Eric Niebler wrote:
Tobias Schwinger wrote:
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
Yep, you're right. I hope find a fix before I leave for vacation on Monday. If I can't and this is a serious issue for you, feel free to revert the change until I can patch this up.
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));
I'll let Doug comment on this one.
The attached patch fixes both problems. Doug, should I commit (to HEAD)? Also see the new test (attached). -- Eric Niebler Boost Consulting www.boost-consulting.com ? boost/utility/result_of_patch.txt Index: boost/utility/result_of.hpp =================================================================== RCS file: /cvsroot/boost/boost/boost/utility/result_of.hpp,v retrieving revision 1.8 diff -b -d -u -r1.8 result_of.hpp --- boost/utility/result_of.hpp 8 Jan 2007 20:38:51 -0000 1.8 +++ boost/utility/result_of.hpp 14 Jan 2007 06:13:50 -0000 @@ -31,6 +31,24 @@ template<typename F, typename FArgs, bool HasResultType> struct result_of_impl; +template<typename F> +struct result_of_void_impl +{ + typedef void type; +}; + +template<typename R> +struct result_of_void_impl<R (*)(void)> +{ + typedef R type; +}; + +template<typename R> +struct result_of_void_impl<R (&)(void)> +{ + typedef R type; +}; + template<typename F, typename FArgs> struct result_of_impl<F, FArgs, true> { @@ -44,9 +62,8 @@ template<typename F> struct result_of_impl<F, F(void), false> -{ - typedef void type; -}; + : result_of_void_impl<F> +{}; } // end namespace detail 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 -b -d -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 14 Jan 2007 06:13:50 -0000 @@ -24,25 +24,27 @@ : detail::result_of_impl<F, F(BOOST_RESULT_OF_ARGS), (detail::has_result_type<F>::value)> {}; #endif +#undef BOOST_RESULT_OF_ARGS + +#if BOOST_PP_ITERATION() >= 1 + namespace detail { 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 (*)(BOOST_RESULT_OF_ARGS), FArgs, false> +struct result_of_impl<R (*)(BOOST_PP_ENUM_PARAMS(BOOST_PP_ITERATION(),T)), FArgs, false> { typedef R type; }; 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 (&)(BOOST_RESULT_OF_ARGS), FArgs, false> +struct result_of_impl<R (&)(BOOST_PP_ENUM_PARAMS(BOOST_PP_ITERATION(),T)), FArgs, false> { typedef R type; }; -#undef BOOST_RESULT_OF_ARGS - -#if BOOST_PP_ITERATION() > 1 && !BOOST_WORKAROUND(__BORLANDC__, BOOST_TESTED_AT(0x551)) +#if !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::*) @@ -84,3 +86,4 @@ #endif } +#endif // 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; }; }; template<typename T> struct int_result_type_template { typedef int result_type; }; template<typename T> struct int_result_of_template { template<typename F> struct result; template<typename This, typename That> struct result<This(That)> { typedef int type; }; }; template<typename T> struct int_result_type_and_float_result_of_template { typedef int result_type; template<typename F> struct result; template<typename This, typename That> struct result<This(That)> { typedef float type; }; }; struct X {}; int main() { using namespace boost; typedef int (*func_ptr)(float, double); typedef int (&func_ref)(float, double); typedef int (*func_ptr_0)(); typedef int (&func_ref_0)(); typedef int (X::*mem_func_ptr)(float); 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; typedef int (X::*mem_func_ptr_0)(); 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<int_result_type_template<void>(float)>::type, int>::value)); BOOST_STATIC_ASSERT((is_same<result_of<int_result_of_template<void>(double)>::type, int>::value)); BOOST_STATIC_ASSERT((is_same<result_of<int_result_of_template<void>(void)>::type, void>::value)); BOOST_STATIC_ASSERT((is_same<result_of<const int_result_of_template<void>(double)>::type, int>::value)); BOOST_STATIC_ASSERT((is_same<result_of<volatile int_result_of_template<void>(void)>::type, void>::value)); BOOST_STATIC_ASSERT((is_same<result_of<int_result_type_and_float_result_of_template<void>(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_ref(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_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_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)); BOOST_STATIC_ASSERT((is_same<result_of<mem_func_ptr_0(X)>::type, int>::value)); return 0; }