sclass TripleElement {
  Triple<S> triple;
  bool position; // 1, 2, 3
  
  *() {}
  *(Triple<S> *triple, int *position) {}
  
  S get() {
    ret position == 0 ? triple.a : position == 1 ? triple.b
      position == 2 ? triple.c : null;
  }
}