Re: [Boost-bugs] [Boost C++ Libraries] #8157: Access violation of const objects

Subject: Re: [Boost-bugs] [Boost C++ Libraries] #8157: Access violation of const objects
From: Boost C++ Libraries (noreply_at_[hidden])
Date: 2013-02-25 20:13:34

#8157: Access violation of const objects
---------------------------------------------------+------------------------
  Reporter:  Michał Kędrzyński <kedrzu@…>          |       Owner:  ramey        
      Type:  Bugs                                  |      Status:  new          
 Milestone:  To Be Determined                      |   Component:  serialization
   Version:  Boost 1.52.0                          |    Severity:  Problem      
Resolution:                                        |    Keywords:  const        
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Comment (by Michał Kędrzyński <kedrzu@…>):

 Replying to [comment:1 ramey]:
 > value change ONLY when being saved.  You example only shows saving.
 Perhaps you might want to test loading into a const object?  Note that
 saving REQUIRES a const object for reasons described in the documentation

 This is of course true, but according to the concept of constant values,
 this should also not happen. User should expect, that object is not
 changing, no matter what actions are being done. This is what i meant
 saying about unexpected behaviour.

 Serialize method could be declared as const:
 {{{
 template<class Archive>
 void serialize(Archive & ar, const unsigned int version) const
 {
     ar & degrees;
     ar & minutes;
     ar & seconds;
     ++degrees;
     ++minutes;
     ++seconds;
 }
 }}}
 Therfore this program would not compile. Forcing user to declare serialize
 method as const would prohibit such a bahaviour without any further
 changes.

 Note, that when you split serialize into save/load methods, save method
 must be declared const for program to be compiled. Thus standalone
 serialize method should also be const, as it is responsible for saving as
 well as loading.

 I am aware, that this is quite big change, as it would change the use of
 library.

 Michał Kędrzyński

-- 
Ticket URL: <https://svn.boost.org/trac/boost/ticket/8157#comment:2>
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