gmmproc, _WRAP_METHOD: Accept ":" in slot_callback parameter
gmmproc, _WRAP_METHOD: Accept ":" in slot_callback parameter

such as slot_callback Gio::SignalProxy_async_callback, useful in gtkmm.

GNOME/glibmm,GNOME/glibmm,GNOME/glibmm,GNOME/glibmm,GNOME/glibmm