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 ///////////////////////////////////////////////////////////////////////////////
14 namespace boost { namespace spirit { namespace x3
18 unused_type() = default;
27 operator=(T const&) const
39 // unused_type can also masquerade as an empty context (see context.hpp)
41 template <typename ID>
42 unused_type get(ID) const
47 friend std::ostream& operator<<(std::ostream& out, unused_type const&)
52 friend std::istream& operator>>(std::istream& in, unused_type&)
58 constexpr auto unused = unused_type{};