C++ function as parameter error

I'm trying to run a function on each node traversed in a Binary Search Tree class I made. Here is the function that traverses the nodes of the BST and runs the function passed in as an argument on each node:

template<class ItemType, class OtherType>
void BinarySearchTree<ItemType, OtherType>::Inorder(void visit(BinaryNode<ItemType, OtherType>&), BinaryNode<ItemType, OtherType>* node_ptr) const {
   if (node_ptr != nullptr) {
      Inorder(visit, node_ptr->GetLeftPtr());
      BinaryNode<ItemType, OtherType> node = *node_ptr;
      visit(node);
      Inorder(visit, node_ptr->GetRightPtr());
   }  // end if
}  // end inorder

This is a private member function of the BST class, so it gets called by a public member function:

template<class ItemType, class OtherType>
void BinarySearchTree<ItemType, OtherType>::InorderTraverse(void visit(BinaryNode<ItemType, OtherType>&)) const
{
   Inorder(visit, root_);
}  // end inorderTraverse

In my main file, I created this function to pass in as the argument:

void displayItem(BinaryNode<string, LinkedQueue<int> >& anItem)

The traversal is called like this:

tree1Ptr->InorderTraverse(displayItem);

When I compile, I get this error, and I have no idea how to fix it.

MainBST.cpp:62:29: error: cannot initialize a parameter of type 'void
      (*)(BinaryNode<std::__1::basic_string<char>, LinkedQueue<int> > &)' with
      an lvalue of type 'void (string &)' (aka 'void (basic_string<char,
      char_traits<char>, allocator<char> > &)'): type mismatch at 1st parameter
      ('BinaryNode<std::__1::basic_string<char>, LinkedQueue<int> > &' vs
      'string &' (aka 'basic_string<char, char_traits<char>, allocator<char> >
      &'))
  tree1Ptr->InorderTraverse(displayItem);
                            ^~~~~~~~~~~
./BinarySearchTree.h:42:29: note: passing argument to parameter 'visit' here
  void InorderTraverse(void visit(BinaryNode<ItemType, OtherType>&)) const;

If anyone understands the error and can decipher it and help me, I will be very grateful. If you need me to drop more code, I'll be glad to do it. Thank you so much!