Re: [boost] [serialization] Enhancing Archives with Archve Adaptors

From: Matthias Troyer (troyer_at_[hidden])
Date: 2005-12-11 04:02:29

Hi Robert,

I have now implemented the array wrappers and, as expected, all of my  
archives also work with that solution. In running the regression  
tests I realized that besides changing the C-array and std::vector  
serialization, the following changes neeed to be done to the core  
serialization library:

1. in archive/detail/iserializer.hpp the following change is needed:

@@ -584,6 +586,10 @@
  inline void load(Archive &ar, const serialization::binary_object &t){
          boost::archive::load(ar,  
const_cast<serialization::binary_object &>(t));
  }
+template<class Archive, class T>
+inline void load(Archive &ar, const serialization::array<T> &t){
+        boost::archive::load(ar, const_cast<serialization::array<T>  
&>(t));
+}

This is needed because the wrappers are usually passed as const  
arguments, and you did the same overload also for nvp and binary_object.

2. in archive/basic_xml_oarchive.hpp the following is needed:

@@ -100,6 +101,20 @@
          this->This()->save_end(t.name());
      }

+    // specific overrides for arrays
+    // want to trap them before the above "fall through"
+
+    template<class T>
+    void save_override(
+                #ifndef BOOST_NO_FUNCTION_TEMPLATE_ORDERING
+                const
+                #endif
+                ::boost::serialization::array<T> & t,
+                int
+        ){
+        archive::save(* this->This(), t);
+    }
+
      // specific overrides for attributes - not name value pairs so we
      // want to trap them before the above "fall through"
      BOOST_ARCHIVE_OR_WARCHIVE_DECL(void)

and in archive/basic_xml_iarchive.hpp:

@@ -81,6 +82,19 @@
          load_end(t.name());
      }

+
+    // specific overrides for arrays
+    template<class T>
+    void load_override(
+                #ifndef BOOST_NO_FUNCTION_TEMPLATE_ORDERING
+                const
+                #endif
+                boost::serialization::array<T> & t,
+                int
+        ){
+        archive::load(* this->This(), t);
+    }
+
      // specific overrides for attributes - handle as
      // primitives. These are not name-value pairs
      // so they have to be intercepted here and passed on to load.

to allow the array wrapper to be serialized although it is not a nvp.  
Note that we cannot just put the array wrapper into an nvp since that  
opuld break compatibility with the old XML archive format.

These changes are in addition to changing the C-array and std::vector  
serialization.

My question to you is whether in light of this additional intrusion  
into the unrelated XML archives you still prefer this solution over  
the save_array/load_array free functions proposed by Dave? If you do  
then I can send you my implementation.

Also, when you find time, could you please answer to my mail of a few  
days ago regarding the issues in std::vector serialization.

Matthias