Binary Search Tree - object instantiation problem

Hi again... sorry to bother you guys so much, but as I've said before, my previous C++ courses did NOT prepare me at all for this data structures class. The assignment is to create a binary search tree with random int values and alternately apply insertions and deletions of random elements. I've got an idea, a basic outline, but I can't seem to instantiate a tree object. I've scoured the book and internet forums, but can't seem to find anything of help. The book assumes we know a lot more than we do; this university's curriculum is awful! Code below, I know I have a lot of garbage in it, but I wanted to narrow down as I decided what I needed and didn't need. Thanks for any help provided! Here are the errors I've been getting:

c:\Documents and Settings\Pbrooks4\My Documents\Visual Studio Projects\Kellett_CS3330_6\Source1.cpp(178): error C2133: 'myTree' : unknown size
//Why in the world would I need to declare a size????

c:\Documents and Settings\Pbrooks4\My Documents\Visual Studio Projects\Kellett_CS3330_6\Source1.cpp(178): error C2262: 'myTree' : cannot be destroyed
//Why not? I've declared a destructor

c:\Documents and Settings\Pbrooks4\My Documents\Visual Studio Projects\Kellett_CS3330_6\Source1.cpp(178): error C2512: 'BinSearchTree' : no appropriate default constructor available
//No? How do you figure?

c:\Documents and Settings\Pbrooks4\My Documents\Visual Studio Projects\Kellett_CS3330_6\Source1.cpp(185): error C2662: 'BinSearchTree<T>::insert' : cannot convert 'this' pointer from 'BinSearchTree' to 'BinSearchTree<T> &'
//This when I tried myTree.insert(nodeVal)... what does this error mean?

c:\Documents and Settings\Pbrooks4\My Documents\Visual Studio Projects\Kellett_CS3330_6\Source1.cpp(178): error C2955: 'BinSearchTree' : use of class template requires template argument list
//Does it? Really?

c:\Documents and Settings\Pbrooks4\My Documents\Visual Studio Projects\Kellett_CS3330_6\Source1.cpp(185): error C3861: 'myTree': identifier not found, even with argument-dependent lookup
//Why won't it accept this instantiation??????

Code:

#include <cmath>
#include <iostream>
#include <ctime>
#include <queue>
#include <stack>

using namespace std;

template<class T>
class Stack : public stack<T> 
{
public:
	T pop() 
	{
		T tmp = top();
		stack<T>::pop();
		return tmp;
	}
};

template<class T>
class Queue: public queue<T>
{
public:
	T dequeue() 
	{
		T tmp = front();
		queue<T>::pop();
		return tmp;
	}
	void enqueue(const T& el)
	{
		push(el);
	}
};

template<class T>
class BinSearchNode
{
public: 
	BinSearchNode()
	{
		left = right = 0;
	}
	BinSearchNode(const T& el, BinSearchNode *l = 0, BinSearchNode *r = 0)
	{
		key = el; 
		left = l; 
		right = r;
	}
	T key;
	BinSearchNode *left, *right;
};

template<class T>
class BinSearchTree
{
public:
	BinSearchTree() //is this not the constructor????
	{
		root = 0;
	}
	~BinSearchTree()
	{
		clear();
	}
	void clear() 
	{
		clear(root);
		root = 0;
	}
	bool isEmpty() const
	{
		return root == 0;
	}
	void preorder()
	{
		preorder(root);
	}
	void inorder()
	{
		inorder(root);
	}
	void postorder()
	{
		postorder(root);
	}
	T* search(const T& el) const
	{
	    return search(root, el);
	}
	void breadthFirst();
	void interativePreorder();
	void interativeInorder();
	void interativePostorder();
	void MorrisInorder();
	void insert(const T&);
	void deleteByMerging(BinSearchNode<T>*&);
	void balance(T*, int, int);
    //......
protected:
	BinSearchNode<T>* root;
	void clear(BinSearchNode<T>*);
	T* search(BinSearchNode<T>*, const T&) const;
	void preorder(BinSearchNode<T>*);
	void inorder(BinSearchNode<T>*);
	void postorder(BinSearchNode<T>*);
	virtual void visit(BinSearchNode<T>* p)
	{
		cout << p->key << ' ';
	}
	//..........
};

template<class T>
T* BinSearchTree<T>::search(BinSearchNode<T>* p, const T& el) const
{
	while(p != 0)
		if(el == p->key)
			return &p->key;
		else if(el < p->key)
			 p = p->left;
		else p = p->right;
		return 0;
}

template<class T>
void deleteByCopying(BinSearchNode<T>*& node)
{
	BinSearchNode<T> *previous, *tmp = node;
	if(node->right == 0)
		node = node->left;
	else if(node->left == 0)
		node = node->right;
	else
	{
		tmp = node->left;
		previous = node;
		while(tmp->right != 0)
		{
			previous = tmp;
		    tmp = tmp->right;
	    }
	node->key = tmp->key;
	if(previous == node)
		previous->left = tmp->left;
	else 
		previous->right = tmp->left;
}
delete tmp;
}


template<class T>
void BinSearchTree<T>::insert(const T& el)
{
	BinSearchNode<T> *p = root, *prev = 0;
	while(p != 0)
	{
		prev = p;
	    if(p->key < el)
		    p = p->right;
	    else
		    p = p->left;
    }
if(root == 0)
    root = new BinSearchNode<T>(el);
else if(prev->key < el)
    prev->right = new BinSearchNode<T>(el);
else
    prev->left = new BinSearchNode<T>(el);
}


int main()
{
	int treeHeight, i, nodeVal;
	BinSearchTree myTree; //trouble!
	cout << "Enter the height of the tree you would like to create: ";
	cin >> treeHeight;
    srand((unsigned)time(0));
	for(i = 1; i <= pow(2, treeHeight); i++)
	{
        nodeVal = (rand()%98)+1;
		myTree.insert(nodeVal);
	}
	return 0;
}

>//Does it? Really?
Yes, really. Try adding one and see your errors magically vanish. Perhaps:

Code:

BinSearchTree<int> myTree;

Thanks, Prelude, I had tried <T> there instead of <int>, and then just given up.

-Patrick

That's basically what template are: a generic class designed to work with any type (int, float, std::string, whatever class you create) that meets its basic requirements. Write it once and use it everywhere. You've already seen (or should see) this in the STL, with std::vector, std::map and so on.