Design Patterns - Decorator - Example 1

#include <iostream>#include <string>using namespace std;// interface Beverageclass Beverage {  public:    virtual string getDescription() {      if (description == "") {        description = "Unknown Beverage";      }      return description;    }    virtual double cost() = 0;  protected:    string description;};// interface CondimentDecorator externs Beverageclass CondimentDecorator : public Beverage {  public:    virtual string getDescription() = 0;};// implements Benverageclass Espresso : public Beverage {  public:    Espresso() {      description = "Espresso";    }    double cost() {      return 1.99;    }};class HouseBlend : public Beverage {  public:    HouseBlend() {      description = "HouseBlend Coffee";    }    double cost() {      return 0.89;    }};// implements CondimentDecoratorclass Mocha : public CondimentDecorator {  public:    Mocha(Beverage *beverage) : beverage(beverage) {    }    string getDescription() {      return beverage->getDescription() + ", Mocha";    }    double cost() {      return 0.20 + beverage->cost();    }  protected:    Beverage *beverage;};class Soy : public CondimentDecorator {  public:    Soy(Beverage *beverage) : beverage(beverage) {    }    string getDescription() {      return beverage->getDescription() + ", Soy";    }    double cost() {      return 0.11 + beverage->cost();    }  protected:    Beverage *beverage;};class Whip : public CondimentDecorator {  public:    Whip(Beverage *beverage) : beverage(beverage) {    }    string getDescription() {      return beverage->getDescription() + ", Whip";    }    double cost() {      return 0.5 + beverage->cost();    }  protected:    Beverage *beverage;};// Exampleint main(int argc, char **argv) {    Beverage *beverage = new Espresso();  cout << beverage->getDescription() << " $" << beverage->cost() << endl;  Beverage *beverage2 = new HouseBlend();  beverage2 = new Mocha(beverage2);  beverage2 = new Mocha(beverage2);  beverage2 = new Whip(beverage2);  cout << beverage2->getDescription() << " $" << beverage2->cost() << endl;  return 0;}