I have just learned C recently, I learned a friend function, suddenly there is an idea, I don't know correctly:
The friend function is actually an ordinary function, but it is declared in the class, so that this friend function can be
With absolute permissions on classes, I think if someone is doing software, declare a friend function (or friend "
Class), but did not define (or implementation), in this case, it is equivalent to leaving a back door, and it will be
The data in the class is manifested by writing a function of the declared friend.
This is just a personal opinion of my beginner, but it may be considered, but I still have a lot of advice!
2004.12.1
