From b2748d7488d65fe362eb57ecf6a7bb9bd9fe5421 Mon Sep 17 00:00:00 2001
From: jzmaddock <john@johnmaddock.co.uk>
Date: Thu, 9 Jul 2026 17:12:22 +0100
Subject: [PATCH] Workaround for clang-18.

---
 include/boost/config/compiler/clang.hpp | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/include/boost/config/compiler/clang.hpp b/include/boost/config/compiler/clang.hpp
index 8cd418ec..c76a6d2b 100644
--- a/include/boost/config/compiler/clang.hpp
+++ b/include/boost/config/compiler/clang.hpp
@@ -315,6 +315,12 @@
 #  define BOOST_NO_CXX17_IF_CONSTEXPR
 #endif
 
+#if !defined(__cpp_template_template_args)
+// Clang-18 doesn't seem to cope with this header, which may be an issue with underlying libstdc++ or not.
+// __cpp_template_template_args seems to be introduced in clang-19:
+#  define BOOST_NO_CXX23_HDR_STACKTRACE
+#endif
+
 // Clang 3.9+ in c++1z
 #if !__has_cpp_attribute(fallthrough) || __cplusplus < 201406L
 #  define BOOST_NO_CXX17_INLINE_VARIABLES