BitSet(N) for large N

Did I see somewhere here or elsewhere some routines or library for read/write of an arbitrary-large array of “bits”.

Something like STL bitset … I did see that there is an STL port (attempt?) but is it clean/easy to install? Other alternatives?

Thanks,
John

Here's the STL port (with bitset): http://andybrown.me.uk/wk/2011/01/15/the-standard-template-library-stl-for-avr-with-c-streams/.