binary trees and protected data

[sporkit]

this ones has keep me up all night long

binTNode.h defines the nodes with a constructor that looks something like this.

public:
binTNode(const T& =T(), binTNode<T>* =0, binTNode<T>* =0);

binTree.h is a friend of binTNode.h and from what i assume should be able to create a new node like so.

root = new binTnode<T>();

however this error comes up.

Undefined                       first referenced
 symbol                             in file
binTNode<int>::binTNode[in-charge](int const&, binTNode<int>*, binTNode<int>*)prog3.o
ld: fatal: Symbol referencing errors. No output written to prog3.exe
collect2: ld returned 1 exit status
bash-3.00$

also the bin tree class creates a

binTNode<T>* root;

pointer without a problem. as for now im fried. any suggestions appreciated.

[grib]

binTree needs to be able to see the definitnion of binTNode(), not just the prototype. Thus

template<class T>
binTNode<T>::binTNode(const T& d=T(), binTNode<T>* l=0, binTNode<T>* r=0) : data(d), left(l), right(r) {}

needs to be in the header(basically)
Normally with templates I go with nested classes and inline functions whenever I can.

template<class T>
class tree {
    struct node {
        T data;
        node *l,*r;
        node(const &d,node *ll=0, node *rr=0) : data(d), l(ll), r(rr) {}
    } *root;
public:
    ...
};

Note: not compiled, milage may vary.