[postgresql]postgresql custom function returns an instance of table type

CREATE OR REPLACE function  test_retable(p_id int)
RETURNS table(id int, name VARCHAR2(50))
LANGUAGE PLPGSQL  
AS $$

 DECLARE
/*
1. Create table
create table test1(c1 int ,c2 varchar2(50));
insert into test1(c1,c2) values(1,'2');
insert into test1(c1,c2) values(2,'2');
insert into test1(c1,c2) values(1,'3');
2. Execute query function
select * from test_retable(1);
*/
    TYPE varray_type IS VARRAY(20) OF INT; 
    v_varray varray_type; 
BEGIN 
    v_varray := varray_type(1, 2, 3, 4, 5);
   RETURN QUERY SELECT c1 AS id, c2 AS name FROM test1 WHERE c1 in  (
  select  regexp_split_to_table(array_to_string(v_varray, ','),',')
 );
 
END ; $$