1/*=============================================================================
2 Copyright (c) 2001-2011 Joel de Guzman
3 Copyright (c) 2018 Kohei Takahashi
4
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_FUSION_SUPPORT_UNUSED_20070305_1038)
9#define BOOST_FUSION_SUPPORT_UNUSED_20070305_1038
10
11#include <boost/fusion/support/config.hpp>
12#include <iosfwd>
13
14#if defined(BOOST_MSVC)
15# pragma warning(push)
16# pragma warning(disable: 4522) // multiple assignment operators specified warning
17#endif
18
19#define BOOST_FUSION_UNUSED_HAS_IO
20
21namespace boost { namespace fusion
22{
23 struct unused_type
24 {
25 BOOST_CONSTEXPR BOOST_FUSION_GPU_ENABLED
26 BOOST_DEFAULTED_FUNCTION(
27 unused_type() BOOST_FUSION_NOEXCEPT_ON_DEFAULTED,
28 {
29 })
30
31 template <typename T>
32 BOOST_CONSTEXPR BOOST_FUSION_GPU_ENABLED
33 unused_type(T const&) BOOST_NOEXCEPT
34 {
35 }
36 };
37
38 BOOST_CONSTEXPR_OR_CONST unused_type unused = unused_type();
39
40 namespace detail
41 {
42 struct unused_only
43 {
44 BOOST_CONSTEXPR BOOST_FUSION_GPU_ENABLED
45 unused_only(unused_type const&) BOOST_NOEXCEPT {}
46 };
47 }
48
49 BOOST_CONSTEXPR
50 inline std::ostream& operator<<(std::ostream& out, detail::unused_only const&) BOOST_NOEXCEPT
51 {
52 return out;
53 }
54
55 BOOST_CONSTEXPR
56 inline std::istream& operator>>(std::istream& in, unused_type&) BOOST_NOEXCEPT
57 {
58 return in;
59 }
60}}
61
62#if defined(BOOST_MSVC)
63# pragma warning(pop)
64#endif
65
66#endif
67