hashval ^ (hashval &gt;&gt; 4)) &amp; 0xF;</code></p>
<p>providing an index between 0 and 15.</p>
<blockquote>
<p>In the actual implementation, the size of the array of hash tables is configurable to a power of two, so it can be 2, 4, 8, 16, 32, ... The following illustration shows a parallel_hash_map with 8 submaps.</p>
</blockquote>
<p><img src="https://github.com/greg7mdp/parallel-hashmap/blob/master/img/index_computation.png?raw=true" alt="index_computation" /></p>
<p>The benefit of this approach would 