Re: [Boost-users] DeSerialization to update content of objectinsteadof construct new object

16 May 2007

      Thank you very much.
I have successfully overloaded the serialization function. Here is the code 
as the reference for other ppl doing the similar modification.

base.h
    #ifndef BASE_H
    #define BASE_H
    ...
    #include
    ...
    class base
    {
       friend class boost::serialization::access;
       template<class Archive>
       void serialize(Archive &ar, const unsigned int /* file_version */){
           ar & BOOST_SERIALIZATION_NVP(m_nID);
        }
        .....
    }
    ...

     #if defined(__SGI_STL_PORT) || defined(_STLPORT_VERSION)
     #define STD _STLP_STD
     #else
     #define STD std
    #endif

    namespace boost {
    namespace serialization {

     //vector
    template
    inline void save(
        Archive & ar,
        const STD::vector &t,
        const unsigned int /* file_version */
    ){
         // record number of elements
        unsigned int count = t.size();
        ar << BOOST_SERIALIZATION_NVP(count);
       for(unsigned int i=0; i< count; i++)
          ar<
     inline void load(
         Archive & ar,
         STD::vector &t,
          const unsigned int  /*file_version*/
     ){
      //   // retrieve number of elements
          unsigned int count;
         ar >> BOOST_SERIALIZATION_NVP(count);
         for(unsigned int i=0; i> boost::serialization::make_nvp("loaditem", *t.at(i));
          }
     }
     }
    ...
   #endif

Barr Ng
...
From: Matthias Troyer 
Reply-To: boost-users@lists.boost.org
To: boost-users@lists.boost.org
Subject: Re: [Boost-users] DeSerialization to update content of 
objectinsteadof construct new object
Date: Wed, 16 May 2007 07:22:28 +1000
Another, maybe easier option, could be to  overload the serialization
functions for std::vector .
Matthias Troyer
On 16 May 2007, at 01:02, Robert Ramey wrote:
...
The code for serialization of a vector is found in serialization/
vector.hpp.
I implemented this code to reconstuct the vector items rather than
just reload them.  I did this for a number of reasons - which for
this discussion are not important.
If this doesn't suit your needs, I would suggest you make your own
version of serialization.hpp which operates differently.  Starting
with the current version it wouldn't be at all hard to do.
If you want to use both current ("standard") method in some
places in addition to your "custom" method, you might consider
making some sort of wrapper which tags your special
vectors with a type which can be distinguished for special
serialization treatment.
Robert Ramey
Ng Pan wrote:
...
Hi
I am using boost serialization to synchronise objects between
different computers (network). The objects would be serializated as a
string instead of a file by using the class stringstream(instead of
fstream). The string would be transferred via TCP/IP layer.
Let simpify the situation as only two computers (Master and Slave)
,both of two computers have N objects and I wanna synchronise their
content. I create a vector of pointer ( std::vector m_vpBase
) which points to the dirty objects. Both of two computers have this
vector. Let assume the vectors are already pointing to the
corresponding objects. For Tx side, it would serialize the objects as
a string. For Rx side, I want to update the content of the objects
that its vector is pointing to.
Tx side:
oa << BOOST_SERIALIZATION_NVP(m_vpBase);
Rx side:
oa >> BOOST_SERIALIZATION_NVP(m_vpBase );
However, the above code would construct new objects.
What i want is just update the content of the objects , not construct
new objects.
I know how to update the content for one object by using pointer (
base * m_pBase).
Tx side:
oa << BOOST_SERIALIZATION_NVP(m_pBase);
Rx side:
oa >> BOOST_SERIALIZATION_NVP(*m_pBase);
But, I don't know how to do for a vector of pointer. If you know,
please give me some hints. Thank you very much.
Regards
Barr Ng
[I found Boost serialization is useful and easy to use. ]
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