From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Gunnar Beutner <gunnar@beutner.name>
Date: Sun, 23 Oct 2022 12:05:20 +0200
Subject: [PATCH] Fix building Boost.System

---
 boost/system/detail/config.hpp              | 2 +-
 boost/system/detail/error_category_impl.hpp | 6 ++++++
 2 files changed, 7 insertions(+), 1 deletion(-)

diff --git a/boost/system/detail/config.hpp b/boost/system/detail/config.hpp
index ad958bcabe2fa05c5242ff11dfcc07004885d86a..26e0a4cae88cb0f80c0532308b92446a04ddf243 100644
--- a/boost/system/detail/config.hpp
+++ b/boost/system/detail/config.hpp
@@ -13,7 +13,7 @@
 
 // BOOST_SYSTEM_HAS_SYSTEM_ERROR
 
-#if !defined(BOOST_NO_CXX11_HDR_SYSTEM_ERROR) && !defined(BOOST_NO_CXX11_HDR_ATOMIC) && !defined(BOOST_NO_CXX11_HDR_MUTEX)
+#if !defined(BOOST_NO_CXX11_HDR_SYSTEM_ERROR) && !defined(BOOST_NO_CXX11_HDR_ATOMIC)
 # define BOOST_SYSTEM_HAS_SYSTEM_ERROR
 #endif
 
diff --git a/boost/system/detail/error_category_impl.hpp b/boost/system/detail/error_category_impl.hpp
index 982c667b3f0b8960aa6e3ecaf1dc15eb01e06436..0335f3504c77b5ea27f8df0d3ba7011389d13e33 100644
--- a/boost/system/detail/error_category_impl.hpp
+++ b/boost/system/detail/error_category_impl.hpp
@@ -98,7 +98,9 @@ inline char const * error_category::message( int ev, char * buffer, std::size_t
 #if defined(BOOST_SYSTEM_HAS_SYSTEM_ERROR)
 
 #include <boost/system/detail/std_category_impl.hpp>
+#ifndef BOOST_NO_CXX11_HDR_MUTEX
 #include <mutex>
+#endif
 #include <new>
 
 namespace boost
@@ -106,6 +108,7 @@ namespace boost
 namespace system
 {
 
+#ifndef BOOST_NO_CXX11_HDR_MUTEX
 namespace detail
 {
 
@@ -117,6 +120,7 @@ template<class = void> struct stdcat_mx_holder
 template<class T> std::mutex stdcat_mx_holder<T>::mx_;
 
 } // namespace detail
+#endif
 
 inline void error_category::init_stdcat() const
 {
@@ -130,7 +134,9 @@ inline void error_category::init_stdcat() const
 
 #endif
 
+#ifndef BOOST_NO_CXX11_HDR_MUTEX
     std::lock_guard<std::mutex> lk( boost::system::detail::stdcat_mx_holder<>::mx_ );
+#endif
 
     if( sc_init_.load( std::memory_order_acquire ) == 0 )
     {