result_of implementation that makes use of C++0x decltype, from Daniel Walker. Fixes #862.

[SVN r45256]

include/boost/utility/detail/result_of_iterate.hpp

@@ -10,6 +10,46 @@
 # error Boost result_of - do not include this file!
 #endif
 
+#if defined(BOOST_HAS_DECLTYPE)
+
+// As of N2588, C++0x result_of only supports function call
+// expressions of the form f(x). This precludes support for member
+// function pointers, which are invoked with expressions of the form
+// o->*f(x). This implementation supports both.
+template<typename F BOOST_PP_COMMA_IF(BOOST_PP_ITERATION())
+         BOOST_PP_ENUM_PARAMS(BOOST_PP_ITERATION(),typename T)>
+struct result_of<F(BOOST_PP_ENUM_PARAMS(BOOST_PP_ITERATION(),T))>
+    : mpl::if_<
+          mpl::or_< is_pointer<F>, is_member_function_pointer<F> >
+        , detail::result_of_impl<
+              F, F(BOOST_PP_ENUM_PARAMS(BOOST_PP_ITERATION(),T)), false
+          >
+        , detail::result_of_decltype_impl<
+              F(BOOST_PP_ENUM_PARAMS(BOOST_PP_ITERATION(),T))
+          >
+      >::type
+{};
+
+namespace detail {
+
+# define BOOST_RESULT_OF_STATIC_MEMBERS(z, n, _) \
+     static T ## n t ## n; \
+  /**/
+
+template<typename F BOOST_PP_COMMA_IF(BOOST_PP_ITERATION())
+         BOOST_PP_ENUM_PARAMS(BOOST_PP_ITERATION(),typename T)>
+class result_of_decltype_impl<F(BOOST_PP_ENUM_PARAMS(BOOST_PP_ITERATION(),T))>
+{
+  static F f;
+  BOOST_PP_REPEAT(BOOST_PP_ITERATION(), BOOST_RESULT_OF_STATIC_MEMBERS, _)
+public:
+  typedef decltype(f(BOOST_PP_ENUM_PARAMS(BOOST_PP_ITERATION(),t))) type;
+};
+
+} // namespace detail 
+
+#else // defined(BOOST_HAS_DECLTYPE)
+
 // CWPro8 requires an argument in a function type specialization
 #if BOOST_WORKAROUND(__MWERKS__, BOOST_TESTED_AT(0x3002)) && BOOST_PP_ITERATION() == 0
 # define BOOST_RESULT_OF_ARGS void
@@ -26,6 +66,8 @@ struct result_of<F(BOOST_RESULT_OF_ARGS)>
 
 #undef BOOST_RESULT_OF_ARGS
 
+#endif // defined(BOOST_HAS_DECLTYPE)
+
 #if BOOST_PP_ITERATION() >= 1 
 
 namespace detail {

include/boost/utility/result_of.hpp

@@ -18,6 +18,9 @@
 #include <boost/mpl/has_xxx.hpp>
 #include <boost/mpl/if.hpp>
 #include <boost/mpl/bool.hpp>
+#include <boost/mpl/or.hpp>
+#include <boost/type_traits/is_pointer.hpp>
+#include <boost/type_traits/is_member_function_pointer.hpp>
 
 #ifndef BOOST_RESULT_OF_NUM_ARGS
 #  define BOOST_RESULT_OF_NUM_ARGS 10
@@ -33,6 +36,7 @@ namespace detail {
 BOOST_MPL_HAS_XXX_TRAIT_DEF(result_type)
 
 template<typename F, typename FArgs, bool HasResultType> struct result_of_impl;
+template<typename F> struct result_of_decltype_impl;
 
 template<typename F>
 struct result_of_void_impl