sinterface IIntMemory64 {
  int get(long idx);
  default int read(long idx) { ret get(idx); }
  void set(long idx, int val);
  long size();
  
  default int[] readArray(long start, int len) {
    int[] a = new[len];
    for i to len:
      a[i] = get(start+i);
    ret a;
  }
  
  default int[] readArray(LongRange r) {
    ret r == null ? null : readArray(r.start, toInt(r.length()));
  }
  
  default long getLong(long idx) {
    ret twoIntsToLong(get(idx), get(idx+1));
  }
  
  default void setLong(long idx, long val) {
    set(idx, firstIntFromLong(val));
    set(idx+1, secondIntFromLong(val));
  }
}

Began life as a copy of #1029248