ef="#mixed_arithmetics">Mixed arithmetics</a></li>
            </ul>
          </li>

          <li><a href="#chaining">Base Class Chaining and Object
          Size</a></li>

          <li><a href="#explicit_instantiation">Separate, Explicit
          Instantiation</a></li>

          <li><a href="#portability">Requirement Portability</a></li>
        </ul>
      </li>

      <li><a href="#example">Example</a></li>

      <li>
        <a href="#arithmetic">Arithmetic operators</a>

        <ul>
          <