ceph/src/boost/libs/hana/include/boost/hana/not_equal.hpp

   1 /*!
   2 @file
   3 Defines `boost::hana::not_equal`.
   4
   5 @copyright Louis Dionne 2013-2016
   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_NOT_EQUAL_HPP
  11 #define BOOST_HANA_NOT_EQUAL_HPP
  12
  13 #include <boost/hana/fwd/not_equal.hpp>
  14
  15 #include <boost/hana/concept/comparable.hpp>
  16 #include <boost/hana/config.hpp>
  17 #include <boost/hana/core/to.hpp>
  18 #include <boost/hana/core/dispatch.hpp>
  19 #include <boost/hana/detail/has_common_embedding.hpp>
  20 #include <boost/hana/detail/nested_to.hpp> // required by fwd decl
  21 #include <boost/hana/equal.hpp>
  22 #include <boost/hana/not.hpp>
  23
  24
  25 BOOST_HANA_NAMESPACE_BEGIN
  26     //! @cond
  27     template <typename X, typename Y>
  28     constexpr auto not_equal_t::operator()(X&& x, Y&& y) const {
  29         using T = typename hana::tag_of<X>::type;
  30         using U = typename hana::tag_of<Y>::type;
  31         using NotEqual = not_equal_impl<T, U>;
  32         return NotEqual::apply(static_cast<X&&>(x), static_cast<Y&&>(y));
  33     }
  34     //! @endcond
  35
  36     template <typename T, typename U, bool condition>
  37     struct not_equal_impl<T, U, when<condition>> : default_ {
  38         template <typename X, typename Y>
  39         static constexpr decltype(auto) apply(X&& x, Y&& y) {
  40             return hana::not_(hana::equal(static_cast<X&&>(x),
  41                                           static_cast<Y&&>(y)));
  42         }
  43     };
  44
  45     // Cross-type overload
  46     template <typename T, typename U>
  47     struct not_equal_impl<T, U, when<
  48         detail::has_nontrivial_common_embedding<Comparable, T, U>::value
  49     >> {
  50         using C = typename hana::common<T, U>::type;
  51         template <typename X, typename Y>
  52         static constexpr decltype(auto) apply(X&& x, Y&& y) {
  53             return hana::not_equal(hana::to<C>(static_cast<X&&>(x)),
  54                                    hana::to<C>(static_cast<Y&&>(y)));
  55         }
  56     };
  57 BOOST_HANA_NAMESPACE_END
  58
  59 #endif // !BOOST_HANA_NOT_EQUAL_HPP