substr can be used as an lvalue: 
my $bytes = length( $bits );

for (my $offset = 0; $offset < $bytes; $offset += 4096) {
    my $chunk = 4096;
    $chunk = $bytes - $offset
        if $offset + $bytes > $bytes;

    substr($bits, $offset, $bytes) = ~ substr($bits, $offset, $bytes);
}

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In reply to Re: In-place bitwise NOT? by snoopy
in thread In-place bitwise NOT? by BrowserUk

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