Re: [Boost-users] Serialization -- serializing a map withshared_ptr values

From: Robert Ramey (ramey_at_[hidden])
Date: 2007-11-09 11:13:54

I can't imagin how something like

                m_offlineMode = true;

even compiles given that save is a "const" function.

If you can't live without this, it suggests that your saving operation
is altering the thing its saving - which would conflict with the
the idea that only one copy of anything is actually saved.

>From looking at this - that's the only think I can ay.

Robert Ramey

  "Oliver Kania" <kania.oliver_at_[hidden]> wrote in message news:1262c4ee0711090524w3a2e1a8i3355283c8c65ed98_at_mail.gmail.com...
  I have the following two data structures:

  std::map<const std::string, boost::shared_ptr< C >, jedox::util::CaseInsensitiv > m_LookupName;
  std::map<unsigned int, boost::shared_ptr< C > > m_LookupId; 

  Before serialization, the shared pointer - values  of the maps do point to sth. meaningful.
  Afterwards, however, they point to data-structures with meaningless content.
  The keys (strings / ints) are serialized / unserialized correctly.  
  I guess its a general problem with serializing shared pointers contained in a std::map as values !?
  BTW: the structures the shared pointers point to do have a serialization method themselves and I a
  assume that it is called when serializing the map. 

  I serialize / unserialize as follows:

  template<class Archive>
              void save( Archive &ar, unsigned int version) const{                
                  m_offlineMode = true;
                  bool oldCachedAll = m_CachedAll; 
                  m_CachedAll   = true;            
                  ar & m_CachedAll;
                  ar & m_offlineMode;
                  // do not serialize the lock -- use the default constructor.
                  // we assume that no iterators that lock the cache do exist when serializing.
                  // ar & m_Lock;
                  ar & m_LookupId;          // 1st structure
                  ar & m_LookupName;    // 2nd structure 
                  ar & m_SequenceNumber;
                  //reset old state for the case we want to continue working
                  m_CachedAll = oldCachedAll;
                  m_offlineMode = false;
              } 

              template<class Archive>
              void load( Archive &ar, unsigned int version) {                            
                  ar & m_CachedAll;
                  ar & m_offlineMode; 
                  // do not serialize the lock -- use the default constructor.
                  // we assume that no iterators that lock the cache do exist when serializing.
                  // ar & m_Lock;
                  ar & m_LookupId; 
                  ar & m_LookupName;
                  ar & m_SequenceNumber;
                  //reset old state for the case we want to continue working
              }

  kind regards, Oliver

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