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Diffstat (limited to 'boost/hana/not_equal.hpp')
-rw-r--r-- | boost/hana/not_equal.hpp | 59 |
1 files changed, 59 insertions, 0 deletions
diff --git a/boost/hana/not_equal.hpp b/boost/hana/not_equal.hpp new file mode 100644 index 0000000000..891bab7499 --- /dev/null +++ b/boost/hana/not_equal.hpp @@ -0,0 +1,59 @@ +/*! +@file +Defines `boost::hana::not_equal`. + +@copyright Louis Dionne 2013-2016 +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 |