Added thirdparty: boost library

thirdparty/include/boost/parameter/aux_/is_placeholder.hpp

@@ -0,0 +1,64 @@
+// 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_IS_PLACEHOLDER_HPP
+#define BOOST_PARAMETER_AUX_IS_PLACEHOLDER_HPP
+
+#include <boost/parameter/config.hpp>
+
+#if defined(BOOST_PARAMETER_CAN_USE_MP11)
+#include <boost/mp11/integral.hpp>
+#else
+#include <boost/mpl/bool.hpp>
+#endif
+
+namespace boost { namespace parameter { namespace aux {
+
+    template <typename T>
+    struct is_mpl_placeholder
+#if defined(BOOST_PARAMETER_CAN_USE_MP11)
+      : ::boost::mp11::mp_false
+#else
+      : ::boost::mpl::false_
+#endif
+    {
+    };
+}}} // namespace boost::parameter::aux
+
+#include <boost/mpl/arg_fwd.hpp>
+
+namespace boost { namespace parameter { namespace aux {
+
+    template <int I>
+    struct is_mpl_placeholder< ::boost::mpl::arg<I> >
+#if defined(BOOST_PARAMETER_CAN_USE_MP11)
+      : ::boost::mp11::mp_true
+#else
+      : ::boost::mpl::true_
+#endif
+    {
+    };
+}}} // namespace boost::parameter::aux
+
+#if defined(BOOST_PARAMETER_CAN_USE_MP11)
+#include <boost/mp11/bind.hpp>
+
+namespace boost { namespace parameter { namespace aux {
+
+    template <typename T>
+    struct is_mp11_placeholder : ::boost::mp11::mp_false
+    {
+    };
+
+    template < ::std::size_t I>
+    struct is_mp11_placeholder< ::boost::mp11::mp_arg<I> >
+      : ::boost::mp11::mp_true
+    {
+    };
+}}} // namespace boost::parameter::aux
+
+#endif  // BOOST_PARAMETER_CAN_USE_MP11
+#endif  // include guard
+