use HTML::Entities qw(decode_entities);
use Devel::Peek;
Dump decode_entities "ü";
Dump decode_entities "€";
__END__

SV = PV(0x5060c8) at 0x5051e8
  REFCNT = 1
  FLAGS = (TEMP,POK,pPOK)
  PV = 0x510920 "\374"\0
  CUR = 1
  LEN = 16
SV = PV(0x5060c8) at 0x5051e8
  REFCNT = 1
  FLAGS = (TEMP,POK,pPOK,UTF8)
  PV = 0x510920 "\342\202\254"\0 [UTF8 "\x{20ac}"]
  CUR = 3
  LEN = 16