visitor Design Pattern in c++

VisitorDesignPattern.cpp

#include <iostream>
#include <list>
#include <memory>
using namespace std;

// Forwards
class VisitorIntf;

// Abstract interface for Element objects
class ElementIntf {
  public:
	virtual ~ElementIntf();
	virtual string name() = 0;
	virtual void accept(shared_ptr<VisitorIntf> object) = 0;
};

ElementIntf::~ElementIntf() {}

// Abstract interface for Visitor objects
class VisitorIntf {
  public:
	virtual ~VisitorIntf();
	virtual void visit(ElementIntf *object) = 0;
};

VisitorIntf::~VisitorIntf() {}

// Concrete element object
class ConcreteElement1 : public ElementIntf {
  public:
	string name();

	void accept(shared_ptr<VisitorIntf> object);
};

string ConcreteElement1::name() { return "ConcreteElement1"; }

void ConcreteElement1::accept(shared_ptr<VisitorIntf> object)
{
	object->visit(this);
}

// Concrete element object
class ConcreteElement2 : public ElementIntf {
  public:
	string name();

	void accept(shared_ptr<VisitorIntf> object);
};

string ConcreteElement2::name() { return "ConcreteElement2"; }

void ConcreteElement2::accept(shared_ptr<VisitorIntf> object)
{
	object->visit(this);
}

// Visitor logic 1
class ConcreteVisitor1 : public VisitorIntf {
  public:
	void visit(ElementIntf *object);
};

void ConcreteVisitor1::visit(ElementIntf *object)
{
	cout << "Visited " << object->name() << " using ConcreteVisitor1." << endl;
}

// Visitor logic 2
class ConcreteVisitor2 : public VisitorIntf {
  public:
	void visit(ElementIntf *object);
};

void ConcreteVisitor2::visit(ElementIntf *object)
{
	cout << "Visited " << object->name() << " using ConcreteVisitor2." << endl;
}

//  Test main program
int main()
{
	list<shared_ptr<ElementIntf>> elementList1;
	elementList1.push_back(make_shared<ConcreteElement1>());
	elementList1.push_back(make_shared<ConcreteElement2>());

	shared_ptr<VisitorIntf> visitor1 = make_shared<ConcreteVisitor1>();

	for (auto element : elementList1) {
	element->accept(visitor1);
	}

	list<shared_ptr<ElementIntf>> elementList2;
	elementList2.push_back(make_shared<ConcreteElement1>());
	elementList2.push_back(make_shared<ConcreteElement2>());
	shared_ptr<VisitorIntf> visitor2 = make_shared<ConcreteVisitor2>();

	for (auto element : elementList2) {
	element->accept(visitor2);
	}
}