what does "##" symbol mean in C++
<blockquote>
  <p><strong>Possible Duplicates:</strong><br>
  <a href="http://stackoverflow.com/questions/672618/macro-expansion-in-c">Macro expansion in C++</a><br>
  <a href="http://stackoverflow.com/questions/1121971/what-is-the-purpose-of-the-operator-in-c-and-what-is-it-called">What is the purpose of the ## operator in C++, and what is it called?</a>  </p>
</blockquote>



<p>What does "##" symbol mean in C++? I came across with it while I was reading someone's source code. More specifically, what does this statement mean:</p>

<pre><code>if ( v &gt; ## = 0.1 * threshold )
</code></pre>
