[PATCH] s/__unused/__dimensions/ in

[Tim Shen via gcc-patches]

Since it's an obvious textual fix, I'm going to check it in directly.

-- 
Regards,
Tim Shen

commit b005916b043f52feed32b646f86ced80f3e5392b
Author: Tim Shen <tims...@google.com>
Date:   Wed Jan 4 19:07:07 2017 -0800

    2017-01-05  Tim Shen  <tims...@google.com>
    
            PR libstdc++/78996
            * include/std/variant: rename __unused to __dimensions to avoid
            naming conflict.

diff --git a/libstdc++-v3/include/std/variant b/libstdc++-v3/include/std/variant
index 899198a..da57ed6 100644
--- a/libstdc++-v3/include/std/variant
+++ b/libstdc++-v3/include/std/variant
@@ -604,17 +604,18 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
   template<typename _Array_type, typename _Variant_tuple, typename _Index_seq>
     struct __gen_vtable_impl;
 
-  template<typename _Result_type, typename _Visitor, size_t... __unused,
+  template<typename _Result_type, typename _Visitor, size_t... __dimensions,
           typename... _Variants, size_t... __indices>
     struct __gen_vtable_impl<
-       _Multi_array<_Result_type (*)(_Visitor, _Variants...), __unused...>,
+       _Multi_array<_Result_type (*)(_Visitor, _Variants...), __dimensions...>,
        tuple<_Variants...>, std::index_sequence<__indices...>>
     {
       using _Next =
          remove_reference_t<typename _Nth_type<sizeof...(__indices),
                             _Variants...>::type>;
       using _Array_type =
-         _Multi_array<_Result_type (*)(_Visitor, _Variants...), __unused...>;
+         _Multi_array<_Result_type (*)(_Visitor, _Variants...),
+                      __dimensions...>;
 
       static constexpr _Array_type
       _S_apply()