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    copied!<p>If don't care of performance, your code is absolutely OK. Otherwise you can do something different.</p> <p>For example Erlang supports Integers of arbitrary size:</p> <pre><code>binary_and(A, B) -&gt; Size = bit_size(A), &lt;&lt;X:Size&gt;&gt; = A, &lt;&lt;Y:Size&gt;&gt; = B, &lt;&lt;(X band Y):Size&gt;&gt;. </code></pre> <p>Or you can handcraft your own binary zip routine:</p> <pre><code>binary_and(A,B) -&gt; binary_and(A, B, &lt;&lt;&gt;&gt;). binary_and(&lt;&lt;A:8, RestA/bytes&gt;&gt;, &lt;&lt;B:8, RestB/bytes&gt;&gt;, Acc) -&gt; binary_add(RestA, RestB, &lt;&lt;Acc/bytes, (A band B):8&gt;&gt;); binary_and(&lt;&lt;&gt;&gt;, &lt;&lt;&gt;&gt;, Result) -&gt; Result. </code></pre> <p>Or optimized version:</p> <pre><code>binary_and(A,B) -&gt; binary_and(A, B, &lt;&lt;&gt;&gt;). binary_and(&lt;&lt;A:64, RestA/bytes&gt;&gt;, &lt;&lt;B:64, RestB/bytes&gt;&gt;, Acc) -&gt; binary_add(RestA, RestB, &lt;&lt;Acc/bytes, (A band B):64&gt;&gt;); binary_and(&lt;&lt;A:8, RestA/bytes&gt;&gt;, &lt;&lt;B:8, RestB/bytes&gt;&gt;, Acc) -&gt; binary_add(RestA, RestB, &lt;&lt;Acc/bytes, (A band B):8&gt;&gt;); binary_and(&lt;&lt;&gt;&gt;, &lt;&lt;&gt;&gt;, Result) -&gt; Result. </code></pre> <p>or more sophisticated</p> <pre><code>binary_and(A,B) -&gt; binary_and({A, B}, 0, &lt;&lt;&gt;&gt;). binary_and(Bins, Index, Acc) -&gt; case Bins of {&lt;&lt;_:Index/bytes, A:64, _/bytes&gt;&gt;, &lt;&lt;_:Index/bytes, B:64, _/bytes&gt;&gt;} -&gt; binary_add(Bins, Index+8, &lt;&lt;Acc/bytes, (A band B):64&gt;&gt;); {&lt;&lt;_:Index/bytes, A:8, _/bytes&gt;&gt;, &lt;&lt;_:Index/bytes, B:8, _/bytes&gt;&gt;} -&gt; binary_add(Bins, Index+1, &lt;&lt;Acc/bytes, (A band B):8&gt;&gt;); {&lt;&lt;_:Index/bytes&gt;&gt;, &lt;&lt;_:Index/bytes&gt;&gt;} -&gt; Acc end. </code></pre> <p>Anyway you have to measure if you are really interested in performance. May be the first one is the fastest for your purposes.</p>
 

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