title: Undefined reference to `round' c language
body: <p>I'm using those imports</p>
  
  <pre><code>#include &lt;stdio.h&gt;
  #include &lt;math.h&gt;
  </code></pre>
  
  <p>and I'm getting <em>undefined reference to `round'</em> at this line:</p>
  
  <pre><code>double res = round(atof(nextVal));
  </code></pre>
  
  <p><em>nextVal</em> is a double value read from a file.</p>
  
  <p>I'm using Eclipse INDIGO.</p>