rem: Vector<T>::assign(int n, const T &e) { resize(0, e); resize(n, e); return *this; }
add: Vector<T *> &assign(int n, T *e = 0) { Base::assign(n, (void *)e); return *this; }
context: Vector<T>::assign(int n, const T &e){    resize(0, e);    resize(n, e);    return *this;}