title: Access iPhone's sandbox Document folder from standard C++ code
body: <p>I'm deploying an iphone application through QtCreator. I'd like to create a simple file using standard C++ libraries. I try to do this in the sandbox Documents folder.</p>
  
  <p>I compiled <code>boost</code>, so I use this library to check if the sandbox Document folder exists.</p>
  
  <p>My application starts in <code>/private/var/mobile/Containers/Bundle/Application/&lt;UUID&gt;/&lt;application name&gt;.app</code>. Then, I simply try to access <code>/private/var/mobile/Containers/Bundle/Application/&lt;UUID&gt;/&lt;application name&gt;.app/../Documents</code> folder (using <code>boost::filesystem::is_directorty</code>), as it does not exist, I try to create it (using <code>boost::filesystem::create_directories</code>), but it fails (boost raises an exception).</p>
  
  <p>Am I doing it wrong? Am I not in the right PATH? Or do I have to set any special permission to my app in order to be able to do this (as for Android, I add to list EXTERNAL_STORAGE in my application manifest).</p>