oserializer.hpp

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            // do a fast save
            mpl::identity<save_only>,
        // else
            // do a fast save only tracking is turned off
            mpl::identity<save_conditional>
        > > >::type typex; 

    static void invoke(Archive & ar, const T & t){
        // check that we're not trying to serialize something that
        // has been marked not to be serialized.  If this your program
        // traps here, you've tried to serialize a class whose trait
        // has been marked "non-serializable". Either reset the trait
        // (see level.hpp) or change program not to serialize items of this class
        BOOST_STATIC_ASSERT((
            mpl::greater_equal<
                boost::serialization::implementation_level<T>, 
                mpl::int_<boost::serialization::primitive_type>
            >::value
        ));
        typex::invoke(ar, t);
    };
};

template<class Archive, class TPtr>
struct save_pointer_type {
    template<class T>
    struct abstract
    {
        static const basic_pointer_oserializer * register_type(Archive & /* ar */){
            // it has? to be polymorphic
            BOOST_STATIC_ASSERT(boost::is_polymorphic<T>::value);
            return NULL;
        }
    };

    template<class T>
    struct non_abstract
    {
        static const basic_pointer_oserializer * register_type(Archive & ar){
            return ar.register_type(static_cast<T *>(NULL));
        }
    };

    template<class T>
    static const basic_pointer_oserializer * register_type(Archive &ar, T & /*t*/){
        // there should never be any need to save an abstract polymorphic 
        // class pointer.  Inhibiting code generation for this
        // permits abstract base classes to be used - note: exception
        // virtual serialize functions used for plug-ins
        typedef 
            BOOST_DEDUCED_TYPENAME mpl::eval_if<
                boost::serialization::is_abstract<T>,
                mpl::identity<abstract<T> >,
                mpl::identity<non_abstract<T> >       
            >::type typex;
        return typex::register_type(ar);
    }

    template<class T>
    struct non_polymorphic
    {
        static void save(
            Archive &ar, 
            T & t
        ){
            const basic_pointer_oserializer & bpos = 
                boost::serialization::singleton<
                    pointer_oserializer<Archive, T>
                >::get_const_instance();
            // save the requested pointer type
            ar.save_pointer(& t, & bpos);
        }
    };

    template<class T>
    struct polymorphic
    {
        static void save(
            Archive &ar, 
            T & t
        ){
            BOOST_DEDUCED_TYPENAME 
            boost::serialization::type_info_implementation<T>::type const
            & i = boost::serialization::type_info_implementation<T>::type
                    ::get_const_instance();

            boost::serialization::extended_type_info const * const this_type = & i;

            // retrieve the true type of the object pointed to
            // if this assertion fails its an error in this library
            assert(NULL != this_type);

            const boost::serialization::extended_type_info * true_type =
                i.get_derived_extended_type_info(t);

            // note:if this exception is thrown, be sure that derived pointer
            // is either registered or exported.
            if(NULL == true_type){
                boost::serialization::throw_exception(
                    archive_exception(archive_exception::unregistered_class)
                );
            }

            // if its not a pointer to a more derived type
            const void *vp = static_cast<const void *>(&t);
            if(*this_type == *true_type){
                const basic_pointer_oserializer * bpos = register_type(ar, t);
                ar.save_pointer(vp, bpos);
                return;
            }
            // convert pointer to more derived type. if this is thrown
            // it means that the base/derived relationship hasn't be registered
            vp = serialization::void_downcast(
                *true_type, 
                *this_type, 
                static_cast<const void *>(&t)
            );
            if(NULL == vp){
                boost::serialization::throw_exception(
                    archive_exception(archive_exception::unregistered_cast)
                );
            }

            // since true_type is valid, and this only gets made if the 
            // pointer oserializer object has been created, this should never
            // fail
            const basic_pointer_oserializer * bpos 
                = archive_pointer_oserializer<Archive>::find(* true_type);
            assert(NULL != bpos);
            if(NULL == bpos)
                boost::serialization::throw_exception(
                    archive_exception(archive_exception::unregistered_class)
                );
            ar.save_pointer(vp, bpos);
        }
    };

    // out of line selector works around borland quirk
    template<class T>
    struct conditional {
        typedef BOOST_DEDUCED_TYPENAME mpl::eval_if<
            is_polymorphic<T>,
            mpl::identity<polymorphic<T> >,
            mpl::identity<non_polymorphic<T> >
        >::type type;
    };

    // used to convert TPtr in to a pointer to a T
    template<class T>
    static void save(
        Archive & ar, 
        const T & t
    ){
        conditional<T>::type::save(ar, const_cast<T &>(t));
    }

    template<class T>
    static void const_check(T & t){
        BOOST_STATIC_ASSERT(! boost::is_const<T>::value);
    }

    static void invoke(Archive &ar, const TPtr t){
        #ifdef BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION
            // if your program traps here, its because you tried to do
            // something like ar << t where t is a pointer to a const value
            // void f3(A const* a, text_oarchive& oa)
            // {
            //     oa << a;
            // }
            // with a compiler which doesn't support remove_const
            // const_check(* t);
        #else
            // otherwise remove the const
        #endif
        register_type(ar, * t);
        if(NULL == t){
            basic_oarchive & boa 
                = boost::serialization::smart_cast_reference<basic_oarchive &>(ar);
            boa.save_null_pointer();
            save_access::end_preamble(ar);
            return;
        }
        save(ar, * t);
    };
};

template<class Archive, class T>
struct save_enum_type
{
    static void invoke(Archive &ar, const T &t){
        // convert enum to integers on save
        const int i = static_cast<int>(t);
        ar << boost::serialization::make_nvp(NULL, i);
    }
};

template<class Archive, class T>
struct save_array_type
{
    static void invoke(Archive &ar, const T &t){
        typedef BOOST_DEDUCED_TYPENAME boost::remove_extent<T>::type value_type;
        
        save_access::end_preamble(ar);
        // consider alignment
        int count = sizeof(t) / (
            static_cast<const char *>(static_cast<const void *>(&t[1])) 
            - static_cast<const char *>(static_cast<const void *>(&t[0]))
        );
        ar << BOOST_SERIALIZATION_NVP(count);
        ar << serialization::make_array(static_cast<value_type const*>(&t[0]),count);
    }
};

} // detail

template<class Archive, class T>
inline void save(Archive & ar, const T &t){
    typedef 
        BOOST_DEDUCED_TYPENAME mpl::eval_if<is_pointer<T>,
            mpl::identity<detail::save_pointer_type<Archive, T> >,
        //else
        BOOST_DEDUCED_TYPENAME mpl::eval_if<is_enum<T>,
            mpl::identity<detail::save_enum_type<Archive, T> >,
        //else
        BOOST_DEDUCED_TYPENAME mpl::eval_if<is_array<T>,
            mpl::identity<detail::save_array_type<Archive, T> >,
        //else
            mpl::identity<detail::save_non_pointer_type<Archive, T> >
        >
        >
        >::type typex;
    typex::invoke(ar, t);
}

#ifndef BOOST_NO_FUNCTION_TEMPLATE_ORDERING

template<class T>
struct check_tracking {
    typedef BOOST_DEDUCED_TYPENAME mpl::if_<
        // if its never tracked.
        BOOST_DEDUCED_TYPENAME mpl::equal_to<
            serialization::tracking_level<T>,
            mpl::int_<serialization::track_never>
        >,
        // it better not be a pointer
        mpl::not_<is_pointer<T> >,
    //else
        // otherwise if it might be tracked.  So there shouldn't
        // be any problem making a const
        is_const<T>
    >::type typex;
    BOOST_STATIC_CONSTANT(bool, value = typex::value);
};

template<class Archive, class T>
inline void save(Archive & ar, T &t){
    // if your program traps here, it indicates that your doing one of the following:
    // a) serializing an object of a type marked "track_never" through a pointer.
    // b) saving an non-const object of a type not markd "track_never)
    // Either of these conditions may be an indicator of an error usage of the
    // serialization library and should be double checked.  See documentation on
    // object tracking.  Also, see the "rationale" section of the documenation
    // for motivation for this checking.
    BOOST_STATIC_WARNING(check_tracking<T>::value);
        save(ar, const_cast<const T &>(t));
}
#endif

} // namespace archive
} // namespace boost

#endif // BOOST_ARCHIVE_OSERIALIZER_HPP