title: Extract the parent folder of a directory using boost::filesystem
body: <p>Suppose I have the following folder</p>
  
  <pre><code>std::string m("C:\MyFolderA\MyFolderB\MyFolderC");
  boost::filesystem::path p(m);
  </code></pre>
  
  <p>Is there anyway for me to extract the parent of this folder. I want to get the string <code>MyFolderB.</code> from the above path.</p>