use utf8;
#use encoding 'utf8';
use Devel::Peek;

my $s = "ö";         # character string
Dump $s;

utf8::encode($s);    # byte string c3 b6 (UTF-8 encoded ö); utf8 flag off
Dump $s;

my $s2 = $s . "ö";   # implicit upgrade of $s
Dump $s2;