 class="special">&lt;</span><span class="keyword">char</span><span class="special">...</span> digits<span class="special">&gt;</span> <span class="keyword">auto</span> <a name="boost.histogram.literals.operator_idm45105994291136"></a><span class="keyword">operator</span><span class="string">""</span><span class="identifier">_c</span><span class="special">(</span><span class="special">)</span><span class="special">;</span>
    <span class="special">}</span>
  <span class="special">}</span>
<span class="speci