antiate the dereference
    operators are specified in terms of expressions which must be valid and
    their return type. The composite operator templates list their component
    templates, which the instantiating type must support, and possibly other
    requirements.</p>

    <h3><a name="dereference">Dereference</a> Operators</h3>

    <p>All the dereference operator templates in this table accept an
    optional template parameter (not shown) to be used for <a href=
    "#chaining">base class chaining