loki factory的使用 例二

1.參照例一配置

// Shape.h

#ifndef Shape_H_INCLUDED_
#define Shape_H_INCLUDED_

#include <string>
#include "loki/Singleton.h"
#include "loki/Factory.h"
using namespace Loki;


class Shape {
public:
	virtual ~Shape() {}
	virtual void Draw() = 0;
};

typedef Loki::SingletonHolder<Loki::Factory<Shape,std::string >> ShapeFactory;

#define REGISTER_SHAPE(className)                                                      \
namespace {                                                                            \
Shape* Create() { return new className; }                                              \
const bool RegisterShape__ = ShapeFactory::Instance().Register( #className, Create );  \
}

#endif // Shape_H_INCLUDED_

// Line.h

#ifndef Line_H_INCLUDED_
#define Line_H_INCLUDED_

#include "Shape.h"

class Line : public Shape {
public:
	virtual void Draw();
};

#endif // Line_H_INCLUDED_

// Line.cpp

#include <iostream>
#include "Line.h"

REGISTER_SHAPE( Line )

void Line::Draw() {
	std::cout << "Line::Draw()" << std::endl;
}

// main.cpp
#include "Shape.h"

int main() {
	Shape* line = ShapeFactory::Instance().CreateObject( "Line" );
	line->Draw();    
	delete line;

	system("PAUSE");
	return 0;
}