mm@cereal:~$ g++ -Wall test.cc
mm@cereal:~$ ./a.out

mm@cereal:~$ cat test.cc
#include <iostream>
#include <sstream>

int main() {
  std::stringstream ss;
  char * f = NULL;
  ss << f;
  std::cout << ss.str() << std::endl;
  return 0;
}