Just a few simple errors - c++

Question

I am getting a few errors that I don't know about and have spent entirely to much time pulling my hair out. Here is my Header:
#ifndef MYBSTREE_H
#define MYBSTREE_H
#include "abstractbstree.h"
#include "MyBSTreeFunc.h"
using namespace std;
template<typename T>
class TreeNode
{
public:
T m_data;
TreeNode* m_right;
TreeNode* m_left;
};
template<typename T>
class MyBSTree:public AbstractBSTree<T> //LINE 18
{
private:
TreeNode<T>* m_root;
public:
void MyBSTree();
int size() const;
bool isEmpty() const;
int height() const;
const T& findMax() const;
const T& findMin() const;
int contains(const T& x) const;
void clear();
void insert(const T& x);
void remove(const T& x);
void printPreOrder() const;
void printPostOrder() const;
void print() const;
};
#endif
And my implementation file:
Line 1-6
void MyBSTree()
{
m_root -> m_data = NULL;
m_root -> m_right = NULL;
m_root -> m_left = NULL;
}
Line 13-21
template<typename T>
bool MyBSTree<T>::isEmpty() const
{
if (m_root== NULL)
return true;
else
return false;
}
Line 28-35
template < typename T >
const T& MyBSTree<T>::findMax() const
{
TreeNode* p = m_root;
while(p -> m_right != NULL)
p = p -> m_right;
return p;
}
The error for line 3 in the implementation says 'm_root' was not declared in this scope. But it's cool with lines 4 and 5. I'm guessing because m_data isn't a pointer? I don't know.
Next, Line 14, and 21, and quite a few others say that it expected an initializer before the '<' token. I assume they are all the same issue so I only put a few here.
Finally, it says for line 18 in the header: "template struct MyBSTree redeclared as a different kind of symbol." It then says Line 1 of my implementation is a previous declaration of 'void MyBSTree". I am assuming those go together.
Thanks for all the help.

Answer 1

You need to fix your constructor declaration:
template < typename T >
classMyBSTree
{
... // some stuff
public:
MyBSTree(); // no return type
... // some stuff
};
You alse need to fix your constructor:
template < typename T >
MyBSTree::MyBSTree() // proper ctor definition
{
m_root -> m_data = T(); // use the initializer for that data type
m_root -> m_right = NULL;
m_root -> m_left = NULL;
}

Answer 2

Lines 1-6: You've define a standalone function in the .cpp named void MyBSTree(). This is not part of the class. It's also bad that you named the function the same as your class. It looks like you want this to be your constructor, in which case you need this (I won't include the template stuff, as it's not the issue):
// in .h
class MyBSTree {
public:
MyBSTree(); // No void
}
// in .cpp
// Uses MyBSTree namespace.
MyBSTree::MyBSTree() { /* initialize your pointers etc */ }
This seems to be your main issue, and may fix the other problems too.

Answer 3

The reason the compiler cannot find m_roots is because your function is not part of the class. You would fix this by putting your function into the class scope with operator :: (e.g. myBSTree::myBSTree(){};)
Template functions cannot be placed in separate files from their class, you need to define all of your template class and function in the same file. Move the implementation of your functions into your header file.