std::unique_ptr<Transfer> transfer(new Transfer(*this, m_next_transfer_id++, url, outfile));
curl_multi_add_handle(m_multi_handle, transfer->get_curl_handle());
m_transfers.push_back(std::move(transfer));
std::unique_ptr<Transfer> transfer(new Transfer(*this, m_next_transfer_id++, url, outfile));
curl_multi_add_handle(m_multi_handle, transfer->get_curl_handle());
m_transfers.push_back(std::move(transfer));