C:\test>1036622 -N=1e3
                  Rate grep build_new_array offset_copy for_splice edit_in_place
grep             678/s   --            -22%        -27%       -34%          -41%
build_new_array  870/s  28%              --         -6%       -15%          -24%
offset_copy      929/s  37%              7%          --        -9%          -19%
for_splice      1024/s  51%             18%         10%         --          -11%
edit_in_place   1150/s  70%             32%         24%        12%            --

C:\test>1036622 -N=1e4
                  Rate for_splice grep offset_copy build_new_array edit_in_place
for_splice      71.5/s         --  -9%        -11%            -22%          -39%
grep            78.7/s        10%   --         -2%            -14%          -33%
offset_copy     80.6/s        13%   2%          --            -12%          -31%
build_new_array 91.3/s        28%  16%         13%              --          -22%
edit_in_place    117/s        64%  49%         46%             29%            --

C:\test>1036622 -N=1e5
                  Rate for_splice grep build_new_array offset_copy edit_in_place
for_splice      1.29/s         -- -75%            -83%        -84%          -85%
grep            5.12/s       296%   --            -33%        -35%          -42%
build_new_array 7.68/s       494%  50%              --         -3%          -14%
offset_copy     7.88/s       509%  54%              3%          --          -11%
edit_in_place   8.89/s       587%  74%             16%         13%            --

C:\test>1036622 -N=1e6
                s/iter for_splice grep build_new_array offset_copy edit_in_place
for_splice        77.9         -- -98%            -98%        -99%          -99%
grep              1.39      5503%   --            -14%        -18%          -38%
build_new_array   1.20      6379%  16%              --         -5%          -28%
offset_copy       1.14      6737%  22%              6%          --          -24%
edit_in_place    0.868      8884%  60%             39%         31%            --


##</code><code>##

:
#! perl -slw
use strict;
use Benchmark qw[ cmpthese ];

our $N //= 1e3;
our $I //= -1;

our @as;
@{ $as[ $_ ] } = 1 .. $N for 0 .. 4;

cmpthese $I, {
    for_splice => q[
        my $ar = $as[0];
        $ar->[$_] =~ /9/ and splice @$ar, $_, 1 for reverse 0 .. $#$ar;
        $I == 1 and print "0: ", "@$ar";
    ],
    grep => q[
        my $ar = $as[1];
        @$ar = grep !/9/, @$ar;
        $I == 1 and print "1: ", "@$ar";
    ],
    offset_copy => q[
        my $ar = $as[2];
        my $o = 0;
        for( 0 .. $#$ar ) {
            $ar->[$_-$o] = $ar->[$_];
            $ar->[ $_ ] =~ /9/ and ++$o;
        }
        $#$ar = $#$ar - $o;
        $I == 1 and print "2: ", "@$ar";
    ],
    build_new_array=>q[
        my $ar = $as[3];
        my @b;
        for( @$ar ) {
            push @b, $_ unless /9/;
        }
        $I == 1 and print "3: ", "@b";
    ],
    edit_in_place=>q[
        my $ar = $as[4];
        my $o = 0;
        for( @$ar ) {
            $ar->[$o++] = $_ unless /9/;
        }
        $#$ar = $o - 1;
        $I == 1 and print "4: ", "@$ar";
    ],
};


##</code><code>##

C:\test>1036622 -N=1e3
                  Rate grep build_new_array offset_copy edit_in_place for_splice
grep            1464/s   --            -20%        -43%          -61%       -65%
build_new_array 1820/s  24%              --        -29%          -52%       -56%
offset_copy     2578/s  76%             42%          --          -32%       -38%
edit_in_place   3803/s 160%            109%         48%            --        -8%
for_splice      4144/s 183%            128%         61%            9%         --

C:\test>1036622 -N=1e4
            (warning: too few iterations for a reliable count)

                 Rate  grep build_new_array offset_copy edit_in_place for_splice
grep            159/s    --            -25%        -44%          -62%       -66%
build_new_array 212/s   33%              --        -26%          -49%       -54%
offset_copy     287/s   80%             36%          --          -31%       -38%
edit_in_place   419/s  163%             98%         46%            --       -10%
for_splice      464/s  191%            119%         62%           11%         --

C:\test>1036622 -N=1e5
                  Rate grep build_new_array offset_copy for_splice edit_in_place
grep            15.4/s   --            -22%        -50%       -69%          -70%
build_new_array 19.8/s  28%              --        -36%       -60%          -62%
offset_copy     31.0/s 102%             57%          --       -37%          -40%
for_splice      49.6/s 222%            151%         60%         --           -4%
edit_in_place   51.6/s 235%            161%         66%         4%            --

C:\test>1036622 -N=1e6
                  Rate grep build_new_array offset_copy edit_in_place for_splice
grep            1.60/s   --            -23%        -51%          -70%       -71%
build_new_array 2.06/s  29%              --        -37%          -61%       -62%
offset_copy     3.28/s 105%             59%          --          -38%       -40%
edit_in_place   5.26/s 229%            155%         60%            --        -4%
for_splice      5.49/s 243%            166%         67%            4%         --