[sigc] source examples question

[Mattheos Kakaris <m kakaris nki nl>]

The downloadable examples on the web page:

http://libsigc.sourceforge.net/doc.shtml

refer to an include file which does not exist in the sigc++ folder: (at
least not in my sigc++ folder):

#include <sigc++/signal_system.h>

has the signal_system header file been replaced by a different one in
the latest distribution?

Mattheos