[sigc] libsigc problems

[luca <luca cappa i-medlab com>]

Hello all,

I explain here two problems i experienced with the latest sigc library.

First of all i cant use no more references as arguments of the bind<> 
function since one of the latest sigc library version (i cant remember 
now exaclty which was the previous one which references were working 
properly with, sorry). Here below i report a test case which does not 
compile (gcc4.03) and which uses references:

class X
{
};

class ClassHandler
{
public:
   sigc::signal<void> signal;
   X x;
   ClassHandler ()
   {
       signal.connect (sigc::bind<X&> (sigc::mem_fun (*this, 
&ClassHandler::on), x));
   }

   ~ClassHandler ()
   {
       std::cout << "~ClassHandler" << std::endl;
       signal.clear ();
   }

   void emitSignal ()
   {
       signal.emit ();
   }

   void on (X& x)
   {
       delete this;
   }
};


The second problem is if anyone has a clue on how to redesign better 
what i am doing in the following code (which is similar to the test case 
above but uses a pointer instead of a reference:


*class* ClassHandler
{
*public*:
   sigc::signal<void> signal;
   X x;
   ClassHandler ()
   {
       signal.*connect* (sigc::bind<X*> (sigc::mem_fun (**this*, &ClassHandler::on), &x));
   }

   ~ClassHandler ()
   {
       std::cout << "~ClassHandler" << std::endl;
       signal.clear ();
   }

   void emitSignal ()
   {
       signal.*emit* ();
   }

   void on (X* x)
   {
       *delete* *this*;
   }
};



//int main (int argc, char *argv[])
{    
   ClassHandler lCA;
   lCA.emitSignal ();

}

The problem is that when i call "delete this" the program will crash 
since i destroyed the object i am emitting the signal from (and also the 
slot will be destroyed indeed). Anyone has a better design to avoid this 
problem?

Greetings,
Luca