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Perl Language Reference Manual
by Larry Wall and others
Paperback (6"x9"), 724 pages
ISBN 9781906966027
RRP £29.95 ($39.95)

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15.8 WARNING

You may not (usefully) use a reference as the key to a hash. It will be converted into a string:

$x{ \$a } = $a;

If you try to dereference the key, it won't do a hard dereference, and you won't accomplish what you're attempting. You might want to do something more like

$r = \@a;
$x{ $r } = $r;

And then at least you can use the values(), which will be real refs, instead of the keys(), which won't.

The standard Tie::RefHash module provides a convenient workaround to this.

ISBN 9781906966027Perl Language Reference ManualSee the print edition