class Event_chord;
class Event_chord_iterator;
class Event_iterator;
-class Folded_repeat_iterator;
class Font_metric;
class Font_size_engraver;
class Global_context;
class Object_key_undumper;
class Open_type_font;
class Output_property;
+class Page_breaking;
class Pango_font;
class Paper_book;
class Paper_column;
class Simultaneous_music_iterator;
class Skyline;
class Skyline_entry;
+class Skyline_pair;
class Slur_configuration;
class Slur_score_state;
class Source_file;