sub return_ref {
    return if rand < 0.3;
    my %hash;
    $hash{foo} = 'bar' if rand < 0.5;
    return \%hash;
}

my $ref = return_ref();
if (ref($ref) eq 'HASH' and %$ref) {
    print "We have a non-empty hash reference.\n";
}
else {
    print "No hash reference, or empty hashref.\n";
}