Sprout/sprout/functional/negate.hpp
2014-02-22 16:32:51 +09:00

45 lines
1.2 KiB
C++

/*=============================================================================
Copyright (c) 2011-2014 Bolero MURAKAMI
Copyright (C) 2011 RiSK (sscrisk)
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_NEGATE_HPP
#define SPROUT_FUNCTIONAL_NEGATE_HPP
#include <utility>
#include <sprout/config.hpp>
#include <sprout/utility/forward.hpp>
namespace sprout {
// 20.8.4 Arithmetic operations
template<typename T = void>
struct negate {
public:
typedef T argument_type;
typedef T result_type;
public:
SPROUT_CONSTEXPR T operator()(T const& x) const {
return -x;
}
};
template<>
struct negate<void> {
public:
typedef void is_transparent;
public:
template<typename T>
SPROUT_CONSTEXPR decltype(-std::declval<T>())
operator()(T&& x)
const SPROUT_NOEXCEPT_EXPR(SPROUT_NOEXCEPT_EXPR(-std::declval<T>()))
{
return -SPROUT_FORWARD(T, x);
}
};
} // namespace sprout
#endif // #ifndef SPROUT_FUNCTIONAL_NEGATE_HPP