=== modified file 'boost/archive/basic_archive.hpp'
--- boost/archive/basic_archive.hpp	2008-05-29 13:43:23 +0000
+++ boost/archive/basic_archive.hpp	2008-05-29 13:46:27 +0000
@@ -82,6 +82,24 @@
     }
 };
 
+struct class_name_optional_type : private boost::noncopyable {
+    char *t;
+    operator const char * & () const {
+        return const_cast<const char * &>(t);
+    }
+    operator char * () {
+        return t;
+    }
+    explicit class_name_optional_type(const char *key_) 
+    : t(const_cast<char *>(key_)){}
+    explicit class_name_optional_type(char *key_) 
+    : t(key_){}
+    class_name_optional_type & operator=(const class_name_optional_type & rhs){
+        t = rhs.t;
+        return *this;
+    }
+};
+
 enum archive_flags {
     no_header = 1,  // suppress archive header info
     no_codecvt = 2,  // suppress alteration of codecvt facet
@@ -113,6 +131,7 @@
 BOOST_CLASS_IMPLEMENTATION(boost::archive::class_id_reference_type, primitive_type)
 BOOST_CLASS_IMPLEMENTATION(boost::archive::class_id_optional_type, primitive_type)
 BOOST_CLASS_IMPLEMENTATION(boost::archive::class_name_type, primitive_type)
+BOOST_CLASS_IMPLEMENTATION(boost::archive::class_name_optional_type, primitive_type)
 BOOST_CLASS_IMPLEMENTATION(boost::archive::object_id_type, primitive_type)
 BOOST_CLASS_IMPLEMENTATION(boost::archive::object_reference_type, primitive_type)
 BOOST_CLASS_IMPLEMENTATION(boost::archive::tracking_type, primitive_type)

=== modified file 'boost/archive/basic_binary_oarchive.hpp'
--- boost/archive/basic_binary_oarchive.hpp	2008-05-29 13:43:23 +0000
+++ boost/archive/basic_binary_oarchive.hpp	2008-05-29 14:01:17 +0000
@@ -104,6 +104,12 @@
         * this->This() << s;
     }
 
+    // explicitly convert to char * to avoid compile ambiguities
+    void save_override(const class_name_optional_type & t, int){
+        const std::string s(t);
+        * this->This() << s;
+    }
+
     BOOST_ARCHIVE_OR_WARCHIVE_DECL(void)
     init();
 

=== modified file 'boost/archive/basic_text_oarchive.hpp'
--- boost/archive/basic_text_oarchive.hpp	2008-05-29 13:43:23 +0000
+++ boost/archive/basic_text_oarchive.hpp	2008-05-29 13:59:56 +0000
@@ -112,6 +112,10 @@
         const std::string s(t);
         * this->This() << s;
     }
+    void save_override(const class_name_optional_type & t, int){
+        const std::string s(t);
+        * this->This() << s;
+    }
 
     BOOST_ARCHIVE_OR_WARCHIVE_DECL(void)
     init();

=== modified file 'boost/archive/basic_xml_oarchive.hpp'
--- boost/archive/basic_xml_oarchive.hpp	2008-05-29 13:43:23 +0000
+++ boost/archive/basic_xml_oarchive.hpp	2008-05-29 14:00:34 +0000
@@ -115,6 +115,8 @@
     BOOST_ARCHIVE_OR_WARCHIVE_DECL(void)
     save_override(const class_name_type & t, int);
     BOOST_ARCHIVE_OR_WARCHIVE_DECL(void)
+    save_override(const class_name_optional_type & t, int);
+    BOOST_ARCHIVE_OR_WARCHIVE_DECL(void)
     save_override(const tracking_type & t, int);
 
     BOOST_ARCHIVE_OR_WARCHIVE_DECL(BOOST_PP_EMPTY()) 

=== modified file 'boost/archive/detail/basic_oarchive.hpp'
--- boost/archive/detail/basic_oarchive.hpp	2008-05-29 13:43:23 +0000
+++ boost/archive/detail/basic_oarchive.hpp	2008-05-29 13:55:17 +0000
@@ -60,6 +60,7 @@
     virtual void vsave(const class_id_optional_type t) = 0;
     virtual void vsave(const class_id_reference_type t) =  0;
     virtual void vsave(const class_name_type & t) = 0;
+    virtual void vsave(const class_name_optional_type & t) = 0;
     virtual void vsave(const tracking_type t) = 0;
 protected:
     basic_oarchive(unsigned int flags);

=== modified file 'boost/archive/detail/common_oarchive.hpp'
--- boost/archive/detail/common_oarchive.hpp	2008-05-29 13:43:23 +0000
+++ boost/archive/detail/common_oarchive.hpp	2008-05-29 13:55:48 +0000
@@ -52,6 +52,9 @@
     virtual void vsave(const class_name_type & t){
         * this->This() << t;
     }
+    virtual void vsave(const class_name_optional_type & t){
+        * this->This() << t;
+    }
     virtual void vsave(const tracking_type t){
         * this->This() << t;
     }

=== modified file 'boost/archive/impl/basic_xml_oarchive.ipp'
--- boost/archive/impl/basic_xml_oarchive.ipp	2008-05-29 13:43:23 +0000
+++ boost/archive/impl/basic_xml_oarchive.ipp	2008-05-29 13:58:53 +0000
@@ -201,6 +201,15 @@
 }
 template<class Archive>
 BOOST_ARCHIVE_OR_WARCHIVE_DECL(void)
+basic_xml_oarchive<Archive>::save_override(const class_name_optional_type & t, int)
+{
+    const char * key = t;
+    if(NULL == key)
+        return;
+    write_attribute(CLASS_NAME(), key);
+}
+template<class Archive>
+BOOST_ARCHIVE_OR_WARCHIVE_DECL(void)
 basic_xml_oarchive<Archive>::save_override(const tracking_type & t, int)
 {
     write_attribute(TRACKING(), t.t); // extra .t is for borland

=== modified file 'libs/serialization/src/basic_oarchive.cpp'
--- libs/serialization/src/basic_oarchive.cpp	2008-05-29 13:43:23 +0000
+++ libs/serialization/src/basic_oarchive.cpp	2008-06-08 14:35:36 +0000
@@ -315,28 +315,34 @@
     const cobject_type & co = register_type(bos);
     if(! co.initialized){
         ar.vsave(co.class_id);
+        const serialization::extended_type_info *eti = & bos.get_eti();
+        const char * key = NULL;
+        if(NULL != eti)
+            key = eti->get_key();
+        if(NULL == key){
+            // without an external class name
+            // we won't be able to de-serialize it so bail now
+            boost::throw_exception(
+                archive_exception(archive_exception::unregistered_class)
+            );
+        }
+
         // if its a previously unregistered class 
         if((cobject_info_set.size() > original_count)){
             if(bos.is_polymorphic()){
-                const serialization::extended_type_info *eti = & bos.get_eti();
-                const char * key = NULL;
-                if(NULL != eti)
-                    key = eti->get_key();
-                if(NULL != key){
-                    // the following is required by IBM C++ compiler which
-                    // makes a copy when passing a non-const to a const.  This
-                    // is permitted by the standard but rarely seen in practice
-                    const class_name_type cn(key);
-                    // write out the external class identifier
-                    ar.vsave(cn);
-                }
-                else
-                    // without an external class name
-                    // we won't be able to de-serialize it so bail now
-                    boost::throw_exception(
-                        archive_exception(archive_exception::unregistered_class)
-                    );
+                // the following is required by IBM C++ compiler which
+                // makes a copy when passing a non-const to a const.  This
+                // is permitted by the standard but rarely seen in practice
+                const class_name_type cn(key);
+                // write out the external class identifier
+                ar.vsave(cn);
+            } else {
+                const class_name_optional_type cno(key);
+                ar.vsave(cno);
             }
+        } else {
+            const class_name_optional_type cno(key);
+            ar.vsave(cno);
         }
         if(bos.class_info()){
             ar.vsave(tracking_type(bos.tracking(m_flags)));