title: How to solve "Unresolved inclusion: <iostream>" in a C++ file in Eclipse CDT?
body: <p>I download <a href="http://www.eclipse.org/cdt/downloads.php" rel="noreferrer">eclipse for c++</a> (cdt-master-8.0.2.zip).</p>
  
  <p>When I write:</p>
  
  <pre><code>#include &lt;iostream&gt;
  </code></pre>
  
  <p>It marks:</p>
  
  <pre><code>Unresolved inclusion: &lt;iostream&gt;
  </code></pre>
  
  <p>How can I fix it?</p>