How to draw to a pixbuf?

[Carlo Wood <carlo alinoe com>]

I have a function that can draw to a cairo_t*.
I need to create a Gtk::IconSet.

Gtk::IconSet wants me to pass a Glib::RefPtr<Gdk::Pixbuf> const&,
so ... I need to:

- create a Gdk::Pixbuf object somehow
- get a related cairo_t* for it.

I tried long and hard and spend several hours trying
to find examples or documentation about this, but
everything I tried core dumped (if it compiled at all).

Can someone please tell me how to do this?

-- 
Carlo Wood <carlo alinoe com>