[boost] [serialization] polymorphic archive destructor slicing

From: Kim Barrett (kab_at_[hidden])
Date: 2006-09-01 14:46:59

In boost-1.33.1 and before, and still in boost-cvs, the base
polymorphic archive classes (polymorphic_iarchive,
polymorphic_oarchive) have non-virtual (default) destructors. The
typical usage pattern for these types is to construct a derived class
and return the base pointer to clients, who only know that the
archive is a polymorphic archive, and not the specific derived class.
This results in the client not being able to correctly delete the
archive, even though the destructor is accessible (and so, easily
invoked). I think that the right solution here is for the base
polymorphic archive classes to define a public virtual destructor.