referencial conlumn contraints and inheritance

Folks,

  I am not sure where to post this.  This may be more of a wishlist item
than a usage question.  I am new to postgresql 7.1.  Table inheritance
in postgres seems wonderfull.  Is there the capability now or any
plans to extend support for inherited tables in column constraints. One
example is a travel db where several tables are defined as:

create table areas (
area_id char(10) primary key,
name varchar(40),
.
description varchar(120) );

create table countries (
.
. ) inherits (areas);

create table states (
.
country_id char(10) references countries ...,
.
. ) inherits (areas);

create table cities (
.
country_id char(10) references countries ...,
.
.) inherits (areas);

Then a destination table set up with a field referencing areas.
Currently postgres appears not to support reference contraints checking
through inherited tables.  Nor does it appear to support subselects in check
constraints.  It would be nice to allow reference checking through the
inherited tables so destination.area_id would be valid for any country,
state, or city area_id entered.

create table destination (
.
area_id char(10) references areas ...,
.
.);

Thanks,

Stuart