Index: detail/error_info_impl.hpp
===================================================================
--- detail/error_info_impl.hpp	(revision 51549)
+++ detail/error_info_impl.hpp	(working copy)
@@ -31,7 +31,7 @@
             };
         }
 
-    template <class Tag,class T>
+    template <class Tag,class T,class Base>
     class
     error_info:
         public exception_detail::error_info_base
@@ -39,6 +39,7 @@
         public:
 
         typedef T value_type;
+        typedef Base base_type;
 
         error_info( value_type const & value );
         ~error_info() throw();
@@ -49,10 +50,11 @@
             return value_;
             }
 
+		protected:
+		std::string value_as_string() const;
+
         private:
-
         char const * tag_typeid_name() const;
-        std::string value_as_string() const;
 
         value_type const value_;
         };
Index: error_info.hpp
===================================================================
--- error_info.hpp	(revision 51549)
+++ error_info.hpp	(working copy)
@@ -3,4 +3,4 @@
 //Distributed under the Boost Software License, Version 1.0. (See accompanying
 //file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
 
-namespace boost { template <class Tag,class T> class error_info; }
+namespace boost { template <class Tag,class T,class Base> class error_info; }
Index: exception.hpp
===================================================================
--- exception.hpp	(revision 51549)
+++ exception.hpp	(working copy)
@@ -6,6 +6,8 @@
 #ifndef UUID_274DA366004E11DCB1DDFE2E56D89593
 #define UUID_274DA366004E11DCB1DDFE2E56D89593
 
+#include <boost/exception/detail/error_info_impl.hpp>
+
 namespace
 boost
     {
@@ -77,57 +79,38 @@
 
     ////////////////////////////////////////////////////////////////////////
 
-    template <class Tag,class T>
-    class error_info;
-
-    typedef error_info<struct tag_throw_function,char const *> throw_function;
-    typedef error_info<struct tag_throw_file,char const *> throw_file;
-    typedef error_info<struct tag_throw_line,int> throw_line;
-
-    template <>
     class
-    error_info<tag_throw_function,char const *>
+	throw_function:public error_info<struct tag_throw_function,char const *,throw_function>
         {
         public:
-        typedef char const * value_type;
-        value_type v_;
-        explicit
-        error_info( value_type v ):
-            v_(v)
+        throw_function( char const * v ):
+		  error_info<tag_throw_function,char const *,throw_function> (v)
             {
             }
         };
 
-    template <>
     class
-    error_info<tag_throw_file,char const *>
+	throw_file:public error_info<struct tag_throw_file,char const *,throw_file>
         {
         public:
-        typedef char const * value_type;
-        value_type v_;
-        explicit
-        error_info( value_type v ):
-            v_(v)
+        throw_file( char const * v ):
+		  error_info<tag_throw_file,char const *,throw_file> (v)
             {
             }
         };
 
-    template <>
     class
-    error_info<tag_throw_line,int>
+	throw_line:public error_info<struct tag_throw_line,int,throw_line>
         {
         public:
-        typedef int value_type;
-        value_type v_;
-        explicit
-        error_info( value_type v ):
-            v_(v)
+        throw_line( int v ):
+		  error_info<tag_throw_line,int,throw_line> (v)
             {
             }
         };
 
-    template <class E,class Tag,class T>
-    E const & operator<<( E const &, error_info<Tag,T> const & );
+    template <class E,class Tag,class T,class Base>
+    E const & operator<<( E const &, error_info<Tag,T,Base> const & );
 
     class exception;
 
@@ -233,8 +216,8 @@
 
         friend char const * exception_detail::get_diagnostic_information( exception const & );
 
-        template <class E,class Tag,class T>
-        friend E const & operator<<( E const &, error_info<Tag,T> const & );
+        template <class E,class Tag,class T,class Base>
+        friend E const & operator<<( E const &, error_info<Tag,T,Base> const & );
 
         template <class>
         friend struct exception_detail::get_info;
Index: info.hpp
===================================================================
--- info.hpp	(revision 51549)
+++ info.hpp	(working copy)
@@ -15,42 +15,42 @@
 namespace
 boost
     {
-    template <class Tag,class T>
+    template <class Tag,class T,class Base>
     inline
     typename enable_if<has_to_string<T>,std::string>::type
-    to_string( error_info<Tag,T> const & x )
+    to_string( error_info<Tag,T,Base> const & x )
         {
         return to_string(x.value());
         }
 
-    template <class Tag,class T>
+	template <class Tag,class T,class Base>
     inline
-    error_info<Tag,T>::
+    error_info<Tag,T,Base>::
     error_info( value_type const & value ):
         value_(value)
         {
         }
 
-    template <class Tag,class T>
+    template <class Tag,class T,class Base>
     inline
-    error_info<Tag,T>::
+    error_info<Tag,T,Base>::
     ~error_info() throw()
         {
         }
 
-    template <class Tag,class T>
+    template <class Tag,class T,class Base>
     inline
     char const *
-    error_info<Tag,T>::
+    error_info<Tag,T,Base>::
     tag_typeid_name() const
         {
         return tag_type_name<Tag>();
         }
 
-    template <class Tag,class T>
+    template <class Tag,class T,class Base>
     inline
     std::string
-    error_info<Tag,T>::
+    error_info<Tag,T,Base>::
     value_as_string() const
         {
         return to_string_stub(*this);
@@ -141,19 +141,20 @@
             };
         }
 
-    template <class E,class Tag,class T>
+    template <class E,class Tag,class T,class Base>
     inline
     E const &
-    operator<<( E const & x, error_info<Tag,T> const & v )
+    operator<<( E const & x, error_info<Tag,T,Base> const & v )
         {
-        typedef error_info<Tag,T> error_info_tag_t;
-        shared_ptr<error_info_tag_t> p( new error_info_tag_t(v) );
+        typedef error_info<Tag,T,Base> error_info_tag_t;
+		shared_ptr<error_info_tag_t> p( new Base(v) );
         exception_detail::error_info_container * c;
         if( !(c=x.data_.get()) )
             x.data_.adopt(c=new exception_detail::error_info_container_impl);
         c->set(p,BOOST_EXCEPTION_STATIC_TYPEID(error_info_tag_t));
         return x;
         }
-    }
 
+ 	}
+
 #endif
Index: info_tuple.hpp
===================================================================
--- info_tuple.hpp	(revision 51549)
+++ info_tuple.hpp	(working copy)
@@ -14,51 +14,51 @@
     {
     template <
         class E,
-        class Tag1,class T1,
-        class Tag2,class T2 >
+        class Tag1,class T1,class Base1,
+        class Tag2,class T2,class Base2 >
     inline
     E const &
     operator<<(
         E const & x,
         tuple<
-            error_info<Tag1,T1>,
-            error_info<Tag2,T2> > const & v )
+            error_info<Tag1,T1,Base1>,
+            error_info<Tag2,T2,Base2> > const & v )
         {
         return x << v.template get<0>() << v.template get<1>();
         }
 
     template <
         class E,
-        class Tag1,class T1,
-        class Tag2,class T2,
-        class Tag3,class T3 >
+        class Tag1,class T1,class Base1,
+        class Tag2,class T2,class Base2,
+        class Tag3,class T3,class Base3 >
     inline
     E const &
     operator<<(
         E const & x,
         tuple<
-            error_info<Tag1,T1>,
-            error_info<Tag2,T2>,
-            error_info<Tag3,T3> > const & v )
+            error_info<Tag1,T1,Base1>,
+            error_info<Tag2,T2,Base2>,
+            error_info<Tag3,T3,Base3> > const & v )
         {
         return x << v.template get<0>() << v.template get<1>() << v.template get<2>();
         }
 
     template <
         class E,
-        class Tag1,class T1,
-        class Tag2,class T2,
-        class Tag3,class T3,
-        class Tag4,class T4 >
+        class Tag1,class T1,class Base1,
+        class Tag2,class T2,class Base2,
+        class Tag3,class T3,class Base3,
+        class Tag4,class T4,class Base4 >
     inline
     E const &
     operator<<(
         E const & x,
         tuple<
-            error_info<Tag1,T1>,
-            error_info<Tag2,T2>,
-            error_info<Tag3,T3>,
-            error_info<Tag4,T4> > const & v )
+            error_info<Tag1,T1,Base1>,
+            error_info<Tag2,T2,Base2>,
+            error_info<Tag3,T3,Base3>,
+            error_info<Tag4,T4,Base4> > const & v )
         {
         return x << v.template get<0>() << v.template get<1>() << v.template get<2>() << v.template get<3>();
         }