Sprout/sprout/math/fabs.hpp
2015-01-10 19:13:57 +09:00

68 lines
1.9 KiB
C++

/*=============================================================================
Copyright (c) 2011-2015 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_FABS_HPP
#define SPROUT_MATH_FABS_HPP
#include <type_traits>
#include <sprout/config.hpp>
#include <sprout/math/detail/config.hpp>
#include <sprout/math/isnan.hpp>
#include <sprout/math/copysign.hpp>
#include <sprout/type_traits/enabler_if.hpp>
namespace sprout {
namespace math {
namespace detail {
#if SPROUT_USE_BUILTIN_CMATH_FUNCTION
inline SPROUT_CONSTEXPR float
builtin_fabs(float x) {
return __builtin_fabsf(x);
}
inline SPROUT_CONSTEXPR double
builtin_fabs(double x) {
return __builtin_fabs(x);
}
inline SPROUT_CONSTEXPR long double
builtin_fabs(long double x) {
return __builtin_fabsl(x);
}
#endif
} // namespace detail
//
// fabs
//
template<
typename FloatType,
typename sprout::enabler_if<std::is_floating_point<FloatType>::value>::type = sprout::enabler
>
inline SPROUT_CONSTEXPR FloatType
fabs(FloatType x) {
return
#if SPROUT_USE_BUILTIN_CMATH_FUNCTION
sprout::math::detail::builtin_fabs(x)
#else
sprout::math::isnan(x) ? sprout::numeric_limits<FloatType>::quiet_NaN()
: x == 0 ? FloatType(0)
: sprout::math::copysign(x, FloatType(0))
#endif
;
}
template<
typename IntType,
typename sprout::enabler_if<std::is_integral<IntType>::value>::type = sprout::enabler
>
inline SPROUT_CONSTEXPR double
fabs(IntType x) {
return sprout::math::fabs(static_cast<double>(x));
}
} // namespace math
using sprout::math::fabs;
} // namespace sprout
#endif // #ifndef SPROUT_MATH_FABS_HPP