#ifndef TREE_H
#define TREE_H
#include <iosfwd>

class Tree
{
public:
    Tree();
    ~Tree();
    void print(std::ostream &) const;
private:
    struct Node
    {
        int data {};
        Node * left {};
        Node * right {};
        ~Node();
    };
    Node * root {};

    // helper function:
    static void print(std::ostream &, Node const * const);
};

#endif