| -----Original Message----- | From: boost-bounces@lists.boost.org | [mailto:boost-bounces@lists.boost.org] On Behalf Of John Maddock | Sent: 01 May 2006 10:42 | To: boost@lists.boost.org | Subject: Re: [boost] [SoC] multi precision arithmetic library | proposal. | | > Yes, I think there would be a positive response to an SOC | proposal in | > this area. You are correct, there is no multiprecision | > arithmetic support in Boost now. However, be aware that | there is some | > prior work already in the boost sandbox. You might want to have a | > look at these links: | > Finally, I'll mention that another possible project in this area | > would be to build a Boost implementation for the Decimal Arithmetic | > proposal. This is a proposal that IBM is making before the standard | > committee. That latest draft is at: | > | > http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2006/n1977.html | > | > It would be fabulous to have a Boost implementation of this proposal | > available. | | Very fabuluous indeed, but have you read the spec? | It make me quiver just to think about it! Since 'the student has all summer', I think that decimal is just a little ambitious! I think just getting infinite precision integers (and perhaps rationals too) in Boost would be a good achieveable target. I find it most diappointing that we have had several implementations in the sandbox but none have survived a review. I am uncertain what higher precision floating-point would be most useful in Boost. An exact (infinite precision) real like http://keithbriggs.info/xrc.html or a defined precision (typically several hundred decimal digits) like NTL RR, or just a higher (128-bit) precision like NTL quad_float, (potentially of interest to MSVC users who are limited to 64-bit doubles == long doubles without even an 80-bit option). Some 'not-so-nice' features of quad_float have popped-up recently - funny epsilon, thread-unsafe... (NB Also I believe NTL is GPL not Boost licence). It may be that these tools are mainly used once only to calculate coefficients, as John Maddock is doing for 'proper' math functions? And so there is less need for these in Boost? Potential users views? Paul -- Paul A Bristow Prizet Farmhouse, Kendal, Cumbria UK LA8 8AB Phone and SMS text +44 1539 561830, Mobile and SMS text +44 7714 330204 mailto: pbristow@hetp.u-net.com http://www.hetp.u-net.com/index.html http://www.hetp.u-net.com/Paul%20A%20Bristow%20info.html