#!/usr/bin/perl
use strict;
use warnings;

use Encode qw( _utf8_on );
use Devel::Peek qw( Dump );

my $foo;
$foo = 'foo';
Dump($foo);

my $bar;
_utf8_on($bar);
$bar =  'bar';  
Dump($bar);

__END__
Outputs: 

SV = PV(0x1801660) at 0x180b59c
  REFCNT = 1
  FLAGS = (PADBUSY,PADMY,POK,pPOK)
  PV = 0x365f20 "foo"\0
  CUR = 3
  LEN = 4
SV = PV(0x1801678) at 0x180b56c
  REFCNT = 1
  FLAGS = (PADBUSY,PADMY,POK,pPOK)
  PV = 0x300bd0 "bar"\0
  CUR = 3
  LEN = 4