[ABAP] Objekt-Referenzen in interner Tabelle (Liste) speichern

TYPES: BEGIN OF ty_user,
         bname      TYPE usr21-bname,
         persnumber TYPE adr6-persnumber,
         addrnumber TYPE adr6-addrnumber,
         smtp_addr  TYPE adr6-smtp_addr,
       END OF ty_user.

CLASS cl_person DEFINITION.
  PUBLIC SECTION.
    METHODS: constructor
      IMPORTING
        i_userdata TYPE ty_user.
    METHODS: print_mail.
  private SECTION.
    DATA: userdata TYPE ty_user.
ENDCLASS.

CLASS cl_person IMPLEMENTATION.
  METHOD constructor.
    userdata = i_userdata.
  ENDMETHOD.

  METHOD print_mail.
    WRITE: / userdata-bname, userdata-smtp_addr.
  ENDMETHOD.
ENDCLASS.

DATA: it_userdata TYPE TABLE OF ty_user.

* interne Tabelle zur Speicherung der Objektreferenzen
DATA: it_persons TYPE TABLE OF REF TO cl_person.
* Objektreferenz
DATA: o_person TYPE REF TO cl_person.

START-OF-SELECTION.
* Daten holen
  SELECT u~bname, u~persnumber, u~addrnumber, a~smtp_addr
    INTO CORRESPONDING FIELDS OF TABLE @it_userdata
    FROM usr21 AS u
    INNER JOIN adr6 AS a ON a~persnumber = u~persnumber AND a~addrnumber = u~addrnumber
    UP TO 10 ROWS.

* Objekte erzeugen und an Referenztabelle anhängen
  LOOP AT it_userdata INTO DATA(wa_user).
    o_person = new cl_person( wa_user ).
    APPEND o_person TO it_persons.
  ENDLOOP.

* Referenztabelle durchloopen und Objekte aufrufen
  LOOP AT it_persons INTO o_person.
    o_person->print_mail( ).
  ENDLOOP.