Re: Serialization of an instance of a Derived Template Class

From: Pritam Gharat (pritam01gharat_at_[hidden])
Date: 2019-11-01 18:48:37

On Fri, Nov 1, 2019 at 3:51 PM Robert Ramey via Boost-users <
boost-users_at_[hidden]> wrote:

> On 11/1/19 4:46 AM, Pritam Gharat via Boost-users wrote:
> > Hi Robert,
> >
> > I have gone through the documentation. Below is the list of things I did
> > for serialization and deserialization.
> >
> >  1. Define serialize function in the class whose instances I wish to
> >     serialize. In my example it is ObjectNew which has pointers of type
> >     Bar_A and Foo_A. Both are base classes and the pointers of these
> >     pointers point to instances of theri derived classes.
> Not sure I'm getting this.  So we have
>         struct Bar_A_base ...
>         struct Foo_A_base ...
>
>         struct Bar_A_derived : public Bar_A_base ...
>         struct Foo_A_base : public Bar_A_base ...
>
>         struct ObjectNew {
>                 Bar_A_base *m_bar_a;
>                 Foo_A_base *m_foo_a;
>                 ...
>                 template<class Archive>
>                 void serialize(Archive & ar, const unsigned in version){
>                         ar & m_bar_a;
>                         ar & m_foo_a;
>                 }
>         };
>
> Right?
>

Yes. Something similar to that. I am attaching the header files for the
class definitions.

> >     So I have
> >     serialize function defined for Bar_A, Foo_A and all their derived
> >     classes (which includes Foo_C, Foo_D, Bar_B, Bar_C).
> sounds good
> >  2. Call to boost::serialization::base_object in the serialize function
> >     of derived classes which in turn calls serialize function of the
> >     corresponding base classes.
> sounds good
> >  3. For classes with non-defualt constructor, I have over-ridden
> >     save_construct_data and load_construct_data functions.
> sounds good
> >  4. Registering derived classes whose instances are pointed by pointers
> >     with types of their base classes using BOOST_CLASS_EXPORT.
> sounds good
> >  5. And finally use boost::archive::text_oarchive and
> >     boost::archive::text_iarchive for serialization and deserialization.
>
> sounds good
> > Please let me know if I have missed something or I am doing something
> wrong.
>
> That sounds about right.
> >
> > Pritam Gharat
> >
> > On Thu, Oct 31, 2019 at 5:13 PM Robert Ramey via Boost-users
> > <boost-users_at_[hidden] <mailto:boost-users_at_[hidden]>>
> wrote:
> >
> >     Have you read the documentation?
> >
> >     Robert Ramey
> >
> >     On 10/31/19 2:47 AM, Pritam Gharat via Boost-users wrote:
> >      > Hi,
> >      >
> >      > I am using Boost to serialize pointers of a base class which
> >     points to
> >      > instances  of a derived template class. I am using boost 1.7.0 and
> >      > running it on Ubuntu 16.04.
> >      >
> >      > The source code of the example is available at
> >      > https://github.com/PritamMG/Boost-Serialization-Example
> >      >
> >      > My example has a base class Bar_A (definition available in
> >      > include/Abstract.hpp) which has a virtual function toStr(). It
> >     has two
> >      > derived classes Bar_B and Bar_C. Bar_B is a template class.
> >      > I have registered the derived classes in sc/Test.cpp. Class
> >     ObjectNew
> >      > (include/Object.hpp) has a member pointer of type Bar_A which
> >     points to
> >      > instances of classes Bar_B and Bar_C.
> >      >
> >      > I get an error as "unregistered class".  I am not sure for which
> >     class
> >      > do I get this error message.
> >      >
> >      > There is also an issue of non-default. If Bar_B does not have a
> >     default
> >      > constructor, save_construct_data and load_construct_data are
> >     over-ridden
> >      > and there I run into an error "too many template-parameter-lists".
> >      >
> >      > How do I define these functions?
> >      >
> >      > Thanks,
> >      > Pritam
> >      >
> >      >
> >      >
> >      >
> >      > _______________________________________________
> >      > Boost-users mailing list
> >      > Boost-users_at_[hidden] <mailto:Boost-users_at_[hidden]>
> >      > https://lists.boost.org/mailman/listinfo.cgi/boost-users
> >      >
> >
> >
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