Re: [Boost-users] [serialization] How to deal with bit fields?

Subject: Re: [Boost-users] [serialization] How to deal with bit fields?
From: Robert Ramey (ramey_at_[hidden])
Date: 2008-09-10 12:10:43

Use split to change into save/load.

Robert Ramey

Sebastian Knopp wrote:
> Hello,
>
> I am a new user of the serialization library and find it is a very
> comfortable solution. But I met a problem concerning the
> serialization of bit fields. For example, look at the following:
>
> struct A
> {
>    int a : 1;
>    int b : 7;
> };
>
>
> Serialization using the following code does not work, because
> bitfields can not be passed by reference.
>
> template<class Archive>
> void serialize(Archive& ar, A& theA, const unsigned int version)
> {
>    ar & make_nvp("a", theA.a);
>    ar & make_nvp("b", theA.b);
> }
>
>
> So, I use this workaround:
>
> template<class Archive>
> void serialize(Archive& ar, A& theA.a, const unsigned int version)
> {
>    bool myA;
>    int myB;
>    if (!Archive::is_loading::value)
>    {
>        myA = (theA.a == 1);
>        myB = theA.b;
>    }
>    ar & make_nvp("a", myA);
>    ar & make_nvp("b", myB);
>    if (Archive::is_loading::value)
>    {
>        theA.a = myA ? 1 : 0;
>        theA.b = myB;
>    }
> }
>
>
> Do you have any suggestions how a more elegant solution could look
> like?
>
> Thanks and bye,
> Sebastian Knopp