signals.cpp

#include <iostream>
#include <string>
#include <map>
#include <list>

class Object
{
public:
  struct s_slot
  {
    Object* o;
    void (Object::*slot)();
  };
protected:
  static std::map< std::string, std::list< s_slot > > _slots;
public:
  void connect(const std::string& s, void (Object::*slot_f)())
  {
    s_slot slot;
    slot.o = this;
    slot.slot = slot_f;
    _slots[s].push_back(slot);
  }
  template < typename T1, typename T2 >
  void emit(const std::string& s, T1 t1, T2 t2)
  {
    std::map< std::string, std::list< s_slot > >::const_iterator itm;

    itm = _slots.find(s);
    if (itm != _slots.end())
      {
	std::list< s_slot >::const_iterator it;
	for (it = itm->second.begin(); it != itm->second.end(); ++it)
	  {
	    ((it->o)->*reinterpret_cast< void (Object::*)(T1, T2) >(it->slot))(t1, t2);
	  }
      }
  }
};

std::map< std::string, std::list< Object::s_slot > > Object::_slots;

class Object2 : public Object
{
public:
  Object2(int c) : _c(c) {}
  void tata(int a, int b)
  {
    std::cout << a + b + _c << std::endl;
  }
protected:
  int _c;
};

class Object3 : public Object
{
public:
  void tutu(int a, int b)
  {
    std::cout << a - b << std::endl;
  }
};

int main()
{
  Object2 o(4);
  Object3 p;

  o.connect("toto", reinterpret_cast< void (Object::*)() >(&Object2::tata));
  p.connect("toto", reinterpret_cast< void (Object::*)() >(&Object3::tutu));
  p.emit("toto", 42, 21);
}