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From: Paul A Bristow (pbristow_at_[hidden])
Date: 2006-05-03 16:43:52


| -----Original Message-----
| From: boost-bounces_at_[hidden]
| [mailto:boost-bounces_at_[hidden]] On Behalf Of Andras Erdei
| Sent: 03 May 2006 21:24
| To: boost_at_[hidden]
| Subject: Re:
| [boost][serialization]Serialisation/deserialisationoffloating
| -point values
| On 5/2/06, Paul A Bristow <pbristow_at_[hidden]> wrote:
| >
| > IMO The real issue here is not whether round-tripping
| should work, but that
| > input from a long enough decimal digit string should
| always give you the nearest floating-point representation.
| >
| > For float this is true, and for double is almost (but not quite) true.
| [i've only read the abstract below, not the whole article,
| William D. Clinger
| How to read floating point numbers accurately Proceedings
| of the ACM SIGPLAN 1990 conference on Programming language
| design and implementation

I've actually read the article!

 - though I must confess I didn't understand it all ;-(

However 'correct' input seems to be achieved by gcc,
and by MSVC for float, and almost for double.

So I stick to my guess that it is a bug.

It shouldn't be a feature IMO.

But I don't think there is anything that we should do (except be aware of
the potential problem).

It is up to Microsoft and/or Dinkumware to do nothing or resolve.


Paul A Bristow
Prizet Farmhouse, Kendal, Cumbria UK LA8 8AB
+44 1539561830 & SMS, Mobile +44 7714 330204 & SMS

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