#include <iostream>
#include <vector>
#include <string>
#include <algorithm>
using namespace std;class Visitor;// Element object
class Element
{public: virtual void Accept(Visitor *pVisitor) = 0;
};class ConcreteElementA : public Element
{private:string m_name; public: ConcreteElementA();string getName(){return m_name;}void Accept(Visitor *pVisitor);
};class ConcreteElementB : public Element
{private:string m_name; public: ConcreteElementB();string getName(){return m_name;}void Accept(Visitor *pVisitor);
};class Visitor
{public:virtual void VisitConcreteElementA(ConcreteElementA *pElementA) = 0;virtual void VisitConcreteElementB(ConcreteElementB *pElementB) = 0;
};class ConcreteVisitor1 : public Visitor
{public:void VisitConcreteElementA(ConcreteElementA *pElementA);void VisitConcreteElementB(ConcreteElementB *pElementB);
};void ConcreteVisitor1::VisitConcreteElementA(ConcreteElementA *pElementA)
{cout << "Visitor1 vist " << pElementA->getName() << endl;
}void ConcreteVisitor1::VisitConcreteElementB(ConcreteElementB *pElementB)
{cout << "Visitor1 vist " << pElementB->getName() << endl;
}class ConcreteVisitor2 : public Visitor
{public:void VisitConcreteElementA(ConcreteElementA *pElementA);void VisitConcreteElementB(ConcreteElementB *pElementB);
};void ConcreteVisitor2::VisitConcreteElementA(ConcreteElementA *pElementA)
{cout << "Visitor2 vist " << pElementA->getName() << endl;
}void ConcreteVisitor2::VisitConcreteElementB(ConcreteElementB *pElementB)
{cout << "Visitor2 vist " << pElementB->getName() << endl;
}ConcreteElementA::ConcreteElementA()
{m_name = "ConcreteElementA";
}void ConcreteElementA::Accept(Visitor *pVisitor)
{pVisitor->VisitConcreteElementA(this);
}ConcreteElementB::ConcreteElementB()
{m_name = "ConcreteElementB";
}void ConcreteElementB::Accept(Visitor *pVisitor)
{pVisitor->VisitConcreteElementB(this);
}// ObjectStructureÀ࣬ÄÜö¾ÙËüµÄÔªËØ£¬¿ÉÒÔÌṩһ¸ö¸ß²ãµÄ½Ó¿ÚÒÔÔÊÐí·ÃÎÊÕß·ÃÎÊËüµÄÔªËØ
class ObjectStructure
{public:void Attach(Element *pElement);void Detach(Element *pElement);void Accept(Visitor *pVisitor);private:vector<Element *> elements;
};void ObjectStructure::Attach(Element *pElement)
{elements.push_back(pElement);
}void ObjectStructure::Detach(Element *pElement)
{vector<Element *>::iterator it = find(elements.begin(), elements.end(), pElement);if (it != elements.end()){elements.erase(it);}
}void ObjectStructure::Accept(Visitor *pVisitor)
{// Ϊÿһ¸öelementÉèÖÃvisitor£¬½øÐжÔÓ¦µÄ²Ù×÷for (vector<Element *>::const_iterator it = elements.begin(); it != elements.end(); ++it){(*it)->Accept(pVisitor);}
}int main()
{ObjectStructure *pObject = new ObjectStructure;ConcreteElementA *pElementA = new ConcreteElementA;ConcreteElementB *pElementB = new ConcreteElementB;pObject->Attach(pElementA);pObject->Attach(pElementB);ConcreteVisitor1 *pVisitor1 = new ConcreteVisitor1;ConcreteVisitor2 *pVisitor2 = new ConcreteVisitor2;pObject->Accept(pVisitor1);pObject->Accept(pVisitor2);if (pVisitor2) delete pVisitor2;if (pVisitor1) delete pVisitor1;if (pElementB) delete pElementB;if (pElementA) delete pElementA;if (pObject) delete pObject;return 0;
}

Visitor1 vist ConcreteElementA
Visitor1 vist ConcreteElementB
Visitor2 vist ConcreteElementA
Visitor2 vist ConcreteElementB