Hmm... Well, derefrencing a hashref can be done in the way you showed up there, but it is perfectly valid to get a scalar back from a hashref this way as well:

$scalar = $$hashref{key};
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and assigning into a hashref can be done in the same way:

my $hashref = {};
$$hashref{key} = $scalar;
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Perhaps taking a look at References quick reference will sum it up nicely.

Thanks,

Scott
Project coordinator of the Generic Model Organism Database Project