tle="Class template category">category</a> <span class="special">:</span> <span class="keyword">public</span> boost::histogram::axis::iterator_mixin&lt; category&lt; Value, MetaData, Options, Allocator &gt; &gt;,
                 <span class="keyword">public</span> metadata_base_t&lt; MetaData &gt;
<span class="special">{</span>
<span class="keyword">public</span><span class="special">:</span>
  <span class="comment">// <a class="link" href="category.html#boost.histogram.axis.categoryconstruct-copy-destruct