Re: [boost] Spurious warning in lexical_cast.hpp
From: Paul A Bristow
From: Alexander Nasonov
I have not get a chance to study the subject yet but I wonder why don't you just set a precision to some huge number, say 32767 or INT_MAX?
This would be hugely wasteful as it would convert everything with 32767 decimal digits, of which, even with 256-bit floating point, 32267 digits would be noise!
<Nit>That implies 500 decimal digits would be non-noise. Actually the formula suggests that a 256 bit mantissa would only need 79 decimal digits. -- Martin Bonner Martin.Bonner@Pitechnology.com Pi Technology, Milton Hall, Ely Road, Milton, Cambridge, CB4 6WZ, ENGLAND Tel: +44 (0)1223 203894
| -----Original Message----- | From: boost-bounces@lists.boost.org | [mailto:boost-bounces@lists.boost.org] On Behalf Of Martin Bonner | Sent: 04 August 2006 12:29 | To: boost@lists.boost.org | Subject: Re: [boost] Spurious warning in lexical_cast.hpp | | From: Paul A Bristow | > From: Alexander Nasonov | >> | >> I have not get a chance to study the subject yet but I | wonder why | >> don't you just set a precision to some huge number, say 32767 or | >> INT_MAX? | > | > This would be hugely wasteful as it would convert everything with | > 32767 decimal digits, of which, even with 256-bit floating point, | > 32267 digits would be noise! | | <Nit>That implies 500 decimal digits would be non-noise. | Actually the | formula suggests that a 256 bit mantissa would only need 79 decimal | digits. <Nitwit> ;-) I remembered the result for 128-bit, and substracted 40, but then over-hyped to 256-bit! But you got the point. </nitwit> - for now at least... Paul
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Martin Bonner -
Paul A Bristow