amp;  operator= (channel_t chan)       { check_gray(); at_c&lt;0&gt;(*this)=chan; <span class="keywordflow">return</span> *<span class="keyword">this</span>; }
<a name="l00150"></a>00150     <span class="keywordtype">bool</span>    operator==(channel_t chan)<span class="keyword"> const </span>{ check_gray(); <span class="keywordflow">return</span> at_c&lt;0&gt;(*this)==chan; }
<a name="l00151"></a>00151 };
<a name="l00152"></a>00152 
<a name="l00154"></a>00154 <span class="comment">//  ColorBasedConcept</sp