#! /usr/bin/perl -w

use strict;
use Benchmark qw/cmpthese/;

my @x = qw/a b c/;

sub with_splice {
    my $aref = shift;
    splice( @$aref, 0, -1 );
}

sub with_range {
    my $aref = shift;
    @{$aref}[0 .. ($#{$aref} - 1)]
}

print 'range ',  join( ' ' => with_range(\@x) ), "\n";
print 'splice ', join( ' ' => with_splice(\@x) ), "\n";

my @z = 0 .. 100_000;

cmpthese(
    shift || 2_000_000, 
    {
        short_splice => sub { with_splice(\@x) },
        short_range  => sub { with_range (\@x) },
    }
);

cmpthese(
    shift || 1_000, 
    {
        long_splice  => sub { with_splice(\@z) },
        long_range   => sub { with_range (\@z) },
    }
);
__RESULTS__
range a b
splice a b
Benchmark: timing 2000000 iterations of short_range, short_splice...
short_range:  9 wallclock secs ( 7.83 usr +  0.00 sys =  7.83 CPU) @ 255489.02/s (n=2000000)
short_splice:  5 wallclock secs ( 5.06 usr +  0.01 sys =  5.07 CPU) @ 394453.00/s (n=2000000)
                 Rate  short_range short_splice
short_range  255489/s           --         -35%
short_splice 394453/s          54%           --
Benchmark: timing 1000 iterations of long_range, long_splice...
long_range: 40 wallclock secs (39.73 usr +  0.02 sys = 39.74 CPU) @ 25.16/s (n=1000)
long_splice:  0 wallclock secs ( 0.01 usr +  0.00 sys =  0.01 CPU) @ 128000.00/s (n=1000)
            (warning: too few iterations for a reliable count)
                Rate  long_range long_splice
long_range    25.2/s          --       -100%
long_splice 128000/s     508600%          --