[gtkmm] Deleting child widgets in a Gtk::Table

[Roger Leigh <roger whinlatter uklinux net>]

I have a widget derived from Gtk::Table containing child widgets.  One
of the functions of my widget is to add and remove columns.  When the
remove_column() method is called, I want to:
* Remove all widgets which are in the column, or overlapping on to it.
* Resize the table to remove the column (the table is homogeneous).

The method looks like this:

    TableList& tl = children();
    for (TableList::iterator cur = tl.begin();
         cur != tl.end();
         ++cur)
      {
        [check the widget overlaps -- this part works]
	cur = tl.erase(cur);
      }

    resize(property_n_rows(), property_n_columns() - 1);
	
With a 3×3 table, this is printed (I added some logging to show the
checking as the attach coordinates):

Check overlap: 2,3,0,3
2,3,2,3 = overlap
Deleting widget at 2,2
 
(epicpos:10851): Gtk-CRITICAL **: file gtkcontainer.c: line 983
(gtk_container_remove): assertion `GTK_IS_WIDGET (widget)' failed
2,3,0,1 = overlap
Deleting widget at 2,0
  
(epicpos:10851): Gtk-CRITICAL **: file gtkcontainer.c: line 983
(gtk_container_remove): assertion `GTK_IS_WIDGET (widget)' failed

The widget with top-left corner (2,1) was skipped.  Am I using the
TableList::erase method incorrectly?  Are the iterators invalidated by
an erase()?


Thanks,
Roger

-- 
Roger Leigh

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