#!/usr/bin/perl

use strict;
use warnings;
use utf8;
use Devel::Peek;
use Data::Dumper;
$Data::Dumper::Useqq = 1;

my %hash = (
    'clé' => 0,
);
my $key = (keys %hash)[0];
Dump($key);
print Dumper($key);

$hash{'clé'} = 1;
$key = (keys %hash)[0];

Dump($key);
print Dumper($key);

utf8::upgrade($key);
Dump($key);
print Dumper($key);

##</code><code>##

SV = PV(0x555ed17dfe60) at 0x555ed1809710
  REFCNT = 1
  FLAGS = (POK,pPOK,UTF8)
  PV = 0x555ed1993ed0 "cl\303\251"\0 [UTF8 "cl\x{e9}"]
  CUR = 4
  LEN = 5
$VAR1 = "cl\x{e9}";
SV = PV(0x555ed17dfe60) at 0x555ed1809710
  REFCNT = 1
  FLAGS = (POK,IsCOW,pPOK)
  PV = 0x555ed1909b10 "cl\351"
  CUR = 3
  LEN = 0
$VAR1 = "cl\351";
SV = PV(0x555ed17dfe60) at 0x555ed1809710
  REFCNT = 1
  FLAGS = (POK,pPOK,UTF8)
  PV = 0x555ed1825350 "cl\303\251"\0 [UTF8 "cl\x{e9}"]
  CUR = 4
  LEN = 10
$VAR1 = "cl\x{e9}";