From 35c4a13e6fe425792a3aad21e30959e0b2082ea4 Mon Sep 17 00:00:00 2001
From: jzmaddock <john@johnmaddock.co.uk>
Date: Thu, 7 Oct 2021 11:31:49 +0100
Subject: [PATCH 1/2] Print out <atomic> macros.

---
 test/config_info.cpp | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/test/config_info.cpp b/test/config_info.cpp
index 7a39e4c3..4a2de132 100644
--- a/test/config_info.cpp
+++ b/test/config_info.cpp
@@ -1294,6 +1294,9 @@ void print_boost_macros()
 #if __has_include(<version>)
 #  include <version>
 #endif
+#if __has_include(<atomic>) && (BOOST_CXX_VERSION > 201100)
+#  include <atomic>
+#endif
 #endif
 
 void print_sd6_macros()
@@ -1494,6 +1497,18 @@ void print_sd6_macros()
     // C++98:
     PRINT_MACRO(__cpp_rtti);
     PRINT_MACRO(__cpp_exceptions);
+
+    // <atomic>:
+    PRINT_MACRO(ATOMIC_INT_LOCK_FREE);
+    PRINT_MACRO(ATOMIC_SHORT_LOCK_FREE);
+    PRINT_MACRO(ATOMIC_LONG_LOCK_FREE);
+    PRINT_MACRO(ATOMIC_LLONG_LOCK_FREE);
+    PRINT_MACRO(ATOMIC_POINTER_LOCK_FREE);
+    PRINT_MACRO(ATOMIC_CHAR_LOCK_FREE);
+    PRINT_MACRO(ATOMIC_WCHAR_T_LOCK_FREE);
+    PRINT_MACRO(ATOMIC_CHAR8_T_LOCK_FREE);
+    PRINT_MACRO(ATOMIC_CHAR16_T_LOCK_FREE);
+    PRINT_MACRO(ATOMIC_CHAR32_T_LOCK_FREE);
 }
 
 void print_separator()

From 7cc7f940072629d901b859631fe29e6adf21ab93 Mon Sep 17 00:00:00 2001
From: jzmaddock <john@johnmaddock.co.uk>
Date: Thu, 7 Oct 2021 13:05:15 +0100
Subject: [PATCH 2/2] Update for present, but broken <concepts> on latest MacOS
 clang.

---
 include/boost/config/stdlib/libcpp.hpp | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/include/boost/config/stdlib/libcpp.hpp b/include/boost/config/stdlib/libcpp.hpp
index c7daab1f..fe4a48d2 100644
--- a/include/boost/config/stdlib/libcpp.hpp
+++ b/include/boost/config/stdlib/libcpp.hpp
@@ -157,6 +157,9 @@
 #if !defined(__cpp_lib_semaphore) || (__cpp_lib_semaphore < 201907L)
 #  define BOOST_NO_CXX20_HDR_SEMAPHORE
 #endif
+#if !defined(__cpp_lib_concepts) || (__cpp_lib_concepts < 202002L)
+#  define BOOST_NO_CXX20_HDR_CONCEPTS
+#endif
 
 #if(_LIBCPP_VERSION < 9000) && !defined(BOOST_NO_CXX20_HDR_SPAN)
 // as_writable_bytes is missing.