{ # X! and x!
  my $t = 'C[3]  x!8 C[2]';
  my @a = (0x73..0x77);
  my $p = pack($t, @a);
  is($p, "\x73\x74\x75\0\0\0\0\0\x76\x77");
  my @b = unpack $t, $p;
  is(scalar @b, scalar @a);
  is("@b", "@a", 'x!8');
  $t = 'x[5] C[6] X!8 C[2]';
  @a = (0x73..0x7a);
  $p = pack($t, @a);
  is($p, "\0\0\0\0\0\x73\x74\x75\x79\x7a");
  @b = unpack $t, $p;
  @a = (0x73..0x75, 0x79, 0x7a, 0x79, 0x7a);
  is(scalar @b, scalar @a);
  is("@b", "@a");
}