tree_assoc_cntnr::node_iterator Interface

# `tree_assoc_cntnr::node_iterator` Interface

Node iterator.

This is an

1. Base classes.
2. Public Methods:
   1. Constructors, destructor, and related.
   2. Access methods.
   3. Movement methods.

## Base classes.

Class | Derivation Type
    const_node_iterator
| public

## Constructors, destructor, and related.

Method | Description | Complexity Guarantee | Exception Guarantee
    inline
      node_iterator
      (const node_pointer p_nd = NULL)
| Default constructor. | O(1) worst. | 3

## Access methods.

Method | Description | Complexity Guarantee | Exception Guarantee
    inline iterator
      operator*
      () const
| Access. | O(1) worst. | 3

## Movement methods.

Method | Description | Complexity Guarantee | Exception Guarantee
    inline node_iterator
      l_child
      ()
| Returns the node iterator associated with the left node. | O(1) worst. | 3
    inline node_iterator
      r_child
      ()
| Returns the node iterator associated with the right node. | O(1) worst. | 3