Yes, but try this one:

use Data::Denter;

my @matrix = ();
$matrix[2]->[3]= "What's goin on?";

print "Before grep:\n", Denter(\@matrix);

#print grep{ /Huh?/ }@$_ for @matrix;
print map { grep{ /Huh?/ }@$_ } @matrix;
print "\nAfter grep:\n", Denter(\@matrix);
[download]

Where is the bug then in Data::Dumper or in Data::Denter or in map, grep, for or autovivification?

$anarion=\$anarion;

s==q^QBY_^=,$_^=$[x7,print