tuple (tuple_size<cv _Tp>): Implement LWG 2313.

	* include/std/tuple (tuple_size<cv _Tp>): Implement LWG 2313.
	* include/std/array (tuple_size, tuple_element): Add Doxygen comments.
	* include/std/utility (tuple_size, tuple_element): Likewise.
	* testsuite/23_containers/array/tuple_interface/tuple_element_neg.cc:
	Adjust dg-error line number.

From-SVN: r210470

libstdc++-v3/ChangeLog

+2014-05-15  Jonathan Wakely  <jwakely@redhat.com>
+
+	* include/std/tuple (tuple_size<cv _Tp>): Implement LWG 2313.
+	* include/std/array (tuple_size, tuple_element): Add Doxygen comments.
+	* include/std/utility (tuple_size, tuple_element): Likewise.
+	* testsuite/23_containers/array/tuple_interface/tuple_element_neg.cc:
+	Adjust dg-error line number.
+
 2014-05-14  Jonathan Wakely  <jwakely@redhat.com>
 
 	* include/std/tuple (__add_c_ref, __add_ref, __add_r_ref): Remove.

libstdc++-v3/include/std/array

@@ -306,6 +306,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
   template<typename _Tp> 
     class tuple_size;
 
+  /// Partial specialization for std::array
   template<typename _Tp, std::size_t _Nm>
     struct tuple_size<_GLIBCXX_STD_C::array<_Tp, _Nm>>
     : public integral_constant<std::size_t, _Nm> { };
@@ -314,6 +315,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
   template<std::size_t _Int, typename _Tp>
     class tuple_element;
 
+  /// Partial specialization for std::array
   template<std::size_t _Int, typename _Tp, std::size_t _Nm>
     struct tuple_element<_Int, _GLIBCXX_STD_C::array<_Tp, _Nm>>
     {

libstdc++-v3/include/std/tuple

@@ -693,18 +693,19 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
   template<typename _Tp>
     struct tuple_size;
 
-  template<typename _Tp, typename _Ts = tuple_size<_Tp>>
-    using __cv_tuple_size = integral_constant<
-             typename remove_cv<decltype(_Ts::value)>::type, _Ts::value>;
-
+  // _GLIBCXX_RESOLVE_LIB_DEFECTS
+  // 2313. tuple_size should always derive from integral_constant<size_t, N>
   template<typename _Tp>
-    struct tuple_size<const _Tp> : __cv_tuple_size<_Tp> { };
+    struct tuple_size<const _Tp>
+    : integral_constant<size_t, tuple_size<_Tp>::value> { };
 
   template<typename _Tp>
-    struct tuple_size<volatile _Tp> : __cv_tuple_size<_Tp> { };
+    struct tuple_size<volatile _Tp>
+    : integral_constant<size_t, tuple_size<_Tp>::value> { };
 
   template<typename _Tp>
-    struct tuple_size<const volatile _Tp> : __cv_tuple_size<_Tp> { };
+    struct tuple_size<const volatile _Tp>
+    : integral_constant<size_t, tuple_size<_Tp>::value> { };
 
   /// class tuple_size
   template<typename... _Elements>

libstdc++-v3/include/std/utility

@@ -84,14 +84,18 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
     class tuple_element;
 
    // Various functions which give std::pair a tuple-like interface.
+
+  /// Partial specialization for std::pair
   template<class _Tp1, class _Tp2>
     struct tuple_size<std::pair<_Tp1, _Tp2>>
     : public integral_constant<std::size_t, 2> { };
 
+  /// Partial specialization for std::pair
   template<class _Tp1, class _Tp2>
     struct tuple_element<0, std::pair<_Tp1, _Tp2>>
     { typedef _Tp1 type; };
  
+  /// Partial specialization for std::pair
   template<class _Tp1, class _Tp2>
     struct tuple_element<1, std::pair<_Tp1, _Tp2>>
     { typedef _Tp2 type; };

libstdc++-v3/testsuite/23_containers/array/tuple_interface/tuple_element_neg.cc

@@ -23,4 +23,4 @@
 
 typedef std::tuple_element<1, std::array<int, 1>>::type type;
 
-// { dg-error "static assertion failed" "" { target *-*-* } 320 }
+// { dg-error "static assertion failed" "" { target *-*-* } 322 }