Binding extra arguments to Glib::signal_timeout

[Emilian Nowak <emiml wp pl>]

Hello,
I'm using gtkmm2.4, and I'm trying, to pass some ustring information to signal_timeout from my main.cc

Here I have
Okno okno;

Glib::signal_timeout().connect(sigc::bind<Glib::ustring>( sigc::mem_fun(okno,
&Okno::update), "sometxt", 250) );

and this singnal handler looks like this:

bool Okno::update(Glib::ustring dane);

And compiler error (g++4.0.3):

main.cc:26: error: no matching function for call to
'Glib::SignalTimeout::connect(sigc::bind_functor<-0x00000000000000001,
sigc::bound_mem_functor1<bool, Okno, Glib::ustring>, Glib::ustring, int,
sigc::nil, sigc::nil, sigc::nil, sigc::nil,
sigc::nil>)' /usr/include/glibmm-2.4/glibmm/main.h:184: note: candidates are:
sigc::connection Glib::SignalTimeout::connect(const sigc::slot<bool,
sigc::nil, sigc::nil, sigc::nil, sigc::nil, sigc::nil, sigc::nil, sigc::nil>&,
unsigned int, int)

Can anyone tell me how to add this extra argument?