wantarray should perhps be called something like callcontext. For this purpose Perl has three contexts: void, scalar and list, and wantarray is undef, false and true.

Note in general that in list context a hash turns into an array in any case - think for example what happens when you pass a hash into a sub. To that extent hashes and arrays are interchangeable.

Consider this:

use warnings;
use strict;
use Data::Dumper;

my %hash = (first => '1', second => '2');

print "Original: " . Dumper (\%hash);

my %newHash = %{inAndOut (%hash)};

print "\nnew hash: " . Dumper (\%newHash);


sub inAndOut {
  my (%hash) = @_;
  
  print "\nin sub: " . Dumper (\%hash);
  return {%hash};
}
[download]

prints:

Original: $VAR1 = {
          'first' => '1',
          'second' => '2'
        };

in sub: $VAR1 = {
          'first' => '1',
          'second' => '2'
        };

new hash: $VAR1 = {
          'first' => '1',
          'second' => '2'
        };
[download]