use v5.14; use Scalar::Util qw/refaddr/; my @closures; my @nonclosures; for my $i (qw/ a b c /) { push @closures, sub { $i }; push @nonclosures, sub { 42 }; } say join "|" => map refaddr($_), @closures; say join "|" => map refaddr($_), @nonclosures;