From 116e0ce7fd5dc2ee352578d98d23158d9e180d90 Mon Sep 17 00:00:00 2001
From: Jonathan Wakely <jwakely@redhat.com>
Date: Fri, 19 Dec 2025 09:12:40 +0000
Subject: [PATCH] libstdc++: Use std::add_lvalue_reference in
 src/c++11/mutex.cc

Adjust the return type to be consistent with how it's declared in
<mutex>.

libstdc++-v3/ChangeLog:

	* src/c++11/mutex.cc [_GLIBCXX_NO_EXTERN_THREAD_LOCAL]
	(__get_once_call): Use std::add_lvalue_reference.
---
 libstdc++-v3/src/c++11/mutex.cc | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/libstdc++-v3/src/c++11/mutex.cc b/libstdc++-v3/src/c++11/mutex.cc
index 82f0afa4cb4..91968ab47bd 100644
--- a/libstdc++-v3/src/c++11/mutex.cc
+++ b/libstdc++-v3/src/c++11/mutex.cc
@@ -42,7 +42,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
   __get_once_callable() noexcept
   { return __once_callable; }
 
-  __typeof__(void (*)())&
+  std::add_lvalue_reference<void (*)()>::type
   __get_once_call() noexcept
   { return __once_call; }