#include <iostream>
#include <vector>
#include <memory>
#include <string>

using namespace std;

class AbstractVal;
typedef unique_ptr<AbstractVal> valptr;

class AbstractVal {
public:
	virtual ~AbstractVal() {}
	virtual void print() = 0;
	virtual valptr clone() = 0;
};

class IntVal : public AbstractVal {
public:
	IntVal(int x) : x_(x) {}
	void print() override { cout << x_; }
	valptr clone() override { return make_unique<IntVal>(*this); }
private:
	int x_;
};

class StringVal : public AbstractVal {
public:
	StringVal(string x) : x_(x) {}
	void print() override { cout << x_; }
	valptr clone() override { return make_unique<StringVal>(*this); }
private:
	string x_;
};

class Seznam {
public:
	Seznam() {}
	Seznam(const Seznam& s) { clone(s); }
	Seznam& operator=(const Seznam& s) {
		if (this != &s) {
			pole.clear();
			clone(s);
		}
		return *this;
	}

	void add(valptr p) { pole.push_back(move(p)); }
	void print() {
		for (auto&& x : pole) {
			x->print();
		}
	}
private:
	vector<valptr> pole;
	void clone(const Seznam& s) {
		for (auto&& x : s.pole) {
			pole.push_back(x->clone());
		}
	}
};

int main() {
	Seznam s1, s2;
	s1.add(make_unique<IntVal>(123));
	s1.add(make_unique<StringVal>("456"));

	s2 = s1;
	s2.print();

	s2 = s2;
	s2.print();
}