lType</span><span class="special">,</span> <span class="identifier">F</span><span class="special">)</span><span class="special">;</span>

    <span class="comment">// <a class="link" href="piecewise_line_idp82782016/param_type.html#idp82784496-bb">friend functions</a></span>
    <span class="keyword">template</span><span class="special">&lt;</span><span class="keyword">typename</span> CharT<span class="special">,</span> <span class="keyword">typename</span> Traits<span class="special">&gt;</span> 
      <sp