Span s(reinterpret_cast<uint8_t*>(client_hello_buf), sizeof(client_hello_buf));
try {
    auto alpns = getALPNProtocols(s);
    for (auto s : alpns.value()) std::cout << s << std::endl;
}
catch (std::exception& e)
{
    std::cout << e.what() << std::endl;
}