use strict;
use warnings;

use Benchmark qw( cmpthese );

my %tests = (
   subst       => '$x =~ s/.//;',
   substr_lval => 'substr($x,0,1) = "";',
   substr_mod  => 'substr($x,0,1,"");',
   reverse     => '$x = reverse $x; chop($x); $x = reverse($x);',
   substr_copy => '$x = substr($x,1);',
);

for (values %tests) {
   $_ = 'use strict; use warnings; my $x = "|0|0|0|0|0|0|"; ' . $_;
}

cmpthese(-5, \%tests);