Some time ago there was some discussion about bit vectors. Perhaps someone
may find something worth copying here.

Steffen Beyer wrote:

>                http://www.perl.com/CPAN/authors/id/S/ST/STBEY/
....
>
> What's new in version 6.0:
> --------------------------
>
>  +  Splitted the Vector.pm module; separated XS and overloaded Perl
>     part for improved performance (reduces loading time for XS part).
>     (See also benchmark.pl in subdirectory "examples".)
>  +  Corrected the handling of numerical overflow in arithmetic methods
>     ("add()", "subtract()", "Multiply()", "from_Dec()", "new_Dec()").
>  +  Methods "add()" and "subtract()" now return the carry as well as
>     the overflow flag if called in list context (only the carry in
>     scalar context, as before).
>  +  Added two new methods "inc()" and "dec()", which return the overflow
>     flag (whereas "increment()" and "decrement()" return the carry
flag).
>     The new methods also allow to copy-and-increment/decrement in
addition
>     to in-place operation.
>  +  Methods "from_Dec()" and "new_Dec()" now allow you to enter large
>     positive numbers which will have the MSB set (this was forbidden
>     previously because these numbers are considered to be negative in
>     two's complement binary representation).
>
> Abstract:
> ---------
>
>     Bit::Vector is an efficient C library which allows you to handle
>     bit vectors, sets (of integers), "big integer arithmetic" (e.g.
>     for cryptography) and boolean matrices, all of arbitrary sizes.
>
>     The library is efficient (in terms of algorithmical complexity)
>     and therefore fast (in terms of execution speed) for instance
>     through the widespread use of divide-and-conquer algorithms.
>
>     The package also includes an object-oriented Perl module for
>     accessing the C library from Perl, and features overloaded
>     operators for maximum ease of use.
>
>     The C library can nevertheless be used stand-alone, without Perl.
....

Conrad Schneiker
(This note is unofficial and subject to improvement without notice.)