Then please, implement a benchmark that exhibits the savings you are concerned about. 

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

our %hash = 'aaaaa' .. 'dzzzz';

cmpthese 1, {
    a => q[
        my @keys = keys %hash;
        my @vals = values %hash;
        my $x;
        $x = "$keys[ $_ ] :: $vals[ $_ ]" for 0 .. $#keys;
    ],
    b => q[
        my( $k, $v, $x );
        $x = "$k :: $v" while ( $k, $v ) = each %hash;
    ]
};

__END__
  s/iter    a    b
a   3.06   -- -41%
b   1.79  70%   --

[download]
Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error.
"Science is about questioning the status quo. Questioning authority".
In the absence of evidence, opinion is indistinguishable from prejudice.

In reply to Re^7: keys and values order on a hash by BrowserUk
in thread keys and values order on a hash by citromatik

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post, it's "PerlMonks-approved HTML":


  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.