I want to copy a nested data structure. The FAQ tells me:
The Data::Dumper module on CPAN is nice for printing out
data structures, and FreezeThaw for copying them. For
example:
use FreezeThaw qw(freeze thaw);
$new = thaw freeze $old;
Where $old can be (a reference to) any kind of data
structure you'd like. It will be deeply copied.
However, the following program:
use FreezeThaw qw(freeze thaw);
use Data::Dumper;
$hashref = { a => {}, b => {} };
print Dumper($hashref);
$copy = thaw freeze $hashref;
print Dumper($copy);
gives the following output:
$VAR1 = {
'a' => {},
'b' => {}
};
$VAR1 = 1;
What's the problem?