diff -Nurp boost_1_42_0.old//boost/mpl/aux_/preprocessed/gcc/template_arity.hpp boost_1_42_0/boost/mpl/aux_/preprocessed/gcc/template_arity.hpp
--- boost/mpl/aux_/preprocessed/gcc/template_arity.hpp	2010-04-01 21:57:59.000000000 +0200
+++ boost/mpl/aux_/preprocessed/gcc/template_arity.hpp	2010-04-01 21:59:13.000000000 +0200
@@ -83,7 +83,7 @@ template< typename F, int N >
 struct template_arity_impl
 {
     BOOST_STATIC_CONSTANT(int, value =
-          sizeof(arity_helper(type_wrapper<F>(), arity_tag<N>())) - 1
+          sizeof(::boost::mpl::aux::arity_helper(type_wrapper<F>(), arity_tag<N>())) - 1
         );
 };
 
diff -Nurp boost_1_42_0.old//boost/mpl/aux_/template_arity.hpp boost_1_42_0/boost/mpl/aux_/template_arity.hpp
--- boost/mpl/aux_/template_arity.hpp	2010-04-01 21:57:59.000000000 +0200
+++ boost/mpl/aux_/template_arity.hpp	2010-04-01 21:58:54.000000000 +0200
@@ -98,7 +98,7 @@ template< typename F, BOOST_MPL_AUX_NTTP
 struct template_arity_impl
 {
     BOOST_STATIC_CONSTANT(int, value = 
-          sizeof(arity_helper(type_wrapper<F>(),arity_tag<N>())) - 1
+          sizeof(::boost::mpl::aux::arity_helper(type_wrapper<F>(),arity_tag<N>())) - 1
         );
 };