Where would you use a friend function vs. a static member function?

Question

We make a non-member function a friend of a class when we want it to access that class\'s private members. This gives it the same access rights as a static member function w

Answer 1

Section 11.5 "The C++ Programming Language" by Bjarne Stroustrup states that ordinary member functions get 3 things:

1. access to internals of class
2. are in the scope of the class
3. must be invoked on an instance

friends get only 1.

static functions get 1 and 2.