From 03dc78f0bae87f929b18258d6aa2a4653c00fb56 Mon Sep 17 00:00:00 2001
From: Peter Dimov <pdimov@gmail.com>
Date: Sun, 27 Sep 2026 20:11:01 +0300
Subject: [PATCH] Use [[msvc::no_unique_address]] under clang-cl, matching msvc

---
 include/boost/config/compiler/clang.hpp | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/include/boost/config/compiler/clang.hpp b/include/boost/config/compiler/clang.hpp
index c76a6d2bf..3cf397175 100644
--- a/include/boost/config/compiler/clang.hpp
+++ b/include/boost/config/compiler/clang.hpp
@@ -365,6 +365,14 @@
 #  define BOOST_MAY_ALIAS __attribute__((__may_alias__))
 #endif
 
+#if defined(_MSC_VER) && _MSC_VER >= 1930
+// In MSVC mode, [[no_unique_address]] is a no-op, matching MSVC,
+// but [[msvc::no_unique_address]] works
+// The condition here must match the one in visualc.hpp, to preserve
+// the ABI compatibility between MSVC and Clang
+#define BOOST_ATTRIBUTE_NO_UNIQUE_ADDRESS [[msvc::no_unique_address]]
+#endif
+
 #ifndef BOOST_COMPILER
 #  define BOOST_COMPILER "Clang version " __clang_version__
 #endif