1 /*=============================================================================
2 Copyright (c) 2001-2014 Joel de Guzman
3 Copyright (c) 2001-2011 Hartmut Kaiser
5 Distributed under the Boost Software License, Version 1.0. (See accompanying
6 file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
7 ==============================================================================*/
8 #if !defined(BOOST_SPIRIT_X3_UNUSED_APRIL_16_2006_0616PM)
9 #define BOOST_SPIRIT_X3_UNUSED_APRIL_16_2006_0616PM
13 #include <boost/mpl/identity.hpp>
15 #if defined(BOOST_MSVC)
16 # pragma warning(push)
17 # pragma warning(disable: 4522) // multiple assignment operators specified warning
20 ///////////////////////////////////////////////////////////////////////////////
21 namespace boost { namespace spirit { namespace x3
36 operator=(T const&) const
49 operator=(unused_type const&) const
55 operator=(unused_type const&)
60 // unused_type can also masquerade as an empty context (see context.hpp)
62 template <typename ID>
63 unused_type get(ID) const
69 auto const unused = unused_type{};
71 inline std::ostream& operator<<(std::ostream& out, unused_type const&)
76 inline std::istream& operator>>(std::istream& in, unused_type&)
82 #if defined(BOOST_MSVC)