Currently, the following has to be done:

bool exist;
Glib::RefPtr<Gnome::Vfs::FileInfo> info;
while ((info = directory_handle.read_next(exist)) && exist) {
  ...
}

The 'exist' argument is cumbersome and seems redundant. Compare if instead
read_next() just returned a null RefPtr, the above could be:

Glib::RefPtr<Gnome::Vfs::FileInfo> info;
while (info = directory_handle.read_next()) {
  ...
}