Re: [Boost-users] Boost serialization: how to register template derivedclass

From: Lifshitz, Yair (yair.lifshitz_at_[hidden])
Date: 2008-05-20 07:32:19

Hi,
 
I hope what I'm saying here makes sense and won't be considered
flooding.
While trying to check the reason for BOOST_CLASS_EXPORT not working with
templates, I found out the problem is simply a preprocessor issue - it
treats each comma as a seperation between values, so 
it treats a template (as below) as two inputs (and the MACRO accepts
only one).
We implemented BOOST_CLASS_EXPORT_WITH_TWO_VALS, and it worked fine with
the template argument below, saving us the need to expand the macro for
each instantiation.
Is there anything we're missing here? Is support for this planned in
future Boost releases?
 
Thanks for your time,
 
Yair Lifshitz
Intel Israel
 
 ----- Forwarded Message ----
From: Robert Ramey <ramey_at_[hidden]>
To: boost-users_at_[hidden]
Sent: Thursday, May 8, 2008 7:49:08 AM
Subject: Re: [Boost-users] Boost serialization: how to register template
derivedclass

what you would really need is something like

 

BOOST_CLASS_EXPORT(KukuBase<int, 5>);

 

BUT the the shorthand macro BOOST_CLASS_EXPORT doesn't like template
instantiations so 

you'll have to expand the macro "by hand" for the class for each set of
template

parameters used.  This is explained in the manual.

 

Robert Ramey

 

"ari vol" <avf99avf_at_[hidden]> wrote in message
news:9202.25698.qm_at_web45110.mail.sp1.yahoo.com...

Hey,

Boost serialization
<http://www.boost.org/doc/libs/1_35_0/libs/serialization/doc/index.html>
: how to register template derived class.

 

The problem in general:

I have the following classes:

- Virtual based class:

 class TemplateBase {  }

- Derived class:

template <class KUKU, int KUKUINT>

class KukuBase : public TemplateBase{ }

 

And I am trying to serialize the derived class KukuBase<KUKU, KUKUINT>
through a pointer of the base type (polymorphism...).

The problem is that I can not find a way to register the class
KukuBase<KUKU, KUKUINT> and thus get unregistered_class
<http://us.mg3.mail.yahoo.com/dc/exceptions.html>  exception. 

 

How to make it works?

 

The cpp file:

 

#include <boost/archive/text_oarchive.hpp>

#include <boost/archive/text_iarchive.hpp>

 

// Serialization

#include <boost/serialization/string.hpp>

#include <boost/serialization/vector.hpp>

#include <boost/serialization/access.hpp>

#include <boost/serialization/base_object.hpp>

#include <boost/serialization/serialization.hpp>

#include <boost/serialization/export.hpp>    

 

#include <fstream>

 

class TemplateBase

{

public:

 TemplateBase() : mI(0) {}

 virtual TemplateBase* Clone() = 0;

 

 int mI;

 

private:

 friend class boost::serialization::access;

 template<class Archive>

 void serialize(Archive & ar, const unsigned int version)

 {

  ar & mI;

 } 

};

 

template <class KUKU, int KUKUINT>

class KukuBase : public TemplateBase

{

public:

  KukuBase() : mZ(1) {}

  TemplateBase* Clone() { return new KukuBase<KUKU, KUKUINT>(*this); }

 

private:

  friend class boost::serialization::access;

  template<class Archive>

  void serialize(Archive & ar, const unsigned int version)

  {

    ar & boost::serialization::base_object<TemplateBase>(*this);

    ar & mZ;

  }

 

  float mZ;

};

 

class foo { 

public:

  foo() : mT(new KukuBase<int, 5>) {};

  

  template<class Archive>

  void serialize(Archive & ar, const unsigned int version)

  {

    ar & mT;

  }

 

  TemplateBase* mT;

};

 

BOOST_CLASS_EXPORT(foo);

//BOOST_CLASS_EXPORT((KukuBase));

BOOST_CLASS_EXPORT(TemplateBase);

 

int main()

{

  std::ofstream ofs("/tmp/kuku");                                     

  boost::archive::text_oarchive ar(ofs);                             

 

  const foo bar;

  ar << bar;

}  

 

 

The program returns:

          terminate called after throwing an instance of
'boost::archive::archive_exception'

what():  unregistered class

Abort

 

And the stuck shows:

 (gdb) bt

#0  0x000000000049e409 in kill ()

#1  0x0000000000470582 in abort () at ../sysdeps/generic/abort.c:88

#2  0x0000000000461bf8 in __gnu_cxx::__verbose_terminate_handler ()

#3  0x000000000045e216 in __cxxabiv1::__terminate ()

#4  0x000000000045e243 in std::terminate ()

#5  0x000000000045e343 in __cxa_throw ()

#6  0x000000000040190c in
boost::throw_exception<boost::archive::archive_exception> ()

#7  0x00000000004015e1 in
boost::archive::detail::save_pointer_type<boost::archive::text_oarchive,
TemplateBase*>::polymorphic<TemplateBase>::save ()

#8  0x000000000040152d in
boost::archive::detail::save_pointer_type<boost::archive::text_oarchive,
TemplateBase*>::save<TemplateBase> ()

#9  0x000000000040142e in
boost::archive::detail::save_pointer_type<boost::archive::text_oarchive,
TemplateBase*>::invoke ()

#10 0x00000000004013aa in
boost::archive::save<boost::archive::text_oarchive, TemplateBase*> ()

#11 0x0000000000401344 in
boost::archive::basic_text_oarchive<boost::archive::text_oarchive>::save
_override<TemplateBase* const> ()

#12 0x00000000004012e8 in
boost::archive::detail::interface_oarchive<boost::archive::text_oarchive
>::operator<< <TemplateBase* const> ()

#13 0x0000000000401299 in
boost::archive::detail::interface_oarchive<boost::archive::text_oarchive
>::operator&<TemplateBase*> ()

#14 0x000000000040124c in foo::serialize<boost::archive::text_oarchive>
()

#15 0x0000000000401197 in
boost::serialization::access::serialize<boost::archive::text_oarchive,
foo> ()

#16 0x0000000000401107 in
boost::serialization::serialize<boost::archive::text_oarchive, foo> ()

#17 0x0000000000400f83 in
boost::serialization::serialize_adl<boost::archive::text_oarchive, foo>
()

#18 0x00000000004022c6 in
boost::archive::detail::oserializer<boost::archive::text_oarchive,
foo>::save_object_data ()

#19 0x0000000000405c59 in
boost::archive::detail::basic_oarchive_impl::save_object ()

#20 0x0000000000400d43 in
boost::archive::detail::save_non_pointer_type<boost::archive::text_oarch
ive, foo>::save_standard::invoke ()

#21 0x0000000000400c6f in
boost::archive::detail::save_non_pointer_type<boost::archive::text_oarch
ive, foo>::invoke ()

#22 0x0000000000400aff in
boost::archive::save<boost::archive::text_oarchive, foo> ()

#23 0x0000000000400a38 in
boost::archive::basic_text_oarchive<boost::archive::text_oarchive>::save
_override<foo const> ()

#24 0x000000000040090e in
boost::archive::detail::interface_oarchive<boost::archive::text_oarchive
>::operator<< <foo const> ()

#25 0x0000000000400423 in main ()

(gdb) Quit

 

 

Thanks,

-Ariella 

 

 

 

________________________________

From: Voloshin, Ariella 
Sent: Tuesday, May 20, 2008 11:10 AM
To: Lifshitz, Yair
Subject: RE: Hey

 

Yes I will use it,

I guess you will need to register the: boost-users_at_lists.boost.org.

The guy that wrote the boost serialization library is Robert Ramey
ramey_at_rrsd.com.

If you like to answer from my email thread please let me know.

 

________________________________

From: Lifshitz, Yair 
Sent: Friday, May 16, 2008 8:55 AM
To: Voloshin, Ariella
Cc: Lifshitz, Yair
Subject: RE: Hey

 

Great! :)
So I hope you're going to use it.

 

Can you send me the Boost owner's mail - I want to have a look and maybe
have a chat with him.

 

 

________________________________

From: Voloshin, Ariella 
Sent: Thursday, May 15, 2008 11:01 PM
To: Lifshitz, Yair
Subject: Hey

It is working, 

Took some time to compile, long story but it is working.

The string is also ok.

 

Thanks,

-Ariella

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