Re: [Boost-users] Serialization of infinite float

From: Robert Ramey (ramey_at_[hidden])
Date: 2007-08-10 21:19:47

This is a known issue with C++ standard i/o.  It is only related to 
serialization
to the extent that serialization depends upon C++ standard i/o.

This comes up on a regular basis. I'm considering trappnig attempts to
serialize NaNs as errors - as I think they always are.  But then I would 
have
to document the trap and how to override it as opposed to adding to
the document why this is not a serialization issue.

Robert Ramey

Arnstein Ressem wrote:
> Hi,
>
> I have run into a problem with the boost xml serialization of
> overflowing floats. On Linux these are being serialized as 'inf' into
> the xml files, but when reading the float back in it results in stream
> errors. I have searched the archives to find an answer to this, but
> without luck. The small program below has been compiled and run on
> 32-bit and 64-bit Linux (RedHat Enterprise Linux 4) with boost 1.33.1
> and 1.34.1. In every case it results in a stream error and the float
> can not be read back in from the xml file.
>
> Does anyone know if this is supposed to work ?
>
> #include <fstream>
> #include <boost/archive/xml_iarchive.hpp>
> #include <boost/archive/xml_oarchive.hpp>
>
> int main()
> {
>   const char fname[] = "float.xml";
>
>   float f = 1.0e+20*1.0e+20;
>
>   {
>     std::ofstream ofs(fname);
>     assert(ofs.good());
>     boost::archive::xml_oarchive oa(ofs);
>     oa << BOOST_SERIALIZATION_NVP(f);
>   }
>
>   {
>     std::ifstream ifs(fname);
>     assert(ifs.good());
>     boost::archive::xml_iarchive ia(ifs);
>     ia >> BOOST_SERIALIZATION_NVP(f);
>   }
>
>   return 0;
> }
>
> Best regards,
> Arnstein Ressem