Re: [boost] New Boost.XInt Library, request preliminary review

Subject: Re: [boost] New Boost.XInt Library, request preliminary review
From: Paul A. Bristow (pbristow_at_[hidden])
Date: 2010-03-26 13:41:21

> -----Original Message-----
> From: boost-bounces_at_[hidden] [mailto:boost-bounces_at_[hidden]] On Behalf Of Chad Nelson
> Sent: Friday, March 26, 2010 4:06 PM
> To: boost_at_[hidden]
> Subject: Re: [boost] New Boost.XInt Library, request preliminary review

> >> Hi! I'm a long-time user (and admirer) of the Boost libraries, and
> >> I've just uploaded a new one to the Boost Vault for consideration:
> >> the Extended Integer (XInt) library, a unlimited-precision integer
> >> library that I've been working on for the last few months. 

I'd leave doing work on docs and testing until you get more positive feedback.

Doxygen can work well (especially when used with Quickbook,
but needs to have useful comments in the C++ code to be more than a list of classes, functions...).
(I used to think Doxygen was used as an excuse not to write docs ;-)
> I did put an example in, in the documentation -- the Fibonacci example.

Sorry I didn't spot these - I expected to find in an /examples subfolder.

Using Quickbook, you can pick out 'snippets' from the source code (.hpp and .cpp)
and this makes the docs much nicer for users, and prevents the code and docs
getting out of sync - saving you work.
 
> > I've not been following the WG21 discussions of Bigger Integers -
> > perhaps you can summarise their response to N1744 (was is "we are too
> > busy dealing with C++0X?").
> 
> Unfortunately I don't know anything about their response, or where I
> could find it. I didn't even know they'd addressed it until last week,
> when I saw mention of n1692 and n1744 in some older posts to this list.

http://gmplib.org/list-archives/gmp-discuss/2006-January/002083.html

"
http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2004/n1692.pdf
http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2005/n1744.pdf
 
Unfortunately, both have been rejected...

(along with N2020 and N1641)

They have been rejected because we felt that they didn't really
address the issue.  At least that is the way I read the proposals. 
Of course, if there is a mature serious proposal I would support it.
"
is not encouraging, for reasons unclear.

http://www.linux2you.dk/JTC1/SC22/WG21/docs/papers/2008/n2598.html

gives the status of the above along with N1744 Michiel Slaters on which yours is based as "open" rather than rejected.

But should not necessarily deter you :-)

A working Boost library in widespread use might change things?

(But the ghost of GMP's GPL licence haunts Big Integer proposals.  As I've said elsewhere, a really good solution must
be switchable to use GMP, if your license requirements permit).

Paul

PS Would you collaborate with a GSoC student to do the Boost-style docs and tests, and more examples?

> > PS  I note it doesn't (yet) specialise std::numeric_limits?
> I've put it on the to-do list. 

I think NaN *is* meaningful for your integer type.
However this is a minor detail that can added later.