Hands-On Design Patterns with C++

Chapter 18

• What is the Visitor pattern?

The Visitor pattern provides a way to separate the implementation of algorithms from the objects they operate on; in other words, it is a way to add operations to classes without modifying them by writing new member functions.

• What problem does the Visitor pattern solve?

The Visitor pattern allows us to extend the functionality of class hierarchies. It can be used when the source code of the class is not available for modification or when such modifications would be difficult to maintain.

• What is double dispatch?

Double dispatch is the process of dispatching a function call (selecting the algorithm to run) based on two factors. Double dispatch can be implemented at runtime using the Visitor pattern ...