How to change the extension of a file?
<p>I am currently working on project where I need to add some message at the end of a file and then I want to change its extension.</p>

<p>I know how to add the message at the end of the file; my code:</p>

<pre><code>_ofstream myfile;
_myfile.open("check.txt", std::ios_base::app);
_myfile &lt;&lt; "Thanks for your help.\n";
</code></pre>

<p>How can I change the file's extension?</p>