I hope my patch-2 edit can be merged into the hdr of the project.

Got a problem:
```cpp
#include <iostream>

class BinaryTree
{
    typedef char value_type;

    struct node
    {
        value_type data;
        node *left, *right;
        node(): left(0), right(0) {}
    };
public:
    BinaryTree(): root(0), count(0) {}

    void readTree(const char * storage)
    {
        c = storage;
        root = buildTree(root);
    }

    void preorder ()
    {
        return preorder (root);
    }
    void inorder  ()
    {
        return inorder  (root);
    }
    void postorder()
    {
        return postorder(root);
    }

    int height()
    {
        return height(root);
    }
    int leaves()
    {
        return count;
    }
private:
    node * root;
    const char * c;
    int    count;

    int height(node * x)
    {
        if (!x) return 0;
        return 1 + (height(x->left) > height(x->right)
                    ? height(x->left) : height(x->right));
    }

    node * buildTree(node * x)
    {
        if (*c == '\0' || *c == '#')
            return x;

        x = new node;
        x->data = *c;

        ++c;
        x->left  = buildTree(x->left);
        ++c;
        x->right = buildTree(x->right);

        if (!x->left && !x->right) ++count;
        return x;
    }

    //Utilities
    void preorder(node * x)
    {
        if (x)
        {
            std::cout << x->data << " ";
            preorder(x->left);
            preorder(x->right);
        }
    }

    void inorder(node * x)
    {
        if (x)
        {
            inorder(x->left);
            std::cout << x->data << " ";
            inorder(x->right);
        }
    }

    void postorder(node * x)
    {
        if (x)
        {
            postorder(x->left);
            postorder(x->right);
            std::cout << x->data << " ";
        }
    }
};

int main()
{
    const char * tree = "ABC#D##E#F##GH##I";
    BinaryTree bt;
    bt.readTree(tree);
    bt.preorder();
    std::cout << std::endl;
    bt.inorder();
    std::cout << std::endl;
    bt.postorder();
    std::cout << std::endl;

    std::cout << "The height of the Binary Tree is "
              << bt.height() << ".\n";
    std::cout << "The number of leaves in the tree is "
              << bt.leaves() << ".\n";*/
}
```
This program crashes when running. In MSVC and gcc, no problem is reported. Is my code wrong?