From c84363b8c5c8b545ea922fd2aa12f14f17990815 Mon Sep 17 00:00:00 2001
From: Patrick Palka <ppalka@redhat.com>
Date: Wed, 10 Jan 2024 19:00:49 -0500
Subject: [PATCH] libstdc++: Use _GLIBCXX_USE_BUILTIN_TRAIT for _Nth_type
Since _Nth_type has a fallback native implementation, use
_GLIBCXX_USE_BUILTIN_TRAIT when checking for __type_pack_element
so that we can easily toggle which implementation to use.
libstdc++-v3/ChangeLog:
* include/bits/utility.h (_Nth_type): Use
_GLIBCXX_USE_BUILTIN_TRAIT instead of __has_builtin.
---
libstdc++-v3/include/bits/utility.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/libstdc++-v3/include/bits/utility.h b/libstdc++-v3/include/bits/utility.h
index 45d7241da9fb..d8a5fb960feb 100644
--- a/libstdc++-v3/include/bits/utility.h
+++ b/libstdc++-v3/include/bits/utility.h
@@ -225,7 +225,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
#endif // C++17
-#if __has_builtin(__type_pack_element)
+#if _GLIBCXX_USE_BUILTIN_TRAIT(__type_pack_element)
template<size_t _Np, typename... _Types>
struct _Nth_type
{ using type = __type_pack_element<_Np, _Types...>; };
--
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