How to use the C socket API in C++ on z/OS

Question: I've been having issues getting the C sockets API to work properly in C++. Specifically, although I am including sys/socket.h, I still get compile time errors telling me that AF_INET is not defined. Am I missing something obvious, or could this be related to the fact that I'm doing this coding on z/OS and my problems are much more complicated?

Update: Upon further investigation, I discovered that there is an #ifdef that I'm hitting. Apparently z/OS isn't happy unless I define which "type" of sockets I'm using with:

#define _OE_SOCKETS

Now, I personally have no idea what this _OE_SOCKETS is actually for, so if any z/OS sockets programmers are out there (all 3 of you), perhaps you could give me a rundown of how this all works?

Sure I can post a test app.

#include <sys/socket.h>

int main()
{
    return AF_INET;
}

Compile/Link Output:
cxx -Wc,xplink -Wl,xplink -o inet_test inet.C
"./inet.C", line 5.16: CCN5274 (S) The name lookup for "AF_INET" did not find a declaration.
CCN0797(I) Compilation failed for file ./inet.C. Object file not created.
A check of sys/sockets.h does include the definition I need, and as far as I can tell, it is not being blocked by any #ifdef statements.
I have however noticed it contains a the following:

#ifdef __cplusplus
  extern "C" {
#endif

which encapsulates basically the whole file. Not sure if it matters.

Solution:

 X/Open

#define _XOPEN_SOURCE_EXTENDED 1
#include <sys/socket.h>

int connect(int socket, const struct sockaddr *address, socklen_t address_len);

Berkeley Sockets

#define _OE_SOCKETS
#include <sys/types.h>
#include <sys/socket.h>

int connect(int socket, struct sockaddr *address, int address_len);