--- /dev/null
+// (C) Copyright John Maddock 2021.
+// 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)
+//
+// We deliberately use assert in here:
+//
+
+#ifndef BOOST_MP_TOOLS_FLOAT128_HPP
+#define BOOST_MP_TOOLS_FLOAT128_HPP
+
+#include <boost/multiprecision/detail/standalone_config.hpp>
+
+#ifdef BOOST_HAS_FLOAT128
+
+namespace boost
+{
+namespace multiprecision
+{
+namespace float128_procs
+{
+extern "C" __float128 ldexpq(__float128, int) throw();
+extern "C" __float128 frexpq(__float128, int*) throw();
+extern "C" __float128 floorq(__float128) throw();
+extern "C" __float128 nextafterq(__float128, __float128) throw();
+extern "C" int isinfq(__float128) throw();
+extern "C" int isnanq(__float128) throw();
+extern "C" __float128 strtoflt128(const char*, char**) throw();
+
+inline __float128 ldexp(__float128 f, int i) throw() { return ldexpq(f, i); }
+inline __float128 frexp(__float128 f, int* p) throw() { return frexpq(f, p); }
+inline __float128 floor(__float128 f) throw() { return floorq(f); }
+
+}
+
+namespace detail {
+
+template <class T>
+struct is_float128 : public std::is_same<__float128, T>
+{};
+
+}
+}
+}
+
+namespace boost {
+namespace math {
+
+ inline __float128 float_next(const __float128& f)
+ {
+ return boost::multiprecision::float128_procs::nextafterq(f, 2 * f);
+ }
+ inline int (isinf)(const __float128& f)
+ {
+ return boost::multiprecision::float128_procs::isinfq(f);
+ }
+ inline int (isnan)(const __float128& f)
+ {
+ return boost::multiprecision::float128_procs::isnanq(f);
+ }
+
+}}
+
+#define BOOST_MP_FLOAT128_USING using boost::multiprecision::float128_procs::ldexp; using boost::multiprecision::float128_procs::frexp; using boost::multiprecision::float128_procs::floor; using boost::math::isinf; using boost::math::isnan;
+
+#else
+#define BOOST_MP_FLOAT128_USING
+
+namespace boost {
+namespace multiprecision {
+namespace detail {
+
+template <class T>
+struct is_float128 : public std::false_type
+{};
+
+}}} // namespace boost::multiprecision::detail
+
+#endif
+
+#endif // BOOST_MP_TOOLS_FLOAT128_HPP