libsigc++ example

[Andreas Volz <lists brachttal net>]

Hello,

I know libsigc++ has an own list, but I'm not subscribed to it. Perhaps
here is someone who could help me. Look at this example:

http://svn.gnome.org/viewvc/libsigc%2B%2B2/trunk/examples/member_method.cc?revision=191&view=markup

While developing an class based on the example code I found out that
it's not needed to inherit "Something" from "sigc::trackable" to get
this example code compiling.

So why is it needed? Is the example code simply old?

regards
Andreas