Suppress a GCC 2.x ICE

[SVN r19235]

include/boost/python/to_python_value.hpp

@@ -101,6 +101,11 @@ namespace detail
   template <class T>
   inline PyObject* registry_to_python_value<T>::operator()(argument_type x) const
   {
+      typedef converter::registered<argument_type> r;
+# if BOOST_WORKAROUND(__GNUC__, < 3)
+      // suppresses an ICE, somehow
+      (void)r::converters;
+# endif 
       return converter::registered<argument_type>::converters.to_python(&x);
   }