boost::filesystem::path directory_or (boost::optional<boost::filesystem::path> dir, boost::filesystem::path a) const;
void add_to_history_internal (std::vector<boost::filesystem::path>& h, boost::filesystem::path p);
void backup ();
boost::filesystem::path directory_or (boost::optional<boost::filesystem::path> dir, boost::filesystem::path a) const;
void add_to_history_internal (std::vector<boost::filesystem::path>& h, boost::filesystem::path p);
void backup ();