title: what is the use of "#@" in c language?
body: <p>The <strong><code>#</code></strong> symbol is used at the start of preprocessor directives (<code>#ifdef</code>, <code>#define</code> etc). <code>#</code> is also used as the stringification operator.</p>
  
  <p><strong><code>##</code></strong> is the token pasting operator.</p>
  
  <p>Then in an online quiz I saw this:</p>
  
  <pre><code>#define MAKECHAR(operand) #@operand
  </code></pre>
  
  <p>What operator is <strong><code>#@</code></strong> and what is it used for?</p>