[Boost-users] Re: Problems serializing via pointers

From: Jeff Flinn (TriumphSprint2000_at_[hidden])
Date: 2004-12-03 17:41:44

"Robert Ramey" <ramey_at_[hidden]> wrote in message
news:coqoda$2t4$1_at_sea.gmane.org...
> OK
>
> Heres the short explanation using float as an example:
>
> Its not a great idea to set the tracking trait for float to tracking
because
> you'll end up tracking ALL the floats int the archive.
>
> So you make a very small class that just contains a float.  That as
wrapper
> class.  This is to function just like a float except that it has a
different
> class.  So it will have the default serialization trace assigned since its
> not a primitive.  This means it will be tracked by default.
>
> struct tracked_float {
>     float m_float;     // the real data
>     template<class Archive>
>     void serialize(Archive &ar, unsigned int version){
>         ar & m_float;
>     }
>     // casting operators - not compiled
>     float operator float () const {
>         return m_float;
>     }
>     float & operator float() {
>         return m_float;
>     }
> };
>
> Now just use tracked_float for those floats you want to serialize through
a

Does 'just use' mean that one would now need to replace all occurrences of
float* data members with tracked_float*'s? As in:

class with_float_ptr
{
    tracked_float* m_tracked_float_ptr;

    ...

    template<class Archive>
    void serialize(Archive &ar, const unsigned int version )
    {
        ar & m_tracked_float_ptr;
    }

};

Or is there a less intrusive manner? I'm just curious, as there are no raw
pointers in anything that I've yet needed to serialize.

> pointer and just float for other float variables.
>
> This is more or less equivalent to using
>
> BOOST_STRONG_TYPEDEF(tracked_float, float)
>
> template<class Archive>
> void serialize(Archive &ar, tracked_float & tf){
>     ar & tf.m_float;
> }
>
> I don't know if that helps - but there it is.

Jeff