Re: [Boost-users] serialization mystery

From: Matthias Troyer (troyer_at_[hidden])
Date: 2007-09-17 05:44:04

On Sep 17, 2007, at 12:45 AM, Neal Becker wrote:

> I'm stumped as to why my template typedef simulation doesn't work with
> serialization.
>
> Here's a simple example:
>
> template<typename T>
> struct A {
> };
>
> template<typename T>
> struct B {
>   typedef A<T> type;
> };
>
> namespace boost { namespace serialization {
>   template<class Archive, class T>
>   inline void serialize (Archive &ar, typename B<T>::type & v, const
> unsigned int file_version) {   <<< This won't work
>   //inline void serialize (Archive &ar, A<T> & v, const unsigned int
> file_version) { <<< This is OK
>     boost::serialization::split_free (ar, v, file_version);
>   }
> }
> }
>
> I expected typename B<T>::type is equivalent to A<T>, but gcc-4.1.2  
> doesn't
> agree.  The latter compiles, but the 1st gives:
> /usr/local/src/boost.hg/boost/serialization/access.hpp:109: error:  
> ‘struct
> A<int>’ has no member named ‘serialize’

This is probably because the default serialize() template which  
forwards to a member function is a better match than your version.

Matthias