[Dbix-class] Cross product joins

[Gavin Carr]

Is there a way to do cross-product joins in DBIx::Class i.e. joins
without a relationship and without the ON/USING clauses? e.g.

  SELECT s.name, distance(s.location, p.centre)
  FROM store s CROSS JOIN postcode p
  WHERE p.postcode = '12345';

'join' doesn't seem like it will work since there's no db relationship
between these tables at all, and my 'from' fu is failing me - the
following:

  $rs = $schema->resultset('Store')->search({
    'p.postcode' => $postcode,
  }, {
    alias => 's',
    from => [
      { s => 'store' },
      [
        { p => 'postcode', -join_type => 'cross' },
        [],
        {},       # or undef, or omitted
      ],
    ],
  });

generates a hanging ON clause:

  ERROR:  syntax error at or near "WHERE" at character 239 [for Statement
  "SELECT [...] FROM store s JOIN postcode p ON  WHERE ( p.postcode = ? )"
  with ParamValues: 1='12345']

Am I doing something wrong here, or is this just not supported? 
(DBIx::Class 0.08010, in case that matters)

Cheers,
Gavin