#!/usr/bin/perl

use strict;
use warnings;

my @regexes = (qr/^.{0}$/, qr/^.{0,}$/, qr/^.{0,1}$/, qr/^.{,1}$/);

for my $re (@regexes) {
	printf "'' =~ /$re/: %s\n", '' =~ /$re/ ? 'true' : 'false';
}