orithm</span> <span class="special">{</span>
      <span class="keyword">template</span><span class="special">&lt;</span><span class="keyword">typename</span> A<span class="special">,</span> <span class="keyword">typename</span> S<span class="special">&gt;</span> <span class="keyword">auto</span> <a class="link" href="../boost/histogram/algorithm/sum.html" title="Function template sum"><span class="identifier">sum</span></a><span class="special">(</span><span class="keyword">const</span> <a class="link" hre