commit 70d6f6e41f77269f7d293c6fbccf978680e68d2a
Author: Jonathan Wakely <jwakely@redhat.com>
Date:   Fri Nov 5 21:40:58 2021

    libstdc++: Fix pack expansions in tuple_size_v specializations
    
    libstdc++-v3/ChangeLog:
    
            * include/std/tuple (tuple_size_v): Fix pack expansion.

diff --git a/libstdc++-v3/include/std/tuple b/libstdc++-v3/include/std/tuple
index 46173935b64..36dc05d97bc 100644
--- a/libstdc++-v3/include/std/tuple
+++ b/libstdc++-v3/include/std/tuple
@@ -1346,11 +1346,11 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
 
 #if __cplusplus >= 201703L
   template<typename... _Types>
-    inline constexpr size_t tuple_size_v<tuple<_Types>>
+    inline constexpr size_t tuple_size_v<tuple<_Types...>>
       = sizeof...(_Types);
 
   template<typename... _Types>
-    inline constexpr size_t tuple_size_v<const tuple<_Types>>
+    inline constexpr size_t tuple_size_v<const tuple<_Types...>>
       = sizeof...(_Types);
 #endif