// File: ex5-1.cpp

#include <iostream>
#include <cstring>
using namespace std;

class thing
{
  private:
	 int eger;
	 double mint;
  public:
	 thing(int x = 0, double y = 0.0);	 	// constructor
	 void copy_a_thing(thing&);
	 void show_a_thing(void) { cout << eger << ' ' << mint << endl; return;}
};

thing::thing(int x, double y)
{
  eger = x;
  mint = y;
}

void thing::copy_a_thing(thing& z)
{
  if (this == &z)
  {
	 cout << "Don't copy me to myself\n";
	 return;
  }
  eger = z.eger;
  mint = z.mint;
  return;
}

int main(void)
{
  thing a(5,3.14);
  thing b(1);
  thing c;
  a.show_a_thing();
  b.show_a_thing();
  c.show_a_thing();
  c.copy_a_thing(a);	// copy thing-a to c
  c.show_a_thing();
  b.copy_a_thing(b);	// copy thing-b to b
  b.show_a_thing();

  return 0;
}