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

xs/include/boost/mpl/void.hpp

@@ -0,0 +1,76 @@
+
+#ifndef BOOST_MPL_VOID_HPP_INCLUDED
+#define BOOST_MPL_VOID_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: void.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/void_fwd.hpp>
+#include <boost/mpl/bool.hpp>
+#include <boost/mpl/aux_/na_spec.hpp>
+#include <boost/mpl/aux_/config/msvc.hpp>
+#include <boost/mpl/aux_/config/workaround.hpp>
+
+BOOST_MPL_AUX_ADL_BARRIER_NAMESPACE_OPEN
+
+//  [JDG Feb-4-2003] made void_ a complete type to allow it to be
+//  instantiated so that it can be passed in as an object that can be
+//  used to select an overloaded function. Possible use includes signaling
+//  a zero arity functor evaluation call.
+struct void_ { typedef void_ type; };
+
+BOOST_MPL_AUX_ADL_BARRIER_NAMESPACE_CLOSE
+
+namespace boost { namespace mpl {
+
+template< typename T >
+struct is_void_
+    : false_
+{
+#if BOOST_WORKAROUND(BOOST_MSVC, < 1300)
+    using false_::value;
+#endif
+};
+
+template<>
+struct is_void_<void_>
+    : true_
+{
+#if BOOST_WORKAROUND(BOOST_MSVC, < 1300)
+    using true_::value;
+#endif
+};
+
+template< typename T >
+struct is_not_void_
+    : true_
+{
+#if BOOST_WORKAROUND(BOOST_MSVC, < 1300)
+    using true_::value;
+#endif
+};
+
+template<>
+struct is_not_void_<void_>
+    : false_
+{
+#if BOOST_WORKAROUND(BOOST_MSVC, < 1300)
+    using false_::value;
+#endif
+};
+
+BOOST_MPL_AUX_NA_SPEC(1, is_void_)
+BOOST_MPL_AUX_NA_SPEC(1, is_not_void_)
+
+}}
+
+#endif // BOOST_MPL_VOID_HPP_INCLUDED