Re: [Boost-users] [Serialization] Restoring from text archive compile error

Subject: Re: [Boost-users] [Serialization] Restoring from text archive compile error
From: Dante Stroe (dante.stroe_at_[hidden])
Date: 2010-06-25 12:01:18

Yep that's what It was, thanks for the help, I guess I should have 
looked further into the error messages. Since however I didn't want to 
modify the implementation of the class, I used the const_cast on the 
constant members which worked just fine. I do have a couple of more 
general questions:
     1) What is the benefit/reason for using 
BOOST_SERIALIZATION_ASSUME_ABSTRACT as it is used in the tutorial 
demo.cpp for an abstract class (it obviously works without it)?
     2) In the case where the base class has no serializable members 
(like it is the case for the my "base" class), I get a warning for 
unused parameter ar as expected, however is there any defacto way to 
bypass that ?

Best and thank you for your answers,
Dante

On 06/25/2010 03:52 PM, Jeff Flinn wrote:
> Dante Stroe wrote:
>> Hello,
>>
>> I am currently trying to serialize the classes of a project I am 
>> working on, but I ran into a few compliation errors and I am kind of 
>> stuck, so I was hoping somebody here could help me on that.
>> I am using the 1.43 version of the boost library and gcc 4.4.1. (I'd 
>> like to add that all the examples in and tutorials from the 
>> documentation work fine for me).
>> I am trying to serialize a base class called "base" and it's derived 
>> class called "de" that use a shared pointer, and afterwards test my 
>> implementation by saving the an instance of a "de" object into a text 
>> archive and then restoring it.
>>
>> These is the serialization implementation for my two classes for 
>> reference:
>>
>> ---"base.h"-----
>> #include<iostream>
>> #include<string>
>> #include<typeinfo>
>> #include "../config.h"
>> #include "../population.h"
>> #include "../rng.h"
>> #include<boost/shared_ptr.hpp>
>> #include<boost/archive/text_iarchive.hpp>
>> #include<boost/archive/text_oarchive.hpp>
>> #include<boost/serialization/version.hpp>
>> #include<boost/serialization/base_object.hpp>
>>
>> namespace pagmo { namespace algorithm {
>>
>> /// Base algorithm class.
>> class base;
>>
>> /// Alias for shared pointer to base algorithm.
>> typedef boost::shared_ptr<base>   base_ptr;
>>
>> /// Base algorithm class.
>>
>> class __PAGMO_VISIBLE base
>>
>> {
>>     public:
>>
>>         base();
>>         /// Evolve method.
>>         virtual void evolve(population&p) const = 0;
>>         /// Clone method.
>>         virtual base_ptr clone() const = 0;
>>         virtual ~base();
>>         std::string human_readable() const;
>>         virtual std::string get_name() const;
>>         virtual bool is_blocking() const;
>>
>>     protected:
>>
>>         virtual std::string human_readable_extra() const;
>>
>>     protected:
>>
>>         /// Random number generator for double-precision floating 
>> point values.
>>         mutable rng_double    m_drng;
>>         /// Random number generator for unsigned integer values.
>>         mutable rng_uint32    m_urng;
>>
>>   private:
>>
>>         friend class boost::serialization::access;
>>     template<class Archive>
>>     void serialize(Archive&ar, const unsigned int version){
>>         std::cout<<   "Serializing base algorithm"<<   version<<   
>> std::endl;
>>         }
>>
>> };
>> }} //namespaces
>>
>> std::ostream __PAGMO_VISIBLE_FUNC&operator<<(std::ostream&, const 
>> base&);
>> --------------------
>>
>> --------"de.h"------
>>
>> #include<string>
>> #include "../config.h"
>> #include "../population.h"
>> #include "base.h"
>> #include<boost/serialization/base_object.hpp>
>>
>> namespace pagmo { namespace algorithm {
>>
>> class __PAGMO_VISIBLE de: public base {
>>
>>   public:
>>
>>       de(int, const double&   = 0.8, const double&   = 0.9, int = 2);
>>       base_ptr clone() const;
>>       void evolve(population&) const;
>>       std::string get_name() const;
>>
>>   protected:
>>
>>       std::string human_readable_extra() const;
>>
>>   private:
>>
>>       friend class boost::serialization::access;
>>       template<class Archive>
>>       void serialize(Archive&ar, const unsigned int version){
>>       std::cout<<   "Serializing de algorithm"<<   version<<   
>> std::endl;;
>>       ar&   boost::serialization::base_object<base>(*this);
>>       ar&   m_gen;
>>       ar&   m_f;
>>       ar&   m_cr;
>>       ar&   m_strategy;
>>       }
>>
>>       const int m_gen;
>>       const double m_f;
>>       const double m_cr;
>>       const int m_strategy;
>> };
>>
>> }} //namespaces
>> ------------------------------
>>
>> Saving works fine (and as far as I can tell, based on the 
>> documentation examples the information is saved correctly in the text 
>> archive). This is the program that I am using to save and restore 
>> from archive:
>
> Looks like you are trying to modify const members when de-serializing. 
> Can you remove the const's? Again, this is just a quick perusal of 
> your posting. You should provide a paired down example demonstrating 
> you problem, which will probably lead you to your problems.
>
> Jeff
>
> Jeff
>
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