Is there a way, using the Gtk library in C, to clone a Gtk button (for instance), and pack it somewhere else in the app. I know you can't pack the same widget twice. And that this code obviously wouldn't work, but shows what happens when I attempt a shallow copy of the button:

GtkButton *a = g_object_new(GTK_TYPE_BUTTON, "label", "o_0", NULL);
GtkButton *b = g_memdup(b, sizeof *b);
gtk_box_pack_start_defaults(GTK_BOX(vbox), GTK_WIDGET(b));

There is surrounding code which creates a vbox and packs it in a window and runs gtk_main(). This will result in these hard to understand error messages:

(main:6044): Gtk-CRITICAL **: gtk_widget_hide: assertion `GTK_IS_WIDGET (widget)' failed

(main:6044): Gtk-CRITICAL **: gtk_widget_realize: assertion `GTK_WIDGET_ANCHORED (widget) || GTK_IS_INVISIBLE (widget)' failed
**
Gtk:ERROR:/build/buildd/gtk+2.0-2.18.3/gtk/gtkwidget.c:8431:gtk_widget_real_map: assertion failed: (GTK_WIDGET_REALIZED (widget))

Along the same lines, if I were to write my own GObject (not necessarily a Gtk widget), is there a good way to write a copy constructor. Im thinking it should be an interface with optional hooks and based mostly on the properties, handling the class's hierarchy in some way.

I'd want to do this:

GtkButton *b = copyable_copy(COPYABLE(a));

If GtkButton could use a theoretical copyable interface.