my $t = threads->new(\&make, a => 'A', b => 'B') ; my $o = $t->join() ;
  show('main', $o) ;

  sub make {
    my %s : shared = @_ ;
    my $m : shared = bless \%s, "MADE" ;
    show('thread', $m) ;
    return $m ;
  } ;

  use Scalar::Util qw(reftype) ;

  sub show {
    my ($t, $x) = @_ ;
    printf "%20s: %s", $t, $x ;
    my $r = reftype($x) || '' ;
    if ($r eq 'SCALAR') { print " = ", defined($$x) ? "'$$x'" : 'undef' ;                        } ;
    if ($r eq 'ARRAY')  { print " = [", join(", ", @$x), "]" ;                                   } ;
    if ($r eq 'HASH')   { print " = {", join(", ", map { "$_ => $$x{$_}" } sort keys %$x), "}" ; } ;
    print "\n" ;
  } ;