Sprout/sprout/utility/pair/first.hpp
2014-02-22 16:32:51 +09:00

30 lines
1 KiB
C++

/*=============================================================================
Copyright (c) 2011-2014 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_UTILITY_PAIR_FIRST_HPP
#define SPROUT_UTILITY_PAIR_FIRST_HPP
#include <sprout/config.hpp>
#include <sprout/tuple/tuple/get.hpp>
#include <sprout/utility/forward.hpp>
#include <sprout/utility/pair/tuple.hpp>
namespace sprout {
//
// first
//
template<typename T>
inline SPROUT_CONSTEXPR auto
first(T&& t)
SPROUT_NOEXCEPT_EXPR(SPROUT_NOEXCEPT_EXPR(sprout::tuples::get<0>(SPROUT_FORWARD(T, t))))
-> decltype(sprout::tuples::get<0>(SPROUT_FORWARD(T, t)))
{
return sprout::tuples::get<0>(SPROUT_FORWARD(T, t));
}
} // namespace sprout
#endif // #ifndef SPROUT_UTILITY_PAIR_FIRST_HPP