/*! @file Defines `boost::hana::comparing`. @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_COMPARING_HPP #define BOOST_HANA_COMPARING_HPP #include #include #include #include namespace boost { namespace hana { namespace detail { template struct equal_by { F f; template constexpr auto operator()(X&& x, Y&& y) const& { return hana::equal(f(static_cast(x)), f(static_cast(y))); } template constexpr auto operator()(X&& x, Y&& y) & { return hana::equal(f(static_cast(x)), f(static_cast(y))); } }; } //! @cond template constexpr auto comparing_t::operator()(F&& f) const { return detail::equal_by::type>{static_cast(f)}; } //! @endcond }} // end namespace boost::hana #endif // !BOOST_HANA_COMPARING_HPP