Re: [Boost-users] serialization pointer to primitive type

From: Robert Ramey (ramey_at_[hidden])
Date: 2006-08-23 10:55:12

Among the default traits for primitive types is no tracking.

So the best way to handle your situation is to use
BOOST_STRONG_TYPEDEF to assign a special
type to your special kind of integer.  Then specify
serialization functions for that type.  Something like

BOOST_STRONG_TYPEDEF(int, my_int)

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

vector<my_int *> v;
ar & v;

Hope this is helpful.

Robert Ramey

Cheok Yan Cheng wrote:
> hello,
>
> i have an int pointer, which pointer to the starting
> address of an array. currently, i need to serialize
> the array elements one by one, at the same time
> serialize the size of the array too.
>
> i try to serialize the dynamic allocated array, just
> like what i did on vector, but fail.
>
> vector<int> v;
> ar & vector; /* no problem. */
>
> int *i = new int[10];
> ar & i; /* compile error. */
>
> i was understand that the serialization library had no
> idea on the size of dynamic allocated array either
> during run-time or compiled time.
>
> i just want to know whether there is any better way to
> serialize on the above mentioned data?
>
> here is the error i get from vc++ 2003.
>
> C:\Boost\include\boost-1_33_1\boost\serialization\access.hpp(109):
> error C2228: left of '.serialize' must have
> class/struct/union type
>
> the below are my full source code. thanks!
>
> #include <fstream>
>
> // include headers that implement a archive in simple
> text format
> #include <boost/archive/text_oarchive.hpp>
> #include <boost/archive/text_iarchive.hpp>
>
> /////////////////////////////////////////////////////////////
> // gps coordinate
> //
> // illustrates serialization for a simple type
> //
> class gps_position
> {
> private:
>    friend class boost::serialization::access;
>    // When the class Archive corresponds to an output
> archive, the
>    // & operator is defined similar to <<.  Likewise,
> when the class Archive
>    // is a type of input archive the & operator is
> defined similar to >>.
>    template<class Archive>
>    void serialize(Archive & ar, const unsigned int
> version)
>    {
>        ar & degrees;
>        ar & minutes;
>        ar & seconds;
>        ar & data;
>    }
>    int degrees;
>    int minutes;
>    float seconds;
>    int* data;
>
> public:
>    gps_position(){};
>    gps_position(int d, int m, float s) :
>        degrees(d), minutes(m), seconds(s)
>    {data = new int[5];}
> };
>
> int main() {
>    // create and open a character archive for output
>    std::ofstream ofs("filename");
>
>    // create class instance
>    const gps_position g(35, 59, 24.567f);
>
>    // save data to archive
>    {
>        boost::archive::text_oarchive oa(ofs);
>        // write class instance to archive
>        oa << g;
>    // archive and stream closed when destructors are
> called
>    }
>
>    // ... some time later restore the class instance
> to its orginal state
>    gps_position newg;
>    {
>        // create and open an archive for input
>        std::ifstream ifs("filename",
> std::ios::binary);
>        boost::archive::text_iarchive ia(ifs);
>        // read class state from archive
>        ia >> newg;
>        // archive and stream closed when destructors
> are called
>    }
>    return 0;
> }
>
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