Re: [Boost-bugs] [Boost C++ Libraries] #3365: Serialization of multi_index_container is non portable.

Subject: Re: [Boost-bugs] [Boost C++ Libraries] #3365: Serialization of multi_index_container is non portable.
From: Boost C++ Libraries (noreply_at_[hidden])
Date: 2011-11-23 09:32:19

#3365: Serialization of multi_index_container is non portable.
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  Reporter:  Ilia V. Sochenkov <ivsochenkov@…>        |       Owner:  joaquin                                         
      Type:  Bugs                                     |      Status:  reopened                                        
 Milestone:  Boost 1.40.0                             |   Component:  multi_index                                     
   Version:  Boost 1.38.0                             |    Severity:  Problem                                         
Resolution:                                           |    Keywords:  multi_index_container serialization, multi_index
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Changes (by Hajo Kirchhoff <mailinglists@…>):

 * cc: mailinglists@… (added)
  * status:  closed => reopened
  * resolution:  fixed =>
  * severity:  Cosmetic => Problem

Comment:

 The changeset may fix this problem (haven't checked), but line 667 (of
 this changeset) might cause data truncation under x64 bit and a compiler
 warning.
 {{{
     serialization::collection_size_type       s;
     detail::serialization_version<value_type> value_version;
     if(version<1){
       std::size_t sz;
       ar>>serialization::make_nvp("count",sz);
       s=sz;  /***** Error here *****/
     }
 }}}
 With x64 bit compilation (Visual Studio 2008, boost 1.44)
 collection_size_type is unsigned int (32 Bit), whereas size_t is an
 unsigned long (64 Bit). The assignment s=sz gets truncated and issues a
 warning

  boost\boost/multi_index_container.hpp(673) : error C4267: 'argument' :
 conversion from 'size_t' to 'const unsigned int', possible loss of data

 Since our project treats this warning as an error, the code does not
 compile.

 The patch here is straightforward: simply cast the result. There is
 nothing we can do in this case anyway and also it is pretty unlikely that
 any user in the world will serialise more than 2^32 items.

 {{{
 @@ -670,7 +670,7 @@
      if(version<1){
        std::size_t sz;
        ar>>serialization::make_nvp("count",sz);
 -      s=sz;
 +      s=(serialization::collection_size_type)sz;
      }
      else{
        ar>>serialization::make_nvp("count",s);
 }}}

-- 
Ticket URL: <https://svn.boost.org/trac/boost/ticket/3365#comment:3>
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