s Fn, class A1, class A2, class A3&gt;
class_&amp; def(char const* name, Fn fn, A1 const&amp; a1, A2 const&amp; a2, A3 const&amp; a3);
</pre>

  <dl class="function-semantics">
    <dt><b>Requires:</b> <code>name</code> is an <a href=
    "definitions.html#ntbs">ntbs</a> which conforms to Python's <a href=
    "http://www.python.org/doc/current/ref/identifiers.html">identifier
    naming rules</a>.</dt>

    <dd>
      <ul>
        <li>If <code>a1</code> is the result of an <a href=
        "overloads.html#