You want to weaken $foo, $bar, and $baz; then you want to keep $foo as a weak reference while making $bar and $baz both a strong, normal reference again. That's the way I read it, so here's one way of doing it: 
#!/usr/bin/perl

use strict;
use warnings;
use Scalar::Util qw(weaken isweak);
use Scalar::Util::Refcount;

my $foo;
my $bar;
my $baz;

my $ref1 = \$foo;
weaken($ref1);
print my $weak = isweak($ref1), "\n";
print refcount($foo), "\n";

my $ref2 = \$bar;
weaken($ref2);
print $weak = isweak($ref2), "\n";
print refcount($baz), "\n";
   
my $ref3 = \$baz;
weaken($ref3);
print $weak = isweak($ref3), "\n";
print refcount($baz), "\n\n";

my $copy1 = $ref2;
$weak = isweak($copy1);

my $copy2 = $ref3;
$weak = isweak($copy2), "\n";

[download]
I used $copy to make $bar and $baz strong again; "isweak" from Scalar::Util to test if the refs were weak. If they're weak, they'll come back true. If they're not weak, they'll come back false; also, I checked the refcount with Scalar::Util::Refcount to double-check what was happening.

Update: Fixed some omissions.

In reply to Re: weak-reference set internally by Khen1950fx
in thread weak-reference set internally by Cagao

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