Re: [Boost-users] Serialization newbie, memory being overwritten?

Subject: Re: [Boost-users] Serialization newbie, memory being overwritten?
From: Robert Ramey (ramey_at_[hidden])
Date: 2012-11-27 02:27:26

Lasse Laursen wrote:
> Hello to you,
>
> I wonder if you might be able to solve this conundrum I've been
> pondering. The boost (1.51) serialization library is giving me some
> trouble. I've been battling back and forth with the library, and I'm
> beginning to think I'm missing some key element.
>
> At first, I had issues to just getting things written out to a file
> without crashes. As far as I could tell, this particular problem was
> compounded by the fact, that I tried to simplify my code by just
> writing a single primitive referenced by a pointer to an object
> containing said primitive. As I've since come to learn, serializing
> pointed-to primitives is apparently not trivial.
>
> I have since, gotten the serialization class to properly write out a
> few simple member primitives from my class, but when I read them back
> using the exact same function, it seems as though a lot - if not all
> - of the pre-existing data in the object, which I am not serializing,
> gets overwritten.
>
> As far as I have been able to tell from the tutorials, I am doing
> everything exactly by the book. I was also concerned that maybe boost
> doesn't allow partial serialization, but this shouldn't be an issue
> either as far as I can tell. I must be making some sort of colossal
> mistake that I just cannot see.
>
> My in and out code is fairly straight forward:
>
> std::string streamPath = PTMFilePath.string();
> std::ifstream ifs(streamPath);
> boost::archive::xml_iarchive ia(ifs);
>
> ia >> BOOST_SERIALIZATION_NVP(aStream);

try

ia >> aStream;

>
> -----
>
> std::string streamPath = PTMFilePath.string();
> std::ofstream ofs(streamPath);
> boost::archive::xml_oarchive oa(ofs);
>
> oa << BOOST_SERIALIZATION_NVP(aStream);

oa << aStream;

>
> ------
>
> My serialization function:
>
> template<class Archive>
> void serialize(Archive &ar, const unsigned int file_version)
> {
> ar & BOOST_SERIALIZATION_NVP(nrOfSamples);
> }
>
> ------
>
> aStream is a pointer to a custom class, where I have allowed boost
> access. I am really confused as to what is causing this. Both pointed
> to data and regular primitives in the aStream class are wiped/altered
> as soon as the program enteres the serialize function, and even
> before the actual data seems to be read.
>
> I must be overlooking something really basic here. I hope someone can
> whack me with the solution stick...
>
> Thanks,
> Lasse