Re: [boost] serialization supportforstd::complexandboost::ublas::vector

From: Robert Ramey (ramey_at_[hidden])
Date: 2005-08-26 22:39:54

Neal Becker wrote:
> Robert Ramey wrote:

> OK, so how does this look?  This implements std::complex and
> ublas::vector. Does not yet support allocator paramater to
> ublas::vector, but I don't
> think that would be difficult to add.

...

> template<typename Archive, typename T>
> inline void save (Archive &ar, const std::complex<T>& z, const
> unsigned int) {
>  ar << boost::serialization::make_nvp ("real", const_cast<const
> T&>(real (z)));
>  ar << boost::serialization::make_nvp ("imag", const_cast<const
> T&>(imag (z)));
> }

This doesn't seem right to me.  real(z) returns a value.  I don't see how 
this can be cast to reference to a const value without a lot of (conforming) 
compilers objecting.  I believe the correct way will be:

const T r = real(z);
ar << boost::serialization::make_nvp ("real", r);
const T i = imag(z);
ar << boost::serialization::make_nvp ("imag", i);

> template<class Archive, class U>
> inline void load (Archive &ar, ublas::vector<U> &v, const unsigned
>  int) { unsigned int count;
>  ar >> count;
>  v.resize (count);
>  typename ublas::vector<U>::iterator it = v.begin();
>  while (count-- > 0) {
>    ar >> *it++;
>  }
> }

I wonder about this - but I know nothing of ublas.  If v.resize actually 
creates the entries I guess it would be just fine.  Now I wonder about my 
own implementation of serialization for std::vector.  It seems yours here is 
more efficient.

Robert Ramey