Compilare: user.cpp: In member function ‘bool cd::operator*=(const cd&)’: user.cpp:24:5: warning: no return statement in function returning non-void [-Wreturn-type] } ^ user.cpp: In member function ‘bool cd::operator/=(const double&)’: user.cpp:33:5: warning: no return statement in function returning non-void [-Wreturn-type] } ^ user.cpp: In function ‘void mult()’: user.cpp:72:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i=0;i<A.size();i++) C[i] = A[i] * B[i]; ~^~~~~~~~~ user.cpp: In function ‘int main()’: user.cpp:83:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i=0;i<A.size();i++) A[i] = B[i] = 0; ~^~~~~~~~~ user.cpp:98:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i=0;i<C.size();i++) if ((int)(C[i].real() + 0.5)) g<<i<<' '<<(int)(C[i].real() + 0.5)<<'\n'; ~^~~~~~~~~