title: linux kernel `min` macros
body: <p>I was looking through linux kernel source code (<code>kernel.h</code>) and I found this macro for <code>min</code> function:</p>
  
  <pre><code>#ifndef max
  #define max(x, y) ({                \
      typeof(x) _max1 = (x);          \
      typeof(y) _max2 = (y);          \
      (void) (&amp;_max1 == &amp;_max2);      \
      _max1 &gt; _max2 ? _max1 : _max2; })
  #endif
  </code></pre>
  
  <p>And now I'm wondering what does <code>(void) (&amp;_max1 == &amp;_max2);</code> line do?</p>