oid's and primary keys on insert

Hello, I know it is posible to get the oid of the last row inserted to
from a cursor.

My question is what happens when/if PostgreSQL stops useing oids?

Or, to put it another way, my application needs to get the primary key
of some rows when they are inserted and not others, is there a future
proof way of doing this?

Thanks

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* Rob Brown-Bayliss
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