Hands-On Design Patterns with C++

Chapter 12

• What is the effect of declaring a function friend?

A non-member friend function has the same access to the members of the class as a member function.

• What is the difference between granting friendship to a function and a function template?

Granting friendship to a template makes every instantiation of this template a friend; this includes instantiations of the same template but with different, unrelated, types.

• Why are binary operators usually implemented as non-member functions?

Binary operators implemented as member functions are always called on the left-hand-side operand of the operator, with no conversions allowed for that object. Conversions are allowed for the right-hand-side operand, according to the type of the argument ...