Initial work for G-code sender and more intensive usage of Boost

xs/include/boost/mpl/is_placeholder.hpp

@@ -0,0 +1,67 @@
+
+#ifndef BOOST_MPL_IS_PLACEHOLDER_HPP_INCLUDED
+#define BOOST_MPL_IS_PLACEHOLDER_HPP_INCLUDED
+
+// Copyright Aleksey Gurtovoy 2001-2004
+//
+// 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)
+//
+// See http://www.boost.org/libs/mpl for documentation.
+
+// $Id: is_placeholder.hpp 49267 2008-10-11 06:19:02Z agurtovoy $
+// $Date: 2008-10-10 23:19:02 -0700 (Fri, 10 Oct 2008) $
+// $Revision: 49267 $
+
+#include <boost/mpl/arg_fwd.hpp>
+#include <boost/mpl/bool.hpp>
+#include <boost/mpl/aux_/yes_no.hpp>
+#include <boost/mpl/aux_/type_wrapper.hpp>
+#include <boost/mpl/aux_/nttp_decl.hpp>
+#include <boost/mpl/aux_/config/ctps.hpp>
+#include <boost/mpl/aux_/config/static_constant.hpp>
+
+namespace boost { namespace mpl {
+
+#if !defined(BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION)
+
+template< typename T >
+struct is_placeholder
+    : bool_<false>
+{
+};
+
+template< BOOST_MPL_AUX_NTTP_DECL(int, N) >
+struct is_placeholder< arg<N> >
+    : bool_<true>
+{
+};
+
+#else
+
+namespace aux {
+
+aux::no_tag is_placeholder_helper(...);
+
+template< BOOST_MPL_AUX_NTTP_DECL(int, N) >
+aux::yes_tag is_placeholder_helper(aux::type_wrapper< arg<N> >*);
+
+} // namespace aux
+
+template< typename T >
+struct is_placeholder
+{
+    static aux::type_wrapper<T>* get();
+    BOOST_STATIC_CONSTANT(bool, value = 
+          sizeof(aux::is_placeholder_helper(get())) == sizeof(aux::yes_tag)
+        );
+    
+    typedef bool_<value> type;
+};
+
+#endif // BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION
+
+}}
+
+#endif // BOOST_MPL_IS_PLACEHOLDER_HPP_INCLUDED