#include <boost/signals2.hpp>

namespace bs2 = boost::signals2;

template<typename Signature> class custom_signal
{
public:
	typedef typename bs2::signal_type<Signature, bs2::keywords::mutex_type<bs2::dummy_mutex> >::type type;
};

int main()
{
	custom_signal<int (void)>::type mysignal;
	return 0;
}