--- /dev/null
+// (C) Copyright John Maddock 2020.
+// Use, modification and distribution are subject to the
+// Boost Software License, Version 1.0. (See accompanying file
+// LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+
+// See http://www.boost.org for most recent version.
+
+// WASM specific config options:
+
+#define BOOST_PLATFORM "Wasm"
+
+#ifdef __has_include
+#if __has_include(<unistd.h>)
+# define BOOST_HAS_UNISTD_H
+#endif
+#endif
+
+// boilerplate code:
+#include <boost/config/detail/posix_features.hpp>
+//
+// fenv lacks the C++11 macros:
+//
+#define BOOST_NO_FENV_H