[libcxx][span] Remove tuple interface

This implements P2116 by removing the tuple interface from std::span.

Differential Revision: https://reviews.llvm.org/D75640

libcxx/include/span

@@ -539,34 +539,6 @@ private:
     size_type __size;
 };
 
-//  tuple interface
-template <class _Tp, size_t _Size>
-struct _LIBCPP_TEMPLATE_VIS tuple_size<span<_Tp, _Size>>
-    : public integral_constant<size_t, _Size> {};
-
-template <class _Tp>
-struct _LIBCPP_TEMPLATE_VIS tuple_size<span<_Tp, dynamic_extent>>; // declared but not defined
-
-
-template <size_t _Ip, class _Tp, size_t _Size>
-struct _LIBCPP_TEMPLATE_VIS tuple_element<_Ip, span<_Tp, _Size>>
-{
-    static_assert( dynamic_extent != _Size, "std::tuple_element<> not supported for std::span<T, dynamic_extent>");
-    static_assert(_Ip < _Size, "Index out of bounds in std::tuple_element<> (std::span)");
-    typedef _Tp type;
-};
-
-template <size_t _Ip, class _Tp, size_t _Size>
-_LIBCPP_INLINE_VISIBILITY constexpr
-_Tp&
-get(span<_Tp, _Size> __s) noexcept
-{
-    static_assert( dynamic_extent != _Size, "std::get<> not supported for std::span<T, dynamic_extent>");
-    static_assert(_Ip < _Size, "Index out of bounds in std::get<> (std::span)");
-    return __s[_Ip];
-}
-
-
 //  as_bytes & as_writable_bytes
 template <class _Tp, size_t _Extent>
 _LIBCPP_INLINE_VISIBILITY

libcxx/www/cxx2a_status.html

@@ -253,7 +253,7 @@ <h3>Paper Status</h3>
 	<tr><td><a href="https://wg21.link/P2101">P2101</a></td><td>LWG</td><td>'Models' subsumes 'satisfies' (Wording for US298 and US300)</td><td>Prague</td><td><i> </i></td><td></td></tr>
 	<tr><td><a href="https://wg21.link/P2102">P2102</a></td><td>LWG</td><td>Make 'implicit expression variations' more explicit (Wording for US185)</td><td>Prague</td><td><i> </i></td><td></td></tr>
 	<tr><td><a href="https://wg21.link/P2106">P2106</a></td><td>LWG</td><td>Alternative wording for GB315 and GB316</td><td>Prague</td><td><i> </i></td><td></td></tr>
-	<tr><td><a href="https://wg21.link/P2116">P2116</a></td><td>LWG</td><td>Remove tuple-like protocol support from fixed-extent span</td><td>Prague</td><td><i> </i></td><td></td></tr>
+	<tr><td><a href="https://wg21.link/P2116">P2116</a></td><td>LWG</td><td>Remove tuple-like protocol support from fixed-extent span</td><td>Prague</td><td>Complete</td><td>11.0</td></tr>
 <!--  	<tr><td></td><td></td><td></td><td></td><td></td><td></td></tr> -->
   </table>