[Boost-bugs] [Boost C++ Libraries] #1942: Pointers to elements in a std::map are not serilaized correctly

Subject: [Boost-bugs] [Boost C++ Libraries] #1942: Pointers to elements in a std::map are not serilaized correctly
From: Boost C++ Libraries (noreply_at_[hidden])
Date: 2008-05-23 06:12:26

#1942: Pointers to elements in a std::map are not serilaized correctly
------------------------------------+---------------------------------------
 Reporter:  bernhard.maeder_at_[hidden]  |       Owner:  ramey        
     Type:  Bugs                    |      Status:  new          
Milestone:  To Be Determined        |   Component:  serialization
  Version:  Boost 1.35.0            |    Severity:  Problem      
 Keywords:                          |  
------------------------------------+---------------------------------------
 When serializing a std::map and some pointers that are referencing onto
 elements of that map, those pointers are not loaded correctly.

 Here's the code:

 {{{

 #include <sstream>
 #include <boost/archive/text_oarchive.hpp>
 #include <boost/archive/text_iarchive.hpp>
 #include <boost/serialization/map.hpp>

 struct dummy
 {
     template<typename Archive>
     void serialize(Archive & ar, const unsigned int version)
     {
     }
 };

 struct map_ref_test
 {
     std::map<std::size_t, dummy> m;
     dummy * ref;

     template<typename Archive>
     void serialize(Archive & ar, const unsigned int version)
     {
         ar & m;
         ar & ref;
     }
 };

 int main()
 {
     std::ostringstream os;

     map_ref_test m;
     m.m[0] = dummy();
     m.m[1] = dummy();
     m.m[2] = dummy();
     m.ref = &(m.m[1]);

     // serialize
     boost::archive::text_oarchive out(os);
     out << const_cast<map_ref_test const &>(m);

     // De-serialize
     map_ref_test m2;
     std::string ser = os.str();
     std::istringstream is(ser);
     boost::archive::text_iarchive in(is);

     in >> m2;

     std::cout << "0:   " << &m.m[0] << std::endl;
     std::cout << "1:   " << &m.m[1] << std::endl;
     std::cout << "2:   " << &m.m[2] << std::endl;
     std::cout << "ref: " << m.ref << std::endl << std::endl;

     std::cout << "0:   " << &m2.m[0] << std::endl;
     std::cout << "1:   " << &m2.m[1] << std::endl;
     std::cout << "2:   " << &m2.m[2] << std::endl;
     std::cout << "ref: " << m2.ref << std::endl;
 }

 }}}

 This creates the following output:


 {{{
 0:   0x805bfc4
 1:   0x805bfe4
 2:   0x805c004
 ref: 0x805bfe4

 0:   0x805ca04
 1:   0x805ca24
 2:   0x805ca44
 ref: 0xbfacad5c
 }}}


 I'd expect the last line to read:


 {{{
 ref: 0x805ca24
 }}}


 The code works for std::vectors, so I'd assume it should work for maps
 also.

-- 
Ticket URL: <http://svn.boost.org/trac/boost/ticket/1942>
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