std::shared_ptr<Cinema> item_to_cinema (wxTreeListItem item) const;
std::shared_ptr<dcpomatic::Screen> item_to_screen (wxTreeListItem item) const;
boost::optional<wxTreeListItem> cinema_to_item (std::shared_ptr<Cinema> cinema) const;
boost::optional<wxTreeListItem> screen_to_item (std::shared_ptr<dcpomatic::Screen> screen) const;
std::shared_ptr<Cinema> item_to_cinema (wxTreeListItem item) const;
std::shared_ptr<dcpomatic::Screen> item_to_screen (wxTreeListItem item) const;
boost::optional<wxTreeListItem> cinema_to_item (std::shared_ptr<Cinema> cinema) const;
boost::optional<wxTreeListItem> screen_to_item (std::shared_ptr<dcpomatic::Screen> screen) const;