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

36 lines
1.1 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_FUNCTIONAL_SHIFT_LEFT_HPP
#define SPROUT_FUNCTIONAL_SHIFT_LEFT_HPP
#include <utility>
#include <sprout/config.hpp>
#include <sprout/utility/forward.hpp>
namespace sprout {
//
// shift_left
//
template<typename T = void>
struct shift_left;
template<>
struct shift_left<void> {
public:
typedef void is_transparent;
public:
template<typename T, typename U>
SPROUT_CONSTEXPR decltype(std::declval<T>() << std::declval<U>())
operator()(T&& x, U&& y)
const SPROUT_NOEXCEPT_IF_EXPR(std::declval<T>() << std::declval<U>())
{
return SPROUT_FORWARD(T, x) << SPROUT_FORWARD(U, y);
}
};
} // namespace sprout
#endif // #ifndef SPROUT_FUNCTIONAL_SHIFT_LEFT_HPP