template <class... Fs, class Timeout, class OnResult, class OnError>
  bool try_request(const typed_actor<Fs...>& dst, Timeout timeout,
                   OnResult on_result, OnError on_error) {
    using on_error_result = decltype(on_error(std::declval<error&>()));
    static_assert(std::is_same_v<void, on_error_result>);
    auto dst_hdl = actor_cast<actor>(dst);
    return (detail::mtl_util<Fs>::request(self_, dst_hdl, timeout, adapter_,
                                          *reader_, on_result, on_error)
            || ...);
  }