">                // Unary updatable operators</span></div>
<div class="line"><a name="l00154"></a><span class="lineno">  154</span>&#160;<span class="comment">                class_type&amp; operator=  (class_type const &amp; x);</span></div>
<div class="line"><a name="l00155"></a><span class="lineno">  155</span>&#160;<span class="comment">                class_type&amp; operator+= (T const &amp; x);</span></div>
<div class="line"><a name="l00156"></a><span class="lineno">  156</span>&#160;<span class="co