Sprout/sprout/functional/cond.hpp
2013-10-26 23:17:09 +09:00

36 lines
1.2 KiB
C++

/*=============================================================================
Copyright (c) 2011-2013 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_COND_HPP
#define SPROUT_FUNCTIONAL_COND_HPP
#include <utility>
#include <sprout/config.hpp>
#include <sprout/utility/forward.hpp>
namespace sprout {
//
// cond
//
template<typename T = void>
struct cond;
template<>
struct cond<void> {
public:
typedef void is_transparent;
public:
template<typename T, typename U, typename V>
SPROUT_CONSTEXPR decltype(std::declval<T>() ? std::declval<U>() : std::declval<V>())
operator()(T&& x, U&& y, V&& z)
const SPROUT_NOEXCEPT_EXPR(SPROUT_NOEXCEPT_EXPR(std::declval<T>() ? std::declval<U>() : std::declval<V>()))
{
return sprout::forward<T>(x) ? sprout::forward<U>(y) : sprout::forward<V>(z);
}
};
} // namespace sprout
#endif // #ifndef SPROUT_FUNCTIONAL_COND_HPP