type_traits (__decay_selector<_Up, [...]): Change according to DR 705.

2007-11-08  Paolo Carlini  <pcarlini@suse.de>

	* include/std/type_traits (__decay_selector<_Up, false, false>):
	Change according to DR 705.
	* include/bits/stl_pair.h (make_pair(_T1&&, _T2&&)): Change
	according to DR 706.
	* include/tr1_impl/tuple: Tweak.

From-SVN: r130001

3 files changed, 43 insertions, 11 deletions

diff --git a/libstdc++-v3/include/bits/stl_pair.h b/libstdc++-v3/include/bits/stl_pair.h
index 7163b62..6623026 100644
--- a/libstdc++-v3/include/bits/stl_pair.h
+++ b/libstdc++-v3/include/bits/stl_pair.h
@@ -211,14 +211,44 @@ _GLIBCXX_BEGIN_NAMESPACE(std)
     make_pair(_T1 __x, _T2 __y)
     { return pair<_T1, _T2>(__x, __y); }
 #else
+  template<typename _Tp>
+    class reference_wrapper;
+
+  // Helper which adds a reference to a type when given a reference_wrapper
+  template<typename _Tp>
+    struct __strip_reference_wrapper
+    {
+      typedef _Tp __type;
+    };
+
+  template<typename _Tp>
+    struct __strip_reference_wrapper<reference_wrapper<_Tp> >
+    {
+      typedef _Tp& __type;
+    };
+
+  template<typename _Tp>
+    struct __strip_reference_wrapper<const reference_wrapper<_Tp> >
+    {
+      typedef _Tp& __type;
+    };
+
+  template<typename _Tp>
+    struct __decay_and_strip
+    {
+      typedef typename __strip_reference_wrapper<
+	typename decay<_Tp>::type>::__type __type;
+    };
+
+  // NB: DR 706.
   template<class _T1, class _T2>
-    inline pair<typename std::decay<_T1>::type,
-		typename std::decay<_T2>::type>
+    inline pair<typename __decay_and_strip<_T1>::__type,
+		typename __decay_and_strip<_T2>::__type>
     make_pair(_T1&& __x, _T2&& __y)
     {
-      return pair<typename std::decay<_T1>::type,
-	          typename std::decay<_T2>::type>(std::forward<_T1>(__x),
-						  std::forward<_T2>(__y));
+      return pair<typename __decay_and_strip<_T1>::__type,
+	          typename __decay_and_strip<_T2>::__type>
+	(std::forward<_T1>(__x), std::forward<_T2>(__y));
     }
 #endif
 
diff --git a/libstdc++-v3/include/std/type_traits b/libstdc++-v3/include/std/type_traits
index 33442ba..38c92ab 100644
--- a/libstdc++-v3/include/std/type_traits
+++ b/libstdc++-v3/include/std/type_traits
@@ -308,21 +308,21 @@ namespace std
 	   bool _IsFunction = is_function<_Up>::value> 
     struct __decay_selector;
 
+  // NB: DR 705.
   template<typename _Up> 
     struct __decay_selector<_Up, false, false>
-    { typedef _Up __type; };
+    { typedef typename remove_cv<_Up>::type __type; };
 
   template<typename _Up> 
     struct __decay_selector<_Up, true, false>
     { typedef typename remove_extent<_Up>::type* __type; };
 
-
   template<typename _Up> 
     struct __decay_selector<_Up, false, true>
     { typedef typename add_pointer<_Up>::type __type; };
 
   template<typename _Tp> 
-  struct decay 
+    struct decay 
     { 
     private:
       typedef typename remove_reference<_Tp>::type __remove_type;
diff --git a/libstdc++-v3/include/tr1_impl/tuple b/libstdc++-v3/include/tr1_impl/tuple
index 52017d6..e71bd41 100644
--- a/libstdc++-v3/include/tr1_impl/tuple
+++ b/libstdc++-v3/include/tr1_impl/tuple
@@ -39,9 +39,6 @@ namespace std
 {
 _GLIBCXX_BEGIN_NAMESPACE_TR1
 
-  template<typename _Tp>
-    class reference_wrapper;
-
   // Adds a const reference to a non-reference type.
   template<typename _Tp>
     struct __add_c_ref
@@ -375,6 +372,10 @@ _GLIBCXX_BEGIN_NAMESPACE_TR1
 	       const tuple<_UElements...>& __u)
     { return !(__t < __u); }
 
+#ifdef _GLIBCXX_INCLUDE_AS_TR1
+  template<typename _Tp>
+    class reference_wrapper;
+
   // Helper which adds a reference to a type when given a reference_wrapper
   template<typename _Tp>
     struct __strip_reference_wrapper
@@ -393,6 +394,7 @@ _GLIBCXX_BEGIN_NAMESPACE_TR1
     {
       typedef _Tp& __type;
     };
+#endif
 
   template<typename... _Elements>
     inline tuple<typename __strip_reference_wrapper<_Elements>::__type...>