Re: [Boost-users] serialization, 1.34/1.35 difference: serializing a vector

From: Filip Peters (filippeters_at_[hidden])
Date: 2008-04-03 15:09:27

Huh? I just got the whole trunk, and built it.
Still the same problem: it can't read in std::vector<int> created with 1.34.1

Anyway how would a fix in trunk help?
-I can't use the released version 1.35, as it can't read in older files.
-I can't use trunk in our program, only released/tested versions. I just tried compiling with trunk, seems there are some other issues in other libraries that would take some work. (something went missing in the signals library)

Yes, I can add item_version into the optimised versions of vector.hpp, but how is it going to work in 1.36?
If you'd tell how you would fix it in the 1.35 version, I could use just that fix in our version, untill 1.35.1 or 1.36 comes out. Without ending up with our own branched version that's always incompatible with the released versions.

thanks,
Filip Peters

----- Original Message ----
From: Robert Ramey <ramey_at_[hidden]>
To: boost-users_at_[hidden]
Sent: Thursday, April 3, 2008 8:32:52 AM
Subject: Re: [Boost-users] serialization, 1.34/1.35 difference: serializing a vector

Looks like the trunk version is already fixed.

Robert Ramey

"Filip Peters" <filippeters_at_[hidden]> wrote in message 
news:753101.4971.qm_at_web30701.mail.mud.yahoo.com...
I looked a bit deeper into the code and found this:

in 1.34.1, a vector would use the code from collections_save_imp.hpp,
which contains the following:
    unsigned int count = s.size();
    ar <<  BOOST_SERIALIZATION_NVP(count);

    if(3 < ar.get_library_version()){
        const unsigned int item_version = version<
            BOOST_DEDUCED_TYPENAME Container::value_type
        >::value;
        ar << BOOST_SERIALIZATION_NVP(item_version);
    }

in 1.35.0, there is an "optimized" version in vector.hpp,

    const collection_size_type count(t.size());
    ar << BOOST_SERIALIZATION_NVP(count);
   if (!t.empty())
      ar << make_array(detail::get_data(t),t.size());

without the item_version.
Loading a vector of a type like int or double, created in 1.34 won't work in 
1.35.

Filip Peters.

Haven't used boost's trac before, but I'll enter it tomorrow.

In the meantime, adding item_version into the optimized versions seems to 
solve my problem, except I have to make sure it doesn't break in the next 
version.

----- Original Message ----
From: Robert Ramey <ramey_at_[hidden]>
To: boost-users_at_[hidden]
Sent: Wednesday, April 2, 2008 6:30:01 PM
Subject: Re: [Boost-users] serialization, 1.34/1.35 difference: serializing 
a vector

Hmm  I don't recal where that might have come from.  Open a TRAK item.

Robert Ramey
"Filip Peters" <filippeters_at_[hidden]> wrote in message
news:859190.51711.qm_at_web30705.mail.mud.yahoo.com...
I just tried serializing a simple vector,
std::vector<unsigned int> vectortest;

If I serialize out in 1.34, I can't read it in in 1.35.
xml result from 1.35:
<vectortest>
    <count>3</count>
    <item>1</item>
    <item>2</item>
    <item>3< /item>
</vectortest>

from 1.34:
<vectortest>
    <count>3</count>
    <item_version>0</item_version>
    <item>1</item>
&n bsp;  <item>2</item>
    <item>3</item>
</vectortest>

Notice the item_version, this causes an exception when reading it in with
1.35....
I need a way to get the behavior from 1.34 back....
Otherwise my files aren't readable anymore.

small testprogram:

#include <boost/config.hpp>

#include <boost/archive/xml_oarchive.hpp>
#include <boost/archive/xml_iarchive.hpp>
//#include <boost/archive/binary_iarchive.hpp>
//#include <boost/archive/binary_oarchive.hpp>

#include <boost/serialization/vector.hpp>
#include <boost/serialization/export.hpp>
#include <fstream>
#include <iomanip>

int _tmain(int argc, _TCHAR* argv[])
{

    std::vector<unsigned int> testvector;
    testvector.push_back(1.);
    testvector.push_back (2.);
    testvector.push_back(3.);

//this in 1.34
        std::ofstream ofs( "testing2.txt", std::ios::binary ) ;
        boost::archive::xml_oarchive oa(ofs);
        oa << boost::serialization::make_nvp("vectortest", testvector);
        ofs.close();

//do this in 1.35
    try{
        std::ifstream ofs( "testing2.txt", std::ios::binary ) ;
        boost::archive::xml_iarchive ia(ofs);
        ia >> boost::serialization::make_nvp("vectortest", testvector2);
      &nb sp; ofs.close();
    }
    catch(boost::archi ve::archive_exception testexception){
    //reading a file from 1.34, will end up here
        std::string error = testexception.what();
    }

return 0;
}

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