Re: [Boost-users] [serialization] Problem deriving from text_oarchive_impl

From: Robert S. Grimes (rsgrimes_at_[hidden])
Date: 2006-03-15 14:37:13

Argh!  Now if only I can remember the attachments!  They are the text
(broken) and binary (works) versions.  My broken text code in question is
presented, in part, below.  The compiler complains about the second friend
line.

-- Code --
#include <iostream>
#include <ostream>
#include <boost/archive/archive_exception.hpp>
#include <boost/archive/text_oarchive.hpp>

template<class Archive>
class rsg_text_oarchive_impl :
  // don't derive from text_oarchive !!!
  public boost::archive::text_oarchive_impl<Archive>
{
    typedef rsg_text_oarchive_impl derived_t;
#ifndef BOOST_NO_MEMBER_TEMPLATE_FRIENDS
public:
#else
    friend class
boost::archive::basic_text_oarchive<rsg_text_oarchive_impl<Archive> >;
    friend class boost::archive::basic_text_oprimitive<std::ostream>;
    friend class boost::archive::save_access;
#endif
public:
    rsg_text_oarchive_impl(std::ostream & os, unsigned int flags = 0) :
        boost::archive::text_oarchive_impl<Archive>(
            os,
            flags | boost::archive::no_header // skip default header
checking
        )
    {
      // use our own header checking
      if (0 == (flags & boost::archive::no_header)){
          os << "<!-- RSG Text Archive -->" << std::endl;
          this->boost::archive::basic_text_oarchive<Archive>::init();
      }
    }
};
-- end Code - more follows here...

> -----Original Message-----
> Subject: [serialization] Problem deriving from text_oarchive_impl
>
>
> Hi,
>
> I'm starting to get the hang of this as I slog through, but it's
> still a bit rough!  I'm able to derive a new archive from
> binary_oarchive_impl, but for some reason, I can't do the same
> with text_oarchive_impl.  Specifically, I get the following error
> (from MS Visual C++ 8.0, using Boost 1.33.1):
>
> 1>..\rsg_text_oarchive.hpp(24) : error C2649:
> 'basic_text_oprimitive<class std::basic_ostream<char,struct
> std::char_traits<char> > >' : is not a 'class'
> 1>  ..\rsg_text_oarchive.hpp(40) : see reference to class
> template instantiation 'rsg_text_oarchive_impl<Archive>' being compiled
>
> The similar line in the binary archive works fine.  Attached are
> the two derived archives in question.  All I'm trying to do (at
> this point) is add a short header in the constructor; next, I'll
> want to add a footer in the destructor.
>
> Thanks!
> -Bob