--- inversive_congruential.hpp.orig	2008-07-21 16:13:54.000000000 +0800
+++ inversive_congruential.hpp	2009-01-23 22:59:09.000000000 +0800
@@ -71,7 +71,7 @@
     return value;
   }
 
-  bool validation(result_type x) const { return val == x; }
+  static bool validation(result_type x) const { return val == x; }
 
 #ifndef BOOST_NO_OPERATORS_IN_NAMESPACE