nk" href="../boost/histogram/axis/variant.html" title="Class template variant">variant</a><span class="special">&lt;</span> <span class="identifier">Us</span><span class="special">...</span> <span class="special">&gt;</span> <span class="special">&amp;</span> v<span class="special">)</span><span class="special">;</span>
    <span class="special">}</span>
  <span class="special">}</span>
<span class="special">}</span></pre>
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