use warnings;
use strict;
use Benchmark qw/cmpthese/;

my @array = ( 'a'..'t' );
my %hash = map { $_ => $array[$_] } 0..$#array;
my $index = 3;
my $expect = 'abcefghijklmnopqrst';
use constant TEST => 0;

cmpthese(-2, {
	splice => sub {
		my @output = @array;
		splice @output, $index, 1;
		join("", @output) eq $expect or die if TEST;
	},
	hash_slice => sub {
		my %ha; @ha{0..$#array} = @array;
		delete $ha{$index};
		my @output = @ha{ sort {$a <=> $b} keys %ha };
		join("", @output) eq $expect or die if TEST;
	},
	swap => sub {
		my @output = @array;
		$output[$index] = pop @output;
		join("", sort @output) eq $expect or die if TEST;
	},
	prehash_del => sub {
		my %ha = %hash;
		delete $ha{$index};
		my @output = @ha{ sort {$a <=> $b} keys %ha };
		join("", @output) eq $expect or die if TEST;
	},
	prehash_local => sub {
		delete local $hash{$index};
		my @output = @hash{ sort {$a <=> $b} keys %hash };
		join("", @output) eq $expect or die if TEST;
	},
	prehash_grep => sub {
		my @output = @hash{ sort {$a <=> $b}
			grep { $_ != $index } keys %hash };
		join("", @output) eq $expect or die if TEST;
	},
	outhash => sub {
		my %output = %hash;
		delete $output{$index};
		join("", @output{ sort {$a <=> $b} keys %output }) eq $expect
			or die if TEST;
	},
});

__END__

                  Rate hash_slice prehash_del prehash_local prehash_grep outhash swap splice
hash_slice    127891/s         --        -10%          -40%         -50%    -68% -85%   -85%
prehash_del   142822/s        12%          --          -33%         -45%    -64% -83%   -84%
prehash_local 214633/s        68%         50%            --         -17%    -46% -75%   -75%
prehash_grep  258191/s       102%         81%           20%           --    -36% -70%   -70%
outhash       400518/s       213%        180%           87%          55%      -- -53%   -54%
swap          847448/s       563%        493%          295%         228%    112%   --    -2%
splice        868423/s       579%        508%          305%         236%    117%   2%     --