typedef axl_bool(* VortexIoIsSetFdGroup)(int fds, axlPointer fd_group, axlPointer user_data)

IO handler definition to perform the "is set" the fd set operation.

fds The socket descriptor to be added.
fd_group The socket descriptor group to be used as destination for the socket.
user_data User defined pointer provided to the function.
axl_true if the socket descriptor is active in the given fd group.