std::vector<std::string::value_type> &buf,

const std::chrono::milliseconds &timeout

) const noexcept {

return this->nonblock_recv(

buf.data(),

buf.size(),

timeout

);

const std::string &buf,

const std::chrono::milliseconds &timeout

) const noexcept {

return this->nonblock_send(

buf.data(),

buf.length(),

timeout

);