Re: [Boost-users] Subject: Serialization, text_Xarchive Why doesn't work?

3 Aug 2006

      Is it possible that m_value is uninitialized?  It is a known
problem that many compilers can can write uninitialized
floating/double values to a text stream and then cannot
read them.  This topic is currently being discussd on
the developer's list - as it arises all the time.

Take a look a test_serial.txt with a text editor.
What does it look like?

Robert Ramey

tkachenkok@gmx.de wrote:
...
I've tried to write my first application with Boost.Serialization
library.
Here is the part of code, where the boost::text_iarchive throws an
exception "boost::archive::archive_exception" "what():  stream
error":
[code]
enum Origin {
    UNKNOWN=0,
    MEASURED,
    AVERAGE };
class OTCValue
{
friend class boost::serialization::access;
template<class Archive>
void serialize(Archive & ar, const unsigned int version)
{
ar & m_value;
ar & m_orig;
}
double m_value;
Origin m_orig;
        ...
};
         ...
const OTCValue val1=(*loaded.second.begin())->get_row(0)[0];
{
std::ofstream ofs("test_serial.txt");
boost::archive::text_oarchive oa(ofs);
oa << val1;
}
OTCValue val;
{
std::ifstream ifs("test_serial.txt");
boost::archive::text_iarchive ia(ifs);
ia >> val; // here is this exceptions thrown
}
        ...
[/code]
And here is a little bit different code, which works great:
[code]
enum Origin {
    UNKNOWN=0,
    MEASURED,
    AVERAGE };
class OTCValue
{
friend class boost::serialization::access;
template<class Archive>
void serialize(Archive & ar, const unsigned int version)
{
ar & m_value;
ar & m_orig;
}
double m_value;
Origin m_orig;
        ...
};
         ...
const OTCValue val1(5.5, MEASURED);
{
std::ofstream ofs("test_serial.txt");
boost::archive::text_oarchive oa(ofs);
oa << val1;
}
OTCValue val;
{
std::ifstream ifs("test_serial.txt");
boost::archive::text_iarchive ia(ifs);
ia >> val;
}
        ...
[/code]
What is the problem? The construction
(*loaded.second.begin())->get_row(0)[0] returns an OTCValue .
I have compiled the boost-1.33.1 from the sources (www.boost.org).
The project I've made is under KDevelop 3.2.2 (initially consol
"Hello World" application)
Operating System: SuSe Linux 10.0
Compiler: gcc version 4.0.2
I hope, that I've gave enouph information. If not, ask what aou need,
you are welcome.
Best regards,
and thanks to all!