Index: boost/lexical_cast.hpp
===================================================================
--- boost/lexical_cast.hpp	(revision 53445)
+++ boost/lexical_cast.hpp	(working copy)
@@ -1111,6 +1111,12 @@
             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
@@ -1158,6 +1164,11 @@
 #endif
             return Target(); // normally never reached (throw_exception)
         }
+
+#ifdef BOOST_MSVC
+# pragma warning( pop )
+#endif
+
     }
 
     template<typename Target, typename Source>