gistfile1.txt

#!/usr/bin/perl

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

sub hoge {
    return;
}

sub fuga {
    return 1;
}

sub piyo {
    return {
        a => hoge(),
        b => fuga(),
    };
}

print Dumper piyo();

Odd number of elements in anonymous hash at /Users/mix3/tmp/sample.pl line 17.
$VAR1 = {
          'a' => 'b',
          '1' => undef
        };