the user's Desktop directory
the user's Documents directory
the user's Downloads directory
the user's Music directory
the user's Pictures directory
the user's shared directory
the user's Templates directory
the user's Movies directory
the number of enum values
These are logical ids for special directories which are defined depending on the platform used. You should use g_get_user_special_dir() to retrieve the full path associated to the logical id.
The #GUserDirectory enumeration can be extended at later date. Not every platform has a directory for every logical id in this enumeration.