Checking an Authorization Scheme within a PL/SQL Block

Recently, I had a quite tricky requirement where within a customer application I needed to check if user has a required role to run a process, edit a field or see an information. Many times these conditions were a combination of different authorization schemes and other rules determined during the runtime of the application. So the problem was not solved by just adding an authorization scheme to the object. More than one authorization scheme needed to be checked together with some other conditions. Using the apex_util package and the function public_check_authorization I was able to successfully acomplish those tasks. This is a modified example of the code I used there:

BEGIN
   IF     (   apex_util.public_check_authorization ('AUTH_GROUP_1')
           OR apex_util.public_check_authorization ('AUTH_GROUP_2')
          )
      AND :p12_status = '0'
   THEN
      RETURN TRUE;
   ELSIF     (   apex_util.public_check_authorization ('AUTH_GROUP_2')
              OR apex_util.public_check_authorization ('AUTH_GROUP_3')
             )
         AND :p12_status = '1'
   THEN
      RETURN TRUE;
   ELSE
      RETURN FALSE;
   END IF;
END;