Invalid name syntax on to_regrole(session_user)

Hello!

I store pg_roles.oid::int as numeric representation of database role.
Now I need to get this number for session user.
I used to_regrole(session_user) function.

Everything works fine till I allow roles with dots in role`s name.

create role "dot.net"
set session authorization 'dot.net';
select to_regrole(session_user); ERROR: invalid name syntax

Is it expected behavior that session_user produces non quoted output and I should use quote_ident anywhere in code session_user?

Is there other way (without extra type conversions) for getting oid of session_user?