I am able to run a query that contains a FUNCTION inside of a WITH clause, which is a new 12c feature, but I get an error when I try to use the same SQL inside a VIEW.
I tried using LiveSQL, but I cannot even get the SQL below to run, which does work on my database.
Perhaps LiveSQL does not have this new 12c feature yet?

This command works when I comment out the 1st line (CREATE VIEW):
--CREATE OR REPLACE VIEW view_test AS
WITH
FUNCTION up(in_desc VARCHAR2) RETURN VARCHAR2 IS
BEGIN
RETURN UPPER(in_desc);
END;
st AS (SELECT up('Chicago') st_desc FROM dual)
SELECT * FROM st
/

But when I add the CREATE VIEW line at the top I get the error below.
ORA-06553: PLS-103: Encountered the symbol "end-of-file" when expecting one of the following...

My Oracle Version: Oracle Database 12c Enterprise Edition Release 12.1.0.2.0
My SQLPLUS Version on Linux: SQL*Plus: Release 11.2.0.3.0

Any help would be greatly appreciated.

SQL> WITH
  2  FUNCTION up(in_desc VARCHAR2) RETURN VARCHAR2 IS
  3  BEGIN
  4  RETURN UPPER(in_desc);
  5  END;
  6  st AS (SELECT up('Chicago') st_desc FROM dual)
  7  SELECT * FROM st
  8  /

ST_DESC
-----------------------------------------------------------
CHICAGO

1 row selected.

SQL> CREATE OR REPLACE VIEW view_test AS
  2  WITH
  3  FUNCTION up(in_desc VARCHAR2) RETURN VARCHAR2 IS
  4  BEGIN
  5  RETURN UPPER(in_desc);
  6  END;
  7  st AS (SELECT up('Chicago') st_desc FROM dual)
  8  SELECT * FROM st
  9  /

View created.