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

using namespace std;

class IntVal;
class StringVal;

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

	virtual void copyFrom(AbstractVal& other) = 0;

	virtual void copyTo(IntVal& other) = 0;
	virtual void copyTo(StringVal& other) = 0;
};

typedef unique_ptr<AbstractVal> valptr;

class IntVal : public AbstractVal {
public:
	int x_;

	IntVal(int x) : x_(x) {}
	void print() override { cout << x_; }

	void copyFrom(AbstractVal& other) override { other.copyTo(*this); }

	void copyTo(IntVal& other) override;
	void copyTo(StringVal& other) override;
};

class StringVal : public AbstractVal {
public:
	string x_;

	StringVal(string x) : x_(x) {}
	void print() override { cout << x_; }
	void copyFrom(AbstractVal& other) override { other.copyTo(*this); }

	void copyTo(IntVal& other) override;
	void copyTo(StringVal& other) override;
};

// Definici metody IntVal::copyTo(StringVal&) bylo potreba presunout az za definici tridy StringVal, aby
// kompilator uz vedel o datove polozce StringVal::x_ (definice ostatnich metod se pro prehlednost presunuly taky)

void IntVal::copyTo(IntVal& other) { other.x_ = this->x_; }
void IntVal::copyTo(StringVal& other) { other.x_ = to_string(this->x_); }

void StringVal::copyTo(IntVal& other) { stringstream ss(this->x_); ss >> other.x_; }
void StringVal::copyTo(StringVal& other) { other.x_ = this->x_; }


int main() {
	valptr a(make_unique<IntVal>(123));
	valptr b(make_unique<StringVal>("456"));
	valptr c(make_unique<IntVal>(789));

	a->copyFrom(*b);
	a->print();
	cout << endl;

	b->copyFrom(*c);
	b->print();

	return 0;
}