template<typename T> static void init_sorting_option(std::vector<tgenerator_::torder_func>& order_funcs, std::function<T>* filter_on)
{
    order_funcs[0] = [this](unsigned i1, unsigned i2)->bool {
        return (*recall_list_)[i1]->filter_on() < (*recall_list_)[i2]->filter_on();
    };
}