Hands-On Design Patterns with C++

Applications of the Template Method

There are many reasons to use the Template Method. In general, it is used to control what can and cannot be sub-classed—as opposed to a general polymorphic override, where the entire virtual function can be replaced, the base class here determines what can and cannot be overridden. Another common use of the Template Method is to avoid code duplication, and in this context, you can arrive to use the Template Method as follows. Suppose that you start with the regular polymorphism—a virtual function—and it overrides. For example, let's consider this toy design for a turn-based combat system for a game:

class Character {    public:    virtual void CombatTurn() = 0;    protected:    int health_;};class Swordsman : public ...