Edit: /usr/include/boost/hana/maximum.hpp (3348B)
/*!
@file
Defines `boost::hana::maximum`.
@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_MAXIMUM_HPP
#define BOOST_HANA_MAXIMUM_HPP
#include
#include
#include
#include
#include // required by fwd decl
#include
#include
#include
BOOST_HANA_NAMESPACE_BEGIN
//! @cond
template
constexpr decltype(auto) maximum_t::operator()(Xs&& xs) const {
using S = typename hana::tag_of::type;
using Maximum = BOOST_HANA_DISPATCH_IF(maximum_impl,
hana::Foldable::value
);
#ifndef BOOST_HANA_CONFIG_DISABLE_CONCEPT_CHECKS
static_assert(hana::Foldable::value,
"hana::maximum(xs) requires 'xs' to be Foldable");
#endif
return Maximum::apply(static_cast(xs));
}
template
constexpr decltype(auto) maximum_t::operator()(Xs&& xs, Predicate&& pred) const {
using S = typename hana::tag_of::type;
using Maximum = BOOST_HANA_DISPATCH_IF(maximum_pred_impl,
hana::Foldable::value
);
#ifndef BOOST_HANA_CONFIG_DISABLE_CONCEPT_CHECKS
static_assert(hana::Foldable::value,
"hana::maximum(xs, predicate) requires 'xs' to be Foldable");
#endif
return Maximum::apply(static_cast(xs),
static_cast(pred));
}
//! @endcond
//////////////////////////////////////////////////////////////////////////
// maximum (with a custom predicate)
//////////////////////////////////////////////////////////////////////////
namespace detail {
template
struct max_by {
Pred pred;
template
constexpr decltype(auto) operator()(X&& x, Y&& y) const {
auto result = (*pred)(x, y);
return hana::if_(result, static_cast(y),
static_cast(x));
}
};
}
template
struct maximum_pred_impl> : default_ {
template
static constexpr decltype(auto) apply(Xs&& xs, Pred&& pred) {
// We use a pointer instead of a reference to avoid a Clang ICE.
return hana::fold_left(static_cast(xs),
detail::max_by{&pred}
);
}
};
//////////////////////////////////////////////////////////////////////////
// maximum (without a custom predicate)
//////////////////////////////////////////////////////////////////////////
template
struct maximum_impl> : default_ {
template
static constexpr decltype(auto) apply(Xs&& xs)
{ return hana::maximum(static_cast(xs), hana::less); }
};
BOOST_HANA_NAMESPACE_END
#endif // !BOOST_HANA_MAXIMUM_HPP