Re: GInterfaces and API Stability

["Morten Welinder" <mwelinder gmail com>]

I notice that there are no padding members in, for example,
GtkCellLayoutIface.  Adding members therefore will change the
struct size which sounds like a clear ABI change to me.

Anyone who did

typedef struct {
    GtkCellLayoutIface clif;
    Bar baz;
} Foo;

is going to see random crashes when dynamically linked with a newer
gtk+.  Not good.  So even the C ABI was broken with

http://svn.gnome.org/viewvc/gtk%2B/trunk/gtk/gtkcelllayout.h?r1=12573&r2=16976

GtkWidgetClass, on the other hand, has extension member to be used
for new signals.  That does not suffer from the above.

Morten