Prevent GMF discards

Author: anarthal

include/boost/mp11/detail/std/cassert.hpp

@@ -1,5 +1,7 @@
 #ifdef BOOST_USE_MODULES
+#ifndef BOOST_COMPATIBILITY_HEADERS_SKIP_IMPORT
 import std;
+#endif
 #else
 #include <cassert>
 #endif

include/boost/mp11/detail/std/cstddef.hpp

@@ -1,5 +1,7 @@
 #ifdef BOOST_USE_MODULES
+#ifndef BOOST_COMPATIBILITY_HEADERS_SKIP_IMPORT
 import std;
+#endif
 #else
 #include <cstddef>
 #endif

include/boost/mp11/detail/std/tuple.hpp

@@ -1,5 +1,7 @@
 #ifdef BOOST_USE_MODULES
+#ifndef BOOST_COMPATIBILITY_HEADERS_SKIP_IMPORT
 import std;
+#endif
 #else
 #include <tuple>
 #endif

include/boost/mp11/detail/std/type_traits.hpp

@@ -1,5 +1,7 @@
 #ifdef BOOST_USE_MODULES
+#ifndef BOOST_COMPATIBILITY_HEADERS_SKIP_IMPORT
 import std;
+#endif
 #else
 #include <type_traits>
 #endif

include/boost/mp11/detail/std/utility.hpp

@@ -1,5 +1,7 @@
 #ifdef BOOST_USE_MODULES
+#ifndef BOOST_COMPATIBILITY_HEADERS_SKIP_IMPORT
 import std;
+#endif
 #else
 #include <utility>
 #endif

modules/boost_mp11.cppm

@@ -1,10 +1,21 @@
 module;
 
-#define BOOST_MP11_INTERFACE_UNIT
 #include <cassert>
-#include <boost/mp11.hpp>
 
 export module boost.mp11;
+import std;
+
+#define BOOST_MP11_INTERFACE_UNIT
+#define BOOST_COMPATIBILITY_HEADERS_SKIP_IMPORT
+
+#ifdef __clang__
+#pragma clang diagnostic push
+#pragma clang diagnostic ignored "-Winclude-angled-in-module-purview"
+#endif
+
+extern "C++" {
+#include <boost/mp11.hpp>
+}
 
 export namespace boost::mp11 {