0001 template <typename T> BNP<T> clone(BNP<T> t) { //深复制
0002    if (!t) return nullptr;
0003    return new BinNode<T>(t->data, nullptr, clone(t->lc), clone(t->rc), t->height, t->color);
0004 } //clone: p ~ Parent;  t ~ source Tree
0005 template <typename T> BinTree<T>::BinTree(BNP<T> t) //复制子树
0006    { _root = clone(t);  _size = t->size(); }
0007 template <typename T> BinTree<T>::BinTree(const BinTree<T>& t) //复制全树
0008    { _root = clone(t._root);  _size = t.size(); }
0009 template <typename T> BinTree<T>& BinTree<T>::operator=(const BinTree<T>& t) { //赋值
0010    if (_root != t._root)
0011       { remove(_root);  _root = clone(t._root);  _size = t.size(); }
0012    return *this;
0013 } //operator=