Perl strings are sequences of Unicode code points, not sequences of bytes. (Well, I think they're stored internally as plain bytes if possible.) 
use Encode qw( encode_utf8 );
my $x = chr(1 << 63);
print length($x), "\n";
print length(encode_utf8($x)), "\n";
print "yep\n" if $x gt chr(255);

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Output: 
Use of code point 0x8000000000000000 is deprecated; the permissible ma
+x is 0x7FFFFFFFFFFFFFFF at foo line 2.
1
13
yep

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In reply to Re^5: Sort undef by Anonymous Monk
in thread Sort undef by Anonymous Monk

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