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

my @numbers = ( 0..20 );
my $index = 3;
my @expect = ( 0..2,4..20 );
use constant TEST => 0;

cmpthese(-2, {
	splice => sub {
		my @output = @numbers;
		splice @output, $index, 1;
		join("\0", @output) eq join("\0", @expect) or die if TEST;
	},
	grep => sub { # https://www.perlmonks.org/?node_id=11123877
		my @output = @numbers[ grep $_ != $index, 0 .. $#numbers ];
		join("\0", @output) eq join("\0", @expect) or die if TEST;
	},
});

__END__

            Rate   grep splice
grep    835107/s     --   -68%
splice 2575950/s   208%     --