Menu
A friend function can be declared in the private or public section of the class. It can be called like a normal function without using the object. A friend function is not in the scope of the class, of which it is a friend. A friend function is not invoked using the class object as it is not in the scope of the class.
No, there's no difference - you just tell that class B is a friend of class A and now can access its private and protected members, that's all.
A friend class in C++ can access the private and protected members of the class in which it is declared as a friend. A significant use of a friend class is for a part of a data structure, represented by a class, to provide access to the main class representing that data structure.
No, there's no difference - you just tell that class B is a friend of class A and now can access its private and protected members, that's all.
Since the syntax friend class B doesn't declare a member of the class A, so it doesn't matter where you write it, class B is a friend of class A.
Also, if you write friend class B in protected section of A, then it does NOT mean that B can access only protected and public members of A.
Always remember that once B becomes a friend of A, it can access any member of A, no matter in which section you write friend class B.
c++ has the notion of 'hidden friends': http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2019/p1601r0.pdf
Which only applies to friend functions that are defined inline. This make it so the functions can only be found via argument-dependent lookups, removing them from enclosing namespace.
If you love us? You can donate to us via Paypal or buy me a coffee so we can maintain and grow! Thank you!
Donate Us With