+std::string longest (std::vector<std::string>&);
+bool key_is_legal_for_numeric_entry (guint keyval);
+void reset_dpi ();
+void set_pango_fontsize ();
+
+inline guint8 convert_color_channel (guint8 src, guint8 alpha);
+void convert_bgra_to_rgba (guint8 const* src,
+ guint8* dst,
+ int width,
+ int height);
+
+void resize_window_to_proportion_of_monitor (Gtk::Window*, int, int);