#include <iostream>
using namespace std;

int main () {

cout << NULL <<endl ;
cout << (NULL == 0)<<endl;


}

cc1plus: warnings being treated as errors
In function 'int main()':
Line 6: warning: passing NULL to non-pointer argument 1 of 'std::basic_ostream<_CharT, _Traits>& std::basic_ostream<_CharT, _Traits>::operator<<(int) [with _CharT = char, _Traits = std::char_traits<char>]'
Line 7: warning: NULL used in arithmetic