1 /*! 2 @file 3 Defines `boost::hana::not_equal`. 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_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> operator ()(X && x,Y && y) const28 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> applynot_equal_impl39 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> applynot_equal_impl52 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 60