gtkmm ToggleButton help

[Rbuen4455]

I am following a beginner tutorial on gtkmm, and the online tutorial doesn't really explain things like how to create widgets. It just explains to you what each widget is, but doesn't provide a code example so I'm left with looking at the documentation.

I am trying to create a simple ToggleButton that will output whether it is active or inactive. If I press the ToggleButton, it will output to the console "ToggleButton active", else if the ToggleButton is pressed again, it will output to the console "ToggleButton inactive". This is what I have so far:

#include <iostream>

#include <gtkmm/application.h>
#include <gtkmm/togglebutton.h>
#include <gtkmm/window.h>

using namespace std;

class ToggleButtons: public Gtk::Window
{
   public:
     ToggleButtons();
     virtual ~ToggleButtons();
   
   protected:
     // Signal handler for ToggleButton
     void togglebutton_toggler(Gtk::ToggleButton *tgbtn);

     // Create the ToggleButton
     Gtk::ToggleButton t_button;
};

ToggleButtons::ToggleButtons()
{
   // Decorate window
   set_title("ToggleButton");
   set_default_size(300, 150);

   t_button.set_label("Toggle Button");
   t_button.set_margin_left(30);
   t_button.set_margin_right(30);
   t_button.set_margin_top(30);
   t_button.set_margin_bottom(30);

   // Sets the event listener for the ToggleButton
   t_button.signal_toggled().connect(sigc::bind(sigc::slot(*this, &ToggleButtons::togglebutton_toggler), t_button));

   // Add the togglebutton to the window
   add(t_button);

   // Show all widgets in the window
   show_all_children();
}

ToggleButtons::~ToggleButtons() { }

void ToggleButtons::togglebutton_toggler(Gtk::ToggleButton *tgbtn)
{
   if(tgbtn->get_active())
     cout << "ToggleButton active!" << endl;
   else
     cout << "ToggleButton inactive!" << endl;
}

int main(int argc, char *argv[])
{
   auto app = Gtk::Application::create(argc, argv, "gtkmm tuts");

   ToggleButtons tgbtn;

   // Shows the window and returns when it's close
   return app->run(tgbtn);
}

This is the line I'm getting an error with:

t_button.signal_toggled().connect(sigc::bind(sigc::slot(*this, &ToggleButtons::togglebutton_toggler), t_button));

And the error says: "gtkmm.cpp:36:59: error: missing template arguments before ‘(’ token
36 | t_button.signal_toggled().connect(sigc::bind(sigc::slot(*this, &ToggleButtons::togglebutton_toggler), t_button));"

What's going on?

[coder777]

It looks like it's not the way to bind paramters. See:

https://wiki.inkscape.org/wiki/index.php/Using_libsigc%2B%2B_signals

Particularly this:

emitter.signal_number_changed.connect(
   sigc::bind<0>(
      sigc::mem_fun(*this, &Receiver::_handleNumberChange),
      emitter)
   )
);