https://bugs.gentoo.org/945916
https://github.com/boostorg/thread/pull/408

From 49ccf9c30a0ca556873dbf64b12b0d741d1b3e66 Mon Sep 17 00:00:00 2001
From: Arvid Norlander <arvid-norlander@users.noreply.github.com>
Date: Fri, 8 Nov 2024 16:48:43 +0100
Subject: [PATCH] Fix build on clang-19 (which checks more things in
 uninstantiated templates)

Fixes issue #402
---
 include/boost/thread/future.hpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/include/boost/thread/future.hpp b/include/boost/thread/future.hpp
index 00f504b9b..d15d7ffa5 100644
--- a/boost/thread/future.hpp
+++ b/boost/thread/future.hpp
@@ -4668,7 +4668,7 @@ namespace detail
       }
       run_it& operator=(BOOST_THREAD_RV_REF(run_it) x) BOOST_NOEXCEPT {
         if (this != &x) {
-          that_=x.that;
+          that_=x.that_;
           x.that_.reset();
         }
         return *this;