Re: [boost] Portable binary integers [was generic polyvalent I/O]

From: Greg Colvin (gcolvin_at_[hidden])
Date: 2000-11-16 11:59:48

From: Beman Dawes <beman_at_[hidden]>
> At 10:48 PM 11/15/2000 +0100, Jens Maurer wrote:
> 
>  >> 3_
>  >> binary could be made a bit portable...
>  >
>  >This would be a portable_binary_writer then.
>  >
>  >Hm... I dimly remember that we had some portable integers in boost,
>  >but I can't find them now.  Beman?
> 
> IIRC, Mark Borgerding, Darin Adler, and I all discussed portable binary 
> integer classes we use in our own work.  They range from minimalist to much 
> more complete, big endian only to both big and little endian.  Some people 
> think that portable integer classes should act like full-fledged arithmetic 
> objects, others (or at least me) see them as representation holders useful 
> for I/O but to be converted to built-in types for any arithmetic 
> operations. Beyond data portability, maximum code portability requires such 
> classes be POD's and that argues for minimalist rather than maximalist 
> designs, IMO. Still other people viewed the need in terms of operations on 
> streams, without a need for actual objects.
> 
> Although there was no consensus on those kinds of design questions, there 
> did seem to be consensus by those who had used them that portable binary 
> integer classes are very useful or even essential for lots of practical 
> applications.
> 
> It would be really nice if someone good at sifting through disparate 
> requirements would put together a proposal broad enough to meet multiple 
> people's needs but narrow enough not to focus on what is basically a pretty 
> simple need.
> 
> Moving beyond integers, http://www.ietf.org/rfc/rfc1832.txt specifies 
> portable formats for other data types.  Personally, I'd be happy with 
> integers, at least as a start.

The last time I needed to do this I went with a big-endian encoding
of a full set of integers and reals, encoded so that they would sort
correctly with memcmp.