sub length_in_grapheme_clusters {
    my $length;
    $length++ while $_[0] =~ m/\X/g;
    return $length;
}

##</code><code>##

sub length_in_grapheme_clusters {
    my $length = () = $_[0] =~ /\X/g;
    return $length;
}

##</code><code>##

sub length_in_grapheme_clusters {
    return 0+( () = $_[0] =~ /\X/g );
}