The __WSAFDIsSet function specifies whether a socket is included in a set of socket descriptors.
Syntax
int __WSAFDIsSet(
SOCKET fd,
fd_set* set
);
Parameters
fd
Descriptor identifying a socket.
set
Pointer to an fd_set structure containing the set of socket descriptors. The __WSAFDIsSet function determines whether the socket specified in the fd parameter is a member of that set.
Return Value
Returns a nonzero integer if the socket is a member of the group specified in the set parameter. Returns zero if the socket is not a member of the group specified in the set parameter.