/*! @file Defines `boost::hana::min`. @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_MIN_HPP #define BOOST_HANA_MIN_HPP #include <boost/hana/fwd/min.hpp> #include <boost/hana/concept/orderable.hpp> #include <boost/hana/config.hpp> #include <boost/hana/core/dispatch.hpp> #include <boost/hana/if.hpp> #include <boost/hana/less.hpp> BOOST_HANA_NAMESPACE_BEGIN //! @cond template <typename X, typename Y> constexpr decltype(auto) min_t::operator()(X&& x, Y&& y) const { using T = typename hana::tag_of<X>::type; using U = typename hana::tag_of<Y>::type; using Min = BOOST_HANA_DISPATCH_IF(decltype(min_impl<T, U>{}), hana::Orderable<T>::value && hana::Orderable<U>::value ); #ifndef BOOST_HANA_CONFIG_DISABLE_CONCEPT_CHECKS static_assert(hana::Orderable<T>::value, "hana::min(x, y) requires 'x' to be Orderable"); static_assert(hana::Orderable<U>::value, "hana::min(x, y) requires 'y' to be Orderable"); #endif return Min::apply(static_cast<X&&>(x), static_cast<Y&&>(y)); } //! @endcond template <typename T, typename U, bool condition> struct min_impl<T, U, when<condition>> : default_ { template <typename X, typename Y> static constexpr decltype(auto) apply(X&& x, Y&& y) { decltype(auto) cond = hana::less(x, y); return hana::if_(static_cast<decltype(cond)&&>(cond), static_cast<X&&>(x), static_cast<Y&&>(y) ); } }; BOOST_HANA_NAMESPACE_END #endif // !BOOST_HANA_MIN_HPP