eyword">typename</span> P::value_type;</div><div class="line">        where PixelValueConcept&lt;value_type&gt;;</div><div class="line">    <span class="keyword">typename</span> P::reference;</div><div class="line">        where PixelConcept&lt;reference&gt;;</div><div class="line">    <span class="keyword">typename</span> P::const_reference;</div><div class="line">        where PixelConcept&lt;const_reference&gt;;</div><div class="line">    <span class="keyword">static</span> <span class="keyword">const</s