Can someone help me change this in to valid gcc11 code? Thanks

void loadFromImpl(const XmlNode& tree, Args&... fields)
    {
        using namespace std::string_literals;

        try
        {
            auto root = tree.get_child(RootNode);
            (loadField(root, fields, std::make_index_sequence<fmt::runtime(fields.size())>{}), ...);
        }
        catch (std::exception& e)
        {
            throw SettingsSerializer::Error{"Settings", "Load settings error: "s + e.what()};
        }
    }