Sprout/sprout/math/fdim.hpp
bolero-MURAKAMI cb1077d247 add copyright
2013-08-08 18:54:33 +09:00

61 lines
2.3 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_MATH_FDIM_HPP
#define SPROUT_MATH_FDIM_HPP
#include <type_traits>
#include <sprout/config.hpp>
#include <sprout/limits.hpp>
#include <sprout/math/detail/config.hpp>
#include <sprout/math/isnan.hpp>
#include <sprout/type_traits/float_promote.hpp>
#include <sprout/type_traits/enabler_if.hpp>
namespace sprout {
namespace math {
namespace detail {
template<
typename FloatType,
typename sprout::enabler_if<std::is_floating_point<FloatType>::value>::type = sprout::enabler
>
inline SPROUT_CONSTEXPR FloatType
fdim(FloatType x, FloatType y) {
return sprout::math::isnan(y) ? y
: sprout::math::isnan(x) ? x
: x == sprout::numeric_limits<FloatType>::infinity() ? sprout::numeric_limits<FloatType>::infinity()
: x == -sprout::numeric_limits<FloatType>::infinity() ? FloatType(0)
: y == sprout::numeric_limits<FloatType>::infinity() ? FloatType(0)
: y == -sprout::numeric_limits<FloatType>::infinity() ? sprout::numeric_limits<FloatType>::infinity()
#if SPROUT_USE_BUILTIN_CMATH_FUNCTION
: std::fdim(x, y)
#else
: x > y ? x - y : FloatType(0)
#endif
;
}
template<
typename ArithmeticType1,
typename ArithmeticType2,
typename sprout::enabler_if<
std::is_arithmetic<ArithmeticType1>::value && std::is_arithmetic<ArithmeticType2>::value
>::type = sprout::enabler
>
inline SPROUT_CONSTEXPR typename sprout::float_promote<ArithmeticType1, ArithmeticType2>::type
fdim(ArithmeticType1 x, ArithmeticType2 y) {
typedef typename sprout::float_promote<ArithmeticType1, ArithmeticType2>::type type;
return sprout::math::detail::fdim(static_cast<type>(x), static_cast<type>(y));
}
} // namespace detail
using sprout::math::detail::fdim;
} // namespace math
using sprout::math::fdim;
} // namespace sprout
#endif // #ifndef SPROUT_MATH_FDIM_HPP