#include <iostream>
#include <vector>
#include <algorithm>
#include <cmath>
#include <string>
using std::string;
using std::cout;
using std::cin;
using std::vector;
using std::endl;
class Object {
public:
virtual string ToString() const = 0;
virtual ~Object() = default;
};
class Apple : public Object {
public:
string ToString() const override {
return "apple!";
}
};
class List : public Object {
public:
string ToString() const override {
return "list";
}
};
class YetAnotherId : public Object {
public:
string ToString() const override {
return "yet another identifier";
}
};
class Smth : public Object {
public:
explicit Smth(const string &id) {
class_id_ = id;
}
string ToString() const override {
return class_id_;
}
private:
string class_id_;
};
Object *my_new_smth_() {
return new Smth(class_id);
}
class Factory {
public:
static Object *Create(const string &id) {
if (id == "apple") {
return new Apple;
} else if (id == "list") {
return new List;
} else if (id == "yet another identifier") {
return new YetAnotherId;
} else {
return my_new_smth_();
}
}
static void Register(const string &id, Object *(*instance_creator)()) {
}
};