Hands-On Design Patterns with C++

Friend Factory

n this chapter, we are going to talk about making friends. We mean the C++ friends here, not friends of C++ (you find those in your local C++ users group). In C++, friends of classes are functions or other classes that are granted special access to the class. In that way, they are not so different from your friends. But C++ can just manufacture friends as needed, on demand!

The following topics will be covered in this chapter:

• How do friend functions work in C++ and what do they do?
• When should you use friend functions versus class member functions?
• How to combine friends and templates
• How to generate friend functions from templates