#include <string>
#include <iostream>
#include <stdexcept>
#include <sstream>

class Var
{
public:
  
  Var(std::string str)
  // TODO initiate implementation as a String from str
  {
  }

  Var(int number)
  // TODO initiate implementation as a String from number
  {
  }

  // TODO add memory managment and special members
  
  void add(int number)
  {
    // TODO call add(number) on implementation
  }
  
  void concat(std::string str)
  {
    // TODO call cancat(str) on implementation
  }
  
  void print(std::ostream& os)
  {
    // TODO call print(os) on implementation
  }
    
private:
    
  // TODO data member named "implementation" to represent either a Number or a String

};

/*
Körexempel:

5
7
757
17
Cannot concat number
*/

int main()
{
    Var n { 5 };
    Var s { "7" };

    n.print(std::cout);
    std::cout << std::endl;

    s.print(std::cout);
    std::cout << std::endl;

    s.add(5);
    s.concat("7");

    s.print(std::cout);
    std::cout << std::endl;

    n.add(12);
    n.print(std::cout);
    std::cout << std::endl;

    try
    {
	n.concat("hello");
    }
    catch // TODO catch something suitable to exception variabel "e"
    {
	std::cout << e.what() << std::endl;
    }
}