The problem with not using weaken has been explained.

But there's also a problem with using weaken. 

sub d {
   my $dir = Practice::Dir->new;
   my $file = Practice::File->new;
   $dir->add_file($file);
   $file->add_dir($dir);
   return $dir;
}

sub f {
   my $dir = Practice::Dir->new;
   my $file = Practice::File->new;
   $dir->add_file($file);
   $file->add_dir($dir);
   return $file;
}

# This works fine.
# `$dir` is a dir with one file.
my $dir = d();


# XXX This fails.
# `$file`'s dir is `undef` even though it wasn't before we returned.
my $file = f();

[download]

The correct solution could be neither.

In reply to Re: Should I use weaken on an object attribute containing a reference to an object which contains reference back to original object? by ikegami
in thread Should I use weaken on an object attribute containing a reference to an object which contains reference back to original object? by nysus

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