Funny thing with WSAStartup()

Hi there!

I have a class named mySocket which is implemented as follow:

////////////////////////////////////////////////////////////////////////////////////////////////////
class mySocket{
private:
WSADATA wsadata;
// ...
public:
////////////////////////////////////////////////////////////////////////////////////////////////////
/// @fn int listen(int nPort)
///
/// @brief Create a socket listening on a specified port
///
/// @param nPort The port number
///
/// @return If success, returns 1. Otherwise, return -1.
////////////////////////////////////////////////////////////////////////////////////////////////////
int listen(int nPort);

// ...
}

int mySocket::listen(int nPort){
int iResult=WSAStartup(MAKEWORD(2,2), &wsadata);
if(iResult!=0){
printf("WSAStartup failsed: %d \n",iResult);
WSACleanup();
return -1;
};
// ...
}
////////////////////////////////////////////////////////////////////////////////////////////////////

In the code above, you can see that wsadata is declared as a property of mySocket. My problem is: WSAStartup() always fails with an error code of 10014 returned. :( But if I move the declaration of wsadata into the method listen(), there's nothing wrong happen. :)

I've had no idea about the error. Can somebody explain to me why?

The problem might be caused by use of the MAKEWORD() macro in the argument list of the function call.

Try this instead:

Code:

---

int mySocket::listen(int nPort){
WORD wVersionRequested = MAKEWORD(2,2);
int iResult=WSAStartup(wVersionRequested , &wsadata);
if(iResult!=0){
printf("WSAStartup failsed: %d \n",iResult);
WSACleanup();
return -1;
};

---