Re: [Boost-users] Serialization with pointer to const object

Subject: Re: [Boost-users] Serialization with pointer to const object
From: Robert Ramey (ramey_at_[hidden])
Date: 2009-07-24 16:10:36

Hmmm - good point.  In the past I sort of made this decision in an ad-hoc
way without thinking too much about it.

Thinking about now.

const * A m_a

is a pointer to a const object. I would not expect the following to work

ar << m_a

I would not expect it to trap at the right level- but at the lower level 
after m_a
is de-referenced to a const A & and THAT is serialized.

I'm not sure where it's traping now though.

Robert Ramey

Emil Dotchevski wrote:
> But in his case the object he is serializing (the pointer itself)
> isn't const. In addition, in the typical use case the object the
> pointer points to is also mutable. Shouldn't the const_cast be in
> Boost Serialization?
>
> Emil Dotchevski
> Reverge Studios, Inc.
> http://www.revergestudios.com/reblog/index.php?n=ReCode
>
> On Fri, Jul 24, 2009 at 9:33 AM, Robert Ramey<ramey_at_[hidden]> wrote:
>> Hmm - a const object is one that can't be changed once created. If
>> you think about it, this conflicts with what serialization is. If in
>> spite of this, you still want to do it, it is possible. Use
>> const_cast. Also there information in the documentation regarding
>> this.
>>
>> Robert Ramey
>>
>> Soumen wrote:
>>> Hi,
>>>
>>> I'm using gcc 4.2.2 and boost 1.35. If I try to serialize pointer to
>>> some const objects, I'm getting compilation problem. Is there any
>>> limitation? Or I need to do certain things differently? I couldn't
>>> figured any solution over net. If there already exist any topic
>>> which points to solution, please point me to that. Otherwise, guide
>>> me to resolve the problem at hand. I'm new to boost.
>>>
>>> Say, my data member in the class myClass is
>>>
>>> const myType *ptr;
>>>
>>> In the serialize() routine, I'm doing it in following way:
>>>
>>> template< class Archive >
>>> void myClass::serialize(Archive &ar, const unsigned int version)
>>> {
>>> ar & ptr;
>>>
>>> // I've tried "ar & const_cast< myType* >(ptr)" and
>>> // "ar & (myType *) ptr" as well - it didn't work
>>>
>>> /* serialize other members */
>>>
>>> }
>>>
>>> Regards,
>>> - Soumen