ex(伪代码)：

# Imagine an array of weak references to objects
my @array = ( $obj1_ref,$obj2_ref,$obj3_ref );

# Some other code here causes the last strong reference
# of $obj2_ref to go out of scope.

# We now have the following array
@array = ( $obj1_ref,undef,$obj3_ref )

是否有一种方法可以使未定义的引用在数组未定义时自动从数组中删除？

我想要@array =($obj1_red,$obj3_ref).

编辑：

我尝试了这个解决方案但它不起作用：

#!/usr/bin/perl
use strict;
use warnings;

{
    package Object;
    sub new { my $class = shift; bless({ @_ },$class) }
}

{
    use Scalar::Util qw(weaken);
    use Data::Dumper;

    my $object = Object->new();

    my $array;
    $array = sub { \@_ }->( grep defined,@$array );

    {
        my $object = Object->new();
        @$array = ('test1',$object,'test3');
        weaken($array->[1]);
        print Dumper($array);
    }

    print Dumper($array);

输出：

$VAR1 = [
          'test1',bless( {},'Object' ),'test3'
        ];
$VAR1 = [
          'test1','test3'
        ];

undef不会自动从阵列中删除.

我错过了什么吗？

编辑2：

I also tried removing undefined values from the array in the DESTROY method of the object,but that doesn’t appear to work either. It appears that since the object is still technically not “destroyed” yet,the weak references are still defined until the DESTROY method is completed…