ceph/src/boost/libs/fusion/include/boost/fusion/support/unused.hpp

   1 /*=============================================================================
   2     Copyright (c) 2001-2011 Joel de Guzman
   3
   4     Distributed under the Boost Software License, Version 1.0. (See accompanying
   5     file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
   6 ==============================================================================*/
   7 #if !defined(BOOST_FUSION_SUPPORT_UNUSED_20070305_1038)
   8 #define BOOST_FUSION_SUPPORT_UNUSED_20070305_1038
   9
  10 #include <boost/fusion/support/config.hpp>
  11 #include <iosfwd>
  12
  13 #include <boost/config.hpp>
  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
  21 namespace boost { namespace fusion
  22 {
  23     struct unused_type
  24     {
  25         BOOST_CONSTEXPR BOOST_FUSION_GPU_ENABLED
  26         unused_type() BOOST_NOEXCEPT
  27         {
  28         }
  29
  30         template <typename T>
  31         BOOST_CONSTEXPR BOOST_FUSION_GPU_ENABLED
  32         unused_type(T const&) BOOST_NOEXCEPT
  33         {
  34         }
  35
  36         template <typename T>
  37         BOOST_FUSION_CONSTEXPR_THIS BOOST_FUSION_GPU_ENABLED
  38         unused_type const&
  39         operator=(T const&) const BOOST_NOEXCEPT
  40         {
  41             return *this;
  42         }
  43
  44         template <typename T>
  45         BOOST_CXX14_CONSTEXPR BOOST_FUSION_GPU_ENABLED
  46         unused_type&
  47         operator=(T const&) BOOST_NOEXCEPT
  48         {
  49             return *this;
  50         }
  51
  52         BOOST_FUSION_CONSTEXPR_THIS BOOST_FUSION_GPU_ENABLED
  53         unused_type const&
  54         operator=(unused_type const&) const BOOST_NOEXCEPT
  55         {
  56             return *this;
  57         }
  58
  59         BOOST_CXX14_CONSTEXPR BOOST_FUSION_GPU_ENABLED
  60         unused_type&
  61         operator=(unused_type const&) BOOST_NOEXCEPT
  62         {
  63             return *this;
  64         }
  65     };
  66
  67     BOOST_CONSTEXPR_OR_CONST unused_type unused = unused_type();
  68
  69     namespace detail
  70     {
  71         struct unused_only
  72         {
  73             BOOST_CONSTEXPR BOOST_FUSION_GPU_ENABLED
  74             unused_only(unused_type const&) BOOST_NOEXCEPT {}
  75         };
  76     }
  77
  78     BOOST_CONSTEXPR
  79     inline std::ostream& operator<<(std::ostream& out, detail::unused_only const&) BOOST_NOEXCEPT
  80     {
  81         return out;
  82     }
  83
  84     BOOST_CONSTEXPR
  85     inline std::istream& operator>>(std::istream& in, unused_type&) BOOST_NOEXCEPT
  86     {
  87         return in;
  88     }
  89 }}
  90
  91 #if defined(BOOST_MSVC)
  92 # pragma warning(pop)
  93 #endif
  94
  95 #endif