It is often repeated that hashes in Perl do not preserve insertion order. Yet:

#!/usr/bin/perl

use strict;
use warnings;
use feature qw/say/;

my %hoh = (
    foo => { value => 'first' },
    bar => { value => 'second' },
    baz => { value => 'third' },
);

for my $elem (sort values %hoh) {
    say "value => " . $elem->{value};
}

[download]

Output:

value => first
value => second
value => third

[download]
<Reveal this spoiler or all in this thread>

Edit and clarification: I'm not saying that you should ever use this (in fact, I'm saying that you shouldn't, the comments below describe why). It looks like as if it really preserved insertion order, but actually the trick relies on implementation details (memory allocation) you can't (or shouldn't want to) control.

In reply to Hashes do preserve insertion order after all by kikuchiyo

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