An other (bad for memory ?) way : 
use YAML;
my $complex_structure;
{
my $complex_structure = Load(Dump($complex_structure));
#Here, $complex_structure is independent
....
}
#Here, you come back to the first $complex_structure
....

[download]
$complex_structure can be quite anything ($ can be replaced with @ or %), and I think it will work even with blessed objects.

In reply to Re: Localizing hash keys in an AoH by Anonymous Monk
in thread Localizing hash keys in an AoH by kennethk

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