#include <string>
class Object {
public:
virtual std::string ToString() const = 0;
virtual ~Object() {}
};
class Factory : public Object {
public:
Factory() {}
explicit Factory(const std::string& class_id) : class_id_(class_id) {}
std::string ToString() const override {
return class_id_;
}
Object* Create(const std::string& class_id) {
return new Factory(class_id);
}
void Register(const std::string& class_id, Object*(*instance_creator)()) {
instance_creator();
}
private:
std::string class_id_;
};