c++ - Class property includes instance of a template class (error C3857) -

i implementing binary tree class identical this one. however, in task, node struct must templated structure. therefore changed struct node to:

template <typename t> class node { public:     t data;     node<t> *left, *right; }

so far good, until added node instance btree member variable:

class btree {     // ...... private:     template <typename t>     node<t> *root = null; // error }

error message says

c3857: multiple template parameter lists not allowed.

i tried move root = null btree's default constructor, not work either.

you cannot have templated variable declaration. there no way specify type use variable. can either make btree template , use type node

template<typename t> class btree {     // ...... private:     node<t> *root = null; // error }

or specify type of node want in btree

class btree {     // ...... private:     node<some_type> *root = null; // error }

Ben