Thread: Trouble with binary tree

I'm currently playing around with binary trees, but it seems I can't even get my insert function to work correctly. When I try to compile my code, i get the following error:

Code:

Unhandled exception at 0x0121145c in testing.exe: 0xC0000005: Access violation reading location 0xcdcdcdcd.

Here is the code

binTree.h

Code:

#ifndef GUARD_BINTREE
#define GUARD_BINTREE

struct node
{
    int data;
    node* link[2];
};

class binTree
{
private:
    node* root;
public:
    binTree(): root(0){}
    void insert(int data);
};

void binTree::insert(int data)
{
    node* new_node = new node;
    new_node->data = data;
    
    //search and insert
    if(root == 0)
    {
        root = new_node;
        return;
    }

    else
    {
        node* it = root;
        int dir;
        while(true)
        {
            dir = it->data < data;

            if(it->link[dir] == 0)
                break;
            else if(it->data == data)
                return;

            it = it->link[dir];
        }

        it->link[dir] = new_node;
    }
}
#endif

main.cpp

Code:

#include "binTree.h"
int main(int argc, char** argv)
{

    binTree tree;
    for(int i = 0; i != 10; i++)
        tree.insert(i);
    return 0;
}

Stepping through with a debugger shows that it is at the location 0xcdcdcdcd. and supposedly happens at

Code:

dir = it->data < data;

Can anyone see what's wrong?

Thanks