Re: [Boost-users] [serialization] Lost in serialization (save_construct_data and reference)

21 Dec 2005

      codeur@altern.org wrote:
...
Hello,
Four questions about serialization :=) Let's go.
1)
I have a class that have a reference on a vector of shared pointers to
objects . Since I have no default constructors I redefined
save_construct_data like this :
template<class Archive>
inline void save_construct_data(
 Archive & ar,
 const MyClass<Real> * t, // CLASS IS TEMPLATED
 const unsigned int file_version)
{
 ar << & t->myref_;
}
I have got the following error (same problem with & operator):
error: no match for 'operator<<' in 'ar <<  [...]
Hmm - assuming you're working with a compiler which supports Partial 
Template Specialization
shouldn't you be using:

 template
 inline void save_construct_data(
  Archive & ar,
  const MyClass<T> *mct, // CLASS IS TEMPLATED
  const unsigned int file_version)
 {
  ar << mct->myref_;  // eliminate the &, pass the object - not the address 
of the object
 }
...
2) I there a tricky way to define this function for all type used to
instantiate MyClass ?
see above
...
3) Is it me or this example in the documentation :
// save data required to construct instance
   ar << t.member1;
   // serialize reference to object as a pointer
   ar << & t.member2;
should be :
ar << t->member1;
ar << & t->member2;
Archives accept objects which are passed by reference - not addresses!!
...
4) Should it be possible to add more examples which use templates in
the library (since a lot of a macros are not available) ?
It should be possible.  Of course whether such a thing happens would be
an entirely different question.
...
Thanks in advance for your help!
You're welcome

Robert Ramey