Eroare de compilare: user.cpp: In function ‘int main()’: user.cpp:42: error: ‘ar’ was not declared in this scope user.cpp:44: error: no match for ‘operator<’ in ‘((std::basic_ostream<char, std::char_traits<char> >*)std::operator<< [with _Traits = std::char_traits<char>](((std::basic_ostream<char, std::char_traits<char> >&)((std::basic_ostream<char, std::char_traits<char> >*)g.std::basic_ofstream<char, std::char_traits<char> >::<anonymous>.std::basic_ostream<_CharT, _Traits>::operator<< [with _CharT = char, _Traits = std::char_traits<char>](a))), 32))->std::basic_ostream<_CharT, _Traits>::operator<< [with _CharT = char, _Traits = std::char_traits<char>](p) < '\012'’