Where are the key codes for GdkEventKey defined?

[Matthias Kaeppler <nospam digitalraid com>]

So, I want to handle key-press events, and I need the constants which 
define the key codes.
I have been searching for hours now, this mailing list, the internet, 
and I even grep'ed through the gtkmm/gdkmm/glibmm header files to find 
out where the key-codes are defined (I suppose there /is/ something like 
GDK_ENTER or such?).
The Gtk+ reference only said it was defined in <gdk/gdkkeysym.h>, but 
this header does not exist in my gtkmm-2.4 installation.

Please don't tell me I have to use raw numbers to catch key events :)

--
Matthias Kaeppler