Hamna shida!
C++: Simplified version of ‘Friends with benefits’ demonstrating friend classes
A friend class in C++ can access the private and protected members of the class in which it is declared as a friend.
Friendship may allow a class to be better encapsulated by granting per-class access to parts of its API that would otherwise have to be public.[2] This increased encapsulation comes at the cost of tighter coupling due to interdependency between the classes.
Properties
- Friendships are not symmetric – if class A is a friend of class B, class B is not automatically a friend of class A.
- Friendships are not transitive – if class A is a friend of class B, and class B is a friend of class C, class A is not automatically a friend of class C.
- Friendships are not inherited – if class Base is a friend of class X, subclass Derived is not automatically a friend of class X; and if class X is a friend of class Base, class X is not automatically a friend of subclass Derived.
From Wikipedia: https://en.wikipedia.org/wiki/Friend_class
In the following example we assign both the Man to be a friend of the Woman and the Woman to be a friend of the Man in order to allow both parties to access the private members of the other.
#include <iostream> using namespace std; class Man; class Woman { friend class Man; public: void touch(Man man); private: void * body; }; class Man { friend class Woman; public: void touch(Woman woman); private: void * body; }; void Woman::touch(Man man) { void * other = man.body; } void Man::touch(Woman woman) { void * other = woman.body; } int main() { Man man; Woman woman; man.touch(woman); woman.touch(man); return 0; }