#include <iostream>
#include <string>

void print_str(std::string const * _str, int _flag = 0){
 static int count_call = 0;
 ++count_call;
 int count_print = _flag ? count_call : 1;

 while(count_print--)
  std::cout << *_str << std::endl;
}

int main(){
 std::string str{"Hello, world!"};

 print_str(&str);
 print_str(&str);
 print_str(&str);
 std::cout << std::endl;

 print_str(&str, 1);
 std::cout << std::endl;

 print_str(&str);

 return (0);
}