n class="special">|</span><span class="special">(</span><a class="link" href="../boost/histogram/axis/option/bitset.html" title="Struct template bitset">bitset</a><span class="special">&lt;</span> <span class="identifier">B1</span> <span class="special">&gt;</span><span class="special">,</span> <a class="link" href="../boost/histogram/axis/option/bitset.html" title="Struct template bitset">bitset</a><span class="special">&lt;</span> <span class="identifier">B2</span> <span class="special">&gt;</span><span c