Index: lexical_cast.hpp
===================================================================
--- lexical_cast.hpp	(revision 49139)
+++ lexical_cast.hpp	(working copy)
@@ -1099,6 +1099,12 @@
             typedef const T * type;
         };
 
+
+#ifdef BOOST_MSVC
+# pragma warning( push )
+# pragma warning( disable : 4702 ) //unreachable code, line 1149
+#endif
+
         template< typename Target
                 , typename Source
                 , bool Unlimited // string representation of Source is unlimited
@@ -1142,6 +1148,11 @@
             throw_exception(bad_lexical_cast(typeid(Source), typeid(Target)));
             return Target(); // normally never reached (throw_exception)
         }
+
+#ifdef BOOST_MSVC
+# pragma warning( pop )
+#endif
+
     }
 
     template<typename Target, typename Source>