SQL> SELECT sq_ttt.currval FROM dual;

   CURRVAL
----------
         3

SQL> SELECT v.dat.oper_date, v.dat.qnt0
  2  FROM
  3  (
  4      SELECT /*+ NO_MERGE */
  5        value(test_TYPE_DATA_QNT) as dat 
  6      FROM dual
  7  ) v    
  8  /

DAT.OPER_   DAT.QNT0
--------- ----------
14-APR-17          0

SQL> SELECT sq_ttt.currval FROM dual;

   CURRVAL
----------
         5

SQL>

SQL> create or replace
  2    type TYPE_DATA_QNT_TBL
  3      as table of TYPE_DATA_QNT
  4  /

Type created.

SQL> select  oper_date,
  2          qnt0
  3    from  table(
  4                TYPE_DATA_QNT_TBL(
  5                                  test_TYPE_DATA_QNT
  6                                 )
  7               )
  8  /

OPER_DATE       QNT0
--------- ----------
14-APR-17          0

SQL> SELECT sq_ttt.currval FROM dual;

   CURRVAL
----------
         6

SQL> 

SQL> WITH
  2    FUNCTION with_function(p_num IN NUMBER) RETURN NUMBER IS
  3    BEGIN
  4      RETURN p_num;
  5    END;
  6  SELECT with_function(deptno)
  7  FROM   dept
  8  /

WITH_FUNCTION(DEPTNO)
---------------------
                   10
                   20
                   30
                   40

SQL> WITH
  2    FUNCTION with_function(p_num IN OUT NUMBER) RETURN NUMBER IS
  3    BEGIN
  4      RETURN p_num;
  5    END;
  6  SELECT with_function(deptno)
  7  FROM   dept
  8  /
SELECT with_function(deptno)
       *
ERROR at line 6:
ORA-06553: PLS-363: expression 'P0' cannot be used as an assignment target


SQL>

SQL> select banner from v$version
  2  /

BANNER
--------------------------------------------------------------------------------
Oracle Database 12c Enterprise Edition Release 12.1.0.1.0 - 64bit Production
PL/SQL Release 12.1.0.1.0 - Production
CORE    12.1.0.1.0      Production
TNS for 64-bit Windows: Version 12.1.0.1.0 - Production
NLSRTL Version 12.1.0.1.0 - Production

SQL> CREATE  SEQUENCE sq_ttt;

Sequence created.

SQL> CREATE TYPE TYPE_DATA_QNT AS OBJECT (
  2           oper_date date,
  3           qnt0  number,
  4           qnt1  number,
  5           qnt2  number
  6  );
  7  /

Type created.

SQL> CREATE or replace
  2  function test_TYPE_DATA_QNT RETURN TYPE_DATA_QNT
  3  DETERMINISTIC
  4  IS
  5    v_sq integer;
  6  BEGIN
  7    v_sq :=  sq_ttt.nextval;
  8    RETURN  TYPE_DATA_QNT(sysdate,0,0,0);
  9  END;
 10  /

Function created.

SQL> SELECT sq_ttt.nextval FROM dual;

   NEXTVAL
----------
         1

SQL> SELECT v.dat.oper_date, v.dat.qnt0
  2  FROM
  3  (
  4      SELECT
  5        value(test_TYPE_DATA_QNT) as dat
  6      FROM dual
  7  ) v
  8  /

DAT.OPER_   DAT.QNT0
--------- ----------
16-APR-17          0

SQL> SELECT sq_ttt.currval FROM dual;

   CURRVAL
----------
         3

SQL>