Revert fix for libstdc++/35637, thanks to other/36901.

2008-08-09  Paolo Carlini  <paolo.carlini@oracle.com>

	Revert fix for libstdc++/35637, thanks to other/36901.
	* include/tr1_impl/type_traits (__is_function_helper): New, uses
	variadic templates.
	(is_function): Forward to the latter.
	(__in_array): Remove.

From-SVN: r138906

libstdc++-v3/ChangeLog

 2008-08-09  Paolo Carlini  <paolo.carlini@oracle.com>
 
+	Revert fix for libstdc++/35637, thanks to other/36901.
+	* include/tr1_impl/type_traits (__is_function_helper): New, uses
+	variadic templates.
+	(is_function): Forward to the latter.
+	(__in_array): Remove.
+
+2008-08-09  Paolo Carlini  <paolo.carlini@oracle.com>
+
 	* config/locale/darwin/ctype_members.cc: Include <cstdio>.
 
 2008-08-08  Paolo Carlini  <paolo.carlini@oracle.com>

libstdc++-v3/include/tr1_impl/type_traits

@@ -183,30 +183,25 @@ _GLIBCXX_BEGIN_NAMESPACE_TR1
     { };
 
   template<typename _Tp>
-    struct __in_array
-    : public __sfinae_types
-    {
-    private:
-      template<typename _Up>
-        static __one __test(_Up(*)[1]);
-      template<typename>
-        static __two __test(...);
-    
-    public:
-      static const bool __value = sizeof(__test<_Tp>(0)) == 1;
-    };
+    struct remove_cv;
 
-  /// is_abstract
-  template<typename _Tp>
-    struct is_abstract;
+  template<typename>
+    struct __is_function_helper
+    : public false_type { };
+
+  template<typename _Res, typename... _ArgTypes>
+    struct __is_function_helper<_Res(_ArgTypes...)>
+    : public true_type { };
+
+  template<typename _Res, typename... _ArgTypes>
+    struct __is_function_helper<_Res(_ArgTypes......)>
+    : public true_type { };
 
   /// is_function
   template<typename _Tp>
     struct is_function
-    : public integral_constant<bool, !(__in_array<_Tp>::__value
-				       || is_abstract<_Tp>::value
-				       || is_reference<_Tp>::value
-				       || is_void<_Tp>::value)>
+    : public integral_constant<bool, (__is_function_helper<typename
+				      remove_cv<_Tp>::type>::value)>
     { };
 
   /// composite type traits [4.5.2].