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- /*!
- @file
- Defines `boost::hana::not_equal`.
- @copyright Louis Dionne 2013-2017
- Distributed under the Boost Software License, Version 1.0.
- (See accompanying file LICENSE.md or copy at http://boost.org/LICENSE_1_0.txt)
- */
- #ifndef BOOST_HANA_NOT_EQUAL_HPP
- #define BOOST_HANA_NOT_EQUAL_HPP
- #include <boost/hana/fwd/not_equal.hpp>
- #include <boost/hana/concept/comparable.hpp>
- #include <boost/hana/config.hpp>
- #include <boost/hana/core/to.hpp>
- #include <boost/hana/core/dispatch.hpp>
- #include <boost/hana/detail/has_common_embedding.hpp>
- #include <boost/hana/detail/nested_to.hpp> // required by fwd decl
- #include <boost/hana/equal.hpp>
- #include <boost/hana/not.hpp>
- BOOST_HANA_NAMESPACE_BEGIN
- //! @cond
- template <typename X, typename Y>
- constexpr auto not_equal_t::operator()(X&& x, Y&& y) const {
- using T = typename hana::tag_of<X>::type;
- using U = typename hana::tag_of<Y>::type;
- using NotEqual = not_equal_impl<T, U>;
- return NotEqual::apply(static_cast<X&&>(x), static_cast<Y&&>(y));
- }
- //! @endcond
- template <typename T, typename U, bool condition>
- struct not_equal_impl<T, U, when<condition>> : default_ {
- template <typename X, typename Y>
- static constexpr decltype(auto) apply(X&& x, Y&& y) {
- return hana::not_(hana::equal(static_cast<X&&>(x),
- static_cast<Y&&>(y)));
- }
- };
- // Cross-type overload
- template <typename T, typename U>
- struct not_equal_impl<T, U, when<
- detail::has_nontrivial_common_embedding<Comparable, T, U>::value
- >> {
- using C = typename hana::common<T, U>::type;
- template <typename X, typename Y>
- static constexpr decltype(auto) apply(X&& x, Y&& y) {
- return hana::not_equal(hana::to<C>(static_cast<X&&>(x)),
- hana::to<C>(static_cast<Y&&>(y)));
- }
- };
- BOOST_HANA_NAMESPACE_END
- #endif // !BOOST_HANA_NOT_EQUAL_HPP
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