When enable-deprecated-api is disabled, no deprecated classes or methods
will be available in gtkmm. For instance, the
Gtk::FileSelection
dialog will not be provided,
because it is replaced by Gtk::FileChooserDialog
. The
reference documentation contains a full list of deprecated
gtkmm API.
If deprecated gtkmm API is available, the
GTKMM_DISABLE_DEPRECATED
macro will not be
defined.