gtkmm4: Box::pack_start()/pack_end()

[Murray Cumming <murrayc murrayc com>]

The gtk_box_pack_start()/pack_end() API changed slightly,
meaning that our C++ pack_start()/pack_end() convenience overloads can
no longer have a default value for our PackOptions convenience enum:
https://git.gnome.org/browse/gtkmm/commit/?id=b07a05bba3a2e1df8778683a4
7e50d8c8f3fb26b

As the commit message says, that's awkward because the behaviour has
now changed silently, meaning you need to do this to get the old
behaviour (assuming my new implementation works as intended):
https://git.gnome.org/browse/gtkmm/commit/?id=214be98c94d85aa5ac79031fa
a5f995e4b797c26

Thoughts? Should we remove these gtkmm-specific
Box::pack_start()/pack_end() methods anyway? That will still have the
same change-of-behaviour problem for this code:
box.pack_start(child)
but if an application also has code like this it will at least cause a
compiler error that forces the developer to think about it:
box.pack_start(child, Gtk::PACK_SHRINK).


-- 
Murray Cumming
murrayc murrayc com
www.murrayc.com