I am trying to pass multiple arguments to the std::thread constructor,however i get the following error:'invoke': no matching overloaded function found. Here is an extract of the concerned code:

The thread creation:
new std::thread(handle_requests,conn.back(), std::ref(OBook),std::ref(Users_db));
The handle_request function declaration:
int handle_requests(SOCKET* ClientSocket, OrderBook& OB, DATABASE& db);

I have tried using the std::ref() wrapper around the Orderbook and DATABASE class ,but the error persists.Thanks for your help!