Hi, here is how it breaks. Let's start with the new bug: 1. typedef int (*func_ptr_0)(); BOOST_STATIC_ASSERT((is_same< result_of<func_ptr_0()>::type, int>::value)); ==> Ambiguous template specialization, this one got introduced by Eric's workaround 2. Although it seems to be the same problem, it's actually a different one (just a typo - see result_of_iterate.patch). This test fails with the RC 1.34 version, too: typedef int (X::*mem_func_ptr_0)(); BOOST_STATIC_ASSERT((is_same< result_of<mem_func_ptr_0(X)>::type, int>::value)); Regards, Tobias Index: boost/utility/detail/result_of_iterate.hpp =================================================================== RCS file: /cvsroot/boost/boost/boost/utility/detail/result_of_iterate.hpp,v retrieving revision 1.4 diff -u -r1.4 result_of_iterate.hpp --- boost/utility/detail/result_of_iterate.hpp 8 Jan 2007 20:38:51 -0000 1.4 +++ boost/utility/detail/result_of_iterate.hpp 13 Jan 2007 23:55:08 -0000 @@ -42,7 +42,7 @@ #undef BOOST_RESULT_OF_ARGS -#if BOOST_PP_ITERATION() > 1 && !BOOST_WORKAROUND(__BORLANDC__, BOOST_TESTED_AT(0x551)) +#if BOOST_PP_ITERATION() >= 1 && !BOOST_WORKAROUND(__BORLANDC__, BOOST_TESTED_AT(0x551)) template<typename R, typename FArgs BOOST_PP_COMMA_IF(BOOST_PP_ITERATION()) BOOST_PP_ENUM_PARAMS(BOOST_PP_ITERATION(),typename T)> struct result_of_impl<R (T0::*) // Boost result_of library // Copyright Douglas Gregor 2003-2004. Use, modification and // distribution is subject to the Boost Software License, Version // 1.0. (See accompanying file LICENSE_1_0.txt or copy at // http://www.boost.org/LICENSE_1_0.txt) // For more information, see http://www.boost.org/libs/utility #include <boost/utility/result_of.hpp> #include <utility> #include <boost/static_assert.hpp> #include <boost/type_traits/is_same.hpp> struct int_result_type { typedef int result_type; }; struct int_result_of { template<typename F> struct result { typedef int type; }; }; struct int_result_type_and_float_result_of { typedef int result_type; template<typename F> struct result { typedef float type; }; }; struct X {}; int main() { using namespace boost; typedef int (*func_ptr)(float, double); typedef int (*func_ptr_0)(); typedef int (&func_ref)(float, double); typedef int (*func_ref_0)(); typedef int (X::*mem_func_ptr)(float); typedef int (X::*mem_func_ptr_0)(); typedef int (X::*mem_func_ptr_c)(float) const; typedef int (X::*mem_func_ptr_v)(float) volatile; typedef int (X::*mem_func_ptr_cv)(float) const volatile; BOOST_STATIC_ASSERT((is_same<result_of<int_result_type(float)>::type, int>::value)); BOOST_STATIC_ASSERT((is_same<result_of<int_result_of(double)>::type, int>::value)); BOOST_STATIC_ASSERT((is_same<result_of<int_result_of(void)>::type, void>::value)); BOOST_STATIC_ASSERT((is_same<result_of<const int_result_of(double)>::type, int>::value)); BOOST_STATIC_ASSERT((is_same<result_of<volatile int_result_of(void)>::type, void>::value)); BOOST_STATIC_ASSERT((is_same<result_of<int_result_type_and_float_result_of(char)>::type, int>::value)); BOOST_STATIC_ASSERT((is_same<result_of<func_ptr(char, float)>::type, int>::value)); // BOOST_STATIC_ASSERT((is_same<result_of<func_ptr_0()>::type, int>::value)); BOOST_STATIC_ASSERT((is_same<result_of<func_ref(char, float)>::type, int>::value)); // BOOST_STATIC_ASSERT((is_same<result_of<func_ref_0()>::type, int>::value)); BOOST_STATIC_ASSERT((is_same<result_of<mem_func_ptr(X,char)>::type, int>::value)); BOOST_STATIC_ASSERT((is_same<result_of<mem_func_ptr_0(X)>::type, int>::value)); BOOST_STATIC_ASSERT((is_same<result_of<mem_func_ptr_c(X,char)>::type, int>::value)); BOOST_STATIC_ASSERT((is_same<result_of<mem_func_ptr_v(X,char)>::type, int>::value)); BOOST_STATIC_ASSERT((is_same<result_of<mem_func_ptr_cv(X,char)>::type, int>::value)); return 0; }