code
falls either "inside" or "outside" of a class interface. There is no
half-way state worth mentioning.

Greg

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