boost/fusion/support/unused.hpp


1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93

/*=============================================================================
    Copyright (c) 2001-2011 Joel de Guzman

    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)
==============================================================================*/
#if !defined(BOOST_FUSION_SUPPORT_UNUSED_20070305_1038)
#define BOOST_FUSION_SUPPORT_UNUSED_20070305_1038

#include <boost/fusion/support/config.hpp>
#include <iosfwd>

#include <boost/config.hpp>
#if defined(BOOST_MSVC)
# pragma warning(push)
# pragma warning(disable: 4522) // multiple assignment operators specified warning
#endif

#define BOOST_FUSION_UNUSED_HAS_IO

namespace boost { namespace fusion
{
    struct unused_type
    {
        BOOST_FUSION_GPU_ENABLED
        unused_type()
        {
        }

        template <typename T>
        BOOST_FUSION_GPU_ENABLED
        unused_type(T const&)
        {
        }

        template <typename T>
        BOOST_FUSION_GPU_ENABLED
        unused_type const&
        operator=(T const&) const
        {
            return *this;
        }

        template <typename T>
        BOOST_FUSION_GPU_ENABLED
        unused_type&
        operator=(T const&)
        {
            return *this;
        }

        BOOST_FUSION_GPU_ENABLED
        unused_type const&
        operator=(unused_type const&) const
        {
            return *this;
        }

        BOOST_FUSION_GPU_ENABLED
        unused_type&
        operator=(unused_type const&)
        {
            return *this;
        }
    };

    unused_type const unused = unused_type();

    namespace detail
    {
        struct unused_only
        {
            BOOST_FUSION_GPU_ENABLED
            unused_only(unused_type const&) {}
        };
    }

    inline std::ostream& operator<<(std::ostream& out, detail::unused_only const&)
    {
        return out;
    }

    inline std::istream& operator>>(std::istream& in, unused_type&)
    {
        return in;
    }
}}

#if defined(BOOST_MSVC)
# pragma warning(pop)
#endif

#endif