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/*!
@file
Defines `boost::hana::max`.
@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_MAX_HPP
#define BOOST_HANA_MAX_HPP
#include <boost/hana/fwd/max.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) max_t::operator()(X&& x, Y&& y) const {
using T = typename hana::tag_of<X>::type;
using U = typename hana::tag_of<Y>::type;
using Max = BOOST_HANA_DISPATCH_IF(decltype(max_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::max(x, y) requires 'x' to be Orderable");
static_assert(hana::Orderable<U>::value,
"hana::max(x, y) requires 'y' to be Orderable");
#endif
return Max::apply(static_cast<X&&>(x), static_cast<Y&&>(y));
}
//! @endcond
template <typename T, typename U, bool condition>
struct max_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<Y&&>(y),
static_cast<X&&>(x)
);
}
};
BOOST_HANA_NAMESPACE_END
#endif // !BOOST_HANA_MAX_HPP
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