Sprout/sprout/tuple/apply.hpp
2016-02-25 18:48:28 +09:00

70 lines
2.4 KiB
C++

/*=============================================================================
Copyright (c) 2011-2016 Bolero MURAKAMI
https://github.com/bolero-MURAKAMI/Sprout
Distributed under the Boost Software License, Version 1.0. (See accompanying
file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
=============================================================================*/
#ifndef SPROUT_TUPLE_APPLY_HPP
#define SPROUT_TUPLE_APPLY_HPP
#include <utility>
#include <type_traits>
#include <sprout/config.hpp>
#include <sprout/index_tuple/metafunction.hpp>
#include <sprout/tuple/tuple/tuple.hpp>
#include <sprout/tuple/tuple/get.hpp>
#include <sprout/tuple/indexes.hpp>
#include <sprout/utility/forward.hpp>
namespace sprout {
namespace tuples {
//
// apply_result
//
namespace detail {
template<typename F, typename Tuple, typename IndexTuple>
struct apply_result_impl;
template<typename F, typename Tuple, sprout::index_t... Indexes>
struct apply_result_impl<F, Tuple, sprout::index_tuple<Indexes...> > {
public:
typedef decltype(
std::declval<F>()(
sprout::tuples::get<Indexes>(std::declval<Tuple>())...
)
) type;
};
} // namespace detail
template<typename F, typename Tuple>
struct apply_result
: public sprout::tuples::detail::apply_result_impl<
F, Tuple,
typename sprout::tuple_indexes<typename std::remove_reference<Tuple>::type>::type
>
{};
//
// apply
//
namespace detail {
template<typename Result, typename F, typename Tuple, sprout::index_t... Indexes>
inline SPROUT_CONSTEXPR Result
apply_impl(F&& f, Tuple&& t, sprout::index_tuple<Indexes...>) {
return SPROUT_FORWARD(F, f)(sprout::tuples::get<Indexes>(SPROUT_FORWARD(Tuple, t))...);
}
} // namespace detail
template<typename F, typename Tuple>
inline SPROUT_CONSTEXPR typename sprout::tuples::apply_result<F, Tuple>::type
apply(F&& f, Tuple&& t) {
return sprout::tuples::detail::apply_impl<typename sprout::tuples::apply_result<F, Tuple>::type>(
SPROUT_FORWARD(F, f), SPROUT_FORWARD(Tuple, t),
sprout::tuple_indexes<typename std::remove_reference<Tuple>::type>::make()
);
}
} // namespace tuples
using sprout::tuples::apply_result;
using sprout::tuples::apply;
} // namespace sprout
#endif // #ifndef SPROUT_TUPLE_APPLY_HPP