sclass StringWithMeta > Meta is CharSequence {
  S string; // final. not null
  
  *() {}
  *(S *string) { assertNotNull(string); }
  
  public int hashCode() { ret _hashCode(string); }
  public bool equals(O o) { ret this == o; }
  
  // This drops the meta
  toString { ret string; }
  
  // implementation of CharSequence methods
  
  public int length() { ret string.length(); }
  public char charAt(int index) { ret string.charAt(index); }
  
  // could change to retain meta
  public CharSequence subSequence(int start, int end) {
    ret string.substring(start, end);
  }
}

Began life as a copy of #1012685