Compilare: user.cpp: In member function ‘bool cartita::operator<(cartita) const’: user.cpp:13:17: warning: statement has no effect [-Wunused-value] this->q < o.q; ^ user.cpp:14:5: warning: no return statement in function returning non-void [-Wreturn-type] } ^ user.cpp: In member function ‘bool str::operator<(str) const’: user.cpp:22:17: warning: statement has no effect [-Wunused-value] this->y < o.y; ^ user.cpp:23:5: warning: no return statement in function returning non-void [-Wreturn-type] } ^