Experimental keys on scalar is now forbidden

[Anonymous Monk]

I used to access my hash of hashes with the following in my old Perl (in a foreach my $word loop):

my @variants = keys $hash{$word}{variants};

In Perl 5.24 I get the following error:

Experimental keys on scalar is now forbidden

What is the right way to write it now?

[haukex]

my @variants = keys $hash{$word}{variants};

What is the right way to write it now?

The "right" way to write it, or rather, the way that will work on any version of Perl 5, is:

my @variants = keys %{ $hash{$word}{variants} };

Update: See also perlreftut, perlref, perldsc, and Experimental push on scalar now forbidden.

As of Perl 5.24, you can also make use of the Postfix Dereference Syntax:

use 5.024;
my @variants = keys $hash{$word}{variants}->%*;

(Update 2: It's actually been present since 5.20, but it was still experimental then and had to be explicitly enabled.)

[huck]

I would use

my @variants = keys %{$hash{$word}{variants}};