ceph/src/boost/boost/hana/detail/operators/comparable.hpp

   1 /*!
   2 @file
   3 Defines operators for Comparables.
   4
   5 @copyright Louis Dionne 2013-2017
   6 Distributed under the Boost Software License, Version 1.0.
   7 (See accompanying file LICENSE.md or copy at http://boost.org/LICENSE_1_0.txt)
   8  */
   9
  10 #ifndef BOOST_HANA_DETAIL_OPERATORS_COMPARABLE_HPP
  11 #define BOOST_HANA_DETAIL_OPERATORS_COMPARABLE_HPP
  12
  13 #include <boost/hana/config.hpp>
  14 #include <boost/hana/core/tag_of.hpp>
  15 #include <boost/hana/fwd/equal.hpp>
  16 #include <boost/hana/fwd/not_equal.hpp>
  17
  18 #include <type_traits>
  19
  20
  21 BOOST_HANA_NAMESPACE_BEGIN namespace detail {
  22     template <typename Tag>
  23     struct comparable_operators {
  24         static constexpr bool value = false;
  25     };
  26
  27     namespace operators {
  28         template <typename X, typename Y, typename = typename std::enable_if<
  29             detail::comparable_operators<typename hana::tag_of<X>::type>::value ||
  30             detail::comparable_operators<typename hana::tag_of<Y>::type>::value
  31         >::type>
  32         constexpr auto operator==(X&& x, Y&& y)
  33         { return hana::equal(static_cast<X&&>(x), static_cast<Y&&>(y)); }
  34
  35         template <typename X, typename Y, typename = typename std::enable_if<
  36             detail::comparable_operators<typename hana::tag_of<X>::type>::value ||
  37             detail::comparable_operators<typename hana::tag_of<Y>::type>::value
  38         >::type>
  39         constexpr auto operator!=(X&& x, Y&& y)
  40         { return hana::not_equal(static_cast<X&&>(x), static_cast<Y&&>(y)); }
  41     } // end namespace operators
  42 } BOOST_HANA_NAMESPACE_END
  43
  44 #endif // !BOOST_HANA_DETAIL_OPERATORS_COMPARABLE_HPP