Re: [Boost-users] boost transfer pointers by serialize

Subject: Re: [Boost-users] boost transfer pointers by serialize
From: Robert Ramey (ramey_at_[hidden])
Date: 2010-08-29 13:05:01

Jack Bryan wrote:
> Dear All,
>
>
> I need to transfer some pointers from one process to another process
> on Open MPI cluster.
>
>
> These pointers are members of a class.
>
>
> They are like:
>
>
> class myClass
> {
> double *;
> int *;
> double**;
> }
>
>
> When I use serialize in boost , I got errors:
>
>
> /boost/serialization/access.hpp:118: error: request for member
> âserializeâ in âtâ, which is of non-class type âdoubleâ

pointers to primitives are not serializable.  The problem is that 
serializing pointers
requires tracking to detect and manage duplicates.  If tracker were 
implemented
for doubles it would automatically track ALL the doubles - probably not what
one would want.

But the solution is easy.

define your own double like this

struct serializable_double {
    double m_d;
    serializable_double(d) : m_d {}
    ...
}

The above can be done automatically with 
BOOST_SERIALIZATION_STRONGTYPEDEF(serializable_double, double)

now you can use

class myClass {
    serializable_double m_sd;
    ...
    template<class Archive>
    void serialize(Archive &ar, const unsigned int version){
        ar & m_sd;
    }
};

this should work as one expects.

Robert Ramey