what is libuv

memory based inheritance

/* uv.h */

/*
 * uv_tcp_t is a subclass of uv_stream_t.
 *
 * Represents a TCP stream or TCP server.
 */
struct uv_tcp_s {
  UV_HANDLE_FIELDS
  UV_STREAM_FIELDS
  int ipc;
};

For simplicity we are ignoring the fact that uv_ipc_t defines more fields than just int ipc