update boost

linx64/include/boost/parameter/aux_/always_true_predicate.hpp

@@ -0,0 +1,42 @@
+// Copyright Cromwell D. Enage 2019.
+// Distributed under 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)
+
+#ifndef BOOST_PARAMETER_AUX_ALWAYS_TRUE_PREDICATE_HPP
+#define BOOST_PARAMETER_AUX_ALWAYS_TRUE_PREDICATE_HPP
+
+#include <boost/parameter/config.hpp>
+#include <boost/mpl/bool.hpp>
+
+#if defined(BOOST_PARAMETER_HAS_PERFECT_FORWARDING)
+#if defined(BOOST_PARAMETER_CAN_USE_MP11)
+#include <boost/mp11/integral.hpp>
+#endif
+#else
+#include <boost/mpl/always.hpp>
+#endif
+
+namespace boost { namespace parameter { namespace aux {
+
+#if defined(BOOST_PARAMETER_HAS_PERFECT_FORWARDING)
+    struct always_true_predicate
+    {
+        template <typename ...>
+        struct apply
+        {
+            typedef ::boost::mpl::true_ type;
+        };
+
+#if defined(BOOST_PARAMETER_CAN_USE_MP11)
+        template <typename ...>
+        using fn = ::boost::mp11::mp_true;
+#endif
+    };
+#else
+    typedef ::boost::mpl::always< ::boost::mpl::true_> always_true_predicate;
+#endif  // BOOST_NO_CXX11_VARIADIC_TEMPLATES
+}}} // namespace boost::parameter::aux
+
+#endif  // include guard
+