boost::function won't link [fixed]

#define evmgr EventManager::GetSingleton()
typedef boost::function<void (Event e)> Handler;

class EventManager : public System, public Singleton<EventManager>
{
private:
	std::map<std::string, std::vector<Handler> > handlers;
	std::list<Event> events;
public:
	void add_handler(std::string type, Handler h);
	void handle_event(const Event e);
	void handle_event_now(const Event& e); //ignore time delay requests

	bool init();
	bool tick();
	bool exit();

	EventManager();
	~EventManager();

};


void EventManager::add_handler(std::string type, Handler h)
{
	handlers[type].push_back(h); //register handler with handler list
}
void EventManager::handle_event_now(const Event& e)
{
	for(std::vector<Handler>::iterator i=handlers[e].begin();
		i != handlers[e.type].end(); ++i)
	{
		(*i)(e); //call the handler, passing the event as an argument
	}
}

EventManager::handle_event(const Event e)
{ events.push_back(e); }

bool EventManager::tick() 
{
	double time=clock.GetTime();
	for(std::list<Event>::iterator i=events.begin();
		i!=events.end(); )
	{
		if ((*i).time >= time) 
		{
			handle_event_now((*i));
		    delete (*i); //fixme is this right
			assert(false); //fix iterator
		}
		else ++i;

	}

	return true;
}

bool Input::init() 
{
    Handler on_keypress; //empty function object
    evmgr.add_handler("key", on_keypress);
    return true;
}
error LNK2019: unresolved external symbol "public: void __thiscall EventManager::add_handler(class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> >,class boost::function<void __cdecl(class Event),class std::allocator<void> >)" (?add_handler@EventManager@@QAEXV?$basic_string@DU?$char_traits@D@std@@V?$allocator@D@2@@std@@V?$function@$$A6AXVEvent@@@ZV?$allocator@X@std@@@boost@@@Z) referenced in function "public: virtual bool __thiscall Input::init(void)" (?init@Input@@UAE_NXZ)