="line">concept PixelConcept&lt;typename P&gt; : ColorBaseConcept&lt;P&gt;, PixelBasedConcept&lt;P&gt;</div><div class="line">{</div><div class="line">    where is_pixel&lt;P&gt;::value == <span class="keyword">true</span>;</div><div class="line">    <span class="comment">// where for each K [0..size&lt;P&gt;::value - 1]:</span></div><div class="line">    <span class="comment">//      ChannelConcept&lt;kth_element_type&lt;P, K&gt;&gt;;</span></div><div class="line"></div><div class="line">    <span class="k