Index: manip.hpp
===================================================================
--- manip.hpp	(revision 83587)
+++ manip.hpp	(working copy)
@@ -11,7 +11,6 @@
 
 #include <boost/config.hpp>
 #include <string>
-#include <vector>
 #include <cctype>
 
 // Tuple I/O manipulators
@@ -38,44 +37,72 @@
 {
     namespace detail
     {
-        template <typename Tag>
-        int get_xalloc_index(Tag* = 0)
+        template<typename Tag>
+        struct xalloc_key_holder 
         {
-            // each Tag will have a unique index
-            static int index = std::ios::xalloc();
-            return index;
-        }
+            static int value;
+            static bool initialized;
+        };
 
-        template <typename Stream, typename Tag, typename T>
-        struct stream_data
+        template<typename Tag>
+        int xalloc_key_holder<Tag>::value = 0;
+
+        template<typename Tag>
+        bool xalloc_key_holder<Tag>::initialized = 0;
+
+        template<typename Tag>
+        struct xalloc_key_initializer_t 
         {
-            struct arena
+            xalloc_key_initializer_t() 
             {
-                ~arena()
+                if (!xalloc_key_holder<Tag>::initialized) 
                 {
-                    for (
-                        typename std::vector<T*>::iterator i = data.begin()
-                      ; i != data.end()
-                      ; ++i)
-                    {
-                        delete *i;
-                    }
+                    xalloc_key_holder<Tag>::value       = std::ios_base::xalloc();
+                    xalloc_key_holder<Tag>::initialized = true;
                 }
+            }
+        };
 
-                std::vector<T*> data;
-            };
+        template <typename Stream, typename Tag>
+        struct stream_data
+        {
+            typedef FUSION_STRING_OF_STREAM(Stream) string_type;
 
-            static void attach(Stream& stream, T const& data)
+            static void attach(Stream& s, string_type const& data)
             {
-                static arena ar; // our arena
-                ar.data.push_back(new T(data));
-                stream.pword(get_xalloc_index<Tag>()) = ar.data.back();
+                delete_this(s); // last manipulator over-writes previous
+
+                get_ptr_ref(s) = new string_type(data);
+
+                s.register_callback(erase, index());
             }
 
-            static T const* get(Stream& stream)
+            static string_type const* get(Stream& s)
             {
-                return (T const*)stream.pword(get_xalloc_index<Tag>());
+                return get_ptr_ref(s);
             }
+
+        private:
+
+            static int index() { return xalloc_key_holder<Tag>::value; }
+
+            static string_type const*& get_ptr_ref(std::ios_base& s)
+            {
+                return (string_type const*&)s.pword(index());
+            }
+
+            static void erase(std::ios_base::event ev, std::ios_base& s, int idx)
+            {
+                if(std::ios_base::erase_event == ev && index() == idx)
+                {
+                    delete_this(s);
+                }
+            }
+
+            static void delete_this(std::ios_base& s)
+            {
+                delete get_ptr_ref(s); get_ptr_ref(s) = 0;
+            }
         };
 
         template <typename Tag, typename Stream>
@@ -85,7 +112,7 @@
 
             typedef FUSION_STRING_OF_STREAM(Stream) string_type;
 
-            typedef stream_data<Stream, Tag, string_type> stream_data_t;
+            typedef stream_data<Stream, Tag> stream_data_t;
 
             string_ios_manip(Stream& str_)
                 : stream(str_)
@@ -301,6 +328,7 @@
 
 #endif // defined(BOOST_NO_TEMPLATED_STREAMS)
 
+
     STD_TUPLE_DEFINE_MANIPULATOR(tuple_open)
     STD_TUPLE_DEFINE_MANIPULATOR(tuple_close)
     STD_TUPLE_DEFINE_MANIPULATOR(tuple_delimiter)
@@ -309,12 +337,21 @@
     STD_TUPLE_DEFINE_MANIPULATOR_FUNCTIONS(tuple_close)
     STD_TUPLE_DEFINE_MANIPULATOR_FUNCTIONS(tuple_delimiter)
 
+
 #undef STD_TUPLE_DEFINE_MANIPULATOR
 #undef STD_TUPLE_DEFINE_MANIPULATOR_FUNCTIONS
 #undef FUSION_STRING_OF_STREAM
 #undef FUSION_GET_CHAR_TYPE
 #undef FUSION_GET_TRAITS_TYPE
 
+namespace detail { namespace /**/ {
+    
+    xalloc_key_initializer_t<tuple_open_tag     > xalloc_key_initializer_tuple_open;
+    xalloc_key_initializer_t<tuple_close_tag    > xalloc_key_initializer_tuple_close;
+    xalloc_key_initializer_t<tuple_delimiter_tag> xalloc_key_initializer_tuple_delimiter;
+
+} }
+
 }}
 
 #endif