#pragma once

#include <boost/config.hpp>
#include <boost/fusion/sequence/utility/unpack_args.hpp>
#include <boost/fusion/sequence/conversion/as_vector.hpp>
#include <boost/fusion/sequence/adapted/mpl.hpp>
#include <boost/function_types/parameter_types.hpp>
#include <boost/function/function1.hpp>

template<class Func>
struct simple_signal : public pack_args
<
simple_signal const,
typename boost::fusion::result_of::as_vector<boost::function_types::parameter_types<Func> >::type,
void
>
{
	typedef boost::function1<void, const sequence_type> function;

	template<class F>
	struct invoke
	{
		invoke(const F& f) : f_(f) {}
		void operator()(const sequence_type& seq) const
		{
			boost::fusion::unpack_args(f_, seq);
		}
		F f_;
	};

	template<class F>
	void connect(const F& f)
	{
		m_functions.push_back(invoke<F>(f));
	}

	// callback from pack_args. 
	void on_packed_args(const sequence_type& seq) const
	{
		for(std::list<function>::const_iterator i = m_functions.begin(); i != m_functions.end(); ++i)
		{
			(*i)(seq);
		}
	}
private:
	std::list<function> m_functions;
};