From: Patrick Palka <ppalka@redhat.com>
Date: Thu, 11 Jan 2024 00:00:49 +0000 (-0500)
Subject: libstdc++: Use _GLIBCXX_USE_BUILTIN_TRAIT for _Nth_type
X-Git-Tag: basepoints/gcc-15~3019
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=c84363b8c5c8b545ea922fd2aa12f14f17990815;p=thirdparty%2Fgcc.git

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.
---

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...>; };