Super basic declaring new templated class objects question

Question

Hello all. I know this is probably a first year question, but I'm having some problems with templates and I haven't found a suitable answer yet. I'm trying to instantiate a new templated class like so:

TreeNode <T>newLeft = new TreeNode(root->data[0]);

Which is refering to a constructor which looks like:

template <class T>
//paramerter receving constructor
TreeNode<T>::TreeNode(T item){
  data[0] = item;
  nodeType = 2;
}//end

And I'm getting the following errors:
error: expected type-specifier before ‘TreeNode’
error: expected `;' before ‘TreeNode’

What is the type-specifier? I can provide more code if necessary, and I know I asked a question about this code earlier, and I'm sure I'll get flamed for it; but I still have questions...

edit: Here's the function it's used in:

template <class T>
void TwoThreeFourTree<T>::splitRoot(){
  TreeNode <T> newRoot;
  newRoot = new TreeNode(root->data[1]);

  TreeNode <T>newLeft = new TreeNode(root->data[0]);

  TreeNode <T>newRight = new TreeNode(root->data[2]);

  newRoot.child[0] = newLeft;
  newRoot.child[1] = newRight;

  newLeft.child[0] = root.child[0];
  newLeft.child[1] = root.child[1];

  newRight.child[0] = root.child[2];
  newRight.child[1] = root.child[3];

  root = newRoot;

}

And I get the same two errors each time I try to create a new object in the function

Answer 1

You forgot T in new, and pointers:

TreeNode<T>* newRoot;
newRoot = new TreeNode<T>(root->data[1]);

Note, you'll need to fix your usage of pointers everywhere, not just here. Remember that this isn't Java or C#, and a variable of type TreeNode<T> is not a reference to T - it is a T. And to build a tree, you need references - that is, pointers. Though you may also want to consider using std::auto_ptr here to guarantee cleanup.