Re: [Boost-users] [serialization] Archive reload

Subject: Re: [Boost-users] [serialization] Archive reload
From: Robert Ramey (ramey_at_[hidden])
Date: 2009-03-02 13:20:25

Ferllings wrote:
> Hello,
>
> I have a Class A with string attributes that I serialize in XML
> format:
> Class A {
> public:
>   string _nom;
>   string _prenom;
>   template<class Archive>
>   void serialize(Archive& ar, const unsigned in version){
>     ar & boost::serialization::make_nvp("Nom", _nom);
>     ar & boost::serialization::make_nvp("Prenom", _prenom);
>   }
> }
>
> The object is correctly saved using this code:
>
> A _a;
>
> void save() const
> {
>     ...
>     oTextArchive::xml_oarchive oTextArchive(ofile);
>     oTextArchive << make_nvp("A", _a);
>     ...
> }
>
> But I want to reload the object, the A attributes aren't updated and
> keep the previous values:
>
> void load()
> {
>     ...
>     iTextArchive::xml_oarchive iTextArchive(ifile);
>     iTextArchive >> make_nvp("A", _a);
>     ...
> }
>
> The only way I found to reload my object is to use an temporary
> object:
> void load()
> {
>     ...
>     A _tmp;
>     iTextArchive::xml_oarchive iTextArchive(ifile);
>     iTextArchive >> make_nvp("A", _tmp);
>     _a = _tmp;
>     ...
> }
>
> Why can't I update the object directly?
>
> Thanks for your help.