#include <boost/function/function0.hpp>
#include <boost/optional/optional.hpp>
#include <boost/fusion/container/vector.hpp>

void foo()
{
    typedef boost::function0<void> func_type;
    typedef boost::fusion::vector1<func_type> data_type;

    boost::optional<data_type> opt;
    boost::optional<data_type> opt2(opt);

    opt2 = opt;
}