Eroare de compilare: user.cpp: In function ‘int main()’: user.cpp:61: error: no matching function for call to ‘eval(int, __gnu_cxx::__normal_iterator<char*, std::basic_string<char, std::char_traits<char>, std::allocator<char> > >, __gnu_cxx::__normal_iterator<char*, std::basic_string<char, std::char_traits<char>, std::allocator<char> > >)’ user.cpp:12: note: candidates are: int eval(char, int, int) user.cpp:24: note: int eval(int, __gnu_cxx::__normal_iterator<char*, std::basic_string<char, std::char_traits<char>, std::allocator<char> > >&, const __gnu_cxx::__normal_iterator<char*, std::basic_string<char, std::char_traits<char>, std::allocator<char> > >&)